Develop Reference

AngularJS - inject trusted code from loaded content

I've hooked up a lazy loader in Angular. It pulls in full templates and extracts key information from that full template in order to populate a partial. This full page template has script tags which load in and then register with the existing app. All of this works fine. My problem is that I'd like to remove the only use of jQuery in this approach.
The root issue is that the JS inside of something.js doesn't execute when using $element.html(), but it does execute when using $.html(), despite the script tag being placed in the DOM in both approaches.
Working code, including lazy loader and post-bootstrap registration of lazy-loaded JS:
$http.get("/path/to/file.html").success(function(response) {
// response is a full HTML page including <doctype>
var partial = getOnlyWhatWeNeed(response);
// partial is now something like: '<script type="text/javascript" src="/path/to/something.js"></script><div ng-controller="somethingCtrl">{{something}}</div>'
// i'd like the following to not rely on full jQuery.
$("#stage").html(partial);
$("#stage").html($compile(partial)($scope)); // it is necessary to do it once before compile so that the <script> tags get dropped in and executed prior to compilation.
});
I've tried what seems like the logical translation:
$element.html($compile(partial)($scope));
and the DOM is created properly, but the JS inside of the loaded <script> tag doesn't actually execute. My research suggested this was an $sce issue, so I tried:
$element.html($compile($sce.trustAsHtml(partial)($scope));
but i get the same result. the DOM is fine, but the JS doesn't actually execute and so I get undefined controller issues.
I've tried playing with $sce.JS and $sce.RESOURCE_URL but the docs didnt elaborate much so I'm not sure I know whether or not what I'm trying is even right.
I've also tried $element[0].innerHTML but I get the same result as $element.html().
Preemptive disclaimer: I can trust the incoming HTML/JS. I know it's inadvisable. This isn't my baby and it is much more complicated than I explained so please try to stay on topic so other people in this position may not have as hard of a time as I am :)
The $http.get happens in a provider, and the $element.html happens in a directive. I consolidated them to remove noise from the problem.

Jquery will find any script tags and evaluate them (either a direct eval or appending them to the head for linked scripts) when calling html(), see this answer. I'm assuming angular's jquery lite doesn't do this. You would need to effectively replicate what jquery is doing and look for script tags in the html you are appending.
Something like this (although I haven't tested it):
$http.get("/path/to/file.html").success(function(response) {
// response is a full HTML page including <doctype>
var partial = getOnlyWhatWeNeed(response);
// partial is now something like: '<script type="text/javascript" src="/path/to/something.js"></script><div ng-controller="somethingCtrl">{{something}}</div>'
var d = document.createElement('div');
d.innerHTML = partial;
var scripts = d.getElementsByTagName('script');
for (var i = 0; i < scripts.length; i++) {
document.head.appendChild(scripts[0]);
}
$("#stage").html($compile(partial)($scope)); // it is necessary to do it once before compile so that the <script> tags get dropped in and executed prior to compilation.
});
This is far from an ideal solution as it gives you no guarantee of when things are loaded and doesn't really handle dependencies across scripts. If you can control the templates it would be simpler to remove the scripts from them and load them independently.

refreshing javascript by renaming src attribute

I want to refresh the output of the script below. Is this json? Do I need to add a crossdomain policy in my site?
<div id="nowplaying">
<script src="http://s4.total-streaming.com/xml.php?station=1269&get=js"></script>
</div>
Edit:
This is what I'm trying based on #alexn advise, but still doesn't refresh.
<div id="nowplaying">
<script id="nowplaying-script" src="http://s4.total-streaming.com/xml.php?station=1269&get=js"></script>
<script>
setInterval(function () {
$('#nowplaying-script').attr('src', 'http://s4.total-streaming.com/xml.php?station=1269&get=js');
}, 1000);
</script>
</div>
Note Firebug: Resource interpreted as script but transferred with MIME type text/html. xml.php:-1

No, it's plain JavaScript. The script will simply output a string. You don't need any cross-domain policies to use this.
To refresh the content, just re-assign the src attribute of your script tag to the same url. You can use setTimeout to do this on a specified interval. Something like this should do it, you need to ad an id attribute to your script tag. The following will refresh every 5:th second.
setInterval(function() {
var element = document.getElementById("nowplaying-script");
element.setAttribute("src", "http://s4.total-streaming.com/xml.php?station=1269&get=js");
}, 5000);
(This is untested)

I would lean towards this being a cache problem.
How about you try this plugin (or look into how it works): http://plugins.jquery.com/project/reload
It essentially would allow you to do this:
setInterval(function () {
$('#nowplaying-script').reload();
}, 1000);
If you don't want to use the plugin, all it's doing is appending the current date to the URI params.
Another thing I noticed is that the script you are loading contains document.write. Even if you managed to get it to reload, it's not going to do what your expecting it to do.
In fact, calling document.write on a already loaded HTML page will cause your page to turn blank and contain only the content passed to document.write.
Now I'm not sure if your script is running on the same hostname as the script you are loading, if isn't you going to need a JSONP API instead of an a script that writes into the page.
If they do not offer a JSONP API, a more hackish way to solve this problem would be to write a server-side script that acts as a proxy. It essentially would load http://s4.total-streaming.com/xml.php?station=1269&get=js, parse it server-side using a substr or RegEx and return back the text that you want, in this case the name of the song currently playing.
Another way to solve this problem would be to overwrite the document.write method and have it print the content into the div instead of onto the screen like this:
document.write = function(songName) {
$('#nowplaying').text(songName);
};
Personally I wouldn't use this solution, but it will work if the other solutions are too complex for you to setup. Keep in mind all calls to document.write on that given page will print the content into your #nowplaying element. You should probably move your SCRIPT tag out of the #nowplaying element too if you use the above solution.

How do I get the original innerHTML source without the Javascript generated contents?

Is it possible to get in some way the original HTML source without the changes made by the processed Javascript? For example, if I do:
<div id="test">
<script type="text/javascript">document.write("hello");</script>
</div>
If I do:
alert(document.getElementById('test').innerHTML);
it shows:
<script type="text/javascript">document.write("hello");</script>hello
In simple terms, I would like the alert to show only:
<script type="text/javascript">document.write("hello");</script>
without the final hello (the result of the processed script).

I don't think there's a simple solution to just "grab original source" as it'll have to be something that's supplied by the browser. But, if you are only interested in doing this for a section of the page, then I have a workaround for you.
You can wrap the section of interest inside a "frozen" script:
<script id="frozen" type="text/x-frozen-html">
The type attribute I just made up, but it will force the browser to ignore everything inside it. You then add another script tag (proper javascript this time) immediately after this one - the "thawing" script. This thawing script will get the frozen script by ID, grab the text inside it, and do a document.write to add the actual contents to the page. Whenever you need the original source, it's still captured as text inside the frozen script.
And there you have it. The downside is that I wouldn't use this for the whole page... (SEO, syntax highlighting, performance...) but it's quite acceptable if you have a special requirement on part of a page.
Edit: Here is some sample code. Also, as #FlashXSFX correctly pointed out, any script tags within the frozen script will need to be escaped. So in this simple example, I'll make up a <x-script> tag for this purpose.
<script id="frozen" type="text/x-frozen-html">
<div id="test">
<x-script type="text/javascript">document.write("hello");</x-script>
</div>
</script>
<script type="text/javascript">
// Grab contents of frozen script and replace `x-script` with `script`
function getSource() {
return document.getElementById("frozen")
.innerHTML.replace(/x-script/gi, "script");
}
// Write it to the document so it actually executes
document.write(getSource());
</script>
Now whenever you need the source:
alert(getSource());
See the demo: http://jsbin.com/uyica3/edit

A simple way is to fetch it form the server again. It will be in the cache most probably. Here is my solution using jQuery.get(). It takes the original uri of the page and loads the data with an ajax call:
$.get(document.location.href, function(data,status,jq) {console.log(data);})
This will print the original code without any javascript. It does not do any error handling!
If don't want to use jQuery to fetch the source, consult the answer to this question: How to make an ajax call without jquery?

Could you send an Ajax request to the same page you're currently on and use the result as your original HTML? This is foolproof given the right conditions, since you are literally getting the original HTML document. However, this won't work if the page changes on every request (with dynamic content), or if, for whatever reason, you cannot make a request to that specific page.

Brute force approach
var orig = document.getElementById("test").innerHTML;
alert(orig.replace(/<\/script>[.\n\r]*.*/i,"</script>"));
EDIT:
This could be better
var orig = document.getElementById("test").innerHTML + "<<>>";
alert(orig.replace( /<\/script>[^(<<>>)]+<<>>/i, "<\/script>"));

If you override document.write to add some identifiers at the beginning and end of everything written to the document by the script, you will be able to remove those writes with a regular expression.
Here's what I came up with:
<script type="text/javascript" language="javascript">
var docWrite = document.write;
document.write = myDocWrite;
function myDocWrite(wrt) {
docWrite.apply(document, ['<!--docwrite-->' + wrt + '<!--/docwrite-->']);
}
</script>
Added your example somewhere in the page after the initial script:
<div id="test">
<script type="text/javascript"> document.write("hello");</script>
</div>
Then I used this to alert what was inside:
var regEx = /<!--docwrite-->(.*?)<!--\/docwrite-->/gm;
alert(document.getElementById('test').innerHTML.replace(regEx, ''));

If you want the pristine document, you'll need to fetch it again. There's no way around that. If it weren't for the document.write() (or similar code that would run during the load process) you could load the original document's innerHTML into memory on load/domready, before you modify it.

I can't think of a solution that would work the way you're asking. The only code that Javascript has access to is via the DOM, which only contains the result after the page has been processed.
The closest I can think of to achieve what you want is to use Ajax to download a fresh copy of the raw HTML for your page into a Javascript string, at which point since it's a string you can do whatever you like with it, including displaying it in an alert box.

A tricky way is using <style> tag for template. So that you do not need rename x-script any more.
console.log(document.getElementById('test').innerHTML);
<style id="test" type="text/html+template">
<script type="text/javascript">document.write("hello");</script>
</style>
But I do not like this ugly solution.

I think you want to traverse the DOM nodes:
var childNodes = document.getElementById('test').childNodes, i, output = [];
for (i = 0; i < childNodes.length; i++)
if (childNodes[i].nodeName == "SCRIPT")
output.push(childNodes[i].innerHTML);
return output.join('');

Getting content of a script file using Javascript

I have the following script element in my web page:
<script src="default.js" type="text/javascript"></script>
Using JavaScript, I want to be able to retrieve the content of the script file. I know I could use an ajax request to get the data but then I am getting something from the server that I already have locally.
So what I would prefer to do is retrieve the content from the DOM (if that's possible) or something that has the same result.
Cheers
Anthony
UPDATE
I was trying to simplify the question, maybe a bad a idea, I thought this way would cause less questions.
The real situation I have is as follows, I actually have
<script type="text/html" class="jq-ItemTemplate_Approval">
...
html template that is going to be consumed by jQuery and jTemplate
...
</script>
Now this works fine but it means each time the page loads I have to send down the template as part of the HTML of the main page. So my plan was to do the following:
<script src="template.html" type="text/html"></script>
This would mean that the browser would cache the content of template.html and I would not have to send it down each time. But to do this I need to be able to get the content from the file.
Also in this case, as far as I know, requesting the content via ajax isn't going to help all that much because it has to go back to the server to get the content anyway.

If I understand you correctly, you don't want to use Ajax to load an html template text, but rather have it loaded with the rest of the page. If you control the server side, you can always include the template text in an invisible div tag that you then reference from Javascript:
<div id="template" style="display:none;">
...template text...
</div>
<script>
// pops up the template text.
alert(document.getElementById("template").innerHTML);
</script>
If you are just looking for to load the template so that you can have it cached, you can put the contents in a variable like this:
<script>
var template = "template text..";
</script>
or you can load it using ajax and store the template in a variable so it is accessible. It's pretty trivial in jquery:
var template;
$.get("template.html", function(data){
template = data;
});

unless you load a script as literal text in the page, it does not exist as text. It is interpreted by the browser and melded into the runtime, with any other scripts.
If you want the source you have to fetch it again,if with Ajax get the responseText.
It will come from the browser cache, and doesn't have to be downloaded again.

I think what you want to do is to assign a variable inside template.js. Then you have the variable available for use wherever you want in jquery. Something like:
var tpl = "<div> ... </div>"
Wouldn't this be a simpler solution to your problem? We do this in Ext JS. I think this will work for you in jQuery.

You could get the attribute of the src of the script and then use XHR to get the contents of the JS file. It's a much cleaner way of doing it IMO. e.g.:-
if(window.XMLHttpRequest) {
var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function() {
if(xhr.status == 200 && xhr.readyState == 4) {
var sourceCode = xhr.responseText;
alert('The source code is:-\n'+sourceCode);
}
}
xhr.open("GET",document.getElementById('scriptID').src,true);
xhr.send(null);
}

Using an iFrame & HTML5 Local Storage
Save the templates for rendering later...
not stoked about the iFrame, but it seems to be working pretty good (haven't ran performance tests yet)
Put the iFrame on the page you want the template on (index.html)
<html>
<head>
<iframe src="mustache.Users.html" onload="this.remove();" class="hidden" id="users_template"></iframe>
</head>
</html>
Make sure the src attribute is set
hide the element until you can get rid of it after it loads
Put this body wrapper around your template (mustache.Users.html)
(don't worry it won't show up in the template)
<body onload="localStorage.setItem('users_template',this.document.body.innerHTML);">
<ul class="list-group" id="users" >
{{#users}}<li>{{name}}</li>{{/users}}
</ul>
</body>
replace 'users_template' with whatever name for your variable
the 'onload' attribute saves the template into localStorage during load
Now You can access your templates from anywhere
localStorage.getItem('users_template')
OR
window.localStorage.getItem('users_template')

What is in the JavaScript file? If it's actual code, you can run functions and reference variables in there just like you had cut and paste them into the webpage. You'll want to put the include line above any script blocks that reference it.
Is this what your looking to accomplish?

Why not use Ajax (well Ajah because its html :-))?
when the server is set up correctly and no no-cache or past expires headers are sent, the browser will cache it.

The way that most JavaScript import files work is they include a script, that immediately calls a function with a parameter of certain text, or of another function. To better illustrate, say you have your main index.html file, set it up like this:
<html>
<head>
</head>
<body>
<script>
let modules = {};
function started(moduleName, srcTxt) {
modules[moduleName] = (srcTxt) //or something similar
}
</script>
<!--now you can include other script tags, and any script tags that will be included, their source can be gotten (if set up right, see later)-->
<script src="someOtherFile.js"></script>
</body>
</html>
now make that other file, someOtherFile.js, and right away when its loaded, simply call that "started" function which should already be declared in the scope, and when thats done, then whatever text is passed, from the file, is stored in the main index.html file. You can even stringify an entire function and put it in, for example:
started("superModule", (function() {
/*
<?myCustomTemplateLanguage
<div>
{something}Entire Javascript / html template file goes here!!{/something}
</div>
?>
*/
}).toString());
now you can access the inner content of the function, and get all the text in between the comments, or better yet, then do other parsing etc, or make some other kind of parsing identifiers at the beginning and end of the comments, as shown above, and get all text in between those

Injecting JavaScript into head element of website using Fiddler

I was thinking of using Fiddler for the following purpose...
I have a JavaScript based service I want to demonstrate to potential clients. In order to show them what their website could look like if they install (i.e. include) my script, I want to set up Fiddler on my PC, so that when fetching the client's website, the
<script type="text/JavaScript" src="myscript.js"></script>
line will be included in the HTML <head> section.
Can this be easily done with Fiddler? Could someone point me to where I may find the documentation covering that, if it is?
Thanks!
----Update----
For the time being I have resorted to using a BHO to add my script to the page. I use execScript(), upon onDocumentComplete, to run a simple piece of JavaScript which appends the .js file I need to the page. But EricLaw's pointers and jitter's answer seem like the way to go for a more complete (and elegant) way to do what I need.
If someone is interested I could upload the BHO code here.
-Thanks!

Open fiddler -> Menu Rules -> Customize Rules (or hit Ctrl+R)
The CustomRule.js file opens. Scroll down until you find the line
static function OnBeforeResponse(oSession: Session)
This is where your code goes. Here you can change the server response before the browser sees it.
The following code sample shows how to include a custom piece of jQuery code which replaces the Unanswered link in the horizontal menu with a link which serves as short cut to Unanswered jQuery Questions
I first show you the jQuery code I want to include
<script type='text/javascript'>
$(function() {
var newLink = 'Unanswered jQuery';
$('div#hmenus div.nav:first ul li:last a').replaceWith(newLink);
});
</script>
Now the fiddler code (based on code found in CustomRules.js and code samples from the FiddlerScript CookBook)
//is it a html-response and is it from stackoverflow.com
if (oSession.oResponse.headers.ExistsAndContains("Content-Type", "html") &&
oSession.HostnameIs("stackoverflow.com")) {
// Remove any compression or chunking
oSession.utilDecodeResponse();
var oBody = System.Text.Encoding.UTF8.GetString(oSession.responseBodyBytes);
// Match the jQuery script tag
var oRegEx = /(<script[^>]*jquery.min.js"><\/script>)/gi;
// replace the script tag withitself (no change) + append custom script tag
oBody = oBody.replace(oRegEx, "$1<script type='text/javascript'>$(function() {$('div#hmenus div.nav:first ul li:last a').replaceWith('Unanswered jQuery');})</script>");
// Set the response body to the changed body string
oSession.utilSetResponseBody(oBody);
}
I think you should now able to hackyourself together a piece of code which fits your problem.
Example
// Match the head end
var oRegEx = /(<\/head>)/gi;
// replace with new script
oBody = oBody.replace(oRegEx, "<script type='text/javascript' src='http://url/myscript.js'></script>$1");

if you use jQuery you can add js on the fly. I would probably think you can have a method which would include/exclude your script based on some query param. This is how you would include JS with jQuery
$.getScript('someScript.js',function(){
//Do something here after your script loads
});

Haven't tried it, but how about GreaseMonkey for IE?