get element by class

[Agrajag]

how can i use a function to get elements by their className?

thanks

[jscheuer1]

Here's one from the Switch Content II script in the DD Library:

function getElementbyClass(rootobj, classname){
var temparray=new Array()
var inc=0
var rootlength=rootobj.length
for (i=0; i<rootlength; i++){
if (rootobj[i].className==classname)
temparray[inc++]=rootobj[i]
}
return temparray
}

You call it with the two parameters, the first param is the root object that the elements with your desired class designation are contained in, the second param is the class name you are looking for. It returns an array containing all children of the root object with that class name.

[Twey]

I've always used this one.

[Agrajag]

thanks twey, that is excellent!

Agrajag

[mwinter]

Originally Posted by Twey

I've always used this one.

Any code that declares itself to be 'the ultimate' requires reviewing. It's fine, though as commented by other reviewers, escaping hyphens is totally unnecessary.

The Array.prototype.push method substitute is bogus, though.

Mike

[Twey]

The IE5-support one?
Does IE5 already have one? Perhaps

if(!Array.push) Array.prototype.push = function(val) {
      this[this.length] = value;
  }

would be better anyway.

Any code that declares itself to be 'the ultimate' requires reviewing.

Heh, yes. I did have a check through it before using it, though.

[mwinter]

Originally Posted by Twey

The IE5-support one?
Does IE5 already have one?

No, the reason for it is valid: prior to JScript 5.5, there was no push method implemention (though it was specified and implemented elsewhere). The suggested implementation is just bad. I added a comment (twice; it barfed on <, unlike here in DDF).

Mike

[Twey]

Originally Posted by Mike@robertnyman.com

if (typeof Array.prototype.push != 'function') {
  Array.prototype.push = function(v) {
    var i = this.length >>> 0,
        j = 0;

    while(j < arguments.length) {this[i++] = arguments[j++];}
    return this.length = i;
  };
}

Only one minor, pedantic qualm: you've defined v but never used it I seem to remember you doing something like this before, also with a argument named "v," as I recall.

[mwinter]

Originally Posted by Twey

Only one minor, pedantic qualm: you've defined v but never used it

Intentional. The Array.prototype.push method is defined as having a length property value of 1. For user-defined functions, the only way to affect the length property is via the formal argument list; the property itself is read only.

Mike

[Twey]

Aha, I see.
Qualm dismissed.