Use code blocks to extend your BizTalk custom XSLT maps

Update 2010-04-13: Grant Samuels commented and made me aware of the fact that inline scripts might in some cases cause memory leaks. He has some further information here and you’ll find a kb-article here.

I’ve posted a few times before on how powerful I think it is in complex mapping to be able to replace the BizTalk Mapper with a custom XSLT script (here’s how to). The BizTalk Mapper is nice and productive in simpler scenarios but in my experience it break down in more complex ones and maintaining a good overview is hard. I’m however looking forward to the new version of the tool in BizTalk 2010 – but until then I’m using custom XSLT when things gets complicated.

Custom XSLT however lacks a few things once has gotten used to have - such as scripting blocks, clever functoids etc. In some previously post (here and here) I’ve talked about using EXSLT as a way to extend the capabilities of custom XSLT when used in BizTalk.

Bye, bye external libraries – heeeello inline scripts ;)

Another way to achieve much of the same functionality even easier is to use embedded scripting that’s supported by the XslTransform class. Using a script block in XSLT is easy and is also the way the BizTalk Mapper makes it possible to include C# snippets right into your maps.

Have a look at the following XSLT sample:

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet
    version="1.0"
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:msxsl="urn:schemas-microsoft-com:xslt"
    xmlns:code="http://richardhallgren.com/Sample/XsltCode"
    exclude-result-prefixes="msxsl code"
    >
    <xsl:output method="xml" indent="yes"/>

    <xsl:template match="@* | node()">
        <Test>
            <UniqueNumber>
                <xsl:value-of select="code:GetUniqueId()" />
            </UniqueNumber>
            <SpecialDateFormat>
                <xsl:value-of select="code:GetInternationalDateFormat('11/16/2003')" />
            </SpecialDateFormat>
            <IncludesBizTalk>
                <xsl:value-of select="code:IncludesSpecialWord('This is a text with BizTalk in it', 'BizTalk')" />
            </IncludesBizTalk>
        </Test>
    </xsl:template>

    <msxsl:script language="CSharp" implements-prefix="code">
        //Gets a unique id based on a guid
        public string GetUniqueId()
        {
            return Guid.NewGuid().ToString();
        }

        //Formats US based dates to standard international
        public string GetInternationalDateFormat(String date)
        {
            return DateTime.Parse(date, new System.Globalization.CultureInfo("en-US")).ToString("yyyy-MM-dd");
        }

        //Use regular expression to look for a pattern in a string
        public bool IncludesSpecialWord(String s, String pattern)
        {
            Regex rx = new Regex(pattern);
            return rx.Match(s).Success;
        }
    </msxsl:script>
</xsl:stylesheet>

All one has to do is to define a code block, reference the xml-namespace used and start coding! Say goodbye to all those external library dlls!

It’s possible to use a few core namespaces without the full .NET namespace path but all namespaces are available as long as they are fully qualified. MSDN has a great page with all the details here.