Have you ever struggled to figure-out what item from a list (list box or drop down list) a user had just selected in the list’s Change event? If so, it’s possible you were trying to use the

rawValue

property in order to get at this information.

Unlike other objects such as exclusion groups, the rawValue property of a list object doesn’t reflect the new selection until the selected value is committed to it (by the user tabbing or clicking away from the list). That means that if you’re trying to, say, make a certain field visible at the moment when a particular item in the list is selected, you can’t use the rawValue property because it still contains the old (previous selection) value.

Instead, you must use the

xfa.event.newText

object/property of the Change event itself and possibly the list object’s

boundItem

function in order to determine the value associated with the new selection.

When scripting any XFA event, you always have access to properties (information) of that event via the

xfa.event

object. In the case of the Change event (which occurs when the list’s selection changes), the

xfa.event.newText

property is of particular interest because it contains the text portion of the item that was just selected in the list. It’s important to note that this is only the text portion because if your list contains items with values that differ from their text (you’ve associated both a text and value part to each item in the list), you’re probably even more interested in determine the value associated with the new text that was just selected in the list. Fortunately, that’s an easy problem to solve as well:

this.boundItem( xfa.event.newText ); // JavaScript
$.boundItem( xfa.event.newText ) // FormCalc

will return the value bound (associated) to the text from the list’s new selection.

So there you have it: When handling a list object’s (list boxes or drop down lists) Change event, don’t rely on the rawValue to get the new selection: Use xfa.event.newText and boundItem(text) instead.

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Posted by Stefan Cameron on September 23rd, 2006
Filed under Events,Scripting

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Mike Potter will be giving a training session on LiveCycle Designer at Adobe MAX 2006 next month.

As he prepares for his session, I’d like to give you an opportunity to influence what he’ll talk about so that his session is as valuable to you as possible:

• Are there specific features you’d like to see a demo for? Dynamic Subforms? Conditional Breaks? Data-Nominated Subforms? Data Binding?
• Should he talk about form design methods like why and when to use repeating (dynamic) subforms, how to validate your form prior to submission, etc.?
• Anything else?

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Posted by Stefan Cameron on September 20th, 2006
Filed under Conferences,MAX 2006

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In response to Lala and malik’s questions on connecting a form to a database (whether it’s Microsoft Access, MySQL, etc. doesn’t really matter), I decided to write a little tutorial on how to do it.

Even if you already know how to do it, I encourage you to pay special attention to the section on Auto-Incremented Table Columns because it might help you understand and resolve some of the issues you may have already run into.

Create a System DSN

First, you need to create a System DSN for your database using the ODBC Data Source Administrator Windows tool.

That will let Acrobat interface with your database when your form is opened in Acrobat in order to be read and/or filled. Because of the DSN, it doesn’t matter what kind of database you need to connect to.

For this tutorial, I’ll be using my FormBuilder database which contains the same kind of movie information found in the XML Data files from various other tutorials I’ve already posted:

Download Movie Database [sql]

This SQL file will create the database and a user if you’re using something like MySQL (for which you can also download a free ODBC driver). You should also be able to easily tweak it to create tables in a Microsoft Access database if that’s what you want to use.

Make a New Data Connection

The second thing you need to do is create a data connection in Designer: From a new or existing form, open the Data View palette (you can use the “Window | Data View” menu item to open it) and choose “New Data Connection” from the palette’s fly-out menu.

In the “New Data Connection” wizard, pick “OLEDB Database” from the first screen, using the “Build” button on the next screen to open the “Data Link Properties” dialog, go to the “Connection” tab and pick the name of the DSN you created in the first step from the first drop down list. Then click the “Test Connection” button to make sure a connection can be established to the database via the DSN.

Click on OK to close the “Data Link Properties” dialog and return to the “New Data Connection” wizard. Now that you’ve chosen a DSN, you’ll be able to specify the resource within that DSN to which the connection should be made: You may either pick a Table from the list, specify a Stored Procedure or specify an SQL Query. If you’re connecting to a single table, you may be able to simply pick its name from the list of tables. If you need to connect to multiple tables in the same data connection, then you’ll need to use a Stored Procedure or an SQL Query.

Auto-Incremented Table Columns

If the table you’re wanting to connect to contains any auto-incrementing columns, you must use the “SQL Query” option instead of simply choosing a table name from the “Table” option. If you pick a table with an auto-increment column, you’ll be able to read from it but you’ll get errors when you try to push data into it. If this is the case, write an SQL Query that selects all columns in the table except for those which are auto-incremented. In the image above, I chose “SQL Query” because the “movie” table I’m connecting to has an auto-incrementing column named “id” that needs to be excluded from the data connection.

Bind Fields to Data Connection Nodes

At this point, you should have a new data connection listed in the Data View palette which contains a list of “nodes”, one for each column in the table(s) you picked while setting-up the data connection:

The next step is to create fields to represent each node in the data connection and bind each field to its respective data node. The easiest way to do this is simply to drag & drop the nodes from the data connection onto your form. This is handy for two important reasons:

1. The Data View palette has inspected the definition of each node and pre-determined the best type of field to use in order to edit its data.
2. When you drop the nodes onto the form, the fields that are created are automatically setup to be bound to their respective data nodes.

The database I’ve connected to is one that uses the Movie Data I’ve used in previous tutorials. In this case, I’ve connected to the Movie table’s “title” and “showTime” columns. Since the “title” column is described as VARCHAR, the Data View palette figured it should be a text field. As for the “showTime” column, described as TIME, it’s set to be a date/time field with its Data Format property preset to Time.

After you’ve completed this step, the Data View palette now shows the data nodes in the data connection as “bound” with special icons:

Add Control Buttons

The last step in this process consists in adding a set of controls to manipulate the records in the database obtained via the data connection. The simplest way to do this is to use a set of buttons where each is assigned one of the following statements (each statement is one line and provided in FormCalc):

xfa.sourceSet.{DataConnectionName}.first()
xfa.sourceSet.{DataConnectionName}.previous()
xfa.sourceSet.{DataConnectionName}.next()
xfa.sourceSet.{DataConnectionName}.last()
xfa.sourceSet.{DataConnectionName}.addNew()
xfa.sourceSet.{DataConnectionName}.update()
xfa.sourceSet.{DataConnectionName}.delete()
xfa.sourceSet.{DataConnectionName}.cancel()

where {DataConnectionName} should be replaced by the name you gave to the data connection you created earlier (“DataConnection” by default).

Each statement above represents a different action to take with the data connection: Move to the first, previous, next or last record, add a new record, update or delete the current record and cancel changes to the current record, respectively.

Note that the “first”, “previous”, “next” and “last” statements imply an “update” by default which means that if you simply use

xfa.sourceSet.{DataConnectionName}.next()

to move to the next record and the user has made changes to the current record, those changes will be committed prior to moving to the next record. If you want those navigation controls not to commit changes (and therefore require the user to explicitly click on the “update” button in order to apply any changes to the current record), you must specify the cancel statement prior to the next statement:

xfa.souceSet.{DataConnectionName}.cancel()
xfa.souceSet.{DataConnectionName}.next()

To help you do this quicker now and in the future, here’s a Library Object Snippet that you can place into the Custom tab of the Library palette (you’ll have to save the XFO file to the following folder on your system: C:\Documents and Settings\{userid}\Application Data\Adobe\Designer\en\objects\custom where userid is your windows user id).

Download Data Connection Controls Snippet [xfo]

Minimum Requirements: Designer 7.0, Acrobat 7.0.

Once you place the file in the folder indicated above, you’ll then have a new object in the Custom tab of your Library palette named “DataConnectionControls”. Simply drag the object onto your form and the buttons will appear, all pre-configured and ready to go.

Run Your Form

Now that the DSN, data connection, fields, bindings and navigation controls have been setup, you should be able to preview your form in Acrobat Pro and see the first record in the database table(s) pre-loaded into the bound fields.

If you’re having problems getting this going, you can check-out my form (assuming you’ve created the FormBuilder database and a DSN for it) to see if you missed any steps:

Download Sample [pdf]

Minimum Requirements: Designer 7.0, Acrobat Standard 7.0.

_{Updated: October 17, 2006}

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Posted by Stefan Cameron on September 18th, 2006
Filed under Data Binding,Tutorials

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I just noticed that Carl Young himself from Carl Young Training Associates is giving a new course on Designer 7 this Fall that looks very interesting (here’s the full course outline if you’re looking for details).

They’ll be in Phoenix, AZ, Nov. 13 – 14, 2006, and Houston, TX, Nov. 27 – 28, 2006.

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Posted by Stefan Cameron on September 15th, 2006
Filed under Designer

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In Designer, you can write scripts using one of two languages: FormCalc and JavaScript. If you’re like me, you’re more familiar with JavaScript because it’s very similar to Java and JScript syntax but when it comes to FormCalc, you’re lost. Well, not completely but you find it very difficult to find documentation on the syntax for loops (like While, For, etc.) which are sometimes essential. Maybe you fall-back on JavaScript in those times but, on average, FormCalc scripts execute much faster than JavaScript scripts so why not harness that performance in our forms?

In this post, I’ll explain the syntax of the If and For expressions in FormCalc. Those of you familiar with Visual Basic or VBScript will likely find this more familiar than the equivalent JavaScript syntax (while I’ll include for comparison however this isn’t a post on JavaScript syntax). In future posts, I’ll add to this collection by discussing the syntax for While and ForEach loops.

Conventions

Before we get started, I should explain a few things about the various syntax blocks you’ll find further down in this post (note that this is simplified for the purposes of this article):

• SimpleExpression: A simple expression like a comparison “i >= 0” that evaluates to true or false or a single entity like “MyVar” (a defined variable) or “5” (a number), for example.
• ExpressionList: A set of 1 or more expressions, each on a separate line.
• Square Brackets: A series of keywords (like “if”, “then”, “for”, “while”, etc.), SimpleExpressions and ExpressionLists grouped within square brackets denote an optional part of the syntax.
• Asterisk Character: Sometimes a closing square bracket is followed by an asterisk (*). This indicates that the optional syntax may be used 0 or more times.
• Question Mark Character: Sometimes a closing square bracket is followed by a question mark (?). This indicates that the optional syntax must be used 1 or more times.

Variables

I assume you’re probably familiar with declaring variables in scripts but just in case, in FormCalc, you declare variables like this:

var MyVar

and you can even declare it and assign it a value in the same step:

var MyVar = 5

If Expression

Let’s look at one of the most essential of all expressions:

FormCalc Syntax

if ( SimpleExpression ) then
    ExpressionList
[ elseif ( SimpleExpression ) then
    ExpressionList]*
[ else
    ExpressionList]?
endif

Based on the syntax, you can do things like (assuming you’ve declared a variable named “i”):

if (i >= 10) then
  i = i + 10
endif

or

if (i >= 10) then
  i = i + 10
elseif (i >= 5) then
  i = i + 5
  i = i * 2
else
  i = i + 1
endif

Hopefully this illustrates the differences in the syntax indicated by the asterisk and question mark characters.

JavaScript Syntax

For comparison, let’s look at the equivalent JavaScript syntax for the two examples above (note the semicolons and curly braces):

if (i >= 10)
  i = i + 10;

or

if (i >= 10)
  i = i + 10;
else if (i >= 5)
{
  i = i + 5;
  i = i * 2;
}
else
  i = i + 1;

For Expression

Often times, in your scripts, you need to execute some statements a certain number of times or iterate through a collection. In those cases (and many others), a For loop may be useful.

FormCalc Syntax

for Variable = StartExpression
        (upto | downto) EndExpression
            [step StepExpression]?
        do
    ExpressionList
endfor

In this syntax, there’s a StartExpression, and EndEExpression and a StepExpression. These are all similar to SimpleExpressions as described earlier. One thing to note about For loops in FormCalc is that “upto” loop will iterate as long as Variable is less-than-or-equal-to (<=) EndExpression whereas a “downto” loop will keep iterating as long as Variable is greater-than-or-equal-to (>=) EndExpression. Also, the variable Variable is implicitely declared in the For expression.

Based on the syntax, you can do things like add the numbers 1 to 10, inclusively, to a list:

for i = 1 upto 10 do
  MyList.addItem(i)
endfor

and then

var nCount = MyList.#items[0].nodes.length

if (nCount >= 2) then
  for nItem = nCount downto 1 step 2 do
    xfa.host.messageBox( MyList.#items[0].nodes.item(nItem - 1) )
  endfor
endif

which would display the value of each even-numbered list item in reverse sequence using a message box as long as there’s at least one even-numbered list item to display.

JavaScript Syntax

For comparison, here are the equivalent JavaScript examples (note the semicolons and curly braces again):

for (var i = 1; i <= 10; i++)
{
  MyList.addItem(i);
}

(in this case, the curly braces are optional but I think this is better style) and then

var nCount = MyList.resolveNode("#items[0]").nodes.length;

if (nCount >= 2)
{
  for (var nItem = nCount; nItem >= 1; nItem - 2)
  {
    xfa.host.messageBox(
      MyList.resolveNode("#items[0]").nodes.item(nItem - 1) );
  }
}

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Posted by Stefan Cameron on September 14th, 2006
Filed under FormCalc

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