Re: [xslt] data callbacks?

[Robert Koberg <rob koberg com>]

On Oct 21, 2008, at 11:37 AM, Paul Miller wrote:

> Just came across libxslt and it's brilliant (and fast!). I was  
> thinking about embedding it into an app as a report generator and I  
> think what I want to do is possible, but I wanted to double-check  
> here first.
>
> I'd like to write some XML that describes a report - basic layout  
> information plus what columns/rows of data to output. But there is  
> no actual data in this XML - the data needs to be generated on the  
> fly within my application. I'd like to stick some custom elements or  
> attributes that cause libxslt to call back into my application using  
> a callback function and replace that element with possibly more  
> elements with specific text nodes.
>
> For example, let's say I have an element like this:
>
>   <data id="income" range="5"/>
>
> In my template, I'd like to convert this to something like this in  
> the resulting XML:
>
>   <data>100.00</data>
>   <data>200.00</data>
>   <data>300.00</data>
>   <data>400.00</data>
>   <data>500.00</data>
>
> So what I'd like to happen is for the xslt to see the "range" and  
> "id" attributes and then call back into my code with information  
> about this element. Then I'd like my code to replace this element  
> with its own set of elements, filling in the data values as it goes.
>
> Is this possible? Is this a good idea? Any suggestions on what API  
> to use to handle this?


You could use the document function. Perhaps target a script like:

<xsl:apply-templates
  select="document(concat('path/to/script?id=', @id, '&amp;range=',  
@range))"/>

You would need to return a well-formed document (your data elems  
wrapped in a root elem), I believe.

best,
-Rob