XSL to get values from nodes basing on the attribute value match - xslt

Question

I am pretty much new to xsl.Currently facing a challenge in transforming the below sample xml to required output.
Sample XML:
<root>
<types>
<entity-type>
<field-type identifier="FieldType1" proxy-ref="TypeA">
<object-name>aclProxy</object-name>
<persistence-class-name>java.lang.Long</persistence-class-name>
</field-type>
<field-type identifier="FieldType2" proxy-ref="TypeB">
<object-name>aclName</object-name>
<persistence-class-name>java.lang.String</persistence-class-name>
</field-type>
</entity-type>
</types>
<custom>
<category identifier="parent" order="1">
<name>%category.parent</name>
</category>
<category identifier="texts" order="2">
<name>%category.Texts</name>
</category>
<field identifier="ArticleID" category-ref="parent" field-type-ref="FieldType1" proxy-entity-ref="ABC">
<name>%field.name</name>
<description>%field.Article.description</description>
</field>
<field identifier="ArticleName" category-ref="texts" field-type-ref="FieldType2" proxy-entity-ref="ABCD">
<name>%field.name.text</name>
<description>%field.Articletext.description</description>
</field>
</custom>
</root>
Output
<field identifier="ArticleID">
<name>%field.name</name>
<description>%field.Article.description</description>
<category-ref-name>%category.parent</category-ref-name>
<field-type-ref>Long</field-type-ref>
<proxy-entity-ref>TypeA</proxy-entity-ref>
</field>
<field identifier="ArticleName" >
<name>%field.name.text</name>
<description>%field.Articletext.description</description>
<category-ref-name>%category.Texts</category-ref-name>
<field-type-ref>String</field-type-ref>
<proxy-entity-ref>TypeB</proxy-entity-ref>
</field>
XSLT which I have been trying:
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:key name="category" match="category" use="#identifier" />
<xsl:key name="field" match="field" use="#category-ref" />
<xsl:apply-templates select="custom[not(key('field',category/#identifier))]"/>
<xsl:template match="/">
<xsl:text>something</xsl:text>
<xsl:value-of select="category/#identifier"/>
<xsl:apply-templates select="."/>
</xsl:template>
<xsl:template match="/">
<xsl:value-of select="field/#identifier"/>
<xsl:variable name="categoryparam" select="key('category', field/#category-ref)" />
<xsl:if test="$categoryparam">
<xsl:apply-templates select="$categoryparam"/>
<xsl:text>something</xsl:text>
</xsl:if>
</xsl:template>
</xsl:stylesheet>
Basically the output should have only field(s) in it referring to the attributes and get the node values.
Any help is much appreciated.
Thanks in advance.

Answer 1

Let us start off with these 2 keys:
<xsl:key name="kCategory" match="category" use="#identifier" />
<xsl:key name="kFieldID" match="field-type" use="#identifier" />
you will need the values in category and field-type nodes later.
This template:
<xsl:template match="/">
<xsl:apply-templates select="root/custom/field"/>
</xsl:template>
will output the target field nodes
Having a template match with the field node to further manipuate the output:
<xsl:template match="field">
<xsl:copy>
<!-- copies the identifier attribute and all children -->
<xsl:copy-of select="#identifier|node()"/>
<category-ref-name>
<!-- gets the child name of the target category node
that matches the category-ref attribute -->
<xsl:value-of select="key('kCategory', #category-ref)/name"/>
</category-ref-name>
<field-type-ref>
<!-- gets the child persistence-class-name of the target
field-type node that matches the field-type-ref attribute,
with further substring manipulations -->
<xsl:value-of select="substring-after(key('kFieldID', #field-type-ref)/persistence-class-name, 'java.lang.')"/>
</field-type-ref>
<proxy-entity-ref>
<!-- gets the attribute proxy-ref of the target
field-type node that matches the field-type-ref
attribute -->
<xsl:value-of select="key('kFieldID', #field-type-ref)/#proxy-ref"/>
</proxy-entity-ref>
</xsl:copy>
</xsl:template>
The whole stylesheet is below:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
exclude-result-prefixes="xs"
version="1.0">
<xsl:strip-space elements="*"/>
<xsl:output indent="yes" omit-xml-declaration="yes"/>
<xsl:key name="kCategory" match="category" use="#identifier" />
<xsl:key name="kFieldID" match="field-type" use="#identifier" />
<xsl:template match="/">
<xsl:apply-templates select="root/custom/field"/>
</xsl:template>
<xsl:template match="field">
<xsl:copy>
<xsl:copy-of select="#identifier|node()"/>
<category-ref-name>
<xsl:value-of select="key('kCategory', #category-ref)/name"/>
</category-ref-name>
<field-type-ref>
<xsl:value-of select="substring-after(key('kFieldID', #field-type-ref)/persistence-class-name, 'java.lang.')"/>
</field-type-ref>
<proxy-entity-ref>
<xsl:value-of select="key('kFieldID', #field-type-ref)/#proxy-ref"/>
</proxy-entity-ref>
</xsl:copy>
</xsl:template>
</xsl:stylesheet>
See it in action (http://xsltfiddle.liberty-development.net/gWmuiJc).