primefaces p:ajax返回值 [英] primefaces p:ajax return value

问题描述

我有一个带有primefaces 4.0的JSF 2.2应用程序.我有一个带有一些复选框的页面.我想要完成的是，当我单击一个复选框时，一个ajax请求将被触发到我的托管bean.该请求将命中一个将返回字符串的方法.因此，我不需要更新元素，而是取回js中的字符串，因为如果实现了该目标，则可以返回JSON.
我有这段代码:

I have a JSF 2.2 app with primefaces 4.0. I have a page with some checklboxes. What I want to acomplish is that when I click on one checkbox an ajax request to be fired to my managed bean. That request will hit a method that will return a string. So i do no need to update an element, but to get back the string in js, because if i achieve that then I can return an JSON.
I have this piece of code :

<p:selectManyCheckbox  id="queues" value="#{viewAssignUsersMB.queueIds}" layout="grid" columns="3" converter="javax.faces.Long" converterMessage="Error."> 
<f:selectItems  value="#{viewAssignUsersMB.queues}" 
                var="queue" 
                itemValue="#{queue.id}" 
                itemLabel="#{queue.application.name}"/>
<p:ajax  process="@this" partialSubmit="true" event="change" listener="#{viewAssignUsersMB.xxx()}" async="true" oncomplete="handleSaveRequest(xhr, status, args)"/>

以及支持bean的此方法:

and this method in backing bean :

public void xxx(){  
  RequestContext.getCurrentInstance().addCallbackParam("stringToBePassed","TriluLilu");
}

和我的js回调方法:

function handleSaveRequest(xhr, status, args) { 
    alert('User with username ' +args.stringToBePassed+ ' is saved successfully');
}

现在我的主要问题是我不知道如何检测上次按下的复选框，因为在后备Bean中，我具有所有选中的复选框(#{viewAssignUsersMB.queueIds})...
有没有更好的方法，因为这是一个很常见的场景/实现该目标的经典"方法是什么?

My main problem now is that I do not know how to detect what checkbox was last pressed as in my backing bean I have all the checked checkboxes (#{viewAssignUsersMB.queueIds})...
Is there a better approach for that, as this is a pretty common scenario/ What is the "classic" way to achieve that ... ?

推荐答案

您可以使用remoteCommand来实现.

You can achieve this by using a remoteCommand.

• 首先:在所有复选框输入上钩住onchange事件.
• 第二:在事件函数处理程序中，获取元素值，并将其值传递给remoteCommand.
• 第三:作为请求参数读取支持Bean中的值.

• First: Hook onchange event on all the checkboxes inputs.
• Second: In the event function handler, get the element value, and pass the value to the remoteCommand.
• Third: Read the value in the backing bean, as a request parameter.

xhtml

xhtml

 <p:selectCheckboxMenu id="selectCheckboxMenuId" widgetVar="selectCheckWV">  
    <f:selectItems value="#{mainBean.map}" />                              
 </p:selectCheckboxMenu>  
 <p:remoteCommand name="submitNewCheckBoxValue" 
                  process="@this selectCheckboxMenuId"
                  actionListener="#{mainBean.sendLastCheckedBox()}" />

javascript

javascript

<script>
   $(document).ready(function() {
      PF('selectCheckWV').inputs.change(function() {
         if($(this).prop('checked'))
            submitNewCheckBoxValue([{name: 'submitedValue', value: $(this).val()}]);
      });
   });
</script>

managedBean

managedBean

public void sendLastCheckedBox() {
    FacesContext facesContext = FacesContext.getCurrentInstance();
    Map map = facesContext.getExternalContext().getRequestParameterMap();
    String submitedValue = (String) map.get("submitedValue");
    FacesMessage facesMessage = new FacesMessage(submitedValue);
    facesContext.addMessage(null, facesMessage);
}

这是一个正常工作的演示，还有一个关于github [1]

Here's a working Demo, and a small example on github [1][2]

希望这会有所帮助.

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