Best practices for working with adaptive forms best-practices-for-working-with-adaptive-forms

Use Apache Maven aem-project-archetype to create and manage structure for AEM project. It creates recommended structure and templates for your AEM project. Also, it provides build automation and change control systems to help manage the project.

• Use the maven archetype:generate command to generate the initial structure.
• Use maven eclipse:eclipse command to generate the eclipse project files and import the project into eclipse.

The FileVault tool or VLT helps you map the content of a CRX or AEM instance to your file system. It provides change control management operations, such as check-in and check-out of the AEM project content. See How to use the VLT Tool.

If you use Eclipse-integrated development environment, you can use AEM Developer tools for seamless integration of Eclipse IDE with AEM instances to create AEM applications. For details, see AEM developer tools for Eclipse.

Do not store any content or make any modifications in /libs folder. Create overlays in /app folders to extend or overwrite default functionalities.

When you create packages to move content, ensure package filter paths are correct and only required paths are mentioned.

Do not store any content or make any modifications in /libs folder. Create overlays in /app folders to extend or overwrite default functionalities.

Define correct dependencies for the packages to force a pre-determined installation order/sequence.

Do not create any referenceable node in /libs or /apps.

An adaptive form template is a specialized AEM page that defines structure and the header-footer information of an adaptive form. A template has preconfigured layouts, styles, and basic structure for an adaptive form. AEM Forms provides out-of-the-box templates and components that you can use to author adaptive forms. However, you can create custom templates and components as per your requirements. It is recommended to gather requirements for additional templates and components you will need in your adaptive forms. For details, see Customizing adaptive forms and components.

AEM Forms lets you create adaptive forms based on the following form models. The form models act as interface for data exchange between a form and AEM system and provide an XML-based structure for data flow within and outside an adaptive form. Also, the form models impose rules and constraints on adaptive forms in the form of schema and XFA constraints.

• None: Adaptive forms created with this option don’t use any form model. The data XML generated from such forms has flat structure with fields and corresponding values.
• XML or JSON schema: XML and JSON schemas represent the structure in which data is produced or consumed by the back-end system in your organization. You can associate a schema to an adaptive form and use its elements to add dynamic content to the adaptive form. The elements of the schema are available in the Data Model Object tab of the content browser for authoring adaptive forms. You can drag-drop the schema elements to build the form.
• XFA form template: It is an ideal form model if you have investments in XFA-based HTML5 forms. It provides a direct way to convert your XFA-based forms into adaptive forms. Any existing XFA rules are retained in the associated adaptive forms. The resulting adaptive forms support XFA constructs, such as validations, events, properties, and patterns.
• Form Data Model: It is a preferred form model if you are looking to integrate your backend systems like databases, web services, and AEM user profile to prefill adaptive forms and write submitted form data back into the backend systems. A Form Data Model editor lets you define and configure entities and services in a form data model that you can use to create adaptive forms. For more information, see AEM Forms Data Integration.

AEM Forms provides out-of-the-box adaptive form templates that you can use to create adaptive forms. You can also create your own templates. AEM provides static and editable templates.

• Static templates are defined and configured by developers.
• Editable templates are created by authors using template editor. The template editor lets you define a basic structure and initial content in a template. Any modification in the structure layer is reflected in all forms using that template. The initial content may include pre-configured theme, prefill service, submit action, and so on. However, these settings can be modified for a form using the form editor. For more information, see Adaptive form templates.

For styling a specific field or panel instance, use inline styling. Alternatively, you can define a class in a CSS file and specify the class name in the CSS Class property of the component.

Include a client library in a component to consistently apply styles across adaptive forms or fragments that use that component. For more information, see Create an adaptive form page component.

Apply styles defined in a client library to select adaptive forms by specifying the path to the client library in the CSS file path field in the adaptive form container properties.

To create a client library of your styles, you can configure the custom CSS file in the Theme Editor base clientlib or in the Form Container properties.

Adaptive forms provide panel layouts, such as responsive, tabbed, accordions, and wizard, to control how form components are laid out in a panel. You can create custom panel layouts and make them available for use by form authors. For more information, see Creating custom layout components for adaptive forms.

You can also customize specific adaptive form components like fields and panel layout.

• Use the Overlay functionality of AEM to modify a copy of a component. It is not recommended to modify default components.
• To customize the layout of out-of-the-box adaptive form components in /libs, create custom layout components in addition to the default layouts.
• Introduce custom interactivities by creating custom widgets or appearances. It is not recommended to modify default components. For more information, see Appearance framework.

See Handling personally identifiable information for recommendations on handling PII data.

Use Objects browser in the sidebar to quickly access fields deep down in the form hierarchy. You can use the search box to search for objects in the form or objects tree to navigate from one object to another.

To view and edit the properties of a component in the components browser in the sidebar, select the component and click . You can also double-click a component to view its properties in the properties browser.

Use keyboard shortcuts to take quick actions on your forms. See AEM Forms Keyboard Shortcuts.

Adaptive form components are recommended for use only in adaptive form pages. The components have dependency on their parent hierarchy. Hence, do not use them in an AEM page.

Use meaningful and unique names for form fields and components to avoid any possible conflicts while writing rules.

Use this operator for a component to refer to itself in a rule expression. It ensures that the rule remains valid even if the component name changes. For example, field1.valueCommit script: this.value > 10.

Use component names when referring to other form components. Use the value property to fetch the value of a field or component. For example, field1.value.

Refer components by relative unique hierarchy to avoid any conflict. For example, parentName.fieldName.

When handling complex or commonly-used rules, consider writing business logic as functions in a separate client library that you can specify and reuse across adaptive forms. The client library should be a self-contained library and should not have any external dependencies, except on jQuery and Underscore.js. You can also use the client library to enforce server-side revalidation of submitted form data.

Adaptive forms provide a set of APIs that you can use to communicate with and perform actions on adaptive forms. Some of the key APIs are as follows. For more information, see JavaScript Library API reference for Adaptive Forms.

• guideBridge.reset(): Resets a form.

• guideBridge.submit(): Submits a form.

• guideBridge.setFocus(somExp, focusOption, runCompletionExp): Sets focus to a field.

• guideBridge.validate(errorList, somExpression, focus): Validates a form.

• guideBridge.getDataXML(options): Gets form data as XML.

• guideBridge.resolveNode(somExpression): Gets a form object.

• guideBridge.setProperty(somList, propertyName, valueList): Sets property of a form object.

• In addition, you can use the following field properties:

  • field.value to change value of a field.
  • field.enabled to enable/disable a field.
  • field.visible to change visibility of a field.

Adaptive form authors may need to write JavaScript code to build business logic in a form. While JavaScript is powerful and effective, it is likely that it could compromise on security expectations. Therefore, you must ensure that the form author is a trusted persona and there are processes to review and approve the JavaScript code before a form is put into production. Administrator can restrict the access to rule editor access to user groups based on their role or function. See Grant rule editor access to select user groups.

You can use expressions in rules to make adaptive forms dynamic. All the expressions are valid JavaScript expressions and use adaptive forms scripting model APIs. These expressions return values of certain types. For more information about expressions and best practices around them, see Adaptive form expressions.

Adobe recommends using JavaScript synchronous operations over asynchronous ones when creating rules with the Rule editor. Use of asynchronous operations is strongly discouraged. However, if you find yourself in a situation where asynchronous operations are unavoidable, it is essential to implement JavaScript Closure functions. By doing so, you can effectively safeguard against any potential race conditions, ensuring your rule implementations deliver optimal performance and maintain stability throughout.

For example, let’s assume we need to fetch data from an external API and then apply some rules based on that data. We use a closure to handle the asynchronous API call and ensure that the rules are applied after the data is fetched. Here is the sample code:

     function fetchDataFromAPI(apiEndpoint, callback) {
      // Simulate asynchronous API call with setTimeout
      setTimeout(() => {
        // Assuming the API call is successful, we receive some data
        const data = {
          someValue: 42,
        };
        // Invoke the callback with the fetched data
        callback(data);
      }, 2000); // Simulate a 2-second delay for the API call
    }
    // Rule implementation using Closure
    function ruleImplementation(apiEndpoint) {
      // Using a closure to handle the asynchronous API call and rule application
      // say you have set this value in street field inside address panel
      var streetField = address.street;
      fetchDataFromAPI(apiEndpoint, (data) => {
        streetField.value = data.someValue;
      });
    }
    // Example usage of the rule implementation
    const apiEndpoint = "https://example-api.com/data";
    ruleImplementation(apiEndpoint);

In this example, fetchDataFromAPI simulates an asynchronous API call using setTimeout. Once the data is fetched, it invokes the provided callback function, which is the closure to handle the subsequent rule application. The ruleImplementation function contains the rule logic.

It is recommended to create adaptive forms using XSD form data model even when converting an XFA to adaptive form, if possible.

Include only those fields and panels in adaptive forms that capture information from the user. Consider keeping static content minimal or use URLs to open them in a separate window.

While every form is designed for a specific purpose, there are some common segments in most forms. For example, personal details, address, employment details, and so on. Create adaptive form fragments for common form elements and sections and use them across forms. You can also save a panel in an existing form as a fragment. Any change in a fragment is reflected in all associated adaptive forms. It promotes collaborative authoring as multiple authors can work simultaneously on different fragments that make up a form.

• Similar to adaptive forms, it is recommended that all fragment-specific styling and custom scripts are defined in the client library using the fragment container dialog. Also, try creating self-sufficient fragments that do not depend on objects outside it.
• Avoid using cross-fragments scripting. If there’s any object outside the fragment that you must refer to, try to make that object a part of the parent form. If the object must still reside in another fragment, refer to it by its name in the script.

Use Save and Resume with auto-save to save the adaptive form periodically and enable users to revisit later to complete the form.

Configure fragments to load lazily. At runtime, fragment marked to load lazily are rendered only when they are required. It significantly reduces the load time for large forms. It is also supported in fragments with repeatable panels. For more information, see Configure lazy loading.

• Do not configure lazy loading on fragments in a responsive grid layout or in the first panel.
• File attachment and Terms and conditions components are not supported in lazily loaded fragments.
• Mark a value in a lazy loaded panel as Use Value Globally if that value is used in some other part the form so that the value is available for use when the containing panel is unloaded.
• Consider writing visibility rules for fragments that should show or hide based on a condition.

Set the value of the Number of calls per request in the Apache Sling Main Servlet to a fairly large number. It enables the Forms server to allow additional calls. The configuration displays a default value of 1500. The value, 1500 calls, is for other Experience Manager components like Sites and Assets. The default value set of adaptive forms is 20000. If you encounter the too many calls error in logs or the form fails to render, try increasing the value to a large number to resolve the issue. If the number of calls are exceeding 20000, that means the form is complex and it might take some time to render the form in browser. This only happens for the first time the form is loaded, after that the form is cached and once the form is cached, there is no significant impact on performance.

AEM Forms provides a prefill service to read data from a pre-defined data XML file and prefill the fields of an adaptive form with the content in the prefill XML file.

The prefill data XML must be compliant with the schema of the form model associated with the adaptive form.

Include afBoundedData and afUnBoundedData sections in the prefill XML to prefill both bound and unbound fields in an adaptive form.

For adaptive forms based on form data model, AEM Forms provides out-of-the-box Form Data Model Prefill Service. The prefill service queries data sources for data model objects in the adaptive form and prefills field values when rendering the form.

You can also use the file, crx, service, or http protocols prefill adaptive forms.

AEM Forms supports custom prefill services that you can plug in as an OSGi service to prefill adaptive forms.

Depending on the form data model an adaptive form is based on, you can configure a template for DoR as follows:

• XFA form template: Use the associated XDP file as the DoR template.
• XSD schema: Use the associated XFA template that uses the same XML schema as used by the adaptive form.
• None: Use auto-generated DoR.

Configure header, footer, images, color, font, and so on, right from the Document of Record tab of the adaptive form editor.

Use DoRService to generate the DoR programmatically.

Exclude hidden fields from the DoR.

Use afAcceptLang request parameter to view DoR in another locale.

Use adaptive form fragments for common elements across forms and localize fragments. It ensures that you localize a fragment once and it reflects in all forms where the localized fragment is used.

Any modifications like adding a new component or applying a script in a localized form are not localized automatically. Therefore, you must finalize a form before localizing it to avoid multiple localization cycles.

Use afAcceptLang request parameter to override the browser locale and render the form in the specified locale. For example, the following URL is forced to render the form in Japanese locale, irrespective of the locale specified in the browser setting:

https://'[server]:[port]'/<contextPath>/<formFolder>/<formName>.html?wcmmode=disabled&afAcceptLang=ja

AEM Forms currently supports localization of adaptive forms content in English (en), Spanish (es), French (fr), Italian (it), German (de), Japanese (ja), Portuguese-Brazilian (pt-BR), Chinese (zh-CN), Chinese-Taiwan (zh-TW), and Korean (ko-KR) locales. However, you can add support for new locales for adaptive forms at runtime. For more information, see Supporting new locales for adaptive forms localization.

Enable HTML client library compression for JavaScript and CSS from Felix Console.

Cache all client libraries at /etc.clientlibs/fd and any additional custom client libraries on AEM dispatcher to increase the responsiveness and security of your published forms. For more information, see Dispatcher.

Do not cache /content/forms/af/ and /content/dam/formsanddocuments/* paths. for detailed information about configuring adaptive forms caching, see Caching adaptive forms.

Enable HTML via web server compression module. For more information, see Performance tuning of AEM Forms server.

Increase calls per request configuration for large forms. See Optimizing performance of large and complex forms.

Create custom error pages shown by error handler.

Secure AEM Forms server.

• Use nosamplecontent run mode to ensure there are no sample content and sample users deployed on the production server. See Running AEM in Production Ready Mode.

Keep the heap size to a minimum of 8 GB. For other settings, see Performance tuning of AEM Forms server.

Use service user sessions instead of admin sessions for executing service-level tasks. For more information, see Service authentication.

Storing draft data: If you are using the Draft feature of adaptive forms, you should implement a custom Service Provide Interface (SPI) to store draft data in more secure storage like database. For more information, see Sample for integrating drafts & submissions component with database.

Storing submission data: If you are using Form Portal Submit Store, you should implement a custom SPI to store submission data in a database. See Sample for integrating drafts & submissions component with database for a sample integration.

You can also write a custom submit action that stores form data and attachment in secure storage. See Writing custom Submit action for adaptive forms for more information.

Length of draft ID: When you save an adaptive form as a draft, a draft ID gets generated to uniquely identify the draft. The minimum value for the length of the draft ID field is 26 characters. Adobe recommends setting the draft ID length to 26 or more characters.