Page History

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• To review basic concepts, refer to OGNL Basics
• #Collections
• Lambda Expressions

Collections (Maps, Lists, Sets)

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Dealing with collections(maps, lists, and sets) in webwork comes often, so here are a few examples using the select tag:
Syntax for list: {e1,e2}. This creates a List containing the String "name1" and "name2".

Code Block
xml xml
<webwork:select label="'lebal'" name="'nmae'" list="{'name1','name2'}" />

Syntax for map: #{key1:value1,key2:value2}. This creates a map that maps the string "foo" to the string "foovalue" and "bar" to the string "barvalue":

Code Block
xml xml
<webwork:select label="'lebal'" name="'nmae'" list="#{'foo':'foovalue', 'bar':'barvalue'}" />

You may need to determine if an element exists in a collection. You can accomplish this with the operations in and not in

Code Block
xml xml
<ui:if test="'foo' in {'foo','bar'}"> muhahaha </ui:if> <ui:else> boo </ui:else> <ui:if test="'foo' not in {'foo','bar'}"> muhahaha </ui:if> <ui:else> boo </ui:else>

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To obtain a subset of just male relatives from the object person:

Code Block
xml xml
person.relatives.{? #this.gender == 'male'}

Lambda Expressions

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OGNL supports basic lamba expression syntax enabling you to write simple functions.

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The lambda expression is everything inside the brackets. The #this variable holds the argument to the expression, which is initially starts at 11.

Code Block
xml xml
<ww:property value="#fib =:[#this==0 ? 0 : #this==1 ? 1 : #fib(#this-2)+#fib(#this-1)], #fib(11)" />