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What's the correct way to send Javascript code along with rendered HTTP to a client?

Mid development I decided to switch to server-side rendering for a better control amongst other benefits. My web application is completely AJAX based, no url redirecting, so the idea here is a website that builds itself up
I just couldn't figure out the proper way to send javascript events/functions along with the html string, or should all the necessary javascript always be preloaded in the static files?
Let's say client clicks a pre-rendered button 'open table'
The server will make a query, build the html table and send it back, but this table also needs javascript triggers and functions to work properly, how are these sent, received and executed?
There are a couple of articles that mention to not use eval() in Javascript, is there any way around this? I don't want to have to preload unnecessary events for elements that don't yet exist
The server is Python and the Client is Javascript/JQuery
Theoretical example :
Client Base Javascript :
$("body").on("click", "#open_table", function() {
$.getJSON('/get_table', function(response){
$("#table_div").append(response.html);
eval(response.javascript()); //??
}
});
Python Server(views.py) :
def get_table(request):
data = {}
#String containing rendered html
data['html'] = get_render_table()
#String containing Javascript code?
data['javascript'] = TABLE_EVENTS_JAVASCRIPT
return HttpResponse(json.dumps(data),content_type='json')
Worth noting my question comes from an experimental/learning perspective

Update:
You can use jQuery.getScript() to lazy load JS. I think this solution is as close as you can get to run JS without using eval().
See this example:
jQuery.getScript("/path/to/script.js", function(data, textStatus, jqxhr) {
/* Code has been loaded and executed. */
console.log( data ); // Data returned
console.log( textStatus ); // Success
console.log( jqxhr.status ); // 200
console.log( "Load was performed." );
});
and "/path/to/script.js" could be a string returned from $.getJOSN response.
Also, the documentation for getScrippt() has examples on how to handle errors and cache files.
Old Answer:
Using .on() attaches events to current and future DOM elements.
You can either attache events prior to DOM insertion or attache event after DOM insertion.
So in your example you can do something like:
$("body").on("click", "#open_table", function() {
$.getJSON('/get_table', function(response){
var code = $(response.html);
code.find(".elementToFind").on("click", function (){
// Code to be executed on click event
});
$("#table_div").append(code);
}
});
I did not test the code but I think it should work.

Assuming you can't just set up an event-binding function and then call it from the main script (the JavaScript you need can't be guessed ahead of time, for example) then one really easy way is just to append the JavaScript to the bottom of the returned HTML content within script tags. When it's appended along with the HTML, the script should simply execute, with no eval() required.
I can't swear that this would work in old browsers, but it's a trick I've used a couple of times, and I've had no problems with it in Firefox, Chrome, or any of the later IE versions.

I think I see what you're asking here, from my understanding you want to send the new "page" asynchorously, and render the new javascript and html. It looks like you already got your request/response down, so i'm not gonna go and talk about sending JSON objects, and the whole "how-to" of sending html and javascript because it looks like you got that part. To do what you want and to dynamically add your javascript in, this stackoverflow question looks like it has what you need
Is there a way to create a function from a string with javascript?
So pertaining to your example, here is how it would look when you recieve the JSON string from your python script:
$("body").on("click", "#open_table", function() {
$.getJSON('/get_table', function(response){
$("#table_div").append(response.html);
/* Create function from string */
var newFunction = Function(response.javascript['param_1'], response.javascript['param_2'], response.javascript['function']);
/* Execute our new function to test it */
newFunction();
}
});
*Your actual function contents would be the string: response.javascript['function']
*Your parameter names if any would be in separate strings ex: response.javascript['param_1']
That is almost a direct copy of the "String to function" code that you can see in the linked question, just replaced it with your relevant code. This code is also assuming that your object is sent with the response.javascript object containing an array with your actual function content and parameter names. I'm sure you could change the actual name of the var too, or maybe put it in an associative array or something that you can keep track of and rename. All just suggestions, but hopefully this works for you, and helps you with your problem.

I am also doing similar work in my project where I had to load partial html using ajax calls and then this partial HTML has elements which requires events to be attached. So my solution is to create a common method to make ajax calls and keep a js method name to be executed post ajax call in html response itself. For example my server returns below html
<input type="hidden" data-act="onPartialLoad" value="createTableEvents" />
<div>.........rest of html response.....<div>
Now in common method, look for input[type='hidden'][data-act='onPartialLoad'] and for each run the method name provided in value attribute (value="createTableEvents")
Dont Use Eval() method as it is not recommended due to security
issues. Check here.
you can run js method using window["method name"]...so here is a part of code that I use.
$.ajax(options).done(function (data) {
var $target = $("#table_div");
$target.fadeOut(function () {
$target.html(data);
$target.fadeIn(function () {
try {
$('input[data-act="onPartialLoad"]', $target).each(function () {
try {
//you can pass parameters in json format from server to be passed into your js method
var params = $(this).attr('params');
if (params == undefined) {
window[$(this).val()]();
}
else {
window[$(this).val()]($.parseJSON(htmlutil.htmlDecode(params)));
}
} catch (e) {
if (console && console.log) {
console.log(e.stack);
console.log($(this).val());
}
}
});
}
catch (e) {
console.log(e.stack);
}
});
});
});
use jQuery.getScript() (as suggested by Kalimah Apps) to load the required js files first.

Firebreath Object in AngularJS

I have tried to include a FireBreath plugin object in an AngularJS view, however when I try to render the view I get this error:
TypeError: Cannot read property 'nodeName' of undefined
I am able to successfully include the object in the view with $compile like this:
$("body").append($compile('<object id="plugin" type="application/x-firebreathplugin" width="0" height="0></object>')($scope));
However, after including the object like this I cannot get my plugin to fire an event in the JS.
Doing something like this:
plugin = document.getElementById('plugin');
console.log(plugin);
Returns
TypeError
In the Chrome console. But I can still do:
plugin.callFunction();
And have a FireBreath method execute. The issue is when I try to get an event to fire in the JS. No matter what I try, I cannot get the event to fire. So this code will never execute:
var addEvent = function(obj, name, func) {
obj.addEventListener(name, func, false);
}
addEvent(document.getElementById('plugin'), 'firebreathEvent', function(data) {
console.log('data ' + data);
});
var plugin = document.getElementById('plugin');
plugin.functionThatTriggersFireBreathEvent();
Does anybody know if it has something to do with accessing the object after calling $compile? I noticed that in regular HTML (before using AngularJS) logging the plugin in the console returns this :
<JSAPI-Auto Javascript Object>
So I am thinking that whatever I am getting with document.getElementById after using $compile is not the same.
What would be easier is is if I could just include the <object> tag in the view.html file and have it display in <body class='ng-view'> but I get the top TypeError, so if anyone has any ideas for that, that would be preferred.
Any help is appreciated. Thanks.

If anyone is interested, because I could not get the event to fire, I followed along to this link:
http://colonelpanic.net/2010/12/firebreath-tips-asynchronous-javascript-calls/
(which I think is your blog #taxilian) to get the data back to the JS.
Plugin Code: Great example in the link.
JS Code:
//attach FireBreath Object to AngularJS View
$("body").append($compile('<object id="plugin" type="application/x-firebreathplugin" width="1" height="1"><param name="onload" value="pluginLoaded"/></object>')($scope));
var callback = function(data) {
//data is an object
console.log(data.resultFromFireBreath);
}
plugin = document.getElementById("plugin");
plugin.getData(callback);
This will have to work for now until someone can figure out how to attach an event to the plugin object after $compile.

I ran into the same problem and was able to make the problem go away by creating a read-only nodeName property in my plugin object. I asked about this in a firebreath forum post and taxilian suggested adding this to JSAPIAuto.cpp, which also worked, so I submitted a pull request with the change.

I once spent about 6 hours trying to make FireBreath plugins work with jquery; it was really educational, but ultimately I determined that it wasn't worth the work.
Long story short is that it's not worth it; particularly since even if you could make it work, it would break on IE9 where FireBreath doesn't support addEventListener (IE never gives it the even info, so it's a little hard to support) and you would need to use attachEvent anyway.

restore overridden window.JSON object

Some code that I don't have control over is overriding the global JSON object without checking if it's already implemented:
var JSON = {
org: "http://www.JSON.org",
copyright: "(c)2005 JSON.org",
license: "http://www.crockford.com/JSON/license.html",
stringify: function(a, g) {
...
The problem is that this version of the JSON parser is very old and has a bug, which is fouling up my attempts at serialization. (Others have had a similar problem with this implementation.)
Can I get at the browser's native implementation? I thought delete would work, but it doesn't. I suspect that's because JSON is an object and not a method in the prototype. Is there some other way to get at it?

You can create an iframe element (which will load about:blank and hence create a new context) and get a JSON object from there.
function restoreJSON() {
var f = document.createElement("iframe");
f.style.display = "none";
document.documentElement.appendChild(f);
window.JSON = f.contentWindow.JSON;
document.documentElement.removeChild(f);
}
about:blank is loaded synchronously, so no need to wait for the load event. While this isn't restoring the original JSON object, it is getting one black-box identical to it.

Since the code that you don't have control over is overriding the original before you come along in the page, you have two options:
Inject an iframe and grab the JSON off the contextWindow (as indicated in the other answer on this question at the time of this edit), or, alternately, just use the https://github.com/douglascrockford/JSON-js JSON library as your own insert. Note that using Crockford's does give cross-browser-guarantees of conformance, but the native implementations are often faster.
An alternative if you have the ability in the future to come along on the page before the offending code, is to inject something before that offending "code that helps" to grab the JSON object:
<html>
<head>
<script>
window.myJson = window.JSON;
</script>
....

How can I use jQuery 1.5.2+ on a Firefox addon?

At first I made a function that received a parameter and returned jQuery such as:
function getjQuery(window)
{
/*jquery code*/(window);
return window.jQuery;
}
But then I got an email form the review and they told me I have to use jQuery file with the original file name and completely unmodified.
I started to search for an alternative and found this solution, but there is no way it work.
jQuery object is created, but I can't find any elements. $("#id").length is always 0. With the previous method it was always found.
My current code (which doesn't work)
AddonNameSpace.jQueryAux = jQuery;
AddonNameSpace.$ = function(selector,context) {
return // correct window
new AddonNameSpace.jQueryAux.fn.init(selector,context||contentWindow);
};
AddonNameSpace.$.fn =
AddonNameSpace.$.prototype = AddonNameSpace.jQueryAux.fn;
AddonNameSpace.jQuery = AddonNameSpace.$;
The jQuery file is loading on my browser.xul overlay:
<script type="text/javascript" src="chrome://addon/content/bin/jquery-1.5.2.min.js" />
Am I loading in the right place?
How can I use jQuery to modify the content on a page (HTML) with the original jQuery file, is it even possible?

You need pass the e.originalTarget.defaultView on the second parameter on jquery..
If you don't jquery will use window.document, which is the window.document from the xul.
Use
gBrowser.addEventListener("DOMContentLoaded", function (e) {
$("#id", e.originalTarget.defaultView).length
}, true);
instead of
$("#id").length;
And, for avoid conflicts with other extensions don't use script in the xul page, use MozIJSSubScriptLoader.
Components.classes["#mozilla.org/moz/jssubscript-loader;1"]
.getService(Components.interfaces.mozIJSSubScriptLoader)
.loadSubScript("chrome://youraddon/content/jquery-1.5.2.min.js");
If you use this method, you load jquery only when you need, avoiding memory leak.

The preferred way to load it is with mozIJSSubScriptLoader so you don't collide with other's extensions. I'm not sure why you're having problems, I can use jQuery in my addon like $("#id").hide() with no additional code (although from the sidebar, now browser.xul).
Either way, this blog post provides a pretty good guide and even has an example xpi to download.

Javascript replace a function with a new one containing dynamic contents

My Javascript knowledge is less experienced, so I might use wrong descriptions in the following.
I have an object in a static .js file:
var Info = {
methodA: function() {
// Call methodB.
this.methodB('test');
},
methodB: function(value) {
// Do stuff
}
}
Now, in an .aspx file, I create a function methodC(value) with varying contents (depending on some data), which I want to insert instead of the above definition of methodB(value):
...
var methodC = function(value) {
// Do different stuff
}
...
My idea has so far been to replace methodB with methodC in the following fashion:
...
Info.methodB = methodC;
...
Using IE's buildin developer tool, I get the following error when calling this.methodB('test'); from Info.methodA():
Object doesn’t support this property
or method
Removing the 'this' from this.methodB('test') results in the error:
Object expected
I don't get any errors using FireBug - probably because I use various frameworks, which might catch the error.
How should I do this or should I use a completely different approach?
Regards, Casper

It should work, you are doing it the right way. The problem lays elsewhere.
update:
This should still work as long as you call methodA on an object, eg Info.methodA().
Maybe you are not understanding the error messages ?
"Object doesn’t support this property or method" means that in the expression "this.methodB()", this doesn't have a property named "methodB". So it means that this is not Info when the code of methodA is executed.
"Object expected" means that the variable methodB is unknown in the current execution context. Of course it is, since methodB is never a variable, only a property of Info.
To debug your problem, you need to know what is this when a code is executed, and why it's not what you think it should be. When you call Info.methodA(), this is set to be Info when methodA begins its execution.