Block an action from executing via Javascript Function

Question

I have the following commandLink

<apex:commandLink value="Save" onClick="Validation();" action="{!ActionMethod}" />

When it's clicked, I would like to stop the action from executing by returning false.

function Validation() {
        return false;
}

The above method does not work, but if I put return false directly in the onClick attribute the behaviour works as expected:

<apex:commandLink value="Save" onClick="return false;" action="{!ActionMethod}" />

Is there a way I can pass this return value up to the onClick attr?

Gist Edit

<apex:commandLink value="Save" onclick="return Validation();" action="{!saveSettings}"/>                        


function Validation() {              
  alert('returning false');   
  return false;                    
}


// Alert shows 'returning false', action still executes.

Answer 1

It should be like this:

<apex:commandLink value="Save" onClick="return Validation();" action="{!ActionMethod}" />

Add the return to the onClick. When Validation return false the onClick will then return false thus preventing the action from occurring

Answer 2

It's better to move the validation into the 'form' tag:

<apex:form id="form" onSubmit="return Validation();">

Answer 3

You can make it work like this

<apex:commandLink value="Save" onClick="Validation();"/>

In your javascript

function Validation() 
{
    var isvalidForm = true;
    //Validation code goes here
    if(Form is not valid)
    {
        isvalidForm = false;
    }
    if(isvalidForm)
    {
        Actionfunc();
    }
}

In your visualforce page

<apex:actionFunction name="Actionfunc" action="ActionMethod"/>

Hope this will solve your problem, ActionMethod gets executed only when it returns true. When it returns false ActionMethod will not be callled.