Comment by em-bee

3 months ago

unfortunately i hit another snag: https://stackoverflow.com/questions/3884927/how-to-use-xsl-v...

nodes you output don't have type "node-set" - instead, they're what is called a "result tree fragment". You can store that to a variable, and you can use that variable to insert the fragment into output (or another variable) later on, but you cannot use XPath to query over it.

the xsl documentation https://www.w3.org/TR/xslt-10/#variables says:

Variables introduce an additional data-type into the expression language. This additional data type is called result tree fragment. A variable may be bound to a result tree fragment instead of one of the four basic XPath data-types (string, number, boolean, node-set). A result tree fragment represents a fragment of the result tree. A result tree fragment is treated equivalently to a node-set that contains just a single root node. However, the operations permitted on a result tree fragment are a subset of those permitted on a node-set. An operation is permitted on a result tree fragment only if that operation would be permitted on a string (the operation on the string may involve first converting the string to a number or boolean). In particular, it is not permitted to use the /, //, and [] operators on result tree fragments.

so using apply-templates on a variable doesn't work. this is actually where i got stuck before. i just was not sure because i could not verify that everything else was correct.

i wonder if it is possible to load the menu from a second document: https://www.w3.org/TR/xslt-10/#document

edit: it is!

    <xsl:apply-templates select="document('nav-menu.xml')/menu">

now i just need to finetune this because somehow the $current param fails now.

5 comments

em-bee

ndriscoll 3 months ago

Ah, I could've sworn that it worked in some version of the page that I tried as I iterated on things, but it could be that the browser just froze on my previously working page and I fooled myself.

Adding xmlns:exsl="http://exslt.org/common" to your xsl:stylesheet and doing select="exsl:node-set($nav-menu-items)/item" seems to work on both Chrome and Librewolf.

em-bee 3 months ago

tried that, getting an empty match.

here is the actual stylesheet i am using:

    <?xml version="1.0" encoding="UTF-8"?>
    <xsl:stylesheet version="1.0" xmlns:exsl="http://exslt.org/common" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns="http://www.w3.org/1999/xhtml">
      <xsl:output method="html"/>

      <xsl:variable name="nav-menu">
        <item href="/">Home</item>
        <item href="/about.xhtml">About</item>
      </xsl:variable>

      <xsl:template match="document">
        <html>
          <head>
            <meta charset="utf-8" />
            <title><xsl:value-of select="title" /></title>
            <link rel="stylesheet" type="text/css" href="site.css" />
          </head>

          <body>
            <!-- <xsl:apply-templates select="document('nav-menu.xml')/menu"> -->
            <xsl:apply-templates select="exsl:node-set($nav-menu)/item">
              <xsl:with-param name="current" select="@name"/>
            </xsl:apply-templates>
            <xsl:apply-templates select="content" />
          </body>
        </html>
      </xsl:template>

      <xsl:template match="item">
        <xsl:param name="current"/>
        <xsl:choose>
          <xsl:when test="@href=$current">
            <a class="selected"><xsl:apply-templates/></a>
          </xsl:when>
          <xsl:otherwise>
            <a href="{@href}"><xsl:apply-templates/></a>
          </xsl:otherwise>
        </xsl:choose>
      </xsl:template>

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

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

documents look like this:

    <?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
    <?xml-stylesheet type="text/xsl" href="site.xsl"?>
    <document name="about">
      <title>About Us</title>
      <content>
        html content here, to be inserted without change
      </content>
    </document>

if i use the document() function, with nav-menu.xml looking like this:

    <menu>
      <item href="/">Home</item>
      <item href="/about.xhtml">About</item>
    </menu>

then i get the menu items, but the test <xsl:when test="@href=$current"> fails

ndriscoll 3 months ago
It looks like it's related to your setting the default namespace xmlns="http://www.w3.org/1999/xhtml". You could either add a xmlns:example="http://example.org/templates" and then replace `item` with `example:item` everywhere, or you can override the default namespace within your variable's scope:
<xsl:variable name="nav-menu-items" xmlns=""> <item href="/">Home</item> <item href="/about.xhtml">About</item> </xsl:variable>
I think you also don't really need to set the default namespace to xhtml, so I believe you could remove that and not worry about namespaces at all (except for xsl and exsl).
The test is failing because it's `/about.xhtml` in the template but `about` outside. You'd either need to add a name attribute to item to compare on or make it match the href.
That should make your thing work if I haven't fooled myself again. :)
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