如何使用 javascript 获取 jsf h:outputText 值？
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how to use javascript to get jsf h:outputText value?
提问by Celia
I have a button has action which can set myBackingBean.myString, and onclick event calls js method to alert that value. I just want to get the value of myString from backing bean by using javascript.
我有一个按钮具有可以设置 myBackingBean.myString 的操作，并且 onclick 事件调用 js 方法来提醒该值。我只想通过使用 javascript 从支持 bean 中获取 myString 的值。
I have a hidden output which has value from backing bean:
我有一个隐藏的输出，它具有来自支持 bean 的价值：
h:outputText id="myOutput" rendered="false" value="#{myBackingBean.myString}"
then I need to alert this value in javascript fxn which triggered by a button:
然后我需要在由按钮触发的 javascript fxn 中提醒这个值：
function myFunction() {
var outPut= document.getElementById("myForm:myOutput").value;
...
}
but i got Object requirederror. How can i fix this?
thanks in advance.
但我有Object required错误。我怎样才能解决这个问题？提前致谢。
回答by Floydian
Make you sure that the h:outputText is rendered (rendered="false" could just not add it to the DOM. If it does not render, it can't be accessed. If you need it hidden, use h:inputHidden instead).
确保 h:outputText 已呈现（rendered="false" 无法将其添加到 DOM。如果它不呈现，则无法访问。如果您需要隐藏它，请改用 h:inputHidden） .
Then make sure that it renders an HTML tag as or acting like a container with the id attribute as "myForm:myOutput".
然后确保它将 HTML 标记呈现为或充当具有 id 属性为“myForm:myOutput”的容器。
Also, the .value javascript accesor is used for input tags, so use inerHTML instead.
此外，.value javascript accesor 用于输入标签，因此请改用 inerHTML。
回答by prageeth
You need not always to have a hidden field to access the Bean Property. You can do it as below.
您不必总是有一个隐藏字段来访问 Bean 属性。您可以按照以下方式进行。
<h:commandButton value="Show" onclick="alert('#{myBackingBean.myString}');"/>
But if you want to change the value of 'myString' when you click the button and then you want to display the new value you should use a <a4j:commandButton/>and it's onCompleteattribute as below.
但是，如果您想在单击按钮时更改“ myString”的值，然后想显示新值，则应使用 a<a4j:commandButton/>并且它的onComplete属性如下所示。
<a4j:commandButton value="Change" action="#{myBackingBean.changeString()}" oncomplete="alert('#{myBackingBean.myString}');" />
