Question

I have an XML document that looks like this:

<?xml version="1.0" encoding="utf-8"?>
<Schema Namespace="EDIManagement.Models.Store" Alias="Self" Provider="System.Data.SqlClient" ProviderManifestToken="2008" xmlns="http://schemas.microsoft.com/ado/2009/02/edm/ssdl" xmlns:store="http://schemas.microsoft.com/ado/2007/12/edm/EntityStoreSchemaGenerator">
  <EntityType Name="AccountRemark">
    <Key>
      <PropertyRef Name="AccountRemarkId" />
    </Key>
    <Property Name="AccountRemarkId" Type="int" Nullable="false" StoreGeneratedPattern="Identity" />
    <Property Name="AccountId" Type="int" Nullable="false" />
    <Property Name="RemarkTypeId" Type="int" Nullable="false" />
    <Property Name="RemarkEnteredAt" Type="datetime" Nullable="false" />
    <Property Name="EnteredBy" Type="nvarchar" Nullable="false" MaxLength="100" />
    <Property Name="Remark" Type="nvarchar(max)" Nullable="false" />
    <Property Name="LastEditedBy" Type="nvarchar" Nullable="false" MaxLength="100" />
  </EntityType>
</Schema>

I am trying to transform it with XSLT so that the new document is identical, with just one line of difference. The line to be changed is this:

    <Property Name="Remark" Type="nvarchar(max)" Nullable="false" />

It should be transformed into this:

    <Property Name="Remark" Type="nvarchar" Nullable="false" MaxLength="300" />

My XSLT transform so far looks like this:

<?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" exclude-result-prefixes="msxsl"
  xmlns:def="http://schemas.microsoft.com/ado/2009/02/edm/ssdl"
>
  <xsl:output method="xml" indent="yes"/>

  <xsl:template match="@* | node()">
    <xsl:copy>
      <xsl:apply-templates select="@* | node()"  />
    </xsl:copy>
  </xsl:template>

  <xsl:template match="def:EntityType/def:Property[@Type='nvarchar(max)']/@*" >
    <xsl:choose>
      <xsl:when test="@Type='nvarchar(max)'">
        <xsl:attribute name="Type">nvarchar</xsl:attribute>
        <xsl:attribute name="MaxLength">300</xsl:attribute>
      </xsl:when>
      <xsl:otherwise>
        <xsl:copy></xsl:copy>
      </xsl:otherwise>
    </xsl:choose>
  </xsl:template>

</xsl:stylesheet>

I’m stepping through the transform with Visual Studio 2010 debugging, and I see that it correctly activates the [@Type='nvarchar(max)']/@* template. The only problem is that the xsl:when test="@Type='nvarchar(max)'" never tests as true. Of course this is bizarre, because if the template itself matched, then this identical condition should match as well.

But because the when test strangely doesn’t become true, my target doesn’t get transformed at all, and I simply end up with an exact copy of the original document. If I change the when clause to xsl:when test="1=1" then it finally tests as true, which demonstrates that overall the transform is correct. But this still begs the question: why is the proper expression never becoming true?

I’m just simply unable to figure why the proper test expression never becomes true. Ideas?

Answer 1

Use this template:

<xsl:template match="def:EntityType/def:Property[@Type = 'nvarchar(max)']">
  <xsl:copy>
    <xsl:apply-templates select="@*"/>
    <xsl:attribute name="Type">nvarchar</xsl:attribute>
    <xsl:attribute name="MaxLength">300</xsl:attribute>
  </xsl:copy>
</xsl:template>