Xsl Apply Templates Definition

This means: “Select all child elements and apply the templates that match them.” For example, if there is a meh child tag and there is a template for an element that matches meh (or a more general match), it will apply that template to that child element. The apply-templates does not select the template, but only tells the engine that the templates should be applied to the selection (in the select attribute) and that the engine should find the appropriate templates for them. The current node and the list of current nodes remain the same throughout the contents of a given pattern rule, with one important exception. XSLT`s other mechanism for iterating through a list of nodes, the xsl:for-each statement, also modifies the current node and the list of current nodes. Like xsl:apply-templates, xsl:for-each iterates over a specific set of nodes in the order of the document (default). But instead of sending the behavior of each node to a template rule, the contents of the xsl:for-each element itself are instantiated (the same content for each node in the list). There are only two possible ways to select a template rule for a node. If the node matches the pattern defined by the match attribute of an xsl:template element, that template is applied. If multiple such matches occur, the model with the highest priority is applied.

Or, if the priorities are equal, the last model found with that priority is applied. If there are no patterns or a match is not found, the XSLT processor enforces a built-in pattern rule. The xsl:apply-templates element can contain only the xsl:sort or xsl:with-param elements. By default, nodes are assigned templates in the order in which they appear. However, if there is one or more xsl:sort statements, the nodes are sorted before the templates are assigned. The actual association of a model with a specific single node is independent of the sort order. The xsl:with-pram element defines the parameters applied to template rules. It is not a self-closing element. The separate fence element is mandatory. The template rule we saw in Example 1 contained an xsl:apply-templates element. There are two things to note about this.

First, its presence illustrates the recursive nature of XSLT processing. From the first virtual call to , recursion continues as long as the xsl:apply-templates statement appears in an instantiated template rule and receives a non-empty list of nodes to process. This process continues until the nodes no longer need to be processed. At this point, the entire result tree has been created. signals the XSLT processor to find the appropriate template to apply based on the type and context of each selected node. XSLT defines a built-in pattern rule for each of the seven node types. This ensures that any call to xsl:apply-templates never finds a matching template rule for the current node, even if your style sheet contains no explicit template rule (an empty style sheet). We will detail the built-in template rules in the built-in template rules section later in this chapter. There are two mechanisms for iterating through a list of nodes: xsl:apply-templates and xsl:for-each.

xsl:apply-templates is an XSLT statement that iterates over a specific set of nodes. It calls the most suitable model rule for each node in the node group. For example, here is a statement that iterates over all nodes returned by the expression foo: For header elements, generates h1 elements and generates li elements. The above syntax has three attributes, namely mode, name, and priority. The name attribute calls functions, mode neglects candidate templates, and priority defines specialty or preferences. If there is no template that matches an element, XSLT has built-in rules that basically say, “Apply the templates to all child elements as well, and if there are text nodes, copy them into the output.” Since the elements of RunInfo do not have a corresponding template in this case, XSLT simply copies the text they contain into the output. This statement applies templates to child nodes of the current node. In other words, it populates the current list of nodes with the set of nodes returned by the node() expression and iterates them in the order of the document, calling the most suitable pattern rule for each node. Forgive me, I just learned XSL and have a hard time understanding the app templates.

As I understand it. apply-templates determines that the nodes match the selection. and check the current XSL document to see if a template is defined for the specified selection nodes. Then apply the style to these nodes. The element selects a group of nodes in the input tree and instructs the processor to apply the correct templates to them. As I understand it, xsl:apply-templates select=”$runinfos” searches for the XSL document and finds the template defined for it. It is as follows. For each node in the select statement, the processor calls the correct pattern rule.