BizTalk HL7 send pipeline error due to line breaks

问题:

I am mapping to an HL7 A31 message using the BizTalk mapper. The map has several inline XSLT scripting functoids.

When the XML is put through the HL7 send pipeline, it generates an error:

The element 'ROL_11_OfficeHomeAddress' has an invalid structure

If I look at the suspended message, I can see why this has happened. The ROL_11 element is empty, and looks like this:

    <ROL_11_OfficeHomeAddress>
    </ROL_11_OfficeHomeAddress>

Between the opening and closing tags, there is a line break and several spaces/tabs due to indenting. This is exactly as generated by the XSLT and I believe it is the line break that is causing the error.

I could wrap the XSLT in an <xsl:if> statement to check for a value before writing the XML. However this problem is occurring in many places and it seems overkill to wrap every single element like this.

What I really want is for BizTalk to automatically convert the element to an empty one, like this:

<ROL_11_OfficeHomeAddress />

I believe this would solve the problem. Is there any way I can tell it to do that?

Things I have already tried:

• Using <xsl:strip-space> but that raised its own error. I think this is because BizTalk wraps the inline XSLT in its own code and thus strip-space was specified in the wrong place.

• Changing the map's grid properties to set Indent to No in the hope the whitespace would be removed. This had no effect on the XML seen in the suspended message.

• Adding the registry key for legacy whitespace handling as per this guidance. Again, this appeared to have no effect at all.

回答1:

If you convert your entire map into XSLT, the below will strip out newlines and whitespace and leave you with an empty tag if there isn't anything but whitespace:

<xsl:element name="ROL_11_OfficeHomeAddress">
  <xsl:if test="normalize-space(ROL_11_OfficeHomeAddress)">
    <xsl:value-of select="normalize-space(ROL_11_OfficeHomeAddress)" />
  </xsl:if>
</xsl:element>

Edit: Biztalk usually generates XSLT like the following in a typical 1:1 nillable element mapping

    <xsl:variable name="var:v2" select="string(ns0:ROL_11_OfficeHomeAddress/@xsi:nil) = 'true'" />
    <xsl:if test="string($var:v2)='true'">
      <ns0:ROL_11_OfficeHomeAddress>
        <xsl:attribute name="xsi:nil">
          <xsl:value-of select="'true'" />
        </xsl:attribute>
      </ns0:ROL_11_OfficeHomeAddress>
    </xsl:if>
    <xsl:if test="string($var:v2)='false'">
      <ns0:ROL_11_OfficeHomeAddress>
        <xsl:value-of select="ROL_11_OfficeHomeAddress/text()" />
      </ns0:ROL_11_OfficeHomeAddress>
    </xsl:if>

So if you did use <xsl:strip-space> it would mean that the element would map to <ROL_11_OfficeHomeAddress></ROL_11_OfficeHomeAddress> if whitespace only, unless you went through the map changing it back to <xsl:element>.

What you could try is to use a call template like the below (nodeXfrm is a node)

<xsl:template name="StripElement">
    <xsl:param name="nodeXfrm"></xsl:param>
    <xsl:variable name="nodeName">
        <xsl:value-of select="local-name($nodeXfrm)"></xsl:value-of>
    </xsl:variable>
    <xsl:element name="{$nodeName}">
        <xsl:if test="normalize-space($nodeXfrm)!=''">
            <xsl:value-of select="$nodeXfrm/text()"/>
        </xsl:if>
    </xsl:element>
</xsl:template>

And then within your map you can call the template for each element you need stripped in this way

  <xsl:call-template name="StripElement">
    <xsl:with-param name="nodeXfrm" select="ROL_11_OfficeHomeAddress"></xsl:with-param>
  </xsl:call-template>

An XSLT guru might be able to do this more elegantly

回答2:

I too was recently having this problem, but in BizTalk 2013. We moved everything to custom XSLT files for mapping our HL7v2. Upon upgrading to 2013, suddenly the <xsl:strip-space> that previously worked, no longer worked.

This is because BizTalk 2013 now uses the XslCompiledTransform class rather than the now obsoleted XslTransform class and it doesn't allow the <xsl:strip-space>. So I too was faced with no global way to strip the whitespace.

However, after much searching and head scratching, I found an obscure blog post with something that worked for my solution:

http://geekswithblogs.net/peterbrouwer/archive/2012/08/17/biztalk-2010ndashlegacy-whitespace-behaviour.aspx

An option in the the Host's settings, for using legacy whitespace did it for us (so far at least).