Tutorial Addendum On XML Technologies - XSL - Declaring and Applying Templates

Since XSL is a accent based on XML, so all XSL statements are accounting as XML elements.

    

In this note, we will apprentice and play with three basal XSL elements:

    

    
• "stylesheet": Desclaring an XSL appearance sheet.


    
• "template": Declaring an XSL transformation template.


    
• "apply-templates": Requesting to administer transformation templates.


    

With them, we can ascendancy the XSL processor:

    

    
• To transform a called aspect by replacing it with a accustomed argument string.


    
• To adjure a transformation of a adolescent aspect aural the transformation
  
      

  of the ancestor element.



    

The stylesheet Element

    

stylesheet: The basis aspect of an XSL file, confined as the XSL acknowledgment

    

statement. It specifies the XSL adaptation number,

    

and assembly the XSL namespace to a name prefix.

    

    
<xsl:stylesheet version="1.0"

    
   xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

    
 XSL_elements

    
</xsl:stylesheet>

    

The arrangement Element

    

template: An XSL element, confined as the arrangement acknowledgment statement.

    

It defines the backup agreeable for elements in the XML antecedent files

    

that matches the defined pattern.

    

    
<xsl:template match="pattern">

    
 replacement_content

    
</xsl:template>

    

where "pattern" is a arrangement acclimated to bout aspect names in the antecedent XML file,

    

and "replace_content" is the achievement to be amid in the aforementioned abode area

    

the analogous elements are.

    

If an aspect in the antecedent XML book is matched, the entire

    

element will be replaced, starting from "<" of the starting tag to ">" of the ending

    

tag. By this definition, the backup includes the aspect name, all attributes,

    

text content, and all sub-elements.

    

Example, we accept the afterward aspect in the antecedent XML file:

    

 

    
<p a="v">

    
 Some argument with a <c>child element</c>.

    
</p>

    

and the afterward arrangement in the XSL file:

    

 

    
<xsl:template match="p">

    
 Backup argument for the aspect "p" in the antecedent XML file.

    
</xsl:template>

    

the achievement will be:

    

 

    
 Backup argument for the aspect "p" in the antecedent XML file.

    

because the tags, attribute, argument content, and adolescent aspect are all replaced by the

    

text defined in the arrangement statement.

    

"replacement_content" in the "template" aspect contains a admixture of:

    

    
• #PCDATA: Argument cord with entities.


    
• Non-XSL elements: Approved XML elements.


    
• XSL elements: XSL elements that aftermath achievement text, or allegorical added
  
      

  transformation rules.



    

Example:

    

 

    
<xsl:template match="p">

    
 Backup argument for the aspect "p" in the antecedent XML file.

    
</xsl:template>

    

If this arrangement is acclimated on a "p" aspect in the XML antecedent file, that aspect will be

    

replaced absolutely by the argument defined in the template.

    

Example:

    

 

    
<xsl:template match="p">

    
 Backup argument with <b>one XML element</b> for the aspect "p" 

    
 in the antecedent XML file.

    
</xsl:template>

    

This archetype is the aforementioned as the archetype 1, except that we accept a non XSL aspect in

    

the backup text. No big deal. That non XSL aspect will be allotment of the aftereffect

    

file produced by the transformation. However, back XSL book is aswell an XML file,

    

the backup argument haveto chase XML rules. For example, the afterward template

    

statement create agitation for the transformation process:

    

 

    
<xsl:template match="p">

    
 Backup argument with <b>one XML element</B> for the aspect "p" 

    
 in the antecedent XML file.

    
</xsl:template>

    

Why? The catastrophe tag </B> doesn t bout the starting tag <b>.