For AEM 6.2 Forms version of this help, see Adaptive forms rule editor.

 

Overview

The rule editor feature in AEM forms empowers forms business users and developers to write rules on adaptive form objects. These rules define actions to trigger on form objects based on preset conditions, user inputs, and user actions on the form. It helps further streamline the form filling experience ensuring accuracy and speed.

The rule editor provides an intuitive and simplified user interface to write rules. It offers a visual editor and a code editor to write rules. Some of the key actions that you can perform on adaptive form objects using rules are:

  • Show or hide an object
  • Enable or disable an object
  • Set a value for an object
  • Validate the value of an object
  • Execute functions to compute the value of an object
  • Invoke a web service and perform an operation
  • Set property of an object

Rule editor replaces the scripting capabilities in AEM 6.1 forms and earlier releases. However, your existing scripts are preserved in the new rule editor. For more information about working with existing scripts in the rule editor, see Impact of rule editor on existing scripts.

Let us first discuss the underlying concepts of the rule editor and then take a deep dive into using it to write and manage rules.

Understanding a rule

A rule is a combination of actions and conditions. In rule editor, actions include activities such as hide, show, enable, disable, or compute the value of an object in a form. Conditions are Boolean expressions that are evaluated by performing checks and operations on the state, value, or property of a form object. Actions are performed based on the value (True or False) returned by evaluating a condition.

The rule editor provides a set of predefined rule types, such as When, Show, Hide, Enable, Disable, Set Value Of, and Validate to help you write rules. Each rule type allows you to define conditions and actions in a rule. The document further explains each rule type in detail.

A rule typically follows one of the following constructs:

Condition-Action

In this construct, a rule first defines a condition followed by an action to trigger. The construct is comparable to if-then statement in programming languages.

In rule editor, the When rule type enforces the condition-action construct.

Action-Condition

In this construct, a rule first defines an action to trigger followed by conditions for evaluation. Another variation of this construct is action-condition-alternate action, which also defines an alternate action to trigger if the condition returns False.

The Show, Hide, Enable, Disable, Set Value Of, and Validate rule types in rule editor enforce the action-condition rule construct. By default, the alternate action for Show is Hide and for Enable is Disable, and vice versa. You cannot change the default alternate action.

Note:

The available rule types, including conditions and actions that you define in rule editor, also depend on the type of form object on which you are creating a rule. The rule editor displays only valid rule types and options for writing condition and action statements for a particular form object type. For example, you do not see Validate, Set Value Of, Enable, and Disable rule types for a panel object.

For more information about rule types available in the rule editor, see Available rule types in rule editor.

Guidelines for choosing a rule construct

While you can achieve most of the use cases by using any rule construct, here are some guidelines to choose one construct over another. For more information about the available rules in rule editor, see Available rule types in rule editor.

  • A typical rule of the thumb when creating a rule is to think about it in the context of the object on which you are writing a rule. Consider that you want to hide or show the field B based on the value a user specifies in the field A. In this case, you are evaluating a condition on field A, and based on the value it returns, you are triggering an action on field B.

    Therefore, if you are writing a rule on field B (the object on which you are evaluating a condition), use the condition-action construct or the When rule type. Similarly, use the action-condition construct or Show or Hide rule type on field A.

  • At times, you need to perform multiple actions based on one condition. In such cases, it is recommended to use the condition-action construct. In this construct, you can evaluate a condition once and specify multiple action statements.

    For example, to hide fields B, C, and D based on the condition that checks for the value a user specifies in field A, write one rule with condition-action construct or When rule type on field A and specify actions to control the visibility of fields B, C, and D. Otherwise, you need three separate rules on fields B, C, and D, where each rule checks the condition and shows or hides the respective field. In this example, it is more efficient to write the When rule type on one object rather than Show or Hide rule type on three objects.

  • To trigger an action based on multiple conditions, it is recommended to use action-condition construct. For example to show and hide field A by evaluating conditions on fields B, C, and D, use Show or Hide rule type on field A.
  • Use condition-action or action condition construct if the rule contains one action for one condition.
  • If a rule checks for a condition and performs an action immediately on providing a value in a field or exiting a field, it is recommended to write a rule with condition-action construct or the When rule type on the field on which the condition is evaluated. 
  • The condition in the When rule is evaluated when a user changes the value of the object on which the When rule is applied. However, if you want the action to trigger when the value changes on the server side, like in case of prepopulating the value, it is recommended to write a When rule that triggers the action when the field is initialized.

Available rule types in rule editor

The rule editor provides a set of predefined rule types that you can use to write rules. Let's look at each rule type in detail. For more information about writing rules in rule editor, see Write rules.

When

The When rule type follows the condition-action-alternate action rule construct, or sometimes, just the condition-action construct. In this rule type, you first specify a condition for evaluation followed by an action to trigger if the condition is satisfied (True).

Using the When rule type, you can evaluate a condition on a form object and perform actions on one or more objects. 

In plain words, a typical When rule is structured as follows:

____________________________________________

When on Object A:

(Condition 1 AND Condition 2 OR Condition 3) is TRUE;

Then, do the following:

Action 1 on Object A;
AND
Action 2 on Object B;
AND
Action 3 on Object C;

_____________________________________________

Note:

You can include either OR or AND operators when writing a complex condition or action statement in a rule. You cannot mix the two operators in a statement.

While you can check for conditions only on the object on which you are writing a When rule, you can trigger the following actions on multiple form objects.  

  • Hide: Hides the specified object.
  • Show: Shows the specified object.
  • Enable: Enables the specified object.
  • Disable: Disables the specified object.
  • Set value of: Computes and sets the value of the specified object. You can set the object value to a string, the value of another object, the computed value using mathematical expression or function, or the value of a property of an object.
  • Invoke web service: Invokes a web service. It requires you to specify a WSDL URL to the web service and then allows selecting an operation to perform.
    Note: Web services that require authentication or return an array as output are currently not supported.
  • Set property: Sets the value of a property of the specified object.
  • Clear Value Of: Clears the value of the specified object.
  • Set Focus: Sets focus on the specified object.
  • Save Form: Saves the form.
  • Submit Forms: Submits the form.
  • Reset Form: Resets the form.
  • Validate Form: Validates the form.
  • Add Instance: Adds an instance of the specified repeatable panel or table row.
  • Remove Instance: Removes an instance of the specified repeatable panel or table row.

Set value

The Set Value Of rule type allows you to set the value of a form object depending on whether the specified condition is satisfied or not. The value can be set to a value of another object, a literal string, a value derived from a mathematical expression or a function, or a value of a property of another object. Similarly, you can check for a condition on a component, string, property, or values derived from a function or mathematical expression.

Note that the Set Value Of rule type is not available for all form objects, such as panels and toolbar buttons.

A standard Set Value Of rule has the following structure:

____________________________________________

Set value of Object A to:

(value of Object B) OR
(string ABC) OR
(object property X of Object C) OR
(value from a function) OR
(value from a mathematical expression);

When:

(Condition 1 AND Condition 2 AND Condition 3) is TRUE;

____________________________________________

Note:

You can include either OR or AND operators when writing a complex condition or action statement in a rule. You cannot mix the two operators in a statement.

Show

Using the Show rule type, you can write a rule to show or hide a form object based on whether a condition is satisfied or not. The Show rule type also triggers the Hide action in case the condition is not satisfied or returns False.

A typical Show rule is structured as follows:

____________________________________________

Show Object A;

When:

(Condition 1 OR Condition 2 OR Condition 3) is TRUE;

Else:

Hide Object A;

____________________________________________

Note:

You can include either OR or AND operators when writing a complex condition or action statement in a rule. You cannot mix the two operators in a statement.

Hide

Similar to the Show rule type, you can use the Hide rule type to show or hide a form object based on whether a condition is satisfied or not. The Hide rule type also triggers the Show action in case the condition is not satisfied or returns False.

A typical Hide rule is structured as follows:

____________________________________________

Hide Object A;

When:

(Condition 1 AND Condition 2 AND Condition 3) is TRUE;

Else:

Show Object A;

____________________________________________

Note:

You can include either OR or AND operators when writing a complex condition or action statement in a rule. You cannot mix the two operators in a statement.

Enable

The Enable rule type lets you enable or disable a form object based on whether a condition is satisfied or not. The Enable rule type also triggers the Disable action in case the condition is not satisfied or returns False.

A typical Enable rule is structured as follows:

____________________________________________

Enable Object A;

When:

(Condition 1 AND Condition 2 AND Condition 3) is TRUE;

Else:

Disable Object A;

____________________________________________

Note:

You can include either OR or AND operators when writing a complex condition or action statement in a rule. You cannot mix the two operators in a statement.

Disable

Similar to the Enable rule type, the Disable rule type allows you to enable or disable a form object based on whether a condition is satisfied or not. The Disable rule type also triggers the Enable action in case the condition is not satisfied or returns False.

A typical Disable rule is structured as follows:

____________________________________________

Disable Object A;

When:

(Condition 1 OR Condition 2 OR Condition 3) is TRUE;

Else:

Enable Object A;

____________________________________________

Note:

You can include either OR or AND operators when writing a complex condition or action statement in a rule. You cannot mix the two operators in a statement.

Validate

The Validate rule type validates the value in a field using an expression. For example, you can write an expression to check that the text box for specifying name doesn't contain special characters or numbers.

A typical Validate rule is structured as follows:

____________________________________________

Validate Object A;

Using:

(Expression 1 AND Expression 2 AND Expression 3) is TRUE;

____________________________________________

Note:

You can include either OR or AND operators when writing a complex condition or action statement in a rule. You cannot mix the two operators in a statement.

Note:

If the specified value doesn't comply with the Validate rule, you can display a validation message to the user. You can specify the message in the Script validation message field in the Title and text tab of the field's Edit component dialog.  

Understanding the rule editor user interface

Rule editor provides a comprehensive yet simple user interface to write and manage rules. You can launch the rule editor user interface from within an adaptive form in authoring mode.

To launch the rule editor user interface:

  1. Open an adaptive form in authoring mode.

  2. Right-click the form object on which you want to write a rule, and click Edit Rules.  The rule editor user interface opens.

    Any existing rules on the selected form objects are listed in this view. For information about managing existing rules, see Manage rules.

  3. Click Create to write a new rule. The visual editor of the rule editor user interface opens by default when you launch the rule editor the first time.

    Rule Editor UI
    Click to view enlarged image

    Let's look at each component of the rule editor UI in detail.

A. Component-rule display

Displays the title of the adaptive form object through which you launched the rule editor and the rule type currently selected. In the above example, the rule editor is launched from an adaptive form object titled Salary and the rule type selected is When.

B. Form objects and functions

The pane on the left in the rule editor user interface includes two tabs — Forms Objects and Functions.

The Form Objects tab shows a hierarchical view of all objects contained in the adaptive form. It displays the title and type of the objects. When writing a rule, you can drag-drop form objects onto the rule editor.

The Functions tab includes a set of built-in functions, such as Sum Of, Min Of, Max Of, Average Of, Number Of, and Validate Form. You can use these functions to compute values in repeatable panels and table rows and use them in action and condition statements when writing rules.   

The Functions tab

Note:

You can perform text search on objects and functions names and titles in Forms Objects and Functions tabs.

C. Form objects and functions toggle

The toggle button, when clicked, toggles the form objects and functions pane.

D. Visual rule editor

Visual rule editor is the area in the visual editor mode of the rule editor user interface where you write rules. It allows you to select a rule type and accordingly define conditions and actions. When defining conditions and actions in a rule, you can drag-drop form objects and functions from the Form Objects and Functions pane.

For more information about using visual rule editor, see Write rules.

E. Visual-code editors switcher

You can switch from visual editor mode to code editor mode of the rule editor, and vice versa, using the switcher right above the rule editor. When you launch rule editor the first time, it opens in the visual editor mode. You can write rules in the visual editor mode or switch to the code editor mode to write a rule script. However, note that if you modify a rule or write a rule in code editor, you cannot switch back to the visual editor for that rule unless you clear the code editor.

AEM forms tracks the rule editor mode you used last to write a rule. When you launch the rule editor next time, it opens in that mode. However, you can also configure a default mode to open the rule editor in the specified mode. To do so:

  1. Go to AEM web console at http://[host]:[port]/system/console/configMgr.
  2. Click to edit Adaptive Form Configuration Service.
  3. choose Visual Editor or Code Editor from the Default Mode for Rule Editor drop-down
  4. Click Save.

F. Done and cancel buttons

The Done button is used to save a rule. You can save an incomplete rule. However, incomplete are invalid and don't execute. Saved rules on a form object are listed when you launch the rule editor next time from the same form object. You can manage existing rules in that view. For more information, see Manage rules.

The Cancel button discards any changes you made to a rule and closes the rule editor.

Write rules

You can write rules using the visual rule editor or the code editor. When you launch the rule editor the first time, it opens in the visual editor mode. You can switch to the code editor mode and write rules. However, note that if you write or modify a rule in code editor, you cannot switch to the visual editor for that rule unless you clear the code editor. When you launch the rule editor next time, it opens in the mode that you used last to create rule.

Let's first look at how to write rules using visual editor.

Using visual editor

Let's understand how to create a rule in visual editor using the following example form.

The Loan Requirements section in the example loan application form requires applicants to specify their marital status, salary, and if married, their spouse's salary. Based on the user inputs, the rule computes the loan eligibility amount and displays in the Loan Eligibility field. Apply the following rules to implement the scenario:

  • The Spouse's Salary field is shown only when the Marital Status is Married.
  • The loan eligibility amount is 50% of the total salary.
Perform the following steps to write rules:
  1. First, write the rule to control the visibility of the Spouse Salary field based on the option user selects for the Marital Status radio button. 

    Open the loan application form in authoring mode. Right-click the Marital Status component and click Edit Rules. Next, click Create to launch the rule editor.

    When you launch the rule editor, the When rule is selected by default. Also, the form object (in this case, Marital Status) from where you launched the rule editor is specified in the When statement.

    While you cannot change or modify the selected object, you can use the rule drop-down, as shown below, to select another rule type. If you want to create a rule on another object, click Cancel to exit the rule editor and launch it again from the desired form object.

  2. Click Select State drop-down and select is equal to. The Enter a String field appears.

    In the Marital Status radio button, Married and Single options are assigned 0 and 1 values, respectively. You can verify assigned values in the Title tab of the Edit radio button dialog as shown below.

  3. In the Enter a String field in the rule, specify 0.

    You have defined the condition as When Marital Status is equal to Married. Next, define the action to perform if this condition is True.

  4. In the Then statement, select Show from the Select Action drop-down.

  5. Drag-drop the Spouse Salary field from the Form Objects tab on the Drop object or select here field. Alternatively, click the Drop object or select here field and select the Spouse Salary field from the pop-up menu, which lists all form objects in the form.

    The rule appears as follows in the rule editor.

    Click Done to save the rule.

  6. Repeat steps 1 through 5 to define another rule to hide the Spouse Salary field if the marital Status is Single. The rule appears as follows in the rule editor.

    Note:

    Alternatively, you can write one Show rule on the Spouse Salary field, instead of two When rules on the Marital Status field, to implement the same behavior.

  7. Next, write a rule to compute the loan eligibility amount, which is 50% of the total salary, and display it in the Loan Eligibility field. To achieve this, create Set value Of rules on Loan Eligibility field.

    In authoring mode, right-click the Loan Eligibility field and click Edit Rules. Next, click Create to launch the rule editor.

  8. Select Set Value Of rule from the rule drop-down.

  9. Click Select Option and select Mathematical Expression. A field to write mathematical expression opens.

  10. In the expression field:

    • Select or drag-drop from the Forms Object tab the Salary field in the first Drop object or select here field.
    • Select Plus from the Select Operator field.
    • Select or drag-drop from the Forms Object tab the Spouse Salary field in the other Drop object or select here field.
  11. Next, click in the highlighted area around the expression field and click Extend Expression.

    In the extended expression field, select divided by from the Select Operator field and Number from the Select Option field. Then, specify 2 in the number field.

    Note:

    You can create complex expressions by using components, functions, mathematical expressions, and property values from the Select Option field.

    Next, create a condition, which when returns True, the expression executes.

  12. Click Add Condition to add a When statement.

    In the When statement:

    • Select or drag-drop from the Forms Object tab the Marital Status field in the first Drop object or select here field.
    • Select is equal to from the Select Operator field.
    • Select String in the other Drop object or select here field and specify Married in the Enter a String field.
    The rule finally appears as follows in the rule editor.

    Click Done to save the rule.

  13. Repeat steps 7 through 12 to define another rule to compute the loan eligibility if the marital Status is Single. The rule appears as follows in the rule editor.

Note:

Alternatively, you can use the Set Value Of statement to compute the loan eligibility in the When rule that you created to show-hide the Spouse Salary field. The resultant combined rule when Marital Status is Single appears as follows in the rule editor.

Similarly, you can write a combined rule to control visibility of the Spouse Salary field and compute loan eligibility when the Marital Status is Married.

Using code editor

The rule editor auto generates the JavaScript code for any rule you create using visual editor. You can switch from visual editor to the code editor to view the generated code. However, if you modify the rule code in the code editor, you cannot switch back to the visual editor. If you prefer writing rules in code editor rather than visual editor, you can write rules afresh in the code editor. The visual-code editors switcher helps you switch between the two modes.

The code editor JavaScript is the expression language of adaptive forms. All the expressions are valid JavaScript expressions and use adaptive forms scripting model APIs. These expressions return values of certain types. For the complete list of adaptive forms classes, events, objects, and public APIs, see JavaScript Library API reference for adaptive forms.

For more information about guidelines to write rules in the code editor, see Adaptive Form Expressions.

Manage rules

Any existing rules on a form object are listed when you right-click the object and click Edit Rules. You can view the title and a preview the rule summary. Furthermore, the UI allows you to expand and view the complete rule summary, change the order of rules, edit rules, and delete rules. 

You can perform the following actions on rules:

  • The Content column in the rule list displays the rule content. If the entire rule content is not visible in the default view, click to expand it.
  • Any new rule you create is stacked at the bottom of the rule list. The rules are executed from top to bottom. The rule at the top executes first followed by other rules of the same type. For example, if you have When, Show, Enable, and When rules at first, second, third, and fourth positions from top, respectively, the When rule at the top gets executed first followed by the When rule at the fourth position. Then, the Show and Enable rules will be executed.
    You can change the order of a rule by clicking  against it or drag-drop it to the desired order in the list.
  • To edit a rule, select the check box next to the rule title. Additional options to edit and delete the rule appear. Click Edit to open the selected rule in the rule editor in visual or code editor mode depending the mode used to create the rule.    
  • To delete a rule, select the rule and click Delete.

Impact of rule editor on existing scripts

In AEM forms versions prior to AEM 6.1 forms feature pack 1, form authors and developers used to write expressions in the Scripts tab of the Edit component dialog to add dynamic behavior to adaptive forms. The Scripts tab is now replaced by the rule editor.

Any scripts or expressions that you must have written in the Scripts tab are available in the rule editor. While you cannot view or edit them in visual editor, you can edit in code editor.  

Some example rules

Triggering multiple actions using the When rule

In a loan application form, you want to capture whether the loan applicant is an existing customer or not. Based on the information user provides, the customer ID field should show or hide. Also, you want to set focus on the customer ID field if the user is an existing customer. The loan application form has the following components:

  • A radio button, Are you an existing Geometrixx customer?, which provides Yes and No options. The value for Yes is 0 and No is 1.
  • A text field, Geometrixx customer ID, to specify the customer ID.
When you write a When rule on the radio button to implement this behavior, the rule appears as follows in the visual rule editor.
Rule in the visual editor

In the example rule, the statement in the When section is the condition, which when returns True, executes the actions specified in the Then section.

The rule appears as follows in the code editor.

Rule in the code editor

Using a function output in a rule

In a purchase order form, you have the following table, in which users will fill in their orders. In this table:

  • The first row is repeatable, so users can order multiple products and specify different quantities. Its element name is Row1.
  • The title of the cell in Product Quantity column of the repeatable row is Quantity. The element name for this cell is productquantity.
  • The second row in the table is non-repeatable and the title of the cell in Product Quantity column in this row is Total Quantity.
A. Row1 B. Quantity C. Total Quantity 

Now, you want to add specified quantities in the Product Quantity column for all products and display the sum in the Total Quantity cell. You can achieve this by writing a Set Value Of rule on the Total Quantity cell as shown below.

Rule in the visual editor

The rule will appear as follows in the code editor.

Rule in the code editor

Validating a field value using expression

In the purchase order form explained in the previous example, you want to restrict user from ordering more than one quantity of any product that is priced more that 10000. To do this, you can write a Validate rule as shown below. 

Rule in the visual editor

The rule will appear as follows in the code editor.

Rule in the code editor

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