f：ajax根据onevent返回值限制侦听器方法调用

Question

How do i check for Onevent javascript function whether it returns true or False ? Because basically what iam trying to do is to restrict the listener method call based on the Javascript return value .

The following code returns syntax error in Firebug .

 <f:ajax event="keyup" render="@form" onevent="return validatePageNumber(event);" listener="#{bean.listenerMethod}"/>

So How can i determine return value and based onthat the lister method should fire .Thanks in advance :)

Answer 1

The onevent attribute must specify a JS function reference name, not a whole JS script. The proper usage of the onevent attribute is

<f:ajax ... onevent="functionName" />

(yes, without parentheses!)

with

function functionName(data) {
    alert(data.status); // Will show 3 times.
}

However, it's clearly the wrong tool for the purpose you had in mind. The onevent should merely reference a listener function which would be invoked 3 times: one before the ajax request is sent, one after the ajax response is arrived, one after the HTML DOM is updated based on ajax response. For proper real world usage examples, see among others Proccess onclick function after ajax call <f:ajax> and Disable/enable commandbutton on ajax event .

Just use the parent component's onXXX attribute instead (where XXX is exactly that <f:ajax event> you'd like to hook on). Eg asusming that it's an <h:inputText> :

<h:inputText ... onkeyup="return validatePageNumber(event)">
     <f:ajax event="keyup" render="@form" />
</h:inputText>