Apache Struts 2 Documentation > Home > Guides > Tag Developers Guide > Struts Tags > Tag Reference > Generic Tag Reference > iterator |
![]() | Please make sure you have read the Tag Syntax document and understand how tag attribute syntax works. |
![]() | The id attribute is deprecated in Struts 2.1.x, and has been replaced by the var attribute. |
Iterator will iterate over a value. An iterable value can be any of: java.util.Collection, java.util.Iterator,
Dynamic Attributes Allowed:false |
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Name |
Required |
Default |
Evaluated |
Type |
Description |
---|---|---|---|---|---|
id | false | false | String | Deprecated. Use 'var' instead | |
status | false | false | false | Boolean | If specified, an instanceof IteratorStatus will be pushed into stack upon each iteration |
value | false | false | String | the iteratable source to iterate over, else an the object itself will be put into a newly created List | |
var | false | false | String | Name used to reference the value pushed into the Value Stack |
The following example retrieves the value of the getDays() method of the current object on the value stack and uses it to iterate over. The <s:property/> tag prints out the current value of the iterator.
<s:iterator value="days"> <p>day is: <s:property/></p> </s:iterator>
The following example uses a Bean tag and places it into the ActionContext. The iterator tag will retrieve that object from the ActionContext and then calls its getDays() method as above. The status attribute is also used to create an IteratorStatus object, which in this example, its odd() method is used to alternate row colours:
<s:bean name="org.apache.struts2.example.IteratorExample" var="it"> <s:param name="day" value="'foo'"/> <s:param name="day" value="'bar'"/> </s:bean> <p/> <table border="0" cellspacing="0" cellpadding="1"> <tr> <th>Days of the week</th> </tr> <p/> <s:iterator value="#it.days" status="rowstatus"> <tr> <s:if test="#rowstatus.odd == true"> <td style="background: grey"><s:property/></td> </s:if> <s:else> <td><s:property/></td> </s:else> </tr> </s:iterator> </table>
The next example will further demonstrate the use of the status attribute, using a DAO obtained from the action class through OGNL, iterating over groups and their users (in a security context). The last() method indicates if the current object is the last available in the iteration, and if not, we need to separate the users using a comma:
<s:iterator value="groupDao.groups" status="groupStatus"> <tr class="<s:if test="#groupStatus.odd == true ">odd</s:if><s:else>even</s:else>"> <td><s:property value="name" /></td> <td><s:property value="description" /></td> <td> <s:iterator value="users" status="userStatus"> <s:property value="fullName" /><s:if test="!#userStatus.last">,</s:if> </s:iterator> </td> </tr> </s:iterator>
<s:action name="entries" var="entries"/> <s:iterator value="#entries.entries" > <s:property value="name" /> <s:property /> <s:push value="..."> <s:action name="edit" var="edit" > <s:param name="entry" value="[0]" /> </s:action> </push> </s:iterator>
<s:iterator status="stat" value="{1,2,3,4,5}" > <!-- grab the index (start with 0 ... ) --> <s:property value="#stat.index" /> <!-- grab the top of the stack which should be the --> <!-- current iteration value (1, ... 5) --> <s:property value="top" /> </s:iterator>
<s:iterator status="stat" value="(5).{ #this }" > <s:property value="#stat.count" /> <!-- Note that "count" is 1-based, "index" is 0-based. --> </s:iterator>