THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
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Performing the equivalent of a "switch" statement in your component template using blocks and a delegate |
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With Tapestry's If component you can only test one condition at a time. In order to distinguish multiple cases, you'd have to write complex nested if/else constructs in your page template and have a checker method for each test inside your page class.
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*JumpStart Demo:*
[If, Not, Negate, Switch, Else, Unless|http://jumpstart.doublenegative.com.au/jumpstart/examples/lang/ifnotnegateswitchelseunless]
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In cases where you have to distinguish multiple cases, the Delegate component comes in. It delegates rendering to some other component, for example a Block. For each case you have, you basically wrap the content inside a Block that doesn't get rendered by default. You then place a Delegate component on your page and point it to a method inside your page class that will decide which of your Blocks should be rendered.
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<html xmlns:t="http://tapestry.apache.org/schema/tapestry_5_1_04.xsd"> <body> <h1>Switch</h1> <t:delegate to="case"/> <t:block t:id="case1"> Here is the content for case1. </t:block> <t:block t:id="case2"> Here is the content for case2. </t:block> <t:block t:id="case3"> Here is the content for case3. </t:block> <t:block t:id="case4"> Here is the content for case4. </t:block> </body> </html> |
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