Creating a variable number of nodes on target document without corresponding data on source document

Question

I'm trying to map two documents witht the BizTalk Mapper and my target document should look like this:

<root>
  <complexType>
     <property>example</property>
  </complexType>
  <filler>
     <padding>9999999</padding>
  </filler>
  <filler>
     <padding>9999999</padding>
  </filler>
  <filler>
     <padding>9999999</padding>
  </filler>
</root>

The number of <filler> nodes that I should create is variable (from 0 to 9). It is basically the result of a calculation (based on some data provided in the source document).

Is there a way to create those <filler> nodes with some combination of functoids?

I tried to use the Table Looping functoid (created a table with only one column, the padding char '9') but doesn't really work because it creates as many <filler> nodes as rows are defined in the table, which is not what I want since the number of rows would have to be variable (again, based on a calculation). What I currently do is pass the message (XmlDocument) to a C# method and then I programmatically append the <filler> nodes. I'm hoping that there is a more "BizTalk-y" way of doing this with the Mapper.

Answer 1

As pointed out, XSLT can create nodes on the target document at will (I didn't know this and this was the key part). Turns out that what I needed is a simple for-loop in XSLT. Once I realized this, a quick Google search yielded the following results:

http://quomon.com/question-How-to-make-a-for-loop-in-xslt-not-for-each-809.aspx

http://snippets.dzone.com/posts/show/930

Another thing worth noting is that (as pointed out by the first link), XSLT is a functional language, not procedural, so sometimes you do have to resort to using recursion or an extension. This case is definitely one of those times since I couldn't use a careful selection of nodes using the select attribute on an xsl:for-each (since this filler data wasn't part of the source document).

Specifically, for this case, what I did was:

Add a Scripting functoid. Add two inputs:

• A constant with value "1" (this is the initial value of the i variable)
• The length of the loop (number of times to repeat the body of the loop)

Paste the following XSLT template as an "Inline XSLT Call Template" script:

<xsl:template name="ForLoop"> 
<xsl:param name="i" />      <!-- index counter, 1-based, will be incremented with every recursive call -->
<xsl:param name="length" /> <!-- exit loop when i >= length -->

<!-- Output the desired node(s) if we're still looping -->
<!-- The base case is when i > length (in that case, do nothing) -->
<xsl:if test="$i &lt;= $length"> 
<Filler>
    <Padding>999999</Padding>
</Filler>
</xsl:if> 

<!-- Call the ForLoop template recursively, incrementing i -->
<xsl:if test="$i &lt;= $length"> 
<xsl:call-template name="ForLoop"> 
<xsl:with-param name="i"> 
<xsl:value-of select="$i + 1"/> 
</xsl:with-param> 
<xsl:with-param name="length"> 
<xsl:value-of select="$length"/> 
</xsl:with-param> 
</xsl:call-template> 
</xsl:if> 
</xsl:template>

Answer 2

I suspect that you will have to solve this problem by altering the XSLT.

Add some logic to create as many filler nodes as the result of your calculation dictates - you could create a template which you call in a loop perhaps, which would append a new filler section.

Hope this points you in the right direction.