Stefan Cameron on Forms
Building intelligent forms using Adobe LiveCycle Designer

Archive for June, 2006

Sorting Lists at Runtime

Have you ever needed to sort the content of a list box or drop down list at runtime (e.g. in a form loaded in PDF with Acrobat or HTML with a browser)?

Unfortunately, neither the XFA nor the AcroForm Object Models give you either properties or methods to achieve this functionality. The only thing available are Sort Ascending and Sort Descending buttons on the list of items you define in the Object palette’s Field tab in Designer — not very useful at runtime! Say you were loading data from an XML Data File into your form and this was populating a list with values that needed to be sorted: There wouldn’t be a built-in way for you to do that.

The only solution I’m aware of at this time is to flex your scripting muscles and write some functions that’ll get you sorting lists (from either list boxes or drop down lists) and that’s exactly what I did today while replying to a post on Adobe’s Designer Forums:

Download Sample [pdf]

Minimum Requirements: Designer 7.0, Acrobat 7.0.

Update: It looks like Acrobat 8.0 broke something that prevents my sample form from working correctly. It has to do with the call to

resolveNodes("#items[*]")

Fortunately, the bug will be fixed in Acrobat’s next release.

As a workaround, I would encourage you to have a look at the new list object properties and methods now available in Acrobat 8.0. You should be able to use a combination of those new properties/methods along with some of the original script in this sample in order to come-up with an update solution that works.

All the code is located in the script object appropriately named, “ScriptObject”.

The idea was to make use of the JavaScript Array object’s built-in sorting function, sort, by giving it a custom sorting function that was able to sort pairs of text and value items. Remember that for XFA choiceList fields, there’s always one <items save=”1”> node but there may be a second <items> node if text and value items are defined.

From Designer’s UI, you define value items by default by entering items in the list on the Object palette’s Field tab. This defines an <items save=”1”> node. If you then go to the Bindings tab and specify values, the items you specified on the Field tab become the “text” items, defined in the second <items> node, and the values are set in the <items save=”1”> node.

When sorting the list, it’s important to maintain the association between text and value item pairs and that’s why the script is a little complex — not to mention the fact that getting items out of an XFA choiceList field (list box or drop down list) isn’t as easy as 1-2-3 either!

So the script attempts to find text and/or value items, create ListItem objects for each pair, sort them using the custom sort function __SortFunction and then replaces the current items in the list with the ones in the sorted order.

Updated: April 11, 2007


Posted by Stefan Cameron on June 29th, 2006
Filed under Scripting,Tutorials

Process All Fields

A common requirement on the Adobe Designer Forums is to find all fields on a form and do something specific with them.

For instance, you may want all mandatory fields to be automatically highlighted when a user attempts to submit a form electronically before having filled all mandatory fields. While Acrobat provides a button to toggle mandatory field highlighting on/off (via the Highlight required fields check box in the yellow Form Field toolbar), Acrobat’s Scripting Object Model doesn’t provide a function to do the same. Therefore, you’re left having to write some script to achieve the same functionality.

Since this is requested so often, I thought I would try to put together some canned script that you can copy and paste into your form in order to instantly have the ability to make changes on everything that’s considered a field on your form.

Download Script [js]
Download Sample [zip]

Minimum Requirements: Designer 7.0, Acrobat 7.0.

The first download is for a JavaScript file which contains the “plug & play” script that you can simply copy & paste into any event handler or script object and immediately start concentrating on what you want to do when you find a button, a check box, a text edit, etc.

It’s divided into two parts: The first (at the top-end of the script) is a series of Field Processor Functions for each field/object type that may be found within a form. Each function receives a reference to the field in question. The second (at the bottom-end of the script) defines the ProcessAllFields function — the brains behind this operation. This function detects the field type and calls the appropriate Field Processor Function.

All you need to do is add script to the Field Processor Function(s) for the field types you need to do stuff with.

The second download contains the JavaScript file along with a sample form which demonstrates how to get from the bare-bones Field Processor Functions and ProcessAllFields function to a solution which finds all non-filled mandatory fields on a form and highlights them with the current Acrobat Highlight Color. You’ll find customized versions of the Field Processor Functions and ProcessAllFields function in the script object (named “ScriptObject” — yes, I know, this is an unbelievably original name!) while the script execution flow begins in the Submit button’s Click event.

When the Submit button is clicked, the form is searched for non-filled (empty) mandatory fields. If such fields are found, they’ll be highlighted, the RemoveHighlight button will be made visible and an error message will be displayed. Otherwise, the Email Submit dialog will open.


Posted by Stefan Cameron on June 26th, 2006
Filed under Scripting,Tutorials

Invalid Flashing Fields

So what’s the use of learning about new toys like AcroForm Objects and AcroForm Field Name Generators if you don’t take the time to play with them? Today felt like the right day to do just that and I came-up with a sample form where invalid fields flash red until the user has entered valid values into them. Only once all fields are valid can the form be submitted.

Update: Check-out the newer version on the new Invalid Flashing Fields 2.0 post.

Download Sample [pdf]

Minimum Requirements: Designer 7.1, Acrobat 7.0.5.

Note: A basic understanding of AcroForm Objects is required for this sample.

The sample form works like this: When the user clicks on the Submit button, there’s a script which looks at all fields on the form and validates them for valid content. In this particular form, the only requirement is for the fields to be filled (i.e. have non-null values). If all fields are filled, the form is them submitted however, if there’s at least one field which isn’t filled, the first-found non-filled field is set to flash red until the user has filled it.

Since XFA doesn’t natively support flashing fields, this is all done using the Acrobat app, Document and Field objects, discussed in greater detail in my previous post on AcroForm Objects, as well as my AcroForm Field Name Generator code.

When a non-filled field is found, the Submit button’s script will get the AcroForm Field object name for the invalid field and use it to generate a small script which will run every time an Acrobat Timer object expires. This timer is created in the following block of code:

moFlashTimerID = app.setInterval(
    "var f = this.getField('GetAcroFormFieldName(oField)');" +
    "if (color.equal(f.fillColor, color.red))" +
    "{ f.fillColor = [" + moAcroFieldFillColor.toString() + "]; }"

    "else" +
    "{ f.fillColor = color.red; }",
  500);

In this block of code, the Acrobat app object’s setInterval method is used to create a timer which will continously expire at a specific interval (in this case, every 500 milliseconds, or 0.5 seconds) and every time it expires, it’ll execute the code specified in the first parameter. Since the timer’s code will execute within the context of the document from which the setInterval method was called, the this keyword will represent Acrobat Document object pertaining to the form. The GetAcroFormFieldName method can then be used to get the AcroForm Field object name pertaining to the invalid field (oField) which is then passed to the Acrobat Document object’s getField method. From there, the AcroForm Field’s fill color is compared to red: If it’s already red, it’s set to a light gray color; otherwise, it’s set to red.

It’s important to note that the setInterval method returns an Acrobat Interval object which can subsequently be used to cancel the interval timer in order to get the field to stop flashing red once the user has filled it with a value. This object is also required in order to ensure the timer is stopped when the form is closed if the user ever decides to close the form while an invalid field is flashing (see the code in the root subform’s (form1) DocClose event).

Updated: August 15, 2006


Posted by Stefan Cameron on June 18th, 2006
Filed under AcroForm Objects,Scripting,Tutorials

AcroForm Field Name Generator

So you’ve read my previous post about AcroForm Objects and now you’re wondering what you do with that stuff. Those more adventurous might even have tried to use the event.target.getField method to do something cool.

If you’re going to do things on the application or the document without attempting to affect a specific field, it’s pretty straight-forward: You just call methods on the app (Acrobat Application) or event.target (Acrobat Document) objects. Getting an AcroForm Field object, however, isn’t as simple as you may think because of the naming conventions used when the Acrobat Form objects are created, based on the XFA Form objects.

Let’s say you have a field, named “MyField”, parented to the second page, named “Page2”, of your form, named “form1”. For some reason, you need to access that field’s pertaining AcroForm Field object. If you tried

event.target.getField("MyField")

you wouldn’t get very far because the actual name of the field is:

form1[0].Page2[0].MyField[0]

Basically, each AcroForm Field object is named with a verbose form of the XFA SOM Expression of its pertaining XFA Form object (also known as a Fully-Qualified SOM Expression).

To help with generating the correct AcroForm Field name for a given XFA Form object, I thought I would write a little bit of script which outputs the Fully-Qualified SOM Expression (which is the AcroForm Field name) for a given XFA Form object:

// Returns the fully-qualified name for the specified object.
//  This means the name always specifies the index.
//  Therefore, if the name is specified, it's "name[index]".
//  If the name isn't specified, it's "#className[index]".
function GetVerboseFieldName(oNode)
{
  // Unnamed nodes have default names which their class name
  //  ("subform", "field", etc.) with a "#" prefix.
  //  Unfortunately, oNode.name won't return this if the node
  //  doesn't have a specific name. It'll just return an empty
  //  string. Also, oNode.index will be undefined. If it weren't
  //  for oNode.index being undefined in this case, we could've
  //  done something like
  //  SOM = "#" + oNode.className + "[" + oNode.index + "]"

  //  but we'll have to use the somExpression property instead
  //  and extract the name out of it because this will return
  //  the "#" name with the correct index.
  // Since somExpression returns the name and index for the
  //  object in all cases (whether the name is specified or
  //  not), we can use the following syntax in all cases:

  var nPos = oNode.somExpression.lastIndexOf(".");

  // If the field has a name, check to see if it has any periods in its name.
  // If that's the case, they'll be escaped with backslashes and we need to
  //  look for another period.
  if (oNode.name != null && oNode.name.length > 0)
  {
    while (nPos > 0)
    {
      if (oNode.somExpression.charAt(nPos - 1) == "\\\\")
      {
        // we found an escaped period, keep looking
        nPos = oNode.somExpression.lastIndexOf(".", nPos - 1);
      }
      else
      {
        // stop looking since we have an unescaped period
        break;
      }
    }
  }

  if (nPos >= 0)
  {
    // get everything after the last "." to the end
    return oNode.somExpression.substr(nPos + 1);
  }
  else
  {
    // in this case, the SOM expression is a single name (unlikely
    //  but theoretically possible)
    return oNode.somExpression;
  }
}

// Returns the Fully-Qualified SOM Expression for the specified field.
function GetFQSOMExp(oField)
{
  var sFQFieldName = GetVerboseFieldName(oField);
  var oParentNode = oField.parent;

  // The absolute root of the XFA Object Model is the xfa object
  //  which contains a single form object, which then contains
  //  what the Hierarchy palette shows as being the "root
  //  subform" ("form1" by default). So we stop when we reach
  //  xfa.form.
  while (oParentNode != xfa.form)
  {
    sFQFieldName = GetVerboseFieldName(oParentNode) +
      "." + sFQFieldName;
    oParentNode = oParentNode.parent;
  }

  return sFQFieldName;
}

You can now take this code and either place it directly inside the event in which you need an XFA Form object’s pertaining AcroForm Field name and call it directly or you can place it in a form-wide Script Object where you can access the code from anywhere.

With this code, changing an XFA Button object’s highlight property such that it gets an outline rectangle when clicked (as opposed to the default which is an inverted fill color) is as easy as this (in JavaScript in the button’s Enter event, assuming you’ve placed the above code directly inside the Enter event):

event.target.getField(GetFQSOMExp(this)).highlight =
  highlight.o;

Beautiful? I think so. Get the Acrobat JavaScript Scripting Reference and go crazy! Just remember: This functionality is only available when your form is loaded in Acrobat.

Updated: February 14, 2007 — Added support for objects with periods in their names.


Posted by Stefan Cameron on June 14th, 2006
Filed under AcroForm Objects,Scripting

Adobe Developer Week

I just got word of this free online event this week at Adobe.

Here’s the blurb:

Join us to learn about the Adobe engagement platform, including Flex, and other Adobe technologies by attending Adobe Developer Week. This free, week-long event features live, online sessions presented by Adobe technology experts. See live demos and get your questions answered by the experts during interactive Q & A sessions. Register online at the Adobe website.

While there are lots of very interesting sessions, these are the ones I found, after a quick search, which are related to LiveCycle:

Don’t wait to sign-up for sessions — spots are limited and they’re going fast!


Posted by Stefan Cameron on June 13th, 2006
Filed under Conferences,General