Stefan Cameron on Forms
Building intelligent forms using Adobe LiveCycle Designer

'Bugs' Category Archive

Bug: Sending WSDL request using repeatable section


When executing a web service (WSDL) data connection, only the last instance of a repeatable element is included in the request.

Here’s an example of a repeatable WSDL element (the “Detail” element containing item number information):

<xsd:element name="Details">
         <xsd:element name="Detail" maxOccurs="unbounded">
                  <xsd:element name="ItemNumber" type="xsd:string"/>

The correct behaviour is that all instances of a repeatable section are used in the request sent to the web service.


Unfortunately, there are no workarounds for this problem however the bug will be fixed in the next release of Acrobat.


Please refer to the Bug List for updated information on the version(s) affected by this bug as well as if and when it was/will be fixed.

Posted by Stefan Cameron on May 2nd, 2007
Filed under Acrobat,Bugs

Bug: Images aren't always embedded into PDFs


Image objects (images and image fields) have a property which you can set to specify whether the image should be embedded or linked (the "Embed Image Data" check box on the Object palette’s Field tab).

When the property is checked, the result is that the image file loaded into the image object is embedded into the XFA Data that’s stored in the form. When the property is unchecked, only the URI (file path or URL) is stored in the XFA Data.

I put emphasis on XFA Data above because it’s important to understand the difference between the XFA layer and the PDF layer of a PDF form in order to understand what this bug is all about: Essentially, an XFA form saved as a PDF file results in a PDF container with the XFA inside (as opposed to saving the form as an XDP where the XFA form is at the top layer). When the PDF form is subsequently filled and saved within Acrobat (Standard or Pro), the image loaded into an image field object is supposed to be saved on one layer or the other depending on the setting of the "Embed Image Data" property on the image field.

When you save a PDF form in Acrobat, what gets saved in the XFA Data (in the XFA layer) depends on the value of the "Embed Image Data" property (which maps to the //field/ui/imageEdit@data attribute). If it’s set to "link" (unchecked), then only the original path to the image file is saved. If it’s set to "embed", then the image file is text-encoded and saved in the data instead of the original file path. In either case, however, the image should always be embedded into the PDF layer (don’t worry, it doesn’t actually get embedded twice, once on each layer, I’m just simplifying things a little here) such that the PDF is self-contained and can be re-distributed without having to ensure that the linked image file remains accessible from any location.

Unfortunately, there are cases when the image file doesn’t get embedded into the PDF layer when it should be. For example, if you have an image field object which is set to link to its image file and you load the image by importing data that contains the file path then save the PDF, the image won’t be embedded into the PDF as expected.


At this time, I’m not aware of any workarounds to the specific issue I stated above (when importing the image’s file path).

The only way to consistently get image files to be embedded into the PDF as they should be — regardless of the image field object’s setting to link or embed its data — is to manually click on the image field object in Acrobat and pick the image file.


Please refer to the Bug List for updated information on the version(s) affected by this bug as well as if and when it was/will be fixed.

Update (May 22, 2008)

This bug was addressed in Acrobat/Reader 8.1 (XFA 2.6, PDF 1.7) in a way that addresses both security and PDF self-containment issues.

For XFA 2.6+ forms (forms authored in Designer 8.1+), images that are linked (referenced) rather than being embedded are now stored (the bits are embedded) in an array in the PDF layer when the PDF form is saved. At runtime, if an image is linked (referenced) rather than embedded, Acrobat/Reader will look for the associated image bits in the PDF layer and, if a match is found, will load the image. This means that Acrobat/Reader no longer goes outside of the PDF to fetch images unless explicitly directed by the user (e.g. the user clicks on an image field and chooses an image on their own) which addresses security issues. The fact that linked images are now stored in the PDF layer also addresses self-containment issues where the nature of a PDF document is that it is a self-contained entity (e.g. when you email a PDF, the recipient can always open it and see its content even if they don’t have access to referenced content — the exception being if the form makes an external data connection to a database or web service or needs an XML data file to be imported).

Image fields with content embedded at design time are still stored in the XFA data as they were before. You may still load an image dynamically from data provided that the data is the actual image bits or, if the data is a link, that there are associated image bits already in the PDF layer (which implies that the image was linked from the form at design-time — for example, you could have 5 hidden image objects each linking to different images and then use a link in the data to control which of those images show up in an image field on your form). In either case (whether the image is loaded via embedded bits or a link), the image bits always end-up in the data submitted from the form. The original link is not included in the submitted data nor is it available at runtime via scripting (unless imported in data via a data connection or XML data file) because it could contain sensitive information (e.g. your username).

Posted by Stefan Cameron on January 23rd, 2007
Filed under Acrobat,Bugs

Bug: Unable to Set Caption or Value Font Separately


I was showing someone how to use Designer 7.0 today and came across a bug in the Font palette. I was trying to show them how to make the caption of a text field bold without making the value bold using the Bold (“B”) button on the Font palette however I could only change both the caption and value fonts together, not separately as one should be able to do using the selector control located at the top of the palette (which reads, “Currently editing Caption and Value…” by default).

Using the selector control, you should be able to set it to “Currently editing Caption properties…”, press the bold button and make only the caption font bold. Unfortunately, that’s not what happens. Instead, both fonts (or, the entire field) is changed to bold.

Rest assured, this bug was immediately fixed in Designer 7.1 — a highly-recommended upgrade because tables were introduced in that version, amongst other things.


The good news is that there’s a simple workaround using script. All you need to do is use the Font palette to make sure that the Bold button isn’t activated (that the field isn’t bolded) and then set the following FormCalc script statements on field’s Initialize event using the Script Editor palette:

$.caption.font.typeface = "Myriad Pro"
$.caption.font.weight = "bold"
$.caption.font.size = "10pt"

Feel free to specify a different font name or point size if you like although I would recommend using the same font name and point size as you specified in the Font palette so that the result doesn’t differ too much from what you see on the canvas.

Finally, preview the form as PDF using the canvas’s PDF Preview tab. When the form is initialized (loaded) in Acrobat, the field’s caption font will be set to the type, weight and size you specified.


Please refer to the Bug List for updated information on the version(s) affected by this bug as well as if and when it was/will be fixed.

Posted by Stefan Cameron on November 3rd, 2006
Filed under Bugs,Designer

Scripting Table Columns

A few days ago, Sergio, one of my regular commenters, posted a question about programmatically adding new columns to a table. My reply to his comment quickly turned into something that I thought should be promoted to a blog post so here it is.

This question required some investigation because it led me to the discovery of a bug related to adding/removing instances of a table column in a form viewed in a version of Acrobat prior to 8.0. More on that later in this post.

The short answer to Sergio’s question is that yes, in fact, you can modify the set of columns in a table programmatically at runtime. You can do this by either using the presence attribute — although this isn’t recommended because it can lead to data merging problems — or you can use Instance Managers to do it, which is the recommended method to use.

Here’s a sample form that contains a table with a “repeatable column”. Using the add and remove buttons that are provided, you can add and remove instances of the 3rd column.

Download Sample [pdf]

Minimum Requirements: Designer 7.1, Acrobat 7.0.5.

Table Structure

To better understand what’s going on here, I’ll start by explaining how tables are represented in XFA. In reality, there are no <table>, <tr> or <td> elements in XFA. What happens is that <subform layout=”table|row”> elements get used. When a subform represents a table, it’s layout attribute is set to table and when it represents a row, it’s set to row.

Table Subforms

If you read about using a subform’s Instance Manager in order to add/remove instances, you should know that a subform only becomes dynamic or repeatable once it’s placed in a flowed container and its set as repeatable using the Object palette’s Binding tab. By default, a <subform layout=”table”> element is flowed from top to bottom. Since the table subform contains row subforms which, in turn contain the cells, that means that every row in a table could easily be set as repeatable and then get an Instance Manager that you could use to add/remove instances of a particular row.

Row Subforms

Just like the table subform, a <subform layout=”row”> is flowed. Its flow direction, however, isn’t top to bottom, it’s right to left. This means that its contents — the cells — are flowed.

Cells and Columns

Table cells are little different. Essentially, since they reside in a row subform which is flowed from right to left, there’s no specific definition for what is a table cell. It’s simply any type of object (text, numeric field, subform, button, etc.) that’s placed within a row subform. The number of objects in the row determines the number of columns there are. Therefore, to have a 3×3 table, you would need 3 row subforms each containing 3 objects.

There’s no actual definition for a table column either. Table columns are inferred by the cells (put simply, without going into details about column spanning). This means that a column consists of objects in separate row subforms which are above and below each other (e.g. the first object on every row make-up the first column in a table).

Adding/Removing Columns

Given the explanations in my little “table primer” above, we now know that table cells are objects which are flowed from right to left within row subforms. Since row subforms are flowed by nature, it means that if a cell were a subform itself, it could be made repeatable and it would then get its own Instance Manager for free! And once we have Instance Managers, we can start adding and removing instances of those cells.

So the trick here lies in converting every cell which constitutes a column into a subform which then contains the type of object you would normally use to display information in that cell (e.g. a text field, a check box, etc.).

Now if you’ve never noticed the Type property on the Field tab in the Object palette before, you’ll want to check it out because it’s about to come in real handy for setting-up a dynamic table column which consists of cells which are all subforms. This property is used to change the type of the selected object(s). For instance, if you put a text field on a form and decide that it should have been a numeric field, you can change it’s type from text field to numeric field simply by using this property. Typically, you cannot change anything into a subform but when you select a table cell which is a text object (the default cell object type when you insert a new table into a form using the Insert Table menu command or the Table object in the Library’s Standard tab), you can, in fact, change it into a subform. So just select each cell in the column and change its type to a subform using this property. The result will be a cell which is a subform that contains a text object. Then you can change the text object into some other field type which better represents the data which will go into the cell.

Making Cell Subforms Repeatable

Unfortunately, this is one case where you’ll have to use the XML Source tab because the repeatable property isn’t available for cell subforms on the Object palette’s Binding tab. Since it’s a valid XFA setting, you can set this yourself using the XML Source.

Switch to the XML Source window by selecting “XML Source” from the top-level View menu. Then, insert the following XML inside each subform which defines a cell:

<occur max="-1"/>

This means that the cell subform goes from looking like this:

<subform layout="tb" name="Col3SF">
  <field name="Cell3" w="29.9999mm" h="10mm">

to looking like this:

<subform layout="tb" name="Col3SF">
  <occur max="-1"/>
  <field name="Cell3" w="29.9999mm" h="10mm">

and signifies that the cell will have one initial and minimum instance and can have as many additional instances as you need (no maximum).

Last but not least, the script!

After all that, the script is actually quite straight-forward: To add an instance of a column just add an instance of every repeatable subform cell that constitute a column. In my sample, I have a 3×3 table and each subform cell is named “Col3SF”. That means that the script looks like this (in JavaScript):


Then, to remove an instance of the column, just do the reverse: Use the Instance Manager’s removeInstance method to remove an instance of each cell subform.

Bug when adding/removing table cell instances

Of course, everything was going great until now… Unfortunately, I discovered a little snag in playing with table column instances while making this sample. Fortunately, the bug has already been fixed in Acrobat 8.


The first manifests itself when the second new instance of a column is added (by adding an instance of a column, I mean adding an instance of each cell subform in each row which collectively constitute a table column — as in my sample script above earlier). As of the second new instance, the cell in the header row will stop appearing in all subsequent instances.

There’s also an issue with removing column instances (by removing an instance of each cell subform). In this case, all new instances are removed until what was originally the first instance to be added is removed, leaving only the original, initial instance. What happens is that part of the last instance to be removed remains rendered on the form which doesn’t really look nice because it looks like the instance is still there (even though you can’t click on the cells anymore).

The problem is that the form’s layout isn’t properly updated after columns are added or removed.


Luckily, there’s the xfa.layout object which gives us a solution to this problem when version of Acrobat prior to 8.0 are used to render the form. More specifically, versions 7.0.5+ since table support didn’t appear until then, when Designer 7.1 was released.

Using the xfa.layout object, you can tell Acrobat to re-render the form at your command. This effectively repaints the entire form and gets rid of any artifacts (those being the incorrectly rendered column instances). So, after adding or removing column instances, just place the following command:


Please use this with caution, however, since it may adversely affect the performance of your form (since this statement will essentially cause the entire form to be re-rendered every time a column is added/removed). That’s why I check the version of Acrobat that’s rendering the form in my sample so that I know whether I need to apply the workaround or not.

The other workaround is simply to use Acrobat 8.0 to render the form (save is as an “Acrobat 7.0.5 Dynamic PDF Form” but open it in Acrobat 8.0). Acrobat 8.0 now properly renders all instances as they get added or removed.


Please refer to the Bug List for updated information on the version(s) affected by this bug as well as if and when it was/will be fixed.

Posted by Stefan Cameron on October 28th, 2006
Filed under Acrobat,Bugs,Instance Manager,Scripting,Tables,Tutorials

Image Field Z-Order Problems


If you’ve ever tried to use an image field’s contents (an image) as the background for a form and wanted to let the user change it at run-time, you’ve probably run into problems if you had placed objects on top of this image field. The most common result is the image field’s contents always appears on top of all other fields which are technically higher in z-order (“in front” in the hierarchy) than the image field.

While this may seem like buggy behaviour, it’s not technically a bug and I’ll try to explain why it isn’t.

The behavior occurs because of the way image fields are translated from XFA objects to AcroForm objects when your form is saved as a PDF and rendered in Acrobat.

The PDF format has a definition for what is called an Annotation object which represents essentially all the “extra” stuff you can add to PDF documents such as comments, stamps, highlighting, etc. When it comes to image fields, their contents is actually an Annotation in the PDF layer as opposed to contents in the XFA layer. Since the PDF layer is above the XFA layer, Annotations can’t be placed behind objects on the XFA layer — hence why the contents of an image field is always displayed above any objects that may be “in front” of it in the XFA hierarchy (z-order).


Unfortunately, there aren’t any workarounds to this problem if you want users to pick the image field’s contents at run-time (in Acrobat) or if you specifically need to use an image field object.

If you are able to restrict the possibilities to a known set of images that you can store in the form at design-time (in Designer), however, then you could embed all the images in separate read-only image objects (note that this is a static image object — not an image field object) and then change their presence attribute (make one visible and all the others invisible) when the user performs an action that would’ve let them change the background image.

Since static image objects (as opposed to image field objects) render their contents in the XFA layer at the moment the form is rendered in Acrobat, their contents appears “behind” all the other objects, as is desired in this case.


Please refer to the Bug List for updated information on the version(s) affected by this bug as well as if and when it was/will be fixed.

Posted by Stefan Cameron on October 4th, 2006
Filed under Acrobat,Bugs