Эффективное использование селектора xslt

Question

Одна из созданных мною таблиц стилей xslt имеет много применений, например:

<xsl:template match="ProductType">
 <xsl:value-of select="../../Title"/>
</xsl:template>

, поэтому мой вопрос заключается в том, будет ли эффективнее создать новый набор узлов вручную, включающий только необходимые данные или, возможно, передаваемые сparams?

Что будет представлять собой лучшую практику для этого случая?

xml будет иметь форму, показанную ниже

<product>
<title>the title</title>
<tags>
<producttype>the product type</producttype>
<tags>
</product>

совпадение шаблона Actall выглядит следующим образом

<xsl:template match="ProductType" xml:space="default">
      <xsl:param name="by" select="by"/>            
      <xsl:choose>
            <xsl:when test="current()='Karaoke MP3+G'">
                  <div class="product-subhead">
                        <h3>Karaoke Song</h3>
                        <h3 class="middle">MP3+G</h3>
                        <h3>100% Legal Download</h3>
                  </div>
                  The track <xsl:value-of select="../../Title"/> is 100% legally covered by MCPS and PPL ensuring the artist <xsl:value-of select="../../Attribution"/> is paid royalties for every sale! Each karaoke track download from Mastermix Digital contains audio and graphics prompts. The song is provided in MP3+G format. Purchase is available through Paypal with all major credit cards.
            </xsl:when> 
            <xsl:when test="current()='Track'">
                  <div class="product-subhead">
                              <h3>Original Version</h3>
                              <h3 class="middle">Available in 320kbps MP3 and WAV</h3>
                              <h3>100% Legal Download</h3>
                        </div>
                        The track <xsl:value-of select="../../Title"/> is 100% legally covered by MCPS and PPL ensuring the artist <xsl:value-of select="../../Attribution"/> is paid royalties for every sale! Each track download from Mastermix Digital is the original artist version and a guaranteed dancefloor filler! The audio is provided in high quality 320kbps mp3 format. Purchase is available through Paypal with all major credit cards.                        
            </xsl:when>
            <xsl:when test="current()='Extended Floorfillers'">
                  <div class="product-subhead">
                              <h3>Extended Version</h3>
                              <h3 class="middle">Available in 320kbps MP3 and WAV</h3>
                              <h3 class="phead3">100% Legal Download</h3>
                        </div>
                        Each extended floorfiller download from Mastermix Digital contains the original artist version mixed to be just that little bit longer! <xsl:value-of select="../../Title"/> is 100% legally covered by MCPS and PPL ensuring the artist <xsl:value-of select="../../Attribution"/> is paid royalties for every sale. The audio is provided in high quality 320kbps mp3 format. Purchase is available through Paypal with all major credit cards.
            </xsl:when>
            <xsl:otherwise>                        
                  <xsl:value-of select="."/>
            </xsl:otherwise> 
      </xsl:choose>
</xsl:template>

и копия xml, как показано ниже

  <Tracks>
    <Track AlbumArtURL="http://api.3.esh-partner.net/GetThumbnail.ashx?ID=07167B09-6365-4908-BFE6-811039D62D5E" IsBundle="true">
      <ReportingCode>MG00089531</ReportingCode>
      <Title Language="en-gb">Complete Number Ones Collection</Title>
      <ExtendedTitle>Every UK No 1 in one download</ExtendedTitle>
      <ExplicitContent>false</ExplicitContent>
      <Attribution>Various Artists</Attribution>
      <Duration Seconds="0">00:00:00</Duration>
      <GRid>A1-0327D-MG00089531-J</GRid>
      <CatalogNr>MFEG090</CatalogNr>
      <OriginalReleaseFormat>CD</OriginalReleaseFormat>
      <OriginalReleaseDate>2009-08-04</OriginalReleaseDate>
      <ReleaseDate>2009-08-04</ReleaseDate>
      <Description Language="en-gb">
        <Long>One amazing collection! This download contains every single number 1 from the Official UK charts, since the charts began back in 1952 right up to the present day (not including the last 2 months)! That's more than 1,000 tracks, all in 320 KBPS (the highest quality, indistinguishable from quality you would get from a CD). 
Save over £600 compared by buying every download individually!</Long>
      </Description>      
      <Tags>
            <ProductType>Track</ProductType>
      </Tags>
      <Attributes>
        <Attribute Type="Text" Description="PriceCode">AA</Attribute>
        <Attribute Type="LookupValue" Description="Category">MasterMix</Attribute>
      </Attributes>
      <Contributors />
      <PriceBand>Mid/Front Premium</PriceBand>
      <RecompilationRights>Yes</RecompilationRights>
    </Track>
  </Tracks>

Answer 1

Эта таблица стилей:

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
 xmlns:h="header"
 exclude-result-prefixes="h">
    <h:header for="Karaoke MP3+G">
        <h1>Karaoke Song</h1>
        <h2>MP3+G</h2>
        <h4>The track</h4>
        <h5>Each karaoke track download from Mastermix Digital contains audio and graphics prompts. The song is provided in MP3+G format.</h5>
    </h:header>
    <h:header for="Track">
        <h1>Original Version</h1>
        <h2>Available in 320kbps MP3 and WAV</h2>
        <h4>The track</h4>
        <h5>Each track download from Mastermix Digital is the original artist version and a guaranteed dancefloor filler! The audio is provided in high quality 320kbps mp3 format.</h5>
    </h:header>
    <h:header for="Extended Floorfillers">
        <h1>Extended Version</h1>
        <h2>Available in 320kbps MP3 and WAV</h2>
        <h3 class="phead3"/>
        <h4>Each extended floorfiller download from Mastermix Digital contains the original artist version mixed to be just that little bit longer!</h4>
        <h5>The audio is provided in high quality 320kbps mp3 format.</h5>
    </h:header>
    <xsl:template match="Track">
        <xsl:variable name="vText" select="document('')/*/h:*[@for=current()/Tags/ProductType]"/>
        <xsl:choose>
            <xsl:when test="$vText">
                <div class="product-subhead">
                    <h3>
                        <xsl:value-of select="$vText/h1"/>
                    </h3>
                    <h3 class="middle">
                        <xsl:value-of select="$vText/h2"/>
                    </h3>
                    <h3>
                        <xsl:copy-of select="$vText/h3/@*"/>
                        <xsl:text>100% Legal Download</xsl:text>
                    </h3>
                </div>
                <xsl:value-of select="$vText/h4"/>
                <xsl:value-of select="Title"/> is 100% legally covered by MCPS and PPL ensuring the artist 
                <xsl:value-of select="Attribution"/> is paid royalties for every sale! 
                <xsl:value-of select="$vText/h5"/> Purchase is available through Paypal with all major credit cards.
            </xsl:when>
            <xsl:otherwise>
                <xsl:value-of select="Tags/ProductType"/>
            </xsl:otherwise>
        </xsl:choose>
    </xsl:template>
</xsl:stylesheet>

Выход:

<div class="product-subhead">
    <h3>Original Version</h3>
    <h3 class="middle">Available in 320kbps MP3 and WAV</h3>
    <h3>100% Legal Download</h3>
</div>
The trackComplete Number Ones Collection is 100% legally covered by MCPS and PPL ensuring the artist 
Various Artists is paid royalties for every sale!
Each track download from Mastermix Digital is the original artist version and a guaranteed dancefloor filler! The audio is provided in high quality 320kbps mp3 format. Purchase is available through Paypal with all major credit cards.

Answer 2

Если вы ссылаетесь на использование ../.. в вашем XPath, то, на мой взгляд, в этом нет ничего плохого.

Но если вы используете product/title во многих под-шаблонах для шаблона product,Один из способов решить эту проблему - использовать туннельный параметр:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0">

  <xsl:template match="product">
    <!-- Do some other stuff here maybe... -->
    <xsl:apply-templates>
      <xsl:with-param name="title" select="title" tunnel="yes"/>
    </xsl:apply-templates>
  </xsl:template>

  <xsl:template match="tags">
    <!-- ... and some more stuff ... -->
    <xsl:apply-templates/>
  </xsl:template>

  <xsl:template match="ProductType">
    <xsl:param name="title" tunnel="yes"/>
    <xsl:value-of select="$title"/>
  </xsl:template>

</xsl:stylesheet>

Используя туннельный параметр, вы сможете выбрать его в любом из шаблонов для любого дочернего узла для продукта.Но приятно то, что вам не нужно отправлять его вручную через все шаблоны, заголовок не нужен.

Вот еще несколько параметров туннелирования: http://www.xml.com/lpt/a/1386

Однакоэтот метод требует XSLT 2.0, но вы можете сделать то же самое в XSLT 1.0, но с оговоркой, что вам нужно передавать параметр через каждый шаблон, который вы обрабатываете.