Rendering Forms as HTML

The Forms service renders forms as HTML in response to an HTTP request from a web browser. A benefit of rendering a form as HTML is that the computer on which the client web browser is located does not require Adobe Reader, Acrobat, or Flash Player (for form Guides (deprecated)).

To render a form as HTML, the form design must be saved as an XDP file. A form design that is saved as a PDF file cannot be rendered as HTML. When developing a form design in Designer that will be rendered as HTML, consider the following criteria:

  • Do not use an object's border properties to draw lines, boxes, or grids on your form. Some browsers may not line up borders exactly as they appear in a preview. Objects may appear layered or may push other objects off their expected position.

  • You can use lines, rectangles, and circles to define the background.

  • Draw text slightly larger than what seems to be required to accommodate the text. Some web browsers do not display the text legibly.

注意: When rendering a form that contains TIFF images using the FormServiceClient object’s renderHTMLForm and renderHTMLForm2 methods, the TIFF images are not visible in the rendered HTML form that is displayed in Internet Explorer or Mozilla Firefox browsers. These browsers do not provide native support for TIFF images.

HTML pages

When a form design is rendered as an HTML form, each second-level subform is rendered as an HTML page (panel). You can view a subform’s hierarchy in Designer. Child subforms that belong to the root subform (the default name of a root subform is form1) are the panel subforms. The following example shows a form design’s subforms.

    form1 
        Master Pages 
        PanelSubform1 
            NestedDynamicSubform 
                TextEdit1 
        PanelSubform2 
            TextEdit1 
        PanelSubform3 
            TextEdit1 
        PanelSubform4 
            TextEdit1

When form designs are rendered as HTML forms, the panels are not constrained to any particular page size. If you have dynamic subforms, they should be nested within the panel subform. Dynamic subforms are able to expand to an infinite number of HTML pages.

When a form is rendered as an HTML form, page sizes (required for paginating forms rendered as PDF) have no meaning. Because a form with a flowable layout can expand to an infinite number of HTML pages, it is important to avoid footers on the master page. A footer beneath the content area on a master page can overwrite HTML content that flows past a page boundary.

You must explicitly move from panel to panel using the xfa.host.pageUp and xfa.host.pageDown methods. You change pages by sending a form to the Forms service and having the Forms service render the form back to the client device, typically a web browser.

注意: The process of sending a form to the Forms service and then having the Forms service render the form back to the client device is referred to as round tripping data to the server.
注意: If you want to customize the look of the HTML Digital Signature button on an HTML form, you must change the following properties in the fscdigsig.css file (within the adobe-forms-ds.ear > adobe-forms-ds.war file):

.fsc-ds-ssb: This style sheet is applicable in case of a blank sign field.

.fsc-ds-ssv: This style sheet is applicable in case of a Valid sign field.

.fsc-ds-ssc: This style sheet is applicable in case of a Valid sign field but data has changed.

.fsc-ds-ssi: This style sheet is applicable in case of a invalid sign field.

.fsc-ds-popup-bg: This style sheet property is not being used.

.fsc-ds-popup-btn: This style sheet property is not being used.

Running scripts

A form author specifies whether a script executes on the server or the client. The Forms service creates a distributed, event processing environment for execution of form intelligence that can be distributed between the client and the server by using the runAt attribute. For information about this attribute or creating scripts within form designs, see LiveCycle Designer 11 Help

The Forms service can execute scripts while the form is being rendered. As a result, you can prepopulate a form with data by connecting to a database or to web services that may not be available on the client. You can also set a button’s Click event to run on the server so that the client will round trip data to the server. This allows the client to run scripts that may require server resources, such as an enterprise database, while a user is interacting with a form. For HTML forms, formcalc scripts can be executed on server only. As a result, you must mark these scripts to run at server or both.

You can design forms that move between pages (panels) by calling xfa.host.pageUp and xfa.host.pageDown methods. This script is placed in a button’s Click event and the runAt attribute is set to Both. The reason you choose Both is so that Adobe Reader or Acrobat (for forms that are rendered as PDF) can change pages without going to the server and HTML forms can change pages by round tripping data to the server. That is, a form is sent to the Forms service, and a form is rendered back as HTML with the new page displayed.

It is recommended that you do not give script variables and form fields the same names such as item. Some web browsers, such as Internet Explorer, may not initialize a variable with the same name as a form field that results in a script error occurring. It is good practice to give form fields and script variables different names.

When rendering HTML forms that contain both page navigation functionality and form scripts (for example, assume that a script retrieves field data from a database each time the form is rendered), ensure that the form script is located in the form:calculate event instead in of the form:readyevent.

Form scripts that are located in the form:ready event are executed only once during the initial rendering of the form and are not executed for subsequent page retrievals. In contrast, the form:calculate event is executed for each page navigation where the form is rendered.

注意: On a multipage form, changes made by JavaScript to a page are not retained if you move to a different page.

You can invoke custom scripts before submitting a form. This feature works on all available browsers. However, it can be used only when users render the HTML form that has its Output Type property set to Form Body. It will not work when the Output Type is Full HTML. Refer to Configuring forms in Administration Help for steps to configure this feature.

You must first define a callback function that is called before submitting the form, where the name of the function is _user_onsubmit. It is assumed that the function will not throw any exception, or if it does, the exception will be ignored. It is recommended to place the JavaScript function in the head section of the html; however, you can declare it anywhere before the end of the script tags that include xfasubset.js.

When formserver renders an XDP that contains a drop-down list, in addition to creating the drop-down list, it also creates two hidden text fields. These text fields store the data of the drop-down list (one stores the display name of the options and other stores the value for the options). Therefore, every time a user submits the form, the entire data of the drop down list is submitted. Assuming that you don't want to submit that much data everytime, you can write a custom script to disable that. For example: The name of the drop down list is drpOrderedByStateProv and it is wrapped under subform header. The name of the HTML input element will be header[0].drpOrderedByStateProv[0]. The name of the hidden fields that store and submit the data of the dropdown have the following names:
header[0].drpOrderedByStateProv_DISPLAYITEMS_[0] header[0].drpOrderedByStateProv_VALUEITEMS_[0]
You can disable these input elements in the following way if you don't want to post the data.
 var __CUSTOM_SCRIPTS_VERSION = 1; //enabling the feature 
    function _user_onsubmit() { 
    var elems = document.getElementsByName("header[0].drpOrderedByStateProv_DISPLAYITEMS_[0]"); 
    elems[0].disabled = true; 
    elems = document.getElementsByName("header[0].drpOrderedByStateProv_VALUEITEMS_[0]"); 
    elems[0].disabled = true;
    }

XFA subsets

When creating form designs to render as HTML, you must restrict your scripting to the XFA subset for scripts in javascript language.

Scripts that run on the client or run on both the client and the server must be written within the XFA subset. Scripts that run on the server can use the full XFA scripting model and also use FormCalc. For information about using JavaScript, see LiveCycle Designer 11 Help.

When running scripts on the client, only the current panel being displayed can use script; for example, you cannot script against fields that are located in panel A when panel B is displayed. When running scripts on the server, all panels can be accessed.

You must also be careful when using Scripting Object Model (SOM) expressions within scripts that run on the client. Only a simplified subset of SOM expressions are supported by scripts that run on the client.

Event timing

The XFA subset defines the XFA events that are mapped to HTML events. There is a slight difference in behavior on the timing of calculate and validate events. In a web browser, a full calculate event is executed when you exit a field. Calculate events are not automatically executed when you make a change to a field value. You can force a calculate event by calling the xfa.form.execCalculate method.

In a web browser, validate events are only executed when exiting a field or submitting a form. You can force a validate event by using the xfa.form.execValidate method.

Forms displayed in a web browser (as opposed to Adobe Reader or Acrobat) conform to the XFA null test (errors or warnings) for mandatory fields.

  • If the null test produces an error and you exit a field without specifying a value, a message box is displayed and you are repositioned to the field after clicking OK.

  • If a null test produces a warning and you exit a field without specifying a value, you are prompted to click either OK or Cancel, giving you the option of proceeding without specifying a value or returning to the field to enter a value.

For more information about a null test, see LiveCycle Designer 11 Help.

Form buttons

Clicking a submit button sends form data to the Forms service and represents the end of form processing. The preSubmit event can be set to run on the client or server. The preSubmit event runs prior to the form submission if it is configured to run on the client. Otherwise, the preSubmit event runs on the server during the form submission. For more information about the preSubmit event, see LiveCycle Designer 11 Help.

If a button has no client-side script associated with it, data is submitted to the server, calculations are performed on the server, and the HTML form is regenerated. If a button contains a client-side script, data is not sent to the server and the client-side script is executed in the web browser.

HTML 4.0 web browser

A web browser that only supports HTML 4.0 cannot support the XFA subset client-side scripting model. When creating a form design to work in both HTML 4.0 and MSDHTML or CSS2HTML, a script that is marked to run at the client will actually run on the server. For example, assume a user clicks a button that is located on a form displayed in an HTML 4.0 web browser. In this situation, the form data is sent to the server where the client-side script is executed.

It is recommended that you place your form logic in calculate events, which run at the server in HTML 4.0 and on the client for MSDHTML or CSS2HTML.

Maintaining presentation changes

As you move between HTML pages (panels), only the state of the data is maintained. Settings such as background color or mandatory field settings are not maintained (if different than the initial settings). To maintain the presentation state, you must create fields (usually hidden) that represent the presentation state of fields. If you add a script to a field’s Calculate event that changes the presentation based on hidden field values, you are able to preserve the presentation state as you move back and forth between HTML pages (panels).

The following script maintains the fillColor of a field based on the value of hiddenField. Assume this script is located in a field’s Calculate event.

    If (hiddenField.rawValue == 1) 
        this.fillColor = "255,0,0" 
    else 
        this.fillColor = "0,255,0"
注意: Static objects are not displayed in a rendered HTML form when nested inside a table cell. For example, a circle and rectangle nested inside a table cell are not displayed within a render HTML form. However these same static objects are properly displayed when located outside of the table.

Digitally signing HTML forms

You cannot sign an HTML form that contains a digital signature field if the form is rendered as one of the following HTML transformations:

  • AHTML

  • HTML4

  • StaticHTML

  • NoScriptXHTML

For information about digitally signing a document, see Digitally Signing and Certifying Documents.

Rendering an accessibility guidelines-compliant XHTML form

You can render a full HTML form that is compliant with accessibility guidelines. That is, the form is rendered within full HTML tags as opposed to the HTML form being rendered within body tags (not a complete HTML page).

Validating form data

It is recommended that you limit your use of validation rules for form fields when rendering the form as an HTML form. Some validation rules may not be supported for HTML forms. For example, when a validation pattern of MM-DD-YYYY is applied to a Date/Time field that is located in a form design that is rendered as an HTML form, it does not work properly, even if the date is typed in properly. However, this validation pattern works properly for forms rendered as PDF.

注意: For more information about the Forms service, see Services Reference for LiveCycle.

Summary of steps

To render an HTML form, perform the following steps:

  1. Include project files.

  2. Create a Forms Client API object.

  3. Set HTML run-time options.

  4. Render an HTML form.

  5. Write the form data stream to the client web browser.

Include project files

Include necessary files into your development project. If you are creating a client application using Java, include the necessary JAR files. If you are using web services, ensure that you include the proxy files.

Create a Forms Client API object

Before you can programmatically import data into a PDF formClient API, you must create a Form Data Integration service client. When creating a service client, you define connection settings that are required to invoke a service.

Set HTML run-time options

You set HTML run-time options when rendering an HTML form. For example, you can add a toolbar to an HTML form to enable users to select file attachments located on the client computer or to retrieve file attachments that are rendered with the HTML form. By default, an HTML toolbar is disabled. To add a toolbar to an HTML form, you must programmatically set run-time options. By default, an HTML toolbar consists of the following buttons:

  • Home: Provides a link to the application’s web root.

  • Upload: Provides a user interface to select files to attach to the current form.

  • Download: Provides a user interface to display the attached files.

When a HTML toolbar appears on a HTML form, a user can select a maximum of ten files to submit along with form data. Once the files are submitted, the Forms service can retrieve the files.

When rendering a form as HTML, you can specify a user-agent value. A user-agent value provides browser and system information. This is an optional value, and you can pass an empty string value. The Rendering an HTML form using the Java API quick start shows how to obtain a user agent value and use it to render a form as HTML.

HTTP URLs to where form data is posted may be specified by setting the target URL using the Forms Service Client API or may be specified in the Submit button contained in the XDP form design. If the target URL is specified in the form design, then do not set a value using the Forms Service Client API.

注意: Rendering an HTML form with a toolbar is optional.
注意: If you render an AHTML form, it is recommended that you do not add a toolbar to the form.

Render an HTML form

To render an HTML form, you must specify a form design created in Designer and saved as an XDP file. You must also select an HTML transformation type. For example, you can specify the HTML transformation type that renders a dynamic HTML for Internet Explorer 5.0 or later.

Rendering an HTML form also requires values, such as URI values that are required to render other form types.

Write the form data stream to the client web browser

When the Forms service renders an HTML form, it returns a form data stream that you must write to the client web browser. When written to the client web browser, the HTML form is visible to the user.

Render a form as HTML using the Java API

Render an HTML form by using the Forms API (Java):

  1. Include project files

    Include client JAR files, such as adobe-forms-client.jar, in your Java project’s class path.

  2. Create a Forms Client API object

    • Create a ServiceClientFactory object that contains connection properties.

    • Create an FormsServiceClient object by using its constructor and passing the ServiceClientFactory object.

  3. Set HTML run-time options

    • Create an HTMLRenderSpec object by using its constructor.

    • To render an HTML form with a toolbar, invoke the HTMLRenderSpec object’s setHTMLToolbar method and pass an HTMLToolbar enum value. For example, to display a vertical HTML toolbar, pass HTMLToolbar.Vertical.

    • To set the locale value for the HTML form, invoke the HTMLRenderSpec object’s setLocale method and pass a string value that specifies the locale value. (This is an optional setting.)

    • To render the HTML form within full HTML tags, invoke the HTMLRenderSpec object’s setOutputType method and pass OutputType.FullHTMLTags. (This is an optional setting.)

    注意: Forms are not successfully rendered in HTML when the StandAlone option is true and the ApplicationWebRoot references a server other than the J2EE application server hosting LiveCycle (the ApplicationWebRoot value is specified using the URLSpec object that is passed to the FormsServiceClient object’s renderHTMLForm method). When the ApplicationWebRoot is another server from the one hosting LiveCycle, the value of the web root URI in the LiveCycle Administration Console needs to be set as the Form's web application URI value. This can be done by logging in to the LiveCycle Administration Console, clicking Services > Forms, and setting the Web Root URI as http://server-name:port/FormServer. Then, save your settings.
  4. Render an HTML form

    Invoke the FormsServiceClient object’s renderHTMLForm method and pass the following values:

    • A string value that specifies the form design name, including the file name extension. If you reference a form design that is part of a LiveCycle application, ensure that you specify the complete path, such as Applications/FormsApplication/1.0/FormsFolder/Loan.xdp.

    • A TransformTo enum value that specifies the HTML preference type. For example, to render an HTML form that is compatible with dynamic HTML for Internet Explorer 5.0 or later, specify TransformTo.MSDHTML.

    • A com.adobe.idp.Document object that contains data to merge with the form. If you do not want to merge data, pass an empty com.adobe.idp.Document object.

    • The HTMLRenderSpec object that stores HTML run-time options.

    • A string value that specifies the HTTP_USER_AGENT header value; for example, Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322).

    • A URLSpec object that stores URI values required to render an HTML form.

    • A java.util.HashMap object that stores file attachments. This is an optional parameter and you can specify null if you do not want to attach files to the form.

    The renderHTMLForm method returns a FormsResult object that contains a form data stream that can be written to the client web browser.

  5. Write the form data stream to the client web browser

    • Create a com.adobe.idp.Document object by invoking the FormsResult object ‘s getOutputContent method.

    • Get the content type of the com.adobe.idp.Document object by invoking its getContentType method.

    • Set the javax.servlet.http.HttpServletResponse object’s content type by invoking its setContentType method and passing the content type of the com.adobe.idp.Document object.

    • Create a javax.servlet.ServletOutputStream object used to write the form data stream to the client web browser by invoking the javax.servlet.http.HttpServletResponse object’s getOutputStream method.

    • Create a java.io.InputStream object by invoking the com.adobe.idp.Document object’s getInputStream method.

    • Create a byte array and populate it with the form data stream by invoking the InputStream object’s read method and passing the byte array as an argument.

    • Invoke the javax.servlet.ServletOutputStream object’s write method to send the form data stream to the client web browser. Pass the byte array to the write method.

Render a form as HTML using the web service API

Render an HTML form by using the Forms API (web service):

  1. Include project files

    • Create Java proxy classes that consume the Forms service WSDL.

    • Include the Java proxy classes into your class path.

  2. Create a Forms Client API object

    Create a FormsService object and set authentication values.

  3. Set HTML run-time options

    • Create an HTMLRenderSpec object by using its constructor.

    • To render an HTML form with a toolbar, invoke the HTMLRenderSpec object’s setHTMLToolbar method and pass an HTMLToolbar enum value. For example, to display a vertical HTML toolbar, pass HTMLToolbar.Vertical.

    • To set the locale value for the HTML form, invoke the HTMLRenderSpec object’s setLocale method and pass a string value that specifies the locale value. For more information, see LiveCycle API Reference.

    • To render the HTML form within full HTML tags, invoke the HTMLRenderSpec object’s setOutputType method and pass OutputType.FullHTMLTags.

    注意: Forms are not successfully rendered in HTML when the StandAlone option is true and the ApplicationWebRoot references a server other than the J2EE application server hosting LiveCycle (the ApplicationWebRoot value is specified using the URLSpec object that is passed to the FormsServiceClient object’s renderHTMLForm method). When the ApplicationWebRoot is another server from the one hosting LiveCycle, the value of the web root URI in the LiveCycle Administration Console needs to be set as the Form's web application URI value. This can be done by logging in to the LiveCycle Administration Console, clicking Services > Forms, and setting the Web Root URI as http://server-name:port/FormServer. Then, save your settings.
  4. Render an HTML form

    Invoke the FormsService object’s renderHTMLForm method and pass the following values:

    • A string value that specifies the form design name, including the file name extension. If you reference a form design that is part of a LiveCycle application, ensure that you specify the complete path, such as Applications/FormsApplication/1.0/FormsFolder/Loan.xdp.

    • A TransformTo enum value that specifies the HTML preference type. For example, to render an HTML form that is compatible with dynamic HTML for Internet Explorer 5.0 or later, specify TransformTo.MSDHTML.

    • A BLOB object that contains data to merge with the form. If you do not want to merge data, pass null. (See Prepopulating Forms with Flowable Layouts.)

    • The HTMLRenderSpec object that stores HTML run-time options.

    • A string value that specifies the HTTP_USER_AGENT header value; for example, Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322). You can pass an empty string if you do not want to set this value.

    • A URLSpec object that stores URI values required to render an HTML form. (See Specify URI values.)

    • A java.util.HashMap object that stores file attachments. This is an optional parameter and you can specify null if you do not want to attach files to the form. (See Attach files to the form.)

    • An empty com.adobe.idp.services.holders.BLOBHolder object that is populated by the method. This parameter value stores the rendered form.

    • An empty com.adobe.idp.services.holders.BLOBHolder object that is populated by the method. This parameter will store the output XML data.

    • An empty javax.xml.rpc.holders.LongHolder object that is populated by the method. This argument will store the number of pages in the form.

    • An empty javax.xml.rpc.holders.StringHolder object that is populated by the method. This argument will store the locale value.

    • An empty javax.xml.rpc.holders.StringHolder object that is populated by the method. This argument will store the HTML rendering value that is used.

    • An empty com.adobe.idp.services.holders.FormsResultHolder object that will contain the results of this operation.

    The renderHTMLForm method populates the com.adobe.idp.services.holders.FormsResultHolder object that is passed as the last argument value with a form data stream that must be written to the client web browser.

  5. Write the form data stream to the client web browser

    • Create a FormResult object by getting the value of the com.adobe.idp.services.holders.FormsResultHolder object’s value data member.

    • Create a BLOB object that contains form data by invoking the FormsResult object’s getOutputContent method.

    • Get the content type of the BLOB object by invoking its getContentType method.

    • Set the javax.servlet.http.HttpServletResponse object’s content type by invoking its setContentType method and passing the content type of the BLOB object.

    • Create a javax.servlet.ServletOutputStream object used to write the form data stream to the client web browser by invoking the javax.servlet.http.HttpServletResponse object’s getOutputStream method.

    • Create a byte array and populate it by invoking the BLOB object’s getBinaryData method. This task assigns the content of the FormsResult object to the byte array.

    • Invoke the javax.servlet.http.HttpServletResponse object’s write method to send the form data stream to the client web browser. Pass the byte array to the write method.