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Rules are probably best described by using examples. This chapter contains numerous real world samples.

On this page:

Calculate a Total

You have a form with three controls and you have assigned them Names N1, N2 and T respectively. When the user enters a value in either N1 or N2 you want to set the value of T to the sum of N1 and N2. The rule would be written as

T.value = N1.value + N2.value;

This rule will automatically fire whenever the user types something in N1 or N2 and will set the value of T appropriately. You can use any legal JavaScript operators in the expression such as subtraction or multiplication. However, it's important to ensure that the calculated value is valid with respect to the type of T. For example, if T was of type integer and the computed value of the expression was decimal (such as 1.5), then the rule would be attempting to set an invalid value in T. This is an error. The rule will set the value as requested, but will mark the field as invalid and take appropriate action such as disabling the submit button, displaying the control with a red background etc. Also, if controls are added to the form from the palette, it is important to ensure they have the correct type. For example, for a numeric calculation as described above, the controls should be of type Numeric (found in the palette).

Show/Hide Billing Address

You have a form with two controls and you have assigned them Names B and S respectively. B is a checkbox with a single option - Yes. If checked the user wishes to enter a different billing address in S and you want to display S. The rule would be written as

if (B[0].value === 'Yes') {
    S.visible = true;
} else {
    S.visible = false;

This rule will automatically fire whenever the user checks or unchecks B and will show/hide the billing address section S. Again, you could use any legal JavaScript expression to compute the visible property of S as long as it evaluates to a boolean true or false value. In this example, you would typically set the checkbox B to be initially unchecked and the section S to be initially hidden.

Show/Hide Message

This form has a radio control named Facility and makes a message visible depending on the selected options.

if (Facility.value === 'Boston' || 
    CompanyFacility.value === 'New York')
    Msg.visible = true;
} else {
    Msg.visible = false;


This form has a radio control named DescribeInDetail and a section control named Details. Details is hidden by default and made visible if the user selects 'Yes'.

When the form is submitted we've configured frevvo to send an email with the form PDF. We only want the Details section to appear on the PDF when the user selects 'Yes'. So we uncheck the printable property on the section control. This property will apply to the section and all controls inside the section. So we do not have to uncheck printable on the inner controls. Then we add this business rule. When the section is visible we also set it to be printable. When the section is hidden we also set it to be not printable.

if (DescribeInDetail.value === 'Yes') { 
    Details.visible = true; 
    Details.printable = true; 
} else { 
    Details.visible = false; 
    Details.printable = false; 

Show/Hide Submit & Cancel

You have a form with multiple tabs. The main tab contains the form and the other tabs contain reference information users may need when completing the form. You only want the submit and cancel buttons visible when the user is in the main tab. This rule hides the submit and cancel buttons when the reference tabs are selected. The control name of the main tab is MainTab.

if (!(MainTab.selected)) {
    Submit.visible = false;
    Cancel.visible = false;
} else {
   Submit.visible = true;
   Cancel.visible = true;

Show/Hide Manager Approval

You have a flow and the first form has a Section for manager approval. The Section is hidden by default. Here is an example of a rule that makes the section visible in the second step of the flow which is a linked activity assigned to the manager role. 

if (form.load) {
  var an = _data.getParameter ("");
  if (an === 'Manager'){
    ManagerApproval.visible = true;
  } else {
    ManagerApproval.visible = false;

Enable/disable a question

You have a form with two controls and you have assigned them Names B and Q respectively. B is a checkbox with a single option - Yes. . If checked the user is a smoker and you wish to ask an additional question in Q. The rule would be written as

if (B[0].value === 'Yes') {
    Q.enabled = true; 
} else {
 Q.enabled = false; 

This rule will automatically fire whenever the user checks or unchecks B and will enable/disable the question in Q. Again, you could use any legal JavaScript expression to compute the enabled property of Q as long as it evaluates to a boolean true or false value.

In this example, you would typically set the checkbox B to be initially unchecked and the control Q to be initially disabled.

Compute Subtotals for Repeating Items

This rule is an example of working with repeating items. Let's say, you have a form with a repeating section representing an Item that the user may purchase. Each section has a Price (with Name P), a Quantity (Name Q) and a Subtotal (Name S). There are multiple items on the page and the number of items on any given page is unknown. The price field is filled in automatically. When the user enters a value in the quantity field for any item, you wish to compute the subtotal.

The rule would be written as:

for (var i = 0; i < S.value.length; i++) { 
  if (Q[i].value > 0) {
    S[i].value = Q[i].value * P[i].value; 
  } else { 
    S[i].value = 0; 

This rule will automatically fire whenever the user enters a value in the quantity field for any item. It will compute the subtotal for each item, for which the quantity is greater than 0 and fill in the subtotal field for that item with the computed value. If a particular item does not have a quantity, the subtotal is not computed.

Compute an Invoice Total

Consider the same form as the example above. Let's say you have a control named Total with Name T. You want to set the value of Total to be the total invoice price, which is the sum of all the computed subtotals above. This rule would be written as:

var tot = 0; 
for (var i = 0; i < S.value.length; i++) {
  tot = tot + S[i].value; 
T.value = tot; 

This rule will fire whenever a subtotal is updated, for example, when it is updated via the rule above. It will add the values of all the subtotals to arrive at an invoice total. Note that you must use a temporary variable to compute the total. If you write the rule as:

T.value = 0; 
for (var i = 0; i < S.value.length; i++) {
  T.value = T.value + S[i].value; 

it will not work correctly. This is due to internal limitations in the way rules are evaluated. You can read more about that here

Note that this rule is working with controls inside a repeat control. To handle the case of a item being deleted from the repeat you need the following addition assuming that the repeat control is named ExpenseRepeat. Table controls are repeats with a different layout. Thus the same applies to the table controls. If your table is named Expense then the repeat is automatically named ExpenseRepeat. In general the table repeat is named <TableName>Repeat.

if (ExpenseRepeat.itemRemoved) {var x;} 

Formatting money values to display in a Message Control

Let's say you have calculated a sum in a Number control in your form and you want to display it in a Message control and format it as a money value with commas and decimal places.  You will need a Number control named Num and a message control named Message in your form. This rule will display the number entered in the number control with commas. If the user enters 5600.44 in the number field then the result in the message control would look like this:"5,600.44".

var x, x1, x2;
if (Num.value > 0) {
    var nStr = Num.value.toFixed(2);
    nStr += '';
    x = nStr.split('.');
    x1 = x[0];
    x2 = x.length > 1 ? '.' + x[1] : '';
    var rgx = /(\d+)(\d{3})/;
    while (rgx.test(x1)) {
 x1 = x1.replace(rgx, '$1' + ',' + '$2');
    Message.value = x1 + x2;

Textarea Max Length

In html there is no way to set a maxLength on a textarea control. This is why the textarea control does not have a maxlength property like the text control does. It is possible to do this via a business rule. This example form has a textarea control named 'Desc' where the user can enter up to a 500 character description. On this control we also set the ErrorMsg property to the string 'You must limit your description to 500 characters'. This message is automatically displayed when the description control is set to invalid by the following business rule.

if (Desc.value.length > 500) {
  Desc.valid = false; 
} else {
  Desc.valid = true; 

You can even customize the error message by adding this line to your rule. Now the error message will tell the user how many characters they are over the maximum allowed.

Desc.status = 'Invalid. Max 20 chars allowed and you have ' + Desc.value.length; 

Textarea newline vs break

Users typically enter multi-line text into textarea controls. If you want to display that text in an html context, for example on a web page or in an html formatted email or in your form's Form Action display message you will need to replace newlines with html breaks. This caused by the fact that line breaks entered into a web form textarea are represented by a single newline character \n while line breaks in an html context are represented by the html break characters.

Our example has a textarea control named Description and a hidden control named DF. The user types into the visible control named Description and a business rules converts the newline characters \n into html breaks.

var x = Description.value; 
x = x.replace(/\\r/g,"");
x = x.replace(/\\n/g,"<br/>");
DF.value = x; 

Dropdown Options

This example automatically sets the option selected in one dropdown based on the option selected in another. This is often useful when you have a form with choices that were dynamically populated. For example, imagine product choices which are descriptive text. When the user selects a product, your form needs to perform an action based on a product ID rather than the descriptive product text. A nice way to do this is to have the rule that dynamically populates the product choices dropdown also populate a product ID dropdown which remains an invisible control in the form. The product choices dropdown control was named Products and the product ID dropdown control was named PID

The 1st rule "Load Products" populates both the visible and hidden dropdowns with options from a database.

/*member productCode, productName, resultSet*/
var x;
if (form.load) {
  eval('x=' + http.get(''));  
    var opts1 = [];
    var opts2 = [];
    for (var i=0; i < x.resultSet.length; i++) {
        if (x.resultSet[i]) {
            opts1[i] = x.resultSet[i].productName;
            opts2[i] = x.resultSet[i].productCode;
  Products.options = opts1;
  PID.options = opts2;
  Products.value = opts1[0]; // default to 1st product option
  PID.value = opts2[0];

Finding a Selected Options Index

The 2nd rule Select Product ID keeps the hidden PID dropdown synchronized with the visible Products dropdown.

if (Products.value.length > 0)
    var i;
    for (var x in Products.options) {
        if ((Products.value + '=' + Products.value) === Products.options[x]){
            i = Products.options.indexOf(Products.options[x]);
  PID.value = PID.options[i].split('=')[0];

In v4 rules using hidden dropdowns to keep descriptive option labels visible to the user while keeping cryptic database values hidden are often no longer necessary. Dropdown options have values distinct from the human visible option labels. The above can now be achieved with a single simpler rule:

/*member description productId resultSet */
var x, opts1;
for (var i=0; i < x.resultSet.length; i++) { 
    if (x.resultSet[i]) { 
            opts1[i] = x.resultSet[i].productId+ '=' + x.resultSet[i].description; 
Rdocnum.options = opts1; 

Here is another rule that dynamically populates both the product choices and product ID dropdowns. This rule calls a REST Service which returns an object rather than the resultset returned by the database connector as shown above. See the section on dynamic content for more details.

/*member ids products */
var x;
if (S.value.length > 0) {
    eval('x=' + http.get('http://localhost:8182/products/?category=' + S.value)); 
    P.options = x.products; 
    ID.options = x.ids; 

Synchronized Selects

The Product Search example above is often used in conjunction with a hidden select control. Imagine that your database table contains a list of products. Each product has product description also a unique product ID. The user needs to select a product from a dropdown on your form. You want to populate the dropdown with the product descriptions. The users do not need to see or know the product IDs but you need to use the ID as the key into the database for other selects. To do this add another hidden dropdown to the form and populate it with the IDs. This example has a visible dropdown name Products and an invisible dropdown named PID. See the rule above that populates these dropdowns dynamically from the database.

This rule below keeps the PID selected option in sync with the selected Product.

var i, x; 
for (x in Products.options) { 
// Determine the index of the selected product in the Products dropdown options 
if (Products.value === Products.options[x]) 
    i = Products.options.indexOf(Products.options[x]); 

// Changed the selected PID to match the selected Product 
PID.value = PID.options[i] + '';

Clearing Dropdown Options

This sample resets a dropdown option to the automatically added blank option. For dropdowns added from palette controls and from schema, frevvo automatically adds a blank option so the dropdown initially shows no choice by default. To reset the dropdown, set the dropdown control's value to null not the empty string. The empty string will not work since the empty string is not a valid option. This form resets the dropdown named size whenever the value of the product option changes.

if (product.value.length > 0) {  
    size.value = null; 

Default Option

When your options are set dynamically as shown below in a business rule, you cannot set a default in on the form designer. You need to set the default in the rule. If your options have <value>=<label> where value is different from label, make sure you set the <control>.value to <value> not <label> and not <value>=<label>

if (form.load) { 
    var cc = ['R=Red', 'B=Blue', 'G=Green'];
    Colors.options = cc;
    Colors.value = 'B';

Populating Dropdown Options from a Google Sheet

Dropdown control options can be dynamically populated from a Google Sheet using a business rule. Here is an example of a rule that populates a dropdown control named Colors with color options from a Google Sheet.

  • Create a Google Sheet with a column named Colors containing a list of colors.

  • Create a Form with a control called Colors.
  • Use this rule to populate the dropdown options with the colors Red, Blue, Green and Orange.
/*member colors, results */
var x;

if (form.load) {
    var readquery = '/google/spreadsheets/query/u/<google username>/p/<google pswd>/s/ColorList/w/Sheet1?media=json';
    eval('x=' + http.get(readquery));

    var opts = [''];
    if (x.results) {
        for (var i = 0; i < x.results.length; i++) {
            if (x.results[i].colors) {
                opts[i + 1] = x.results[i].colors;
    Colors.options = opts;    //Colors is the name of my dropdown control


Refer to this documentation for more information about frevvo and the Google Connector

Checkbox Options - Assigning Color to Checkbox Choices

Checkbox controls are different from all other frevvo palette controls in that they are multi-select. Therefore the way to write rules with checkbox controls are in many ways similar to rules with repeat controls. This rule has a checkbox controls with name colorPalette with the options: purple, green, blue, yellow, orange. The form also contains a text control with name colorChoice. This rule assigns colorChoice the choices selected from colorPalette.

var choices = ''; 
for (var i = 0; i < colorPalette.value.length; i++) 
    choices = choices + colorPalette[i].value; 
colorChoice.value = choices; 

Notice that similar to repeat controls, due to an internal evaluation limitation, you must collect the choices in a variable inside the for loop. And then assign that control Name.value to that variable outside the for loop.

This rule is another example showing how checkbox controls are array types.

if (colorPalette.value.length > 0) 
    colorChoice.value = 'Thank you for choosing colors'; 
    colorChoice.value = 'Please choose colors...'; 

Checkbox Options - Making a Control Visible/Invisible Based on Checkbox Choices

This rule makes visible/invisible a control based on which checkbox options a user selects. This form contains a multi select checkbox named Structures. If the user selects the option "Detached Garage" or "House", we want to make visible a text field named Details.

Again since a checkbox is multi select, it is handled as an array. The array will contain all selected (checked) options.

It is important to note that when a checkbox is added to the form from the palette and its options are multiple words containing spaces, the option array has converted each space character to the '_' character. We must make the comparison as shown below. Checkbox controls from schema do not have space replaced with '_'.

var found = false; 
for (var i = 0; i < Structures.value.length; i++) 
    if (Structures[i].value === 'Detached_Garage' || 
        Structures[i].value === 'House') { 
      found = true; 
if (found === true) { 
    Details.visible = true; 
} else { 
    Details.visible = false; 
    Details.value = null; 

Note that when we hide Details we also clear its value. This is because the user may have selected one of the Structures checkboxes that made Details visible AND entered a value into Details. And then they may have changed their minds and uncheck the option that caused Details to become visible. If you don't want the value entered into Details to be in your form submission, clear the value when hiding it.

Many Checkbox Comments

This rule makes an associated comment input control visible and required when a checkbox is checked. The for loop determines which checkboxes are checked and sets an appropriately named variable to true. Depending on the value of checkbox the associated input control will be made visible and required via the if/else and will be hidden and not-required when it is un-checked again. This is a very common rule design pattern.

You can style this form so the comment input controls align with the checkbox options. See details and download a working sample form here

var heartProblem = false;
var foodAllergy = false;
var rashes = false;
var jointInjury = false;
var asthma = false;
var moodiness = false;

for (var i = 0; i < MedicalIssues.value.length; i++)
  if (MedicalIssues[i].value === 'heart_problem') {
    heartProblem = true;
  } else if (MedicalIssues[i].value === 'food_allergy') {
    foodAllergy = true;
  } else if (MedicalIssues[i].value === 'rashes') {
    rashes = true;
  } else if (MedicalIssues[i].value === 'joint_injury') {
    jointInjury = true;
  } else if (MedicalIssues[i].value === 'asthma') {
    asthma = true;
  } else if (MedicalIssues[i].value === 'moodiness') {
    moodiness = true;

if (heartProblem === true) {
  heartProblemDetails.visible = true;
  heartProblemDetails.required = true;
} else {
  heartProblemDetails.visible = false;
  heartProblemDetails.required = false;
  //heartProblemDetails.value = null;

if (foodAllergy === true) {
  foodAllergyDetails.visible = true;
  foodAllergyDetails.required = true;
} else {
  foodAllergyDetails.visible = false;
  foodAllergyDetails.required = false;
  //foodAllergyDetails.value = null;

if (rashes === true) {
  rashesDetails.visible = true;
  rashesDetails.required = true;
} else {
  rashesDetails.visible = false;
  rashesDetails.required = false;
  //rashesDetails.value = null;

if (jointInjury === true) {
  jointInjuryDetails.visible = true;
  jointInjuryDetails.required = true;
} else {
  jointInjuryDetails.visible = false;
  jointInjuryDetails.required = false;
  //jointInjuryDetails.value = null;

if (asthma === true) {
  asthmaDetails.visible = true;
  asthmaDetails.required = true;
} else {
  asthmaDetails.visible = false;
  asthmaDetails.required = false;
  //asthmaDetails.value = null;

if (moodiness === true) {
  moodinessDetails.visible = true;
  moodinessDetails.required = true;
} else {
  moodinessDetails.visible = false;
  moodinessDetails.required = false;
  //moodinessDetails.value = null;

Checkbox Initialization

Since checkbox options are multi-select, in order to select multiple options via a rule you must use this syntax. The correct way to initialize the checkbox control value is to collect all required options in an array and then assign that array as the value of your checkbox control.  In this example CB is the name of a checkbox controls with the following options: red, green, blue. This rule selects all of the options.

CB.value = ['red', 'green', 'blue']; 

To clear all checked options in the control named CB:

CB.value = []; 

Displaying Selected Checkbox Labels

In this example, the rule displays the labels of the checkboxes the user selects.

var x;
var selectedcolors = '';

for (var i = 0; i < RGB.value.length; i++) 
    var v = RGB[i].value; 
    for (x in RGB.options) {

        var opt = RGB.options[x]; 
        var val= opt.split('=')[0]; 
        var lab= opt.split('=')[1];
        if (v === val) { 
            selectedcolors = selectedcolors + ' ' + lab; 

T/F Boolean

T/F controls are simplified checkbox controls with only a single visible option. This rule makes the control named "s" visible if the T/F control named "agree" is checked and invisible if the T/F control named "agree" is unchecked.

if (agree[0].value === 'true') {
  s.visible = true;
} else {
  s.visible = false;

To clear a checkmark from a T/F control you must set the value to null and ensure that the control is not required as follows:

agree.required = false;
agree.value = null;

Repeating Checkboxes

Checkboxes inside repeat controls must be treated as an array (each checkbox control's values) of checkbox option values which is inside another array (the repeating checkbox control itself). This form example has a repeating section containing two controls -- Message which is a text control and AreYouAttending which is a checkbox control with a single option 'yes'. To access the selected options the syntax is:

AreYouAttending[i].value[0] === 'yes'

for (var i = 0; i < AreYouAttending.value.length; i++) 
    if (AreYouAttending[i].value[0] === 'yes') {
        Message[i].value = Name.value + 
               ' is attending event #' + i; 

String Concatenation

Message controls can be used in business rules to create summary information on your form from values entered into earlier form fields. This rule uses javascript variables to concatenate form field values, text strings and html to format a nice summary page:

var totalAssets = TotalAutoValue.value + TotalBankValue.value + TotalRealEstateValue.value;

BasicSummaryMsg.value =  
"<b>Name:</b> " + FirstName.value + " " + LastName.value + "<br/>" + 
"<b>Phone:</b> " + Phone.value + "<br/>" + 
"<b>Email:</b> " + EmailAddress.value;

if (MilitaryOrCivilian.value === 'Military') { 
DetailedSummaryMsg.value =  
"<b>Military Info:</b><br/>" +  "Military ID: " + MilitaryID.value + "<br/>" + 
"Rank: " + Rank.value + "<br/>" + 
"CurrentTitle: " + CurrentTitle.value + "<br/>" + 
"Years of Service: " + YearsOfService.value + "<br/>"; 
} else if (MilitaryOrCivilian.value === 'Civilian') { 
DetailedSummaryMsg.value =  
"<b>Civilian Info:</b><br/>" +  
"SSN: " + SSN.value + "<br/>" + 
"Current Employer: " + CurrentEmployer.value + "<br/>" + 
"Current Title: " + CurrentTitle2.value + "<br/>" + 
"Start Date: " + StartDate.value + "<br/>"; 

FinancialSummaryMsg.value = 
"<b>Total Assets:</b> $" + totalAssets + 
"<br/>" + "Total Bank Assets: $" + TotalBankValue.value + "<br/>" + 
"Total Real Estate Value: $" + TotalRealEstateValue.value + "<br/>" + 
"Total Auto Value: $" + TotalAutoValue.value + "<br/>";

Note when using field values from repeat controls you must use a javascript var and assign the concatenation to the var and then the var to the frevvo message control value. For example imagine you have a message control named Summary and a repeat control named Account:

var acctSummary = ''; 
for (var i = 0; i < Account.value.length; i++) { 
    if (Q[i].value > 0) { 
        acctSummary = acctSummary + 'Account #' + i + ': ' + Account[i].value + '<br/>'; 
Summary.value = acctSummary; 

Dynamic Labels, Help, Hints

You can set the value of control labels, help and hint dynamically in a rule. For example imagine you do not know the label, help or hint at design time but would rather set it dynamically when a user opens your form.

if (form.load) 
  Text99.label = 'New Label'; 
  Text99.hint = 'New Hint'; = 'New Help'; 

In the above example the label, help and hint is still hard-coded. It's just being set from the rule rather than in the form designer controls' properties. To make this more useful you can initialize these properties from _data parameters:

if (form.load)
   Text99.label = _data.getParameter('label'); 
   Text99.hint = _data.getParameter('hint'); = _data.getParameter('help'); 

Since _data.getParameter enables access to values passed to the form that are not bound to actual controls this is often a very useful pattern.


This rule makes the message control nickNameThankYou visible when the user enters a value into the nickName input text control. And then hides the message control if the user deletes the value in nickName.

if (nickName.value.length > 0 ) 
    nickNameThankYou.visible = true; 
    nickNameThankYou.visible = false; 

Visible/Invisible Section

Often section controls contain many inner controls. For example imagine a form that contains a person's medical history. One of the questions on the form asks if the patient uses a hearing aid. If they answer yes, then you want to collect more details on their hearing aid usage such as left ear, right ear, bilateral; hearing aid brand; etc. If they answer no then you want to hide all the questions specific to hearing aids. Also when the answer is yes you want to require them to answer all the hearing aid detailed questions.

Avoid using message controls, images & video controls inside a section that contains other controls that you may want to make invisible. Since these three control types always contains a value, it can cause a section, or other controls in a section, to become required, and this can disable the form's Submit button. If you must include these controls, place them outside the section. Another alternative is to write rules for the individual controls within a section to set them to visible/invisible or required/not required

Imagine this example form has a section named HearingAid. By default HearingAid visible is set to false in the form designer.

When they answer yes, you must set HearingAid.visible=true AND also each required field inside the section to field.required = true. If they then change the answer to no then another rule makes the HearingAid.visible=false AND all the field.required=false. If the HearingAid section contains many child controls this rule becomes very long and tedious to write

We can simplify this by using the required property for sections. In the designer default all controls that must be answered inside HearingAid to required. Default the HearingAid section to not required and not visible. Your rule can be much simpler. By setting HearingAid.required=false all the inner controls recursively also become required=false.

if (useAid.value === 'no') {
    // Hide 
    HearingAid.visible = false; 
    HearingAid.required = false; 
} else { 
    // Show 
    HearingAid.visible = true; 
    HearingAid.required = true; 

It is not currently possible to effect required for controls from XSD schema. This functionality will be added in a future release of frevvo. See the documentation for Data Sources and Schemas for details on implementing a Show/Hide rule with XSD controls.

Select Tab

This rule makes a specific tab the selected tab based on the choice of a radio control. The radio is named SelectTab and has three options: person, auto, home. The tabs are named personTab, autoTab and homeTab. Tabs also can be selected based on trigger controls or other input controls using the same method show here. 

if (SelectTab.value.length > 0)
    autoTab.selected = false; 
    homeTab.selected = false; 
    personTab.selected = false;

    if (SelectTab.value === 'Auto') 
        autoTab.selected = true; 
    } else if (SelectTab.value === 'Home') {
        homeTab.selected = true;
    } else {
        personTab.selected = true;

Next Tab

This form contains a trigger control at the bottom of each tab labeled "Next". When "Next" is clicked the trigger rule executes and makes the next tab the selected tab. This assists the user in navigating through the form. The Tabs are named T1, T2, T3, T4. The trigger controls are named C1, C2, C3

// Navigate Tabs 
if (C1.clicked) { 
    T2.selected = true; 
} else if (C2.clicked) {
    T3.selected = true; 
} else if (C3.clicked) { 
    T4.selected = true; 

Expand/Collapse Section

This form has three sections. The first section is expanded and the 2nd and 3rd are collapsed. When the user files in the 1st section they click a "Next" trigger control which causes that section to collapse and the next section to expand. The trigger controls are named next1 and next2. And the sections are named: step1, step2, step3. 

    step1.expanded = false; 
    step2.expanded = true; 

    step2.expanded = false; 
    step3.expanded = true; 

Security Subject Information

You can use a form.load rule to pre-populate fields in your form with information about the currently logged in user. For example, if you have controls in your form named Id, FirstName, LastName, Email and Roles, the following rule will prefill those fields as indicated below.

var x;
if (form.load) { 
    // User Information 
    Id.value = _data.getParameter(''); // Username 
    FirstName.value = _data.getParameter(''); 
    LastName.value = _data.getParameter(''); 
    Email.value = _data.getParameter(''); 
    var roles = _data.getParameter ("subject.roles"); 
    if (roles) { 
        eval ('x=' + roles); 
        Roles.options = x; 

This rule is useful in a workflow where you want to make a the tab named Review visible only for the workflow activity named Manager Review.

if (form.load) { 
    if (_data.getParameter('') === 'Manager Review')  {
        Review.visible = true; 

Multiple Choice

This rule makes the appropriate input text controls visible depending on the choice a user makes in a radio option controls searchChoice.

if (searchChoice.value === 'Organizations') 
    orgname.visible = true; 
    firstname.visible = false; 
    lastname.visible = false; 
    clientId.visible = false; 
else if (searchChoice.value === 'Individuals') 
    orgname.visible = false; 
    firstname.visible = true; 
    lastname.visible = true; 
    clientId.visible = false; 
} else if (searchChoice.value === 'Client ID') 
    orgname.visible = false; 
    firstname.visible = false; 
    lastname.visible = false; 
    clientId.visible = true; 

Dynamic Options

Selection controls' (radios, checkboxes, dropdowns, T/F) options can be set dynamically via rules rather than statically via the control's options property. However if the control comes from an XSD schema data source rather than one of the standard palette controls, then the designer must take care to not set the options to something outside of what is valid for that schema element. For example if your XSD has a string enumeration and list valid options as 'red', 'green', and 'blue', then you should not use a rule to dynamically set the options to 'small', 'medium', 'large'. If you do then then your form will not work correctly in use mode. If a user selects the option 'small' they will get a validation error on the form. This is because 'small' is not one of the options allowed by your underlying XSD schema.

Triggers & Dynamic Options

This rule is executed when the user clicks the trigger controls with Name ''search''. It then dynamically sets options on a dropdown list control with Name coffeeShopList.

if (search.clicked) 
    coffeeShopList.options = ['Koffee', 'Starbucks', 'Willoughbys', 'Dunkin Donuts'];

Now replace the hard coded list of coffee shops with a rule that invokes an http.get. This must return an X-JSON header which contains a JSON object. The object is evaluated and assigned to the variable x. In this case the JSON object contains an options field of type array. See the section on dynamic content for more details.

var x;
if (search.clicked) 
    eval('x=' + http.get('http://(your webhost)/getCoffeeShopList'));  
    coffeeShopList.options = x.options; 

Triggers do not work in repeating items.

Value Change & Dynamic Options

This rule dynamically sets the options in a dropdown list based on the value selected in another form field. This form contains three fields named Products, Series and Model. The series options are set dynamically based on the product selection. Also when a new product is selected we enable the series dropdown and both clear and disable the model dropdown. This form contains other rules which set the models based on the selected series. 

if (product.value === 'Laserjet Printers') 
    series.options = [' ', 'Laserjet5 series', 'Laserjet6 series']; 
    series.enabled = true; 
    model.options = []; 
    model.enabled = false; 

Dynamic Control Initialization using JSON

This rule handles the case of initializing multiple control values based on the selection of a dropdown control. It handles this case better than using a long if/else construct by using a JSON string. First add options to the dropdown named SalesRep in the format <value>=<label> where <value> will be used as an index key into a JSON array of details about each person.

Megan=Megan Smith 
Jim=Jim Brown 
Nancy=Nancy Jones 
Brian=Brian Jones 

Then write a rule that first sets up a javascript JSON syntax array with the contact information for each person. The rules then uses the dropdown value to index into the contactInfo array to set the details for the selected person into four other form controls.

/*member '' Brian Jim Megan Nancy cell email phone */
var contactInfo = { 
    "" : {  
        name : "", 
        email : "", 
        phone : "", 
        cell : "" 
    "Megan" : {  
         name : "Megan Smith", 
         email :, 
         phone : "(203) 694-2439 Ext. 516", 
         cell : "(203) 337-3242" 
    "Jim" : {  
        name : "Jim Brown", 
        email :, 
        phone : "203-208-2999", 
        cell : "" 
    "Nancy" : {  
        name : "Nancy Jones", 
        email :, 
        phone : "203-208-2991",  
        cell : "" 
    "Brian" : {  
        name : "Brian Jones", 
        email :, 
        phone : "203-748-6502", 
        cell : "" 
var repId = SalesRep.value;
SalesRepName.value = contactInfo[repId].name; 
SalesRepEmail.value = contactInfo[repId].email; 
SalesRepPhone.value = contactInfo[repId].phone; 
SalesRepCell.value = contactInfo[repId].cell;

Try this simple Clinic Location form which uses this approach to initialize its controls.

Verify User

This rule executes when the user enters a value into the Username text field. It uses the built-in isUniqueUserId() method that returns false if the user already exists. If the user already exists this rule then sets the value of a message control, makes that message control visible on the form and sets the Username valid property to false so that Username field displays as invalid to guide the user to make a correction. See the section on dynamic content for more details.

if (U.value.length > 0) {  
    if (frevvo.isUniqueUserId(user.value, tenant.value) === false) { 
        M.value = 'User: ' + U.value + ' already exists'; 
        M.visible = true; 
        U.valid = false; 
    } else { 
        M.visible = false; 

Digital Signature

This form uses a rule to pass a username and password to a LDAP Active Directory authentication service. If authentication fails the form makes an error message control visible. If authentication succeeds the form disables the username form field and replaces the password field with a date field set to the current date. The form contains a trigger control named sign, username and password fields named u and p respectively, a date field named d and a message field named m.

/*member auth */
var x;
if (sign.clicked) { 
    // passwords may contain characters that need url encoding 
    var p_encode = encodeURIComponent(p.value);

    eval('x=' + http.get('http://(your webhost)/authServices/signForm?username=' + 
                          u.value + '&password=' + p_encode));

    if (x.auth) { 
        var dt = new Date(); 
        var day = dt.getDate(); 
        var month = dt.getMonth() + 1; 
        var year = dt.getFullYear(); 
        d.value = month + '-' + day + '-' + year;

        d.visible = true; 
        u.enabled = false; 
        p.visible = false; 
        sign.visible = false; 
        m.visible = false; 
    } else { 
    m.visible = true; 

The authService is an example HTTP servlet that returns a JSON response.

public void doGet (HttpServletRequest request, HttpServletResponse response) 
    throws ServletException, IOException {
    try { 
        String username = request.getParameter(REQUEST_SIG_USERNAME); 
        String password = request.getParameter(REQUEST_SIG_PASSWORD); 
        password = URLDecoder.decode(password, "UTF-8"); 
        // Authenticate Signature 
        authenticateUser(response, username, password);  
    } catch (Exception e) { 
        throw new ServletException(e); 

private void authenticateUser(HttpServletResponse response, String u, String p) { 
    if (realm.authenticate(u, p) === null) 
        response.addHeader(RESPONSE_JSON_HEADER, "{auth:false}"); 
        response.addHeader(RESPONSE_JSON_HEADER, "{auth:true}"); 

Here's another example form that requires a doctor's signature. This shows how the form works in use mode. The first image contains a dropdown to select one of the doctor's authorized to sign the form and a text control where they enter their PIN code.

This image shows the case where the doctor entered an invalid PIN and the error message becomes visible.

This image shows the case of a valid PIN. Today's date is entered into the date control via the rule and made visible and disabled from edit. The username dropdown is disabled and the PIN and Sign controls are hidden.

Calculate Net Worth

This form contains two rules. One is adding values entered into a column of assets and a column of liabilities and calculating netWorth. The 2nd rule is checking the value of netWorth and displaying an error message and marking netWorth invalid if liabilities exceed assets since the form designer does not want the form to be submitted in that state.

if (netWorth.value < 0) 
    assetsExceedLiabilitiesMsg.visible = true; 
    netWorth.valid = false; 
    assetsExceedLiabilitiesMsg.visible = false; 
    netWorth.valid = true; 

When a rule sets <control>.invalid the control background turns red and the submit button grays out just as if the user had entered an invalid value into a phone control. frevvo treats it exactly the same way. This is a good way to dynamically control your form's valid state.

Dates and Times

Working with dates and times is very common in most forms. The samples below show you how to create the most common business logic with dates and times. 

frevvo dates can be set in the user's local timezone by using the built-in date, time and date/time methods such as frevvo.currentDateTime(). See Built-in Methods for a complete method list. If you use the base javascript date object you will get UTC timezone.

Many of the samples below use the javascript Date() object. Since business rules run on the form server these dates will be in the timezone where the form server was installed. There are techniques below to convert to different timezones as you need.

The Date/Time control uses a "T" to separate the date and time when initializing from a business rule. For example, the syntax shown below will initialize a Date/Time control named DtTm to May 15, 2012 at 4:20 am.

DtTm.value = "5/15/2012T4:20";

Date controls will successfully initialize via a rule or an xml document when the data provided has a single digit for the month and/or the day. The rule below can be used to initialize a form with a date and date/time control. Notice the Date.Value and Date+Time.value rule identifiers have a single digit for the month.  

Date.value = "2011-2-10";
Date_Time.value = "2011-1-23T20:20:20";

The Date/Time control will display an "Invalid Value" error if single digits for the month and/or day are used .

 Change the Date_Time.value = "2011-1-23T20:20:20"; to Date_Time.value = "2011-01-23T20:20:20"; in the rule or the xml document for successful initialization.

Rules initializing time and date/time controls will not work in a form.load rule unless you specify a timezone on the form's Url via the _formTz Url parameter. This is because the form server needs to know the timezone in which to return the date and time. If you do not specify a _formTz the methods will return null and the control values will remain blank. The timezone strings can be found here. For example, to specify Eastern time: &_formTz=America/NewYork. This URL parameter is not needed if your form/flow only contains Date controls.


This example form automatically determines today's date and then calculates the person's age in the control named 'Age' when they enter their birth date into the control named 'BirthDate'.

if (BirthDate.value.length > 0) {
  var today = new Date();
  var dob = BirthDate.value.split('-'); 
  var dob2 = new Date(dob[0],dob[1]-1,dob[2]);
  var age = today.getFullYear() - dob2.getFullYear();
  if (today.getMonth() < dob2.getMonth() || 
     (today.getMonth() === dob2.getMonth() &&
      today.getDate() < dob2.getDate())) {
    age -= 1;
  if (age >= 0) {
     Age.value = age;
  } else {
     Age.value = null;


This form initializes the hospital discharge date using a rule, and when the user enters the admission date a 2nd rule calculates the number of days the patient stayed in the hospital.

/ Calculate Hospital Stay Duration 
if (A.value !== '' && D.value !== '') { 
    var da = A.value.split('-'); 
    var Ams = new Date(da[0],da[1],da[2]); 
    da = D.value.split('-'); 
    var Dms = new Date(da[0],da[1],da[2]);
    if (Ams > Dms) { 
        Days.value = 'Discharge date must be after Admission Date'; 
    } else { 
        Days.value = (Dms - Ams) / (1000*60*60*24) + ' days'; 


Duration (between Date/Time)

Here is a rule example to calculate the time difference between two Date/Time values in hours:minutes format :

 if (StartDateTime.value !== '' && EndDateTime.value !== '') {
    var d = StartDateTime.value.split('-');
    var d1 = d[2].split('T');
    var t = d1[1].split('Z')[0];
    var t1 = t.split(':');
    var startDate = new Date(d[0],d[1],d1[0], t1[0], t1[1], t1[2]);
    d = EndDateTime.value.split('-');
    d1 = d[2].split('T');
    t = d1[1].split('Z')[0];
    var t1 = t.split(':');
    var endDate = new Date(d[0],d[1],d1[0], t1[0], t1[1], t1[2]);
    var diff = endDate.getTime() - startDate.getTime();
    var hours = Math.floor(diff / 1000 / 60 / 60);
    diff -= hours * 1000 * 60 * 60;
    var minutes = Math.floor(diff / 1000 / 60);
    TimeToComplete.value = (hours < 9 ? "0" : "") + hours + ":" + (minutes < 9 ? "0" : "") + minutes;

Today's Date and Time

Use frevvo' built-in date and time methods to set your date, time, and date/time controls to the current date and time in the user's local timezone.

if (form.load) {
  Tm.value = frevvo.currentTime();
  Dt.value = frevvo.currentDate();
  DtTm.value = frevvo.currentDateTime();

The currentTime(), currentDate() and currentDateTime() will not work in a form.load rule unless you specify a timezone on the form's Url via the _formTz Url parameter. This is because the form server needs to know the timezone in which to return the date and time. If you do not specify a formTz the methods will return null and the control values will remain blank. For example &formTz=America/New_York will set the control values to the current date and time in the eastern timezone.

Date/Time Stamp

This rule sets a control named Signature to the value of a control named Name plus a date/time stamp. Note that it is better to use the frevvo built-in date and time methods if you want to set the date to the user's local timezone. The following method will set the date to the form server's timezone.

var today=new Date(); 
var m = today.getMonth() + 1; 
var d = today.getDate(); 
var y = today.getFullYear(); 
var h = today.getHours(); var min = today.getMinutes(); var todayStr = m + '-' + d + '-' + y + ' ' + h + ':' + min; Signature.value = 'Signed by ' + Name.value + ' on ' + todayStr;

Invalid if Before Today

This rule makes the date control invalid if the date entered isn't before today's date.

// frevvo currentDate method gets today in users timezone
var today = frevvo.currentDate().split('-');
var today_date = new Date(today[0], today[1]-1, today[2]); 
var bd = DOB.value.split('-'); 
var bd_date = new Date(bd[0],bd[1]-1,bd[2]);

if (bd_date > today_date) { 
    MyMsg.value = 'Birth Date must be earlier than today!!!!';   
    DOB.valid = false; 
} else { 
    MyMsg.value = 'This is a good Birth Date: ' + DOB.value; 
    DOB.valid = true; 

Use frevvo.currentDate() rather than the javascript new Date() since the latter gets today's date in the Live Forms server's timezone while the frevvo currentDate() correctly gets today's date in the user's timezone.

Date no more then 14 days from Today

This rule checks that the date entered into a control named AppointmentDate is no more than 14 days greater than today's date.

var date1 =; 
var date2 = Appointment.value; 
date1 = date1.split("-"); 
date2 = date2.split("-"); 
var sDate = new Date(date1[0]+"/"+date1[1]+"/"+date1[2]); 
var eDate = new Date(date2[0]+"/"+date2[1]+"/"+date2[2]); 
var DaysApart = Math.round((eDate-sDate)/86400000);
if (DaysApart > 14) { 
    Appointment.status = "Date should be within 14 days from today's date."; 
} else if (DaysApart < 0) { 
    Appointment.status = "Date should not be earlier to today's date."; 

Date no more then 30 days ago

This rule checks that the date entered into a control named EventStartDate is not more then 30 days ago.

if (EventStartDate.value !== "") { 
    var date1 =; 
    var date2 = EventStartDate.value; 
    date1 = date1.split("-"); 
    date2 = date2.split("-"); 
    var sDate = new Date(date1[0]+"/"+date1[1]+"/"+date1[2]); 
    var eDate = new Date(date2[0]+"/"+date2[1]+"/"+date2[2]); 
    var days = Math.round((eDate-sDate)/86400000);
if (!eval(parseInt(days,10) > parseInt(-30,10))) { 
    EventStartDate.valid = false; 
    EventStartDate.status = "The date entered can only go back a maximum of 30 days from the current date. Please try again.";
} else { 
    EventStartDate.valid = true; 

 Add # of Years, Months or Days to a Date

Here is a rule that will add 3 years to a given date.  For example, to calculate the expiration date of a three year contract by adding three years to the starting date, your form could have two date controls, one used to enter the starting date and the other to show the contract expiration date. This rule will take the date from the StartingDate field, add 3 years to it and populate the result in a field named ExpirationDate.

if(StartingDate.value.length > 0) {   
  var md = StartingDate.value.split('-');
  var today=new Date();  
  var hour = today.getHours();  
  var oldDate = new Date(md[0],md[1]-1,md[2],hour); 
  var year = parseInt(oldDate.getFullYear(), 10);  
  var month = parseInt(oldDate.getMonth(), 10);  
  var date = parseInt(oldDate.getDate(), 10);
  var newDate = new Date(year + 3, month, date, hour); 
  var m = newDate.getMonth()+1;  
  var d = newDate.getDate();  
  var y = newDate.getFullYear();   
  var newDateStr = m + '-' + d + '-' + y;  
  ExpirationDate.value = newDateStr; 

 Change the "3" in this line to the number of years that you want to add - var newDate = new Date(year + 3, month, date, hour);

Central Timezone adjusted for Daylight Savings

This rule adjust today's date in UTC timezone to Central timezone and adjust for daylight savings time. This additional conversion is most commonly needed for  Online users as the javascript Date() and frevvo' both return today's date in UTC timezone.

// Converts UTC to either CST or CDT 
if (form.load) 
    var today = new Date(); 
    var DST = 1; // If today falls outside DST period, 1 extra hr offset 
    var Central = 5; // Minimum 5 hr offset from UTC 
    // Is it Daylight Savings Time? 
    var yr = today.getFullYear(); 
    // 2nd Sunday in March can't occur after the 14th 
    var dst_start = new Date("March 14, "+yr+" 02:00:00"); 
    // 1st Sunday in November can't occur after the 7th 
    var dst_end = new Date("November 07, "+yr+" 02:00:00"); 
    var day = dst_start.getDay(); // day of week of 14th 
    // Calculate 2nd Sunday in March of this year 
    dst_start.setDate(14-day); day = dst_end.getDay(); // day of the week of 7th 
    // Calculate first Sunday in November of this year dst_end.setDate(7-day); 
    // Does today fall inside of DST period? 
    if (today >= dst_start && today < dst_end) { DST = 0; 
    // Adjust Date for Central Timezone 
    today.setHours(today.getHours() - Central - DST);   
    var m = today.getMonth() + 1; 
    var d = today.getDate(); 
    var da = today.getDay(); 
    var y = today.getFullYear(); 
    var h = today.getHours(); 
    var min = today.getMinutes(); 
    if (min < 10) { min = '0' + min;} 
    var timezone = ['CDT', 'CST']; 
    var dom = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 
               'Thursday', 'Friday', 'Saturday']; 
    var todayStr = dom[da] + ' ' + m + '-' + d + '-' + y + ' ' + h + ':' + min + ' ' + timezone[DST];  
    DateTime.value = todayStr; 

Hours >= 4 and <= 6 Apart

This rule makes sure the end time is at least 4 hours great then the start time but no more then 6 hours later then the start time. Also start time must be on or after 1:00. The times must be entered in military units. TS is the name of the Time Start control and TE is the name of the Time End control.

  • Use Text controls for the start and end times
  • Use this pattern in the control to ensure valid military times 1:00 or greater: ([1-9]|1[0-9]|2[0-4]):([0-5][0-9])
if (TS.value.length > 0 && TE.value.length > 0) { 
    var sTime = TS.value.split(':'); 
    var sHour = sTime[0]; 
    var sMin = sTime[1]; 
    var sMins = sHour * 60 + parseInt(sMin,10);
    var eTime = TE.value.split(':'); 
    var eHour = eTime [0]; 
    var eMin = eTime [1]; 
    var eMins = eHour * 60 + parseInt(eMin,10);
    if ((eMins - sMins) < 4*60 || (eMins - sMins) > 6*60) 
        TE.valid = false; 
    } else { 
    TE.valid = true; 


The date control can be set to either just a date, just a time, or a combined date/time. Here are several examples of initializing a time control name Tm;

/ Both set the control name Tm to the same time
Tm.value = '8:30 pm'; // uses am/pm notation
Tm.value = ' 20:00'; // uses military time
// Initialize a date/time uses a "T" to separate the values
DtTm.value = "5/15/2012T4:20";
// Copying values
Tm2.value = Tm.value;
Dt2.value = Dt.value;
DtTm2.value = DtTm.value;

Tenants, Roles, Users

frevvo have several built-in methods that enable you to access information about your form server such as the list of tenants; users in a tenant; and roles in a tenant. See built-in methods for the complete list. Some of these methods return a boolean true/false value. Others return a JSON string. Here is a sample of how to use these methods.

*member roles tenants users */
var x;
  eval('x=' + frevvo.listTenants());
  Tenants.options = x.tenants; // Init a dropdown list of all tenants on this form server
if(tenant.value.length > 0)
 // Check if a tenant already exists
 if (frevvo.isUniqueRoleId(role.value, tenant.value) === false) {
    ErrMsg.value = 'The role ' + role.value + ' already exists in tenant ' + tenant.value;
  // Init dropdown with all tenant users
  eval('x=' + frevvo.listUsers(tenant.value));
  Users.options = x.users;
  // Init dropdown with all tenant roles
  eval('x=' + frevvo.listRoles(tenant.value));
  Roles.options = x.roles;
  // Init dropdown will all tenant roles except admin roles
  eval('x=' + frevvo.listRoles(tenant.value, false));
  RolesNA.options = x.roles;
// Verify that a role already exists in the tenant
if(role.value.length > 0)
  t.value = frevvo.isUniqueRoleId(role.value, tenant.value);
  if (frevvo.isUniqueRoleId(role.value, tenant.value) === false) {
    ErrMsg.value = 'The role ' + role.value + ' already exists in tenant ' + tenant.value; 

Here is an example of populating a dropdown list of all tenants on the form server with value is set to tenant Id and label is set to the tenant description returned in the JSON string. The frevvo.listTenants() method returns a string like this: {"tenants":["Default tenant","My Test Tenant"],"ids":["d",""]}. The eval function parses that string into an object that we can iterate as follows:

/*member tenants ids */

  TA.value = frevvo.listTenants();
  var x;
  eval('x=' + frevvo.listTenants());
  var opts = [];
  for (var i = 0; i < x.tenants.length; i++) {
    opts[i] = x.ids[i] + '=' + x.tenants[i];
  // Initialize dropdown of all tenants on the form server 
  TenantList.options = opts;

Repeat Item Added

This rule executes when a new item is added to a repeat. Imagine your form contains a repeating section named Employee with name Erepeat. NOTE: that the name Erepeat is set on the Repeat control and not on the Section control. The Employee section control contains many controls such as Name, Phone, etc.. and a dropdown control labeled Manager and named M. It also contains a radio control labeled Employee Shift named ES whose options have been set to 'Day' and 'Evening'.

frevvo will execute this rule each time a user clicks "+" on the repeat to add a new item. Here we want to default the Employee Shift ES to the value 'Day', and populate the Manager dropdown dynamically with values from the frevvo Database Connector.

Usually your form will have a form.load rule to initialize dropdown options for the 1st repeat item visible on your form by default.

/*member firstname lastname options resultSet value */
var x;
if (form.load) 
    var baseURL = '';
    // Manager Dropdown 
    eval('x=' + http.get(baseURL + 'Manager'));
    var opts = ['']; // default 1st option to blank 
    for (var i=0; i < x.resultSet.length; i++) { 
        if (x.resultSet[i]) { 
            opts[i+1] = x.resultSet[i].lastname+ ", " + x.resultSet[i].firstname; 
  // Repeat item index 0 is on the form by default 
  M[0].options = opts; 
  ES[0].value = 'Day'; // default the employee shift to day 

Now when a new item gets added when a user clicks the "+" icon we can save the overhead of going back to the database to retrieve dynamic options.

if (Erepeat.itemAdded) 
    var index = Erepeat.itemIndex; // which item is this in the list
    // No need to go back to the database for options. 
    // We already retrieved them in form.load rule for repeat item index 0 
    M[index].options = M[0].options; 
    ES[index].value = 'Day'; // default the employee shift to day 

Tables are repeats. So the same rule can be written for a table control. The name of a table's repeat is always <TableName>Repeat. For example if you name your table Children. Then the repeat is named ChildrenRepeat.

Repeat Item Added - Collapse Other Items

This rule executes when a new item is added to a repeat. This form contains a repeating section with a templatized label. It is nice to collapse the other items when adding a new item to keep the repeat list small and grid-like. Medrepeat is the name of the repeat control. Medication is the name of the section control inside the repeat.

if (Medrepeat.itemAdded) 
    var index = Medrepeat.itemIndex; 
    for (var i = 0; i < Medication.value.length; i++) { 
        if (i !== index) {
            Medication[i].expanded = false; 
        else {
            Medication[i].expanded = true;  

Repeat Dynamic Min/Max

It is not currently possible to change a repeat control's min and max properties in a business rule. This feature may be added in a future release. One solution is to use hidden section controls rather than a repeat control. For example imagine an airline reservation form where the number of traveler detail rows displayed and required is based on the number of airline tickets purchased. This example form allows a maximum of 3 ticket purchases. So, first add 3 section controls for traveler details. It is important to make sure that you name the travel detail section controls uniquely -- Traveler1 is the name of the first section, Traveler2 is the name of the second section, etc.. Next uncheck the visible and required property on all 3 section controls. Then add a business rule that makes the number of sections visible and required based on the number of purchased airline tickets.

Traveler1.visible = false;
Traveler2.visible = false;
Traveler3.visible = false;
Traveler1.required = false;
Traveler2.required = false;
Traveler3.required = false;

for (var i=0; i < NumTickets.value; i++) {
 if (i >= 0) {
  Traveler1.visible = true;
  Traveler1.required = true;
 if (i >= 1) {
  Traveler2.visible = true;
  Traveler2.required = true;
 if (i >= 2) {
  Traveler3.visible = true;
  Traveler3.required = true;


Tables are identical to repeat controls when referenced in business rules. Tables are a grid layout of repeating items. All the rule examples in this chapter that discuss repeats apply also to tables. The one important note is that you cannot explicitly name the repeat control inside your table. The repeat control inside a table is automatically named as <TableName>Repeat. For example a table named Expense automatically has a repeat named ExpenseRepeat. The rule ExpenseRepeat.itemAdded and ExpenseRepeat.itemIndex references an item added to your table and that item's index respectively.

One special consideration for tables is that rules which dynamically set the column header label, hint and help messages must use the array syntax. This is somewhat counter-intuitive since each column appears to have only a single label, help and hint. Here is the rule to dynamically set these three properties: 

FirstName[0].label = 'blah label';
FirstName[0].hint = 'blah hint';
FirstName[0].help = 'blah help';

You can change a table control to a repeat control via the Control Type or Display As properties, depending on whether the table was dragged and dropped from the palette or added from schema. When you change a table to a repeat or vice versa and there are referencing rules, it is recommended that you check the rules to ensure you have the correct syntax. 

A section in a repeat will behave differently than a table row when using a rule to set the valid property. For Example, drag and drop a table control into your form. Name it T. Then drag and drop a section into the same form. Name it S. Add a control to the section. Name the control C. Drop the section into a repeat named R. Add this rule to the form.

Hiding the Minus Icon on a Table Row

You can hide the  minus icon of a table row using a business rule. For example, the designer may not want to allow users to delete rows in a table that is populated from a back end system. Hiding the delete icon on these rows eliminates accidental deletion. The rule must set the table rows deletable attribute. You will not see this property listed on the Table control property pane but it will be listed in the Form Outline tool. 

Let's take a look at a simple example. Users are instructed to enter a capital Y in a table if they are planning on calling a customer. The user enters the "Y" then tabs to the company name column. The minus icon for that row will disappear.  

In this example, the name of the table control is CustomerTable and column 0 in the table is named ContactCustomer.

Here is the rule:

for (var i=0; i<ContactCustomer.value.length; i++) {
    if (ContactCustomer[i].value === "Y") {
        CustomerTableItem[i].deletable = false;
    } else {
        CustomerTableItem[i].deletable = true;

Notice the TableItem deletable property is set to false when a capital Y is entered in the first column. This will remove the minus icon for that row of the table. The for loop cycles through the table rows until the Max# property is reached. 

Clearing Values in a Table

This rule clears the values from all rows in a table. Notice the For loop that iterates over all the rows. Inside the loop a null value is assigned to all the columns in the table row.

 for (var i = 0; i < Col0.value.length; i++) { 
    Col0[i].value = null;
    Col1[i].value = null;
    Col2[i].value = null;

You cannot clear an entire table from a rule.


Rules can be used to initialize field values. This is a very useful feature and is often used to dynamically populate dropdown options from a database. Rules using form.load are triggered when a form first loads and when a workflow is loaded from a task list.

Rules using itemAdded only execute for repeat items added when the user clicks +, and for those added from an initial instance document (See Document URIs). It does '''not''' execute for those items that you have added to your form in the Form Designer. You can either add defaults directly via the form designer or add a 2nd rule to your form as follows.

These two rules together initialize the dropdown fields inside a repeat that are already in the form via the Form Designer, as well as those added each time a user clicks "+" on the repeat to add a new item & via initial documents. These controls are initialized based on a value set in another field.

//1st Rule - Default Items
if (form.load) 
    // The form contains two repeat items by default.
    if (department.value === 'Marketing') { 
        Managers[0].options = ['Joe', 'Mary', 'Stan', 'Cindy'];
        Managers[1].options = ['Joe', 'Mary', 'Stan', 'Cindy']; 
    if (department.value === 'Sales') {
        Managers[0].options = ['Lou', 'George', 'Wendy']; 
        Managers[1].options = ['Lou', 'George', 'Wendy'];  
//2nd Rule - Items Added
if (Erepeat.itemAdded) 
    var index = Erepeat.itemIndex; // which item is this in the list  
    ES[index].value = 'Day'; // default the employee shift to day
    // Use options already selected in form.load rule 
    Managers[index].options = Managers[0].options; 

This rule is useful in a workflow where you want to make a the tab named Review visible only for the workflow activity named Manager Review. See Built-in Data for more details on _data.getParameter and

if (form.load) { 
    if (_data.getParameter('') === 'Manager Review') { 
Review.visible = true; 


Rules can be used to finalize field values after the users clicks the form's submit button but prior to the Form and Doc Action execution. Rules using form.unload are triggered when the form user clicks the submit button and for workflows when the user clicks continue to go to the next activity or finish to complete the flow.

One common example use is for an order form order number. You may only want to assign a unique sequential order number to each order submission. You could initialize the form's order number when the form loads using form.load. However if someone start filling in the order form but never submit it you do not want to consume the next order number in sequence if it will never be used. Using form.unload you can assign the number after the submit button click but before the form data is submitted.

Here OrderNum is the name of a invisible control.

/*member num */
var x;
if (form.unload) 
    eval('x=' + http.get('http://(your webhost)/json/getNextOrdernum'));  
    OrderNum.value = x.num;

Geo Location

Rules can be used to save a snapshot of location information of any form. For example, an insurance company may want to capture the GPS location of their representatives filling out a form used for audit purposes. The designer can use the frevvo Geo Location feature in conjunction with rules like the ones shown in the examples below to accomplish this. When the form loads in the browser, the user will be prompted by to allow/disallow the use of location services. If permission is granted, the position will be calculated and server will be updated via an Ajax which causes the rule to fire. If the user denies permission or there is a timeout, the server will get an Ajax with an error.

Use the special rule identifier, form.positionUpload, to set up a rule in a form that will execute every time the form location is updated. See Rules Position Data for the complete list of available position.* data that you can access from your rules.

if (form.positionUpdated) {
  Latitude.value = _data.getParameter ("position.latitude");
  Longitude.value = _data.getParameter ("position.longitude");
  Accuracy.value = _data.getParameter ("position.accuracy");
  PositionError.value = _data.getParameter ("position.error.message");

Here is an example of a location tab on a Police Report form.

Checking the Detailed Loc checkbox in the Form Property pane and implementing a rule like the one shown will go to Google Maps to get additional information and a map associated with the location.

if (form.positionUpdated) {
  Latitude.value = _data.getParameter ("position.latitude");
  Longitude.value = _data.getParameter ("position.longitude");
  Accuracy.value = _data.getParameter ("position.accuracy");
  PositionError.value = _data.getParameter ("position.error.message");

  StreetNumber.value = _data.getParameter ("position.street_number");
  StreetLine1.value = _data.getParameter ("position.route");
  City.value = _data.getParameter ("position.locality");
  State.value = _data.getParameter ("position.administrative_area_level_1");
  County.value = _data.getParameter ("position.administrative_area_level_2");
  Country.value = _data.getParameter ("");
  ZipCode.value = _data.getParameter ("position.postal_code");

  CompleteStreetAddress.value = _data.getParameter ("position.street_address");

When you run the form (unless you get a timeout or error) the address will automatically get filled in and the Google map will display.  

Sequential Numbers

The Google Spreadsheet connector can also be used to generate unique sequential numbers. This technique should not be used if you have multiple people using the form at the same time as it's possible that two people simultaneously opening the same form could get the same sequential number.

In this example have a checkbook form where we want to initialize a field named CheckNum with the next sequential check book number when the form loads. Here is our Google spreadsheet:

Here is the rule that reads the next sequential number from the spreadsheets and updates plus 1. See Connecting to Google Spreadsheets for more details.

/*member nextid results */
var x;
if (form.load) { 
    var readmethod = 
'<google username>/p/<google password>/s/SequentialNumberGenerator/w/Sheet1?media=json&query=formname="Checkbook"';
    var updatemethod = 
'<google username>/p/<google password>/s/SequentialNumberGenerator/w/Sheet1?media=json&query=formname="Checkbook"';
    eval('x=' + http.get(readmethod)); 
    var id = 'unknown'; 
    if (x.results === null) 
        { CheckNum.value = 'error'; 
    } else if (x.results.length === 0) { 
        CheckNum.value = 'No Match'; 
    } else { 
    id = x.results[0].nextid; 
    CheckNum.value = id; 
    id = id*1 + 1; 
    if (id !== 'unknown') { 
    eval('x=' + http.put(updatemethod + '&updates=nextid=')); 

Unique ID

Forms such as invoices, bills of lading, etc often need to be stamped with a unique ID. The Sequential Number example is one approach, however it has some limitations. One is that you must guarantee that only one person at a time is filling out your form. This is because there is no mutex around the read and update of the Google spreadsheet cell.

Here is a simpler method if your unique IDs do not need to be sequential. The data named is guaranteed to be unique for every new form instance. You can just use it as follows:

if (form.load) 
    InvoiceNum.value = _data.getParameter(''); 

An another approach is using the javascript Date method as follows.

  // some VERY likely unique number
  var n = new Date().valueOf().toString();
  PONumber.value = n;

Repeat Item Initialization

The rule above was one example of initializing a newly added repeating control with a default list of options. This same concept is useful if you want to initialize a repeating control's value. When you add a repeat to your form in the Form Designer you can set a default value in any of those repeating controls visible in the designer. However when the user clicks "+" while using the form to add an additional item the default entered in the Form Designer is not automatically used in this new item. In order to accomplish this you can add a simple rule as follows:

This rule initializes the value of one of the fields in the repeat to a default of '0'. RepeatTrack is the name of the repeat control containing the input control named albumOnly. This rule will execute each time a new RepeatTrack item is added when the user clicks "+".

ItemAdded and itemIndex are properties of the Repeat control.

if (RepeatTrack.itemAdded) 
    var index = RepeatTrack.itemIndex; 
    albumOnly[index].value = 0; 

Again, to initialize repeat items already on your form in the Form Designer by default, either enter your initial default values directly into the in the Form Designer or add this rule.

if (form.load) 
    for (var i=0; i < albumOnly.value.length; i++) { 
        albumOnly[i].value = 0; 

This rule takes into account a repeat where min > 1. If min is 0 or 1, you can simplify this further by removing the for loop and simply have albumOnly[0].value = 0 inside the if (form.load).

Repeat ItemAdded by Init Doc

ItemAdded also executes when frevvo adds items found in an init doc. You may want to only initialize items added when the user clicks "+" on the form. And not those added from an initial document. This form contains a Mailing Label that repeats. Each label needs a unique ID assigned. However once the form is submitted the assigned IDs are saved in the database via the form's Doc URI. When the form loads it adds items automatically from rows in the database. They already have assigned Ids. We only need to assign new Ids in the sequence when the user manually adds a new Mailing Label by clicking the "+" button on the form. MLrepeat is the name of the Mailing Label repeat. MLmid is the name of the ID field in the repeat.

if (MLrepeat.itemAdded)
  var index = MLrepeat.itemIndex;

   // This rule is fired both when the user clicks "+" 
   // and when frevvo adds items found in the init doc. 
   // Need to assign new mid only when user clicks "+" 
  // New items added via "+" will have a zero length value. 
  if (MLmid[index].value.length === 0) { 
    // Assign unique ID to label so it can be referenced 
    // in RI Mailing Labels field 
    // Count the number of existing mailing labels on the form 
    var maxId = 0; 
    for (var i=0; i < MLmid.value.length; i++) 
     if (MLmid[i].value > maxId) { 
       maxId = MLmid[i].value; 
   var next = parseInt(maxId, 10) + 1; 
   MLmid[index].value = next.toFixed(0); 

Repeat Item Increment

You can easily auto populate incremental items numbers in repeats using a business rule. In this example Erepeat is the name of the repeat control and Item is the name of the item control inside the repeat. You also need to set 1 as the default value of first repeating Item control directly into your form field via the form designer as shown here.

if (Erepeat.itemAdded || Erepeat.itemRemoved){
  for(var i = 0; i < Item.value.length; i++) {
    Item[i].value = i+1;

Display Uploaded Image

A rule can dynamically display an image uploaded to your form via the upload control. In this example the upload control is named 'u'. The form also must contain a message control as a place holder for displaying the uploaded image. The rule dynamically creates a URL to the uploaded image in the frevvo temporary attachment repository. The upload control's value 'u.value' is a GUID that uniquely identifies the attachment. The uploaded image will be included in the submissions pdf.

if (u.value.length > 0) {
  var baseUrl = "/frevvo/web/tn/" +
      _data.getParameter('') +
      "/user/"+_data.getParameter('') +
      "/app/"+_data.getParameter('') +
  im.value = '<img src="' +
         baseUrl + '/attachment/' + u.value+'/does_not_matter"/>';

Here is the example form before and after the user has upload the frevvo.logo,orange.png image:

This rule is a bit more complex to handle the case where the user uploaded multiple images via the upload control.

var x = "";
for(var i=0; i< u.value.length; i++) {
  x = x + u[i].value + ",";
var y = x.split(',');
var baseUrl = _data.getParameter('_frevvo_base_url') + 
      "frevvo/web/tn/" +
      _data.getParameter('') +
      "/user/"+_data.getParameter('') +
      "/app/"+_data.getParameter('') +
if(y[0].length === 1) {
  im.value = "<img src='" + baseUrl + "/attachment/"+u.value+"/does_not_matter'/>";
} else {
  var z = "";
  for(var i=0; i<= y.length; i++) {
    z = z + "<img src='" + baseUrl + "/attachment/"+ y[i] +"/does_not_matter'/>" + "<br/>";
  im.value = z;

Search Popup

frevvo forms can initialize dynamically from backend systems. A common form design pattern is the master/detail. An example of master/detail is a form that contains an order number or employee Id. When the user enters an existing Id into the form field you want all other form fields to populate dynamically from values in a database. This is done using a form created from XSD data source generated by the  database connector. This part of the master/detail form design pattern needs no business rule. It happens automatically using the Doc Action manually set document URIs. See the  DB Connector Tutorial for complete detail on how to initialize your form using a Doc Action document URI to your database.

This form was created from employee.xsd generated by the frevvo database connector. The master Id is a control from that XSD named racfid. The key to this design pattern is in using the master Id in the form's doc action document URI. In this example the form's doc action document URI for the employee document is set to:http://localhost:8082/database/myqset/employee?racfid={racfid}.

Often the master Id is a cryptic number not easily remembered by people using your form. It is a common and useful form design pattern to populate the master Id using a lookup search.

Here is an example form that allows user to view existing employee records and to update their information.

If you know the RACF ID for an employee you can simply type it into that field. If the RACF ID is found in the database the form will automatically populate all other fields from the database (because of the doc action document uri setting). However if you do not know the employee's RACF ID you can click the Find Employee trigger.

This trigger control is named FindEmployee and fires the following rule that makes the search condition section control visible.

//Show Employee Search Criteria 
if (FindEmployee.clicked) 
    EmployeeSearch_s1.visible = true; 
    EmployeeSearch_s1.expanded = true; 

The section control contains controls that are the search criteria for finding a RACF ID based on other pieces of information you may know about an employee such as name, type, email address. The values entered into the search criteria can be partial values. For instance entering a name "Smith" will find all employees whose name contains the letters "Smith". If you also select email, it will find all employees whose name contains "Smith" and have an email address containing the string "frevvo".

This is the rule that fires when you click the trigger control named Search.

/*member clicked racfid resultSet type */
var x;
if (Search.clicked) {
 eval('x=' + 
    var opts= []; 
    for (var i=0; i < x.resultSet.length; i++) { 
        if (x.resultSet[i]) { 
            opts[i] = x.resultSet[i].racfid + "=" + 
                      x.resultSet[i].name + ", " +  
    SearchMsg.value = x.resultSet.length +  
    ' Matches Found. Change your criteria and click "search" to try again.'; 
    SearchMsg.visible = true; 
    SearchResults.options = opts; 
    SearchResults.visible = true; 

The Search returns one or more matches and dynamically populates a dropdown control named SearchResults. You can change the search criteria to narrow or expand you search. When you select one of the matches from the SearchResults dropdown this 3rd rule executes to copy the selection into the RACF ID control.

//Select from Search results 
if (SearchResults.value.length > 0) 
    racfid.value = SearchResults.value;
    // Hide Employee Search and clear values 
    EmployeeSearch.visible = false; 
    SearchMsg.visible = false; 
    SearchResults.visible = false; 
    SearchResults.options = []; 

Once the value is copied into RACF ID the form automatically loads all other values in the form from the database. This is due to the form action document Uri setting.

The values in the employee loaded into the form can now be edited. When the users clicks the form's submit button the values will automatically be updated in the database record. This is due to the form action document Uri setting.

LDAP Custom Attributes

You can use a business rule to pull custom attributes from your LDAP server into your form. You will have to modify your LDAP configuration and write a rule using _data.getParameter. Details are explained here.







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