Overriding function in complicated prototype javascript

Question

I'm a bit stuck on a problem which I can't solve, I performed investigation on internet and on this site, but I can't find the answer to my question.

So basically I have a javascript file, which I cannot modify, so I have another javascript file which should catch the method when it is called and override it.

Normally I know how it works and I already done the function overriding, but I don't know how to solve this issue.

I have a very big script, but I will show just a small piece of it:

Microsoft.Office.Server.Ajax.NavResizer.prototype = {
    $6: null,
    $7: null,
......
$20:function ($p0) {
    if (this.$1E) {
        $p0.preventDefault();
    } 
},
$21: function ($p0) {
    var $0 = $p0.target;
    this.$1F = ($0 === this.$A);
    if (this.$1F || $0 === this.$B) {
        this.$1E = $0;
        this.$18 = $p0.clientX;
        this.$19 = $p0.clientY;
        Sys.UI.DomEvent.removeHandler(this.$1E, 'mousedown', this.$12);
        var $1 = document.body; Sys.UI.DomEvent.addHandler($1, 'mouseup', this.$13);
        Sys.UI.DomEvent.addHandler($1, 'mousemove', this.$14);
        $1.style.cursor = (this.$1F) ? 'e-resize' : 'n-resize';
        this.$1A = this.get_$42();
        this.$1B = this.get_$43();
        $1.focus();
        Sys.UI.DomEvent.addHandler($1, 'selectstart', this.$15);
        $p0.preventDefault();
    } 
},
$22: function ($p0) {
    this.$34($p0);
    var $0 = document.body;
    Sys.UI.DomEvent.removeHandler($0, 'mouseup', this.$13);
    Sys.UI.DomEvent.removeHandler($0, 'mousemove', this.$14);
    Sys.UI.DomEvent.addHandler($0, 'selectstart', this.$15); 
    $0.style.cursor = 'default';
    Sys.UI.DomEvent.addHandler(this.$1E, 'mousedown', this.$12);
    this.$1E = null;
},
$23: function ($p0) {
    this.$34($p0);
},
$24: function ($p0) {
    this.$26();
},
....

Basically this is the part of the script: so lets say I want to override function: $22: function ($p0) in the script in another javascript file, how do i do that?

I would appreciate any help.

A small update, some good examples were provided but they are not working. The environment where i run this sript is SharePoint, normally when I did override I used this method:

var oldFixRibbonAndWorkspaceDimensions = window.FixRibbonAndWorkspaceDimensions;
window.FixRibbonAndWorkspaceDimensions = function () {
    this.MyFixRibbonAndWorkspaceDimensions();
};

function MyFixRibbonAndWorkspaceDimensions(){...}

And it didn't matter when i load the script as this function was only called when the default function was called not before not after. Just in the same time. But with the example which were provided here, the function is trying to execute on the document.ready()

Stephen · Accepted Answer · 2012-10-12 13:01:29Z

2

You want to permanently override it? Just do this:

Microsoft.Office.Server.Ajax.NavResizer.prototype.$22 = function($p0) {
    // your code.
};

As long as your script is executed after the original is defined, you're good.

answered Oct 12, 2012 at 13:01

Stephen

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1 Comment

Alnedru Over a year ago

yeah but original script is run i dont know when, as it is by default, how can i let my script run after? :/

bbg · Accepted Answer · 2013-07-24 02:06:11Z

2

Old post.. but this works for me:

ExecuteOrDelayUntilScriptLoaded(overrideNavResizer, "NavResizer.js");

function overrideNavResizer(){

    Microsoft.Office.Server.Ajax.NavResizer.prototype.$22 = function($p0) {
    // your code.
};
}

answered Jul 24, 2013 at 2:06

bbg

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Comments

happyCoda · Accepted Answer · 2012-10-12 13:03:10Z

1

In your new script:

Microsoft.Office.Server.Ajax.NavResizer.prototype.$22 = function () {//your function code}

answered Oct 12, 2012 at 13:03

happyCoda

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Comments

Bergi · Accepted Answer · 2012-10-12 13:03:54Z

1

Assuming you have access to the prototype object (it's in global scope) and your scripts runs after it, that is easy:

var proto = Microsoft.Office.Server.Ajax.NavResizer.prototype,
    oldMethod = proto.$22;
proto.$22 = function newMethod(args, …){
    …
};

answered Oct 12, 2012 at 13:03

Bergi

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4 Comments

Alnedru Over a year ago

yeah looks easy but i get an error Microsoft is undefined ... what does it mean?

Bergi Over a year ago

Just what I said: The object must be globally available. I don't know enough about your environment (where/when those scripts run, in which scope those code snippets are), but if you don't have access to that object you're lost.

Alnedru Over a year ago

can you tell me how can i load it after the other script? The other script is executed on demand, how about this function ExecuteOrDelayUntilScriptLoaded but dont know how to use it with this

Bergi Over a year ago

No idea, but it seems you will need to tell us more about your environment

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