Reference C# code in an external file within msxsl tags
質問
I'm using a system which consists of many complex XSL transforms which each work on large XML files. A proprietary program compiles the XSLT on each of the XML files, before passing the XML files to our databases.
The XSL transforms almost always involve C# functions within <msxsl>
tags, many which are repeated between several files with the code copied manually. I'm trying to implement a system where a general repository of functions are stored in one file, and then loaded into the XSLT file before being read by the <msxsl>
tags.
My problem is that I have been unable to find a way to have the code within <msxsl>
loaded from an external file. Here's an example of what I mean:
The transform with the function hard-coded:
...
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:msxsl="urn:schemas-microsoft-com:xslt"
xmlns:cs="urn:my-scripts-csharp">
...
<msxsl:script language="C#" implements-prefix="cs">
<![CDATA[
public string emphasise(string input) {
return input+"!";
}
]]>
</msxsl:script>
...
Whilst I'd like the function loaded externally:
...
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:msxsl="urn:schemas-microsoft-com:xslt"
xmlns:cs="urn:my-scripts-csharp">
...
<msxsl:script language="C#" implements-prefix="cs">
<--- file loaded here --->
</msxsl:script>
...
Where the source file would be something like:
<![CDATA[
public string emphasise(string input) {
return input+"!";
}
]]>
Is this possible? The functions are generally complex (unlike this example) and cannot be reproduced with XSLT code. Would namespace
and using
keywords from the external file be read or would I have to include them outside of it with <msxsl:using>
tags?
I'm quite new to the use of <msxsl>
tags, and if I'm misunderstanding something fundamental then do please let me know!
解決
I. Here is how to do it:
File: C:\temp\delete\c#script.xsl
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:msxsl="urn:schemas-microsoft-com:xslt"
xmlns:cs="urn:my-scripts-csharp">
<msxsl:script language="C#" implements-prefix="cs">
<![CDATA[
public string emphasise(string input)
{
return input+"!";
}
]]></msxsl:script>
</xsl:stylesheet>
Your transformation:
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:msxsl="urn:schemas-microsoft-com:xslt"
xmlns:cs="urn:my-scripts-csharp">
<xsl:include href="C:\temp\delete\c#script.xsl"/>
<xsl:template match="/">
<xsl:value-of select="cs:emphasise('Hello')"/>
</xsl:template>
</xsl:stylesheet>
When this transformation is performed (on any XML document), the wanted result is produced:
Hello!
Warning: Using inline scripts like these is known to cause memory fragmentation if the transformation is repeated many times and this can lead to memory leaks.
I strongly recommend not to use inline scripts at all. A better, more efficient and safe approach is to have all necessary extension functions in an extension object -- read about the XsltArgumentList
class and its AddExtensionObject()
method.
他のヒント
You can reference code in external assemblies using : http://msdn.microsoft.com/en-us/library/ms256188.aspx - that could provide a way of moving your code to an external location