Applied XML Programming for Microsoft .NET.pdf - Csbdu.in

Table 7-3: XSLT Instructions for Control FlowInstruction ……DescriptionApplies the internal template only ifthe specified XPath expressionevaluates to true.Similar to the C# switch statement;represents a multiple-choicestatement. Each test is expressedusing an statement,while the elementrepresents the default choice. Thestatement evaluates all the blocks until the testexpression returns true. When thathappens, the correspondingtemplate is applied. If no test issuccessful, the template is invoked.Although this list of commands lacks a for statement, you can still realize a loop thatruns a specified number of times by using the XPath position function. Of course,position returns the index of the current context node and is not a general variablecounter. On the other hand, XSLT instructions are designed to work on XPath nodesets,not to arrange general-purpose programs.Layout InstructionsA typical task for an XSLT script is the creation of new elements and attributes.Sometimes attributes and node elements can be hard-coded in script; sometimes this isjust impossible to do. The XSLT statements listed in Table 7-4 let you programmaticallycreate layout elements.Table 7-4: XSLT Instructions for LayoutInstructionDescriptionCreates an element with thespecified name. The namespaceattribute indicates the URI of thecreated element, if any. The element contains atemplate for the attributes andchildren of the created element.Creates an attribute node andattaches it to an output element.The name attribute denotes thename of the attribute, andnamespace indicates thenamespace URI, if any. Thecontents of this element specify thevalue of the attribute. Note that can also be useddirectly on output elements, notonly in conjunction with.243