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how to extend document.getElementsBy*() in Firefox

Dormilich
8,652 Expert Mod 8TB
I want to add (prototype) a method to the node list returned by document.getElementsByName() (and related, i.e. NodeList resp. HTMLCollection).

unfortunately, neither the NodeList nor the HTMLCollection interface seem to be prototypable in Firefox. (NodeList works in Safari & Opera, don't know about IE)

has anyone of you an idea how to solve this?

note: this matter has already been discussed, though I didn't find any solution to this problem. (beside prototyping into Object interface).
Jun 16 '09 #1
11 4014
acoder
16,027 Expert Mod 8TB
I don't think this is possible. Either create a function which does the job or create your own object with the nodelist and then extend that instead.
Jun 16 '09 #2
Dormilich
8,652 Expert Mod 8TB
you mean substituting document.getElementsBy*() with my own function (kind of)?
Jun 16 '09 #3
gits
5,390 Expert Mod 4TB
may be you could live with something like that:

Expand|Select|Wrap|Line Numbers
  1. document.baseGetElementsByTagName = document.getElementsByTagName;
  2.  
  3. document.getElementsByTagName = function(n) {
  4.     top.console.log(this.baseGetElementsByTagName(n));
  5. }
  6.  
  7. document.getElementsByTagName('div');
kind regards
Jun 16 '09 #4
acoder
16,027 Expert Mod 8TB
@Dormilich
Not necessarily. You could have a function which does whatever you want to do with the node-list and pass it the result of document.getElementsBy*(). If that's not to your liking, create your own object and pass it the node-list and extend to your heart's content.
Jun 16 '09 #5
Dormilich
8,652 Expert Mod 8TB
@gits: that won't do, since I don't want to do that for every method that's returning a HTMLCollection.

@acoder: passing the NodeList as argument seems indeed the best way.

maybe I'll do both in a try-catch block…
Jun 17 '09 #6
gits
5,390 Expert Mod 4TB
hmmm ... what about that simple loop for that task? :) (FF + Firebug to test in console)

Expand|Select|Wrap|Line Numbers
  1. function extendMethod(fn) {
  2.     top.console.log(fn);
  3.  
  4.     document['base' + fn] = document[fn];
  5.  
  6.     document[fn] = function(n) {
  7.         nodeList = this['base' + fn](n);
  8.         nodeList = doSomethingWithNodeList(nodeList);
  9.  
  10.         return nodeList;
  11.     };
  12. }
  13.  
  14. for (var i in document) {
  15.     if (/getElements/.test(i)) {
  16.         extendMethod(i);
  17.     }
  18. }
  19.  
  20. function doSomethingWithNodeList(nl) {
  21.     top.console.log(nl);
  22. }
  23.  
  24. document.getElementsByClassName('normal');
  25.  
that would always pass the nodelist for all 'getElements'-methods to a function called 'doSomethingWithNodeList' ... before the 'getElements'-method returns

kind regards
Jun 17 '09 #7
Dormilich
8,652 Expert Mod 8TB
I have to bear that in mind, maybe I can use it sometimes…

that's what I want to do:
Expand|Select|Wrap|Line Numbers
  1. document.getElementsByClassName("attachEvent").addEventForEach("click", doSomething, false, some_param);
obviously the initial thought was to extend HTMLCollection or NodeList. but alas, I don't want to call a function (i.e. attach an event) every time I get a HTMLCollection from the document. seems like I have to use a function, where I pass the NodeList…

EDIT: hm, maybe I can do something with prototype's bind() method…
Jun 17 '09 #8
gits
5,390 Expert Mod 4TB
the construct does that exactly? here is just a litle adaption to have it a bit more generic :)

Expand|Select|Wrap|Line Numbers
  1. function extendMethod(fn) {
  2.     top.console.log(fn);
  3.  
  4.     document['base' + fn] = document[fn];
  5.  
  6.     document[fn] = function(n, eachFn) {
  7.         nodeList = this['base' + fn](n);
  8.         nodeList = eachFn(nodeList);
  9.  
  10.         return nodeList;
  11.     };
  12. }
  13.  
  14. for (var i in document) {
  15.     if (/getElements/.test(i)) {
  16.         extendMethod(i);
  17.     }
  18. }
  19.  
  20. document.getElementsByClassName('normal', function(n) {
  21.     for (var i in n) top.console.log(n[i]);
  22. });
  23.  
this expl. code could just simply integrated into any oo framework etc. and now it' s able to get an eachFn param passed to the getElements-method ... that is a function that should be called with every node of the returned nodelist.

kind regards
Jun 18 '09 #9
Dormilich
8,652 Expert Mod 8TB
@gits
in the end it's like calling eachFn(nodeList) inside the getElementsBy*() method. so I just moved the function call from outside to inside… well, for my current problem this rather seems not worth it.

thanks anyway for the insight into method manipulation.
Jun 18 '09 #10
gits
5,390 Expert Mod 4TB
:) nothing to thank for ... i currently think about such things too since you asked that question ... and for our current goal those ideas above might help us sometimes ;) ...

kind regards
Jun 18 '09 #11
Dormilich
8,652 Expert Mod 8TB
found some talk about DOM iteration 1, 2. this could be a useful starting point.
Jun 18 '09 #12

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