| /* |
| * $Id$ |
| * |
| * Copyright 2006 The Apache Software Foundation. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.struts2.components; |
| |
| import java.io.Writer; |
| import java.util.Iterator; |
| |
| import org.apache.struts2.util.MakeIterator; |
| import org.apache.struts2.views.jsp.IteratorStatus; |
| |
| import com.opensymphony.xwork2.util.OgnlValueStack; |
| |
| /** |
| * <!-- START SNIPPET: javadoc --> |
| * |
| * <p>Iterator will iterate over a value. An iterable value can be either of: java.util.Collection, java.util.Iterator, |
| * java.util.Enumeration, java.util.Map, array.</p> <p/> <!-- END SNIPPET: javadoc --> |
| * |
| * <!-- START SNIPPET: params --> |
| * |
| * <ul> |
| * |
| * <li>status (String) - if specified, an instanceof IteratorStatus will be pushed into stack upon each iteration</li> |
| * |
| * <li>value (Object) - the source to iterate over, must be iteratable, else an the object itself will be put into a |
| * newly created List (see MakeIterator#convert(Object)</li> |
| * |
| * <li>id (String) - if specified the current iteration object will be place with this id in Struts stack's context |
| * scope</li> |
| * |
| * </ul> |
| * |
| * <!-- END SNIPPET: params --> |
| * |
| * <!-- START SNIPPET: example1description --> |
| * |
| * <p>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.</p> |
| * |
| * <!-- END SNIPPET: example1description --> |
| * |
| * <pre> |
| * <!-- START SNIPPET: example1code --> |
| * <s:iterator value="days"> |
| * <p>day is: <s:property/></p> |
| * </s:iterator> |
| * <!-- END SNIPPET: example1code --> |
| * </pre> |
| * |
| * |
| * <!-- START SNIPPET: example2description --> |
| * |
| * <p>The following example uses a {@link 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 a {@link IteratorStatus} object, which in this example, its odd() method is used to alternate row |
| * colours:</p> |
| * |
| * <!-- END SNIPPET: example2description --> |
| * |
| * |
| * <pre> |
| * <!-- START SNIPPET: example2code --> |
| * |
| * <s:bean name="org.apache.struts2.example.IteratorExample" id="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> |
| * |
| * <!-- END SNIPPET: example2code --> |
| * </pre> |
| * |
| * <!--START SNIPPET: example3description --> |
| * |
| * <p> 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 seperate the users using a comma: </p> |
| * |
| * <!-- END SNIPPET: example3description --> |
| * |
| * <pre> |
| * <!-- START SNIPPET: example3code --> |
| * |
| * <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> |
| * |
| * <!-- END SNIPPET: example3code --> |
| * </pre> |
| * <p> |
| * |
| * <!-- START SNIPPET: example4description --> |
| * |
| * </p> The next example iterates over a an action collection and passes every iterator value to another action. The |
| * trick here lies in the use of the '[0]' operator. It takes the current iterator value and passes it on to the edit |
| * action. Using the '[0]' operator has the same effect as using >s:property />. (The latter, however, does not |
| * work from inside the param tag). </p> |
| * |
| * <!-- END SNIPPET: example4description --> |
| * |
| * <pre> |
| * <!-- START SNIPPET: example4code --> |
| * |
| * <s:action name="entries" id="entries"/> |
| * <s:iterator value="#entries.entries" > |
| * <s:property value="name" /> |
| * <s:property /> |
| * <s:push value="..."> |
| * <s:action name="edit" id="edit" > |
| * <s:param name="entry" value="[0]" /> |
| * </s:action> |
| * </push> |
| * </s:iterator> |
| * |
| * <!-- END SNIPPET: example4code --> |
| * </pre> |
| * |
| * <!-- START SNIPPET: example5description --> |
| * |
| * </p>To simulate a simple loop with iterator tag, the following could be done. |
| * It does the loop 5 times. |
| * |
| * <!-- END SNIPPET: example5description --> |
| * |
| * <pre> |
| * <!-- START SNIPPET: example5code --> |
| * |
| * <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 (0, 1, ... 5) --> |
| * <s:property value="top" /> |
| * </s:iterator> |
| * |
| * <!-- END SNIPPET: example5code --> |
| * </pre> |
| * |
| * @s.tag name="iterator" tld-body-content="JSP" tld-tag-class="org.apache.struts2.views.jsp.IteratorTag" |
| * description="Iterate over a iterable value" |
| */ |
| public class IteratorComponent extends Component { |
| protected Iterator iterator; |
| protected IteratorStatus status; |
| protected Object oldStatus; |
| protected IteratorStatus.StatusState statusState; |
| protected String statusAttr; |
| protected String value; |
| |
| public IteratorComponent(OgnlValueStack stack) { |
| super(stack); |
| } |
| |
| public boolean start(Writer writer) { |
| //Create an iterator status if the status attribute was set. |
| if (statusAttr != null) { |
| statusState = new IteratorStatus.StatusState(); |
| status = new IteratorStatus(statusState); |
| } |
| |
| OgnlValueStack stack = getStack(); |
| |
| if (value == null) { |
| value = "top"; |
| } |
| iterator = MakeIterator.convert(findValue(value)); |
| |
| // get the first |
| if ((iterator != null) && iterator.hasNext()) { |
| Object currentValue = iterator.next(); |
| stack.push(currentValue); |
| |
| String id = getId(); |
| |
| if ((id != null) && (currentValue != null)) { |
| //pageContext.setAttribute(id, currentValue); |
| //pageContext.setAttribute(id, currentValue, PageContext.REQUEST_SCOPE); |
| stack.getContext().put(id, currentValue); |
| } |
| |
| // Status object |
| if (statusAttr != null) { |
| statusState.setLast(!iterator.hasNext()); |
| oldStatus = stack.getContext().get(statusAttr); |
| stack.getContext().put(statusAttr, status); |
| } |
| |
| return true; |
| } else { |
| super.end(writer, ""); |
| return false; |
| } |
| } |
| |
| public boolean end(Writer writer, String body) { |
| OgnlValueStack stack = getStack(); |
| if (iterator != null) { |
| stack.pop(); |
| } |
| |
| if (iterator!=null && iterator.hasNext()) { |
| Object currentValue = iterator.next(); |
| stack.push(currentValue); |
| |
| String id = getId(); |
| |
| if ((id != null) && (currentValue != null)) { |
| //pageContext.setAttribute(id, currentValue); |
| //pageContext.setAttribute(id, currentValue, PageContext.REQUEST_SCOPE); |
| stack.getContext().put(id, currentValue); |
| } |
| |
| // Update status |
| if (status != null) { |
| statusState.next(); // Increase counter |
| statusState.setLast(!iterator.hasNext()); |
| } |
| |
| return true; |
| } else { |
| // Reset status object in case someone else uses the same name in another iterator tag instance |
| if (status != null) { |
| if (oldStatus == null) { |
| stack.getContext().put(statusAttr, null); |
| } else { |
| stack.getContext().put(statusAttr, oldStatus); |
| } |
| } |
| super.end(writer, ""); |
| return false; |
| } |
| } |
| |
| /** |
| * if specified, an instanceof IteratorStatus will be pushed into stack upon each iteration |
| * @s.tagattribute required="false" type="Boolean" default="false" |
| */ |
| public void setStatus(String status) { |
| this.statusAttr = status; |
| } |
| |
| /** |
| * the iteratable source to iterate over, else an the object itself will be put into a newly created List |
| * @s.tagattribute required="false" |
| */ |
| public void setValue(String value) { |
| this.value = value; |
| } |
| |
| } |
