result EXSLT func result public domain 3 Jeni Tennison 2001-03-31
  • Added static constraint such that func:result cannot have any following sibling elements aside from xsl:fallback.
  • Made the instantiation of more than one func:result element an unrecoverable error.
  • Changed the result of a calling a function where no func:result element is instantiated to be an empty string rather than an empty result tree fragment.
 3.1 Jeni Tennison 2001-04-28 Added static constraint that forces func:result to be a descendant of func:function. 3.2 Jeni Tennison 2001-05-22
  • Added vendor implementations in Saxon and 4XSLT
  • Changed status to stable
 3.3 Jeni Tennison 2001-08-15 Added vendor implementation in libxslt. 3.4 Craig Stewart 2002-08-20 Added Xalan-J implementation to the list. 3.5 Craig Stewart 2002-11-12 Updated 4XSLT version to 0.12.0a3.

When an func:result element is instantiated, during the instantiation of a func:function element, the function returns with its value. The value of the func:result element is determined in a similar way to variable-binding elements as described in [11.2 Values of Variables and Parameters] of [XSLT].

It is an error for a func:result element to not be a descendant of func:function. It is an error for a func:result element to have any following sibling elements aside from the xsl:fallback element.

It is an error if instantiating the content of the func:function element results in the instantion of more than one func:result elements.

Thus the following is an error if the value of the context node when the function is called is equal to the string 'yes', as two func:result elements are instantiated: one within the xsl:if and one directly within the func:function: 

<func:function name="my:func1">
   <xsl:if test=". = 'yes'">
      <func:result select="true()" />
   </xsl:if>
   <func:result select="false()" />
</func:function>

It is an error if a func:result element occurs within an func:result element. Thus the following is an error: 

<func:function name="my:func2">
   <func:result>
      <func:result select="." />
   </func:result>
</func:function>

It is an error if instantiating the content of a variable-binding element (i.e. xsl:variable, xsl:param) results in the instantiation of an func:result element. Thus the following is an error: 

<func:function name="my:func3">
   <xsl:variable name="foo">
      <func:result select="." />
   </xsl:variable>
</func:function>

Return Values

The func:result element can specify the value of the variable in three alternative ways.

  • If the func:result element has a select attribute, then the value of the attribute must be an expression and the returned value is the object that results from evaluating the expression. In this case, the content must be empty.

  • If the func:result element does not have a select attribute and has non-empty content (i.e. the func:result element has one or more child nodes), then the content of the func:result element specifies the value. The content of the func:result element is a template, which is instantiated to give the returned value. The value is a result tree fragment equivalent to a node-set containing just a single root node having as children the sequence of nodes produced by instantiating the template. The base URI of the nodes in the result tree fragment is the base URI of the func:result element.

    It is an error if a member of the sequence of nodes created by instantiating the template is an attribute node or a namespace node, since a root node cannot have an attribute node or a namespace node as a child. An XSLT processor may signal the error; if it does not signal the error, it must recover by not adding the attribute node or namespace node.

  • If the func:result element has empty content and does not have a select attribute, then the returned value is an empty string. Thus 

    <func:result />

    is equivalent to 

    <func:result select="''"/>