h:commandButton即使在将disabled更改为true并使用a4j:commandButton重新呈现它之

Question

我有一个带有inputtext的页面，我在其中键入要搜索的作者的名称，当我单击a4j:commandButton searchButton时，我想启用h:commandButton GoToBUtton，如果搜索没有返回作者并且禁用该按钮，如果搜索返回作者。首先，GoToButton应该被禁用，这是默认行为。

问题是，goToButton总是被禁用，它永远不会改变。怎么了?

<h:form>
 <div align="left">
<rich:panel id="panel" style="width:310px">
           <h:panelGrid columns="3">
              Nome do autor: <h:inputText id="nameInput" 
              value="#{insertAuthControllerPt1.nameToSearch}"/>
                <a4j:commandButton id="searchButton" value="Procurar" 
           action="#{insertAuthControllerPt1.searchAuthor()}"
            render="authorTable, goToButton">              
           </a4j:commandButton>
           </h:panelGrid>  
       </rich:panel> 

   <h:panelGrid id="authorTable">
       <rich:dataTable value="#{insertAuthControllerPt1.authorListOfMap}"  var="result">
            <c:forEach items="#{insertAuthControllerPt1.variableNames}" var="vname">
                 <rich:column>
                     <f:facet name="header">#{vname}</f:facet>
                      #{result[vname]}
                 </rich:column> 
            </c:forEach>    
       </rich:dataTable>
       <br /> 
   </h:panelGrid>

<h:commandButton id="goToButton" value="Go" action="InsertAuthorPt2" 
           disabled="#{insertAuthControllerPt1.disabled}">
             <f:setPropertyActionListener target="#{insertAuthorController.flag}"
                         value="true" />      
           </h:commandButton>
 </div>
</h:form>

insertauthcontrollert1 .java的搜索方法

public class InsertAuthorControllerPt1 {
    private boolean disabled;
    private String nameToSearch;
    private List<String> variableNames;
    private List<Map<String, String>> authorListOfMap;
    private String flag;
    private Map<String, Object> sessionMap;
    private List<Author> authors; 
    public InsertAuthorControllerPt1() {
        this.authorListOfMap = new ArrayList<Map<String, String>>();
        this.variableNames = new ArrayList<String>();
        this.sessionMap = new HashMap<String, Object>();
        this.authors = new ArrayList<Author>();
        this.disabled = true;
    }
    public void searchAuthor() {
            this.variableNames.clear();
            this.authorListOfMap.clear();
           if( this.nameToSearch.equals("") ) {
                this.disabled = true;
           } else {
             try {
                this.findAuthorByNameOperation(this.sessionMap, this.flag, this.nameToSearch);
            }catch(NullPointerException n) {
                this.disabled = false;
                }catch (Exception e) {
                e.printStackTrace();
            } 
                if( (authors != null) && (!authors.isEmpty()) ) {
                    this.disabled = true;
                    for( Author author : authors ) {
                        Map<String, String> map = new HashMap<String, String>();
                        map.put("URI", author.getUri().toString());
                        map.put("Nome", author.getName());
                        map.put("Email", author.getEmail());
                        this.authorListOfMap.add(map);  
                    }
              this.addVariableNames();
            }
}

Answer 1

首先，非常不鼓励混合使用JSTL标记和Facelets标记(参见:JSTL在JSF2 Facelets中…有意义吗?)

那么您将使用f:ajax标记。在动作执行后，您将基本上使用ajax调用来呈现goToButton

<h:commandButton id="searchButton" value="Search" action="#{insertAuthControllerPt1.searchAuthor()}">
    <f:ajax render="goToButton">
</h:commandButton>

不要错过在JSF中使用AJAX:

Java教程:发送Ajax请求Max Katz:学习JSF2: Ajax在JSF -使用f:ajax标签
• Lincoln Baxter:渲染表单外的组件

Answer 2

将h:commandButton更改为a4j:commandButton并添加render属性:

<a4j:commandButton id="searchButton" value="Search" 
    action="#{insertAuthControllerPt1.searchAuthor()}"
    render="goToButton" />