XSL compare and change XML structure

[E Robb]

I've been working with XSL a little and can do simple things but this I have no idea where to begin.

Anything that does not match the Option ID in Options I would like removed from PayBill entityid.

Abbreviated XML original Structure:

<?xml version="1.0" encoding="UTF-8"?>
<test>
<Items type="INOUT-SUP">
              <Item entityid="230137">
                <PayBill entityid="186555">BB-Regular</PayBill>
                 <Notes>Non-Expense</Notes>
              </Item>
              <Item entityid="230138">
                <PayBill entityid="142232">PayBill</PayBill>
                <Notes>Non-Expense</Notes>
              </Item>
              <Item entityid="230139">
                <PayBill entityid="142672">Mileage</PayBill>
                <Notes>Expense</Notes>
              </Item>
 </Items>
 <Options>
        <OptionGroup name="PayBill Expense">
            <Option id="142672">Mileage</Option>
            <Option id="1234">Dummy expense</Option>
        </OptionGroup>
</Options>
</test>

Code that I would like to achive with XSL transform

<?xml version="1.0" encoding="UTF-8"?>
<test>
<Items type="INOUT-SUP">
              <Item entityid="230139">
                <PayBill entityid="142672">Mileage</PayBill>
                <Notes>Expense</Notes>
              </Item>
 </Items>
 <Options>
        <OptionGroup name="PayBill Expense">
            <Option id="142672">Mileage</Option>
            <Option id="1234">Dummy expense</Option>
        </OptionGroup>
</Options>
</test>

Would greatly appreciate a nudge in the right direction

[Paul Clapham]

When your requirements say "I want the output to look just like the input except..." then your starting point is an identity transformation. Then add templates which do the specific modifications you're interested in.

[E Robb]

Paul Clapham wrote:When your requirements say "I want the output to look just like the input except..." then your starting point is an identity transformation. Then add templates which do the specific modifications you're interested in.

Hi Paul,

I have a template for upper level sortling of dates in the xml which goes something like this. I would like to incorporate the transformation based on comparing two properties but I dont have a clue as to how to incoprorate it.

	//xsl to format entity days from oldest to newest. entities are not returned by date in xml
	public String xslFormat() throws Exception {
		String xsl = "<?xml version='1.0' encoding='UTF-8'?>"+
			"<xsl:stylesheet version='1.0' xmlns:xsl='http://www.w3.org/1999/XSL/Transform'>"+
			 "<xsl:output method='xml' indent='yes'/>"+
			 //copy all nodes including XML tags otherwise xml tags are removed
			 "<xsl:template match='@*|node()' priority='-1'>"+
				"<xsl:copy>"+
				  "<xsl:apply-templates select='@*|node()'/>"+
				"</xsl:copy>"+
			  "</xsl:template>"+
			  
			//sort each item in items attribute INOUT. Exlude <Items type='EXPENSE'> by attribute		 
			"<xsl:template match=\"Items[@type='INOUT']\"> "+ 
				"<Items type='INOUT'>"+ //reset top tier tag
				"<xsl:apply-templates>"+					
					//sort Items by string because xsl doesnt have date sort. XML date format is yyyy-MM-dd
					//xsl has a number sort where the date could be joined removing "-" but this should work.
					"<xsl:sort select='substring(Date,1,4)'/>"+ //<!-- year sort -->
					"<xsl:sort select='substring(Date,6,2)'/>"+ // <!-- month sort --> 
					"<xsl:sort select='substring(Date,9,2)'/>"+ //<!-- day sort -->
				"</xsl:apply-templates>"+
				"</Items>"+					
                "</xsl:template>"+
			"</xsl:stylesheet>";
			
		return xsl;
	}

Can you elaborate more on how I can compare one properties elements to another properties elements and eliminate anything that does match as I mentioned my original post. Heck I would be happy on terms to google to accomplish the structure from my original post.

Thanks

[Paul Clapham]

Well, displaying the XSLT code as a concatenation of Java strings is kind of an odd thing to do, but as far as I can see you've already done what I suggested. There's what looks like the identity transformation at the beginning, and then there's a template which does something with elements which look like <Items type="INOUT">. So that's a good start.

Now, your problem is that you want to drop some <Item> elements which satisfy some condition? Then you write another template which matches <Item> elements. If the element satisifes the condition, then write out the element and inside it you do xsl:apply-templates.

And if I were you I would put that XSLT code into its own file, rather than mixing it up with Java code like that. Easier to maintain, especially having to make sure you do the quotes and apostrophes right.

[E Robb]

Paul Clapham wrote:Well, displaying the XSLT code as a concatenation of Java strings is kind of an odd thing to do, but as far as I can see you've already done what I suggested. There's what looks like the identity transformation at the beginning, and then there's a template which does something with elements which look like <Items type="INOUT">. So that's a good start.

Now, your problem is that you want to drop some <Item> elements which satisfy some condition? Then you write another template which matches <Item> elements. If the element satisifes the condition, then write out the element and inside it you do xsl:apply-templates.

And if I were you I would put that XSLT code into its own file, rather than mixing it up with Java code like that. Easier to maintain, especially having to make sure you do the quotes and apostrophes right.

Your first paragraph is correct. I should not be doing strings like that. Jeeze I feel like boozo the clown.

OK can do a xsl:template match but how do I delete? "PayBill entityid="142232"" doesnt equal "Option id="142672"" so Parent of PayBill entity <Item entityid="230138"> and its children need to be removed from the xml.

Sorry Im really a newbie to XSL.

[Paul Clapham]

You don't delete anything. The identity transformation copies everything, except the nodes which you match in the other templates. In those templates it's up to you to output whatever you need.

So in the existing template, you output a copy of the <Items> element, only with its children sorted by date.

And in your new template, you only output a copy of the <Item> element if it should be in the output document. Otherwise, you don't output anything.

And your remaining question is how to write an XPath expression to determine whether an <Item> element needs to be kept, right? You seem to have a general idea, so see if you can produce a more precise description.

[g tsuji]

Suppose you've already an identity transformation somewhere. You can add this specific template to do the specific job.

<xsl:template match="Item[PayBill/@entityid]">
    <xsl:choose>
        <xsl:when test="
            parent::Items[@type='INOUT-SUP']
            /following-sibling::Options/OptionGroup[@name='PayBill Expense']
            /Option[@id=current()/PayBill/@entityid]
        ">
            <xsl:copy>
                <xsl:apply-templates />
            </xsl:copy>
        </xsl:when>
        <xsl:otherwise>
            <!-- do nothing or do whatever otherwise -->
        </xsl:otherwise>
    </xsl:choose>
</xsl:template>

[E Robb]

Brilliant your a life saver! Im so new to xsl I didnt know where to begin! This give me a great overview, works a treat and I can modify it for a more complicated XML structure.

Thank You!