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generator

Please make sure you have read the Tag Syntax document and understand how tag attribute syntax works.

Description

Generate an iterator based on the val attribute supplied.

NOTE: The generated iterator will ALWAYS be pushed into the top of the stack, and poped at the end of the tag.

Generate an iterator for a iterable source.

Attributes

Dynamic Attributes Allowed:

false
 

Name

Required

Default

Evaluated

Type

Description

converter false false org.apache.struts2.util.IteratorGenerator.Converter The converter to convert the String entry parsed from val into an object
count false false Integer The max number entries to be in the iterator
performClearTagStateForTagPoolingServers false false false Boolean Whether to clear all tag state during doEndTag() processing
separator true false String The separator to be used in separating the val into entries of the iterator
val true false String The source to be parsed into an iterator
var false false String The name to store the resultant iterator into page context, if such name is supplied

Examples

Example 1: generate a simple iterator

<s:generator val="%{'aaa,bbb,ccc,ddd,eee'}">
 <s:iterator>
     <s:property /><br/>
 </s:iterator>
</s:generator>

This generates an iterator and print it out using the iterator tag.

Example 2: generate an iterator with count attribute

<s:generator val="%{'aaa,bbb,ccc,ddd,eee'}" count="3">
 <s:iterator>
     <s:property /><br/>
 </s:iterator>
</s:generator>

This generates an iterator, but only 3 entries will be available in the iterator generated, namely aaa, bbb and ccc respectively because count attribute is set to 3.

Example 3: generate an iterator with var attribute

<s:generator val="%{'aaa,bbb,ccc,ddd,eee'}" count="4" separator="," var="myAtt" />
<%
 Iterator i = (Iterator) pageContext.getAttribute("myAtt");
 while(i.hasNext()) {
     String s = (String) i.next(); %>
     <%=s%> <br/>
<%    }
%>

This generates an iterator and put it in the PageContext under the key as specified by the var attribute.

Example 4: generate an iterator with comparator attribute

<s:generator val="%{'aaa,bbb,ccc,ddd,eee'}" converter="%{myConverter}">
 <s:iterator>
     <s:property /><br/>
 </s:iterator>
</s:generator>
public class GeneratorTagAction extends ActionSupport {

  ....

  public Converter getMyConverter() {
     return new Converter() {
         public Object convert(String value) throws Exception {
             return "converter-"+value;
         }
     };
  }

  ...

}

This will generate an iterator with each entries decided by the converter supplied. With this converter, it simply add “converter-“ to each entries.