为什么要显式地将process ="@ this"添加到p:commandButton来调用操作？

Question

我知道我们需要显式添加process="@this"以获取p:commandbutton调用的操作,并且我也知道process属性默认为@formprimefaces.

由于进程是默认的,@form因此按钮也不会与表单中的其他元素一起处理,并且应该调用其操作.

任何人都可以解释这背后的确切原因吗？

Answer 1

过程@form的意思是当前形式commandLink/Button
过程@this意味着的电流分量commandLink/Button.检查以下代码.

process.xhtml

<h:form id="form1">
    <h:inputText value="#{ProcessBean.id}" id="id"/><br/>
    <h:panelGroup id="panel_1">
        <h:inputText value="#{ProcessBean.name}" id="name"/><br/>
    </h:panelGroup>
    <h:panelGroup id="panel_2">
        <h:inputText value="#{ProcessBean.address}"/>
        <br/>
        <p:commandButton process="@form" value="Btm1" id="button1" action="#{ProcessBean.show}"/><!-- Default -->
        <p:commandButton process="@this" value="Btm2" id="button2" action="#{ProcessBean.show}"/>
        <p:commandButton process="@this form1:panel_1" value="Btm3" id="button3" action="#{ProcessBean.show}"/>
    </h:panelGroup>
</h:form>  

ProcessBean.java

@ManagedBean(name = "ProcessBean")
public class ProcessBean {
    private String id;
    private String name;
    private String address;
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }

    public void show() {
        System.out.println(id);
        System.out.println(name);
        System.out.println(address);
    }
}

让我们的用户输入输入框

001     -> id
Jone    -> name
London  -> address

单击button1,JSF component(Eg : id, name, address)整个表单将被处理.输出将是:

001
Jone
London

单击button2,该过程将是其自身(例如:button2).没有流程id, name, address.输出将是:

null
null
null

点击button3,JSF component(Eg : name) 整个过程panel_1,button3并将进行处理.输出将是:

null
Jone
null

不调用你的动作方法？调用之前可能存在验证或转换失败.