javascript如何防止输入字段中出现多个点

Question

I'm trying to develop functionality for input generated by jsf. I already have javascript code that uses the onkeypressed to prevent putting non-numeric values by user:

function validateNumberKey(event){
    return  (45<event.charCode && event.charCode<58 && event.shiftKey==false && DotTracker().prototype.wasPressed())
    || (event.keyCode==8) || (event.keyCode==9) 
}

the code that findsout if user pressed dot is here:

function DotTracker() {
    var dotPressed = false;
    this.wasPressed = function() {
        var currentDot = dotPressed;
        dotPressed = true;
        return currentDot; 
    };

}

And simplified input reference:

<input type="text" id="inpurCP" onfocus="new DotTracker()" onkeypressed="validateNumberKey(event)"/>

I'm pretty sure that something goes wrong with calling wasPressed() method. But I'm not quite familiar with javascript though...

Answer 1

Ok I solve the problem. Instead of using DotTracker() . I created another function:

function wasDotPressed(event) {
    var index = -1;
    if(event.charCode == 46) {
        var currentValue = event.currentTarget.value;
        index = currentValue.indexOf('.');
    }   
    return index == -1;
}

and add the relevant line of code to the validateNumberKey(event) :

function validateNumberKey(event){
    return  (45<event.charCode && event.charCode<58 && event.shiftKey==false && wasDotPressed(event))
    || (event.keyCode==8) || (event.keyCode==9) 
}

And finally it works :). Hope that it help anyone that is struggling such problem.