Related
Any idea why the piece of code below does not add the script element to the DOM?
var code = "<script></script>";
$("#someElement").append(code);
The Good News is:
It's 100% working.
Just add something inside the script tag such as alert('voila!');. The right question you might want to ask perhaps, "Why didn't I see it in the DOM?".
Karl Swedberg has made a nice explanation to visitor's comment in jQuery API site. I don't want to repeat all his words, you can read directly there here (I found it hard to navigate through the comments there).
All of jQuery's insertion methods use
a domManip function internally to
clean/process elements before and
after they are inserted into the DOM.
One of the things the domManip
function does is pull out any script
elements about to be inserted and run
them through an "evalScript routine"
rather than inject them with the rest
of the DOM fragment. It inserts the
scripts separately, evaluates them,
and then removes them from the DOM.
I believe that one of the reasons jQuery
does this is to avoid "Permission
Denied" errors that can occur in
Internet Explorer when inserting
scripts under certain circumstances.
It also avoids repeatedly
inserting/evaluating the same script
(which could potentially cause
problems) if it is within a containing
element that you are inserting and
then moving around the DOM.
The next thing is, I'll summarize what's the bad news by using .append() function to add a script.
And The Bad News is..
You can't debug your code.
I'm not joking, even if you add debugger; keyword between the line you want to set as breakpoint, you'll be end up getting only the call stack of the object without seeing the breakpoint on the source code, (not to mention that this keyword only works in webkit browser, all other major browsers seems to omit this keyword).
If you fully understand what your code does, than this will be a minor drawback. But if you don't, you will end up adding a debugger; keyword all over the place just to find out what's wrong with your (or my) code. Anyway, there's an alternative, don't forget that javascript can natively manipulate HTML DOM.
Workaround.
Use javascript (not jQuery) to manipulate HTML DOM
If you don't want to lose debugging capability, than you can use javascript native HTML DOM manipulation. Consider this example:
var script = document.createElement("script");
script.type = "text/javascript";
script.src = "path/to/your/javascript.js"; // use this for linked script
script.text = "alert('voila!');" // use this for inline script
document.body.appendChild(script);
There it is, just like the old days isn't it. And don't forget to clean things up whether in the DOM or in the memory for all object that's referenced and not needed anymore to prevent memory leaks. You can consider this code to clean things up:
document.body.removechild(document.body.lastChild);
delete UnusedReferencedObjects; // replace UnusedReferencedObject with any object you created in the script you load.
The drawback from this workaround is that you may accidentally add a duplicate script, and that's bad. From here you can slightly mimic .append() function by adding an object verification before adding, and removing the script from the DOM right after it was added. Consider this example:
function AddScript(url, object){
if (object != null){
// add script
var script = document.createElement("script");
script.type = "text/javascript";
script.src = "path/to/your/javascript.js";
document.body.appendChild(script);
// remove from the dom
document.body.removeChild(document.body.lastChild);
return true;
} else {
return false;
};
};
function DeleteObject(UnusedReferencedObjects) {
delete UnusedReferencedObjects;
}
This way, you can add script with debugging capability while safe from script duplicity. This is just a prototype, you can expand for whatever you want it to be. I have been using this approach and quite satisfied with this. Sure enough I will never use jQuery .append() to add a script.
I've seen issues where some browsers don't respect some changes when you do them directly (by which I mean creating the HTML from text like you're trying with the script tag), but when you do them with built-in commands things go better. Try this:
var script = document.createElement( 'script' );
script.type = 'text/javascript';
script.src = url;
$("#someElement").append( script );
From: JSON for jQuery
It is possible to dynamically load a JavaScript file using the jQuery function getScript
$.getScript('http://www.whatever.com/shareprice/shareprice.js', function() {
Display.sharePrice();
});
Now the external script will be called, and if it cannot be loaded it will gracefully degrade.
What do you mean "not working"?
jQuery detects that you're trying to create a SCRIPT element and will automatically run the contents of the element within the global context. Are you telling me that this doesn't work for you? -
$('#someElement').append('<script>alert("WORKING");</script>');
Edit: If you're not seeing the SCRIPT element in the DOM (in Firebug for example) after you run the command that's because jQuery, like I said, will run the code and then will delete the SCRIPT element - I believe that SCRIPT elements are always appended to the body... but anyway - placement has absolutely no bearing on code execution in this situation.
This works:
$('body').append($("<script>alert('Hi!');<\/script>")[0]);
It seems like jQuery is doing something clever with scripts so you need to append the html element rather than jQuery object.
Try this may be helpful:
var fileref=document.createElement('script');
fileref.setAttribute("type","text/javascript");
fileref.setAttribute("src","scriptAnalytics.js");
document.getElementsByTagName("head")[0].appendChild(fileref);
I want to do the same thing but to append a script tag in other frame!
var url = 'library.js';
var script = window.parent.frames[1].document.createElement('script' );
script.type = 'text/javascript';
script.src = url;
$('head',window.parent.frames[1].document).append(script);
<script>
...
...jQuery("<script></script>")...
...
</script>
The </script> within the string literal terminates the entire script, to avoid that "</scr" + "ipt>" can be used instead.
Adding the sourceURL in the script file helped as mentioned in this page:
https://blog.getfirebug.com/2009/08/11/give-your-eval-a-name-with-sourceurl/
In the script file, add a statement with sourceURL like "//# sourceURL=foo.js"
Load the script using jQuery $.getScript() and the script will be available in "sources" tab in chrome dev tools
Your script is executing , you just can't use document.write from it. Use an alert to test it and avoid using document.write. The statements of your js file with document.write will not be executed and the rest of the function will be executed.
This is what I think is the best solution. Google Analytics is injected this way.
var (function(){
var p="https:" == document.location.protocol ? "https://" : "http://";
d=document,
g=d.createElement('script'),
s=d.getElementsByTagName('script')[0];
g.type='text/javascript';
g.src=p+'url-to-your-script.js';
s.parentNode.insertBefore(g,s); })();
You don't need jQuery to create a Script DOM Element. It can be done with vanilla ES6 like so:
const script = "console.log('Did it work?')"
new Promise((resolve, reject) => {
(function(i,s,o,g,r,a,m){
a=s.createElement(o),m=s.getElementsByTagName(o)[0];
a.innerText=g;
a.onload=r;m.parentNode.insertBefore(a,m)}
)(window,document,'script',script, resolve())
}).then(() => console.log('Sure did!'))
It doesn't need to be wrapped in a Promise, but doing so allows you to resolve the promise when the script loads, helping prevent race conditions for long-running scripts.
Append script to body:
$(document).ready(function() {
$("<script>", { src : "bootstrap.min.js", type : "text/javascript" }).appendTo("body");
});
Another way you can do it if you want to append code is using the document.createElement method but then using .innerHTML instead of .src.
var script = document.createElement( 'script' );
script.type = 'text/javascript';
script.innerHTML = 'alert("Hey there... you just appended this script to the body");';
$("body").append( script );
I tried this one and works fine. Just replace the < symbol with that \x3C.
// With Variable
var code = "\x3Cscript>SomeCode\x3C/script>";
$("#someElement").append(code);
or
//Without Variable
$("#someElement").append("\x3Cscript>SomeCode\x3C/script>");
You can test the code here.
Can try like this
var code = "<script></" + "script>";
$("#someElement").append(code);
The only reason you can't do "<script></script>" is because the string isn't allowed inside javascript because the DOM layer can't parse what's js and what's HTML.
I wrote an npm package that lets you take an HTML string, including script tags and append it to a container while executing the scripts
Example:
import appendHtml from 'appendhtml';
const html = '<p>Hello</p><script src="some_js_file.js"></script>';
const container = document.getElementById('some-div');
await appendHtml(html, container);
// appendHtml returns a Promise, some_js_file.js is now loaded and executed (note the await)
Find it here: https://www.npmjs.com/package/appendhtml
Just create an element by parsing it with jQuery.
<div id="someElement"></div>
<script>
var code = "<script>alert(123);<\/script>";
$("#someElement").append($(code));
</script>
Working example: https://plnkr.co/edit/V2FE28Q2eBrJoJ6PUEBz
Any idea why the piece of code below does not add the script element to the DOM?
var code = "<script></script>";
$("#someElement").append(code);
The Good News is:
It's 100% working.
Just add something inside the script tag such as alert('voila!');. The right question you might want to ask perhaps, "Why didn't I see it in the DOM?".
Karl Swedberg has made a nice explanation to visitor's comment in jQuery API site. I don't want to repeat all his words, you can read directly there here (I found it hard to navigate through the comments there).
All of jQuery's insertion methods use
a domManip function internally to
clean/process elements before and
after they are inserted into the DOM.
One of the things the domManip
function does is pull out any script
elements about to be inserted and run
them through an "evalScript routine"
rather than inject them with the rest
of the DOM fragment. It inserts the
scripts separately, evaluates them,
and then removes them from the DOM.
I believe that one of the reasons jQuery
does this is to avoid "Permission
Denied" errors that can occur in
Internet Explorer when inserting
scripts under certain circumstances.
It also avoids repeatedly
inserting/evaluating the same script
(which could potentially cause
problems) if it is within a containing
element that you are inserting and
then moving around the DOM.
The next thing is, I'll summarize what's the bad news by using .append() function to add a script.
And The Bad News is..
You can't debug your code.
I'm not joking, even if you add debugger; keyword between the line you want to set as breakpoint, you'll be end up getting only the call stack of the object without seeing the breakpoint on the source code, (not to mention that this keyword only works in webkit browser, all other major browsers seems to omit this keyword).
If you fully understand what your code does, than this will be a minor drawback. But if you don't, you will end up adding a debugger; keyword all over the place just to find out what's wrong with your (or my) code. Anyway, there's an alternative, don't forget that javascript can natively manipulate HTML DOM.
Workaround.
Use javascript (not jQuery) to manipulate HTML DOM
If you don't want to lose debugging capability, than you can use javascript native HTML DOM manipulation. Consider this example:
var script = document.createElement("script");
script.type = "text/javascript";
script.src = "path/to/your/javascript.js"; // use this for linked script
script.text = "alert('voila!');" // use this for inline script
document.body.appendChild(script);
There it is, just like the old days isn't it. And don't forget to clean things up whether in the DOM or in the memory for all object that's referenced and not needed anymore to prevent memory leaks. You can consider this code to clean things up:
document.body.removechild(document.body.lastChild);
delete UnusedReferencedObjects; // replace UnusedReferencedObject with any object you created in the script you load.
The drawback from this workaround is that you may accidentally add a duplicate script, and that's bad. From here you can slightly mimic .append() function by adding an object verification before adding, and removing the script from the DOM right after it was added. Consider this example:
function AddScript(url, object){
if (object != null){
// add script
var script = document.createElement("script");
script.type = "text/javascript";
script.src = "path/to/your/javascript.js";
document.body.appendChild(script);
// remove from the dom
document.body.removeChild(document.body.lastChild);
return true;
} else {
return false;
};
};
function DeleteObject(UnusedReferencedObjects) {
delete UnusedReferencedObjects;
}
This way, you can add script with debugging capability while safe from script duplicity. This is just a prototype, you can expand for whatever you want it to be. I have been using this approach and quite satisfied with this. Sure enough I will never use jQuery .append() to add a script.
I've seen issues where some browsers don't respect some changes when you do them directly (by which I mean creating the HTML from text like you're trying with the script tag), but when you do them with built-in commands things go better. Try this:
var script = document.createElement( 'script' );
script.type = 'text/javascript';
script.src = url;
$("#someElement").append( script );
From: JSON for jQuery
It is possible to dynamically load a JavaScript file using the jQuery function getScript
$.getScript('http://www.whatever.com/shareprice/shareprice.js', function() {
Display.sharePrice();
});
Now the external script will be called, and if it cannot be loaded it will gracefully degrade.
What do you mean "not working"?
jQuery detects that you're trying to create a SCRIPT element and will automatically run the contents of the element within the global context. Are you telling me that this doesn't work for you? -
$('#someElement').append('<script>alert("WORKING");</script>');
Edit: If you're not seeing the SCRIPT element in the DOM (in Firebug for example) after you run the command that's because jQuery, like I said, will run the code and then will delete the SCRIPT element - I believe that SCRIPT elements are always appended to the body... but anyway - placement has absolutely no bearing on code execution in this situation.
This works:
$('body').append($("<script>alert('Hi!');<\/script>")[0]);
It seems like jQuery is doing something clever with scripts so you need to append the html element rather than jQuery object.
Try this may be helpful:
var fileref=document.createElement('script');
fileref.setAttribute("type","text/javascript");
fileref.setAttribute("src","scriptAnalytics.js");
document.getElementsByTagName("head")[0].appendChild(fileref);
I want to do the same thing but to append a script tag in other frame!
var url = 'library.js';
var script = window.parent.frames[1].document.createElement('script' );
script.type = 'text/javascript';
script.src = url;
$('head',window.parent.frames[1].document).append(script);
<script>
...
...jQuery("<script></script>")...
...
</script>
The </script> within the string literal terminates the entire script, to avoid that "</scr" + "ipt>" can be used instead.
Adding the sourceURL in the script file helped as mentioned in this page:
https://blog.getfirebug.com/2009/08/11/give-your-eval-a-name-with-sourceurl/
In the script file, add a statement with sourceURL like "//# sourceURL=foo.js"
Load the script using jQuery $.getScript() and the script will be available in "sources" tab in chrome dev tools
Your script is executing , you just can't use document.write from it. Use an alert to test it and avoid using document.write. The statements of your js file with document.write will not be executed and the rest of the function will be executed.
This is what I think is the best solution. Google Analytics is injected this way.
var (function(){
var p="https:" == document.location.protocol ? "https://" : "http://";
d=document,
g=d.createElement('script'),
s=d.getElementsByTagName('script')[0];
g.type='text/javascript';
g.src=p+'url-to-your-script.js';
s.parentNode.insertBefore(g,s); })();
You don't need jQuery to create a Script DOM Element. It can be done with vanilla ES6 like so:
const script = "console.log('Did it work?')"
new Promise((resolve, reject) => {
(function(i,s,o,g,r,a,m){
a=s.createElement(o),m=s.getElementsByTagName(o)[0];
a.innerText=g;
a.onload=r;m.parentNode.insertBefore(a,m)}
)(window,document,'script',script, resolve())
}).then(() => console.log('Sure did!'))
It doesn't need to be wrapped in a Promise, but doing so allows you to resolve the promise when the script loads, helping prevent race conditions for long-running scripts.
Append script to body:
$(document).ready(function() {
$("<script>", { src : "bootstrap.min.js", type : "text/javascript" }).appendTo("body");
});
Another way you can do it if you want to append code is using the document.createElement method but then using .innerHTML instead of .src.
var script = document.createElement( 'script' );
script.type = 'text/javascript';
script.innerHTML = 'alert("Hey there... you just appended this script to the body");';
$("body").append( script );
I tried this one and works fine. Just replace the < symbol with that \x3C.
// With Variable
var code = "\x3Cscript>SomeCode\x3C/script>";
$("#someElement").append(code);
or
//Without Variable
$("#someElement").append("\x3Cscript>SomeCode\x3C/script>");
You can test the code here.
Can try like this
var code = "<script></" + "script>";
$("#someElement").append(code);
The only reason you can't do "<script></script>" is because the string isn't allowed inside javascript because the DOM layer can't parse what's js and what's HTML.
I wrote an npm package that lets you take an HTML string, including script tags and append it to a container while executing the scripts
Example:
import appendHtml from 'appendhtml';
const html = '<p>Hello</p><script src="some_js_file.js"></script>';
const container = document.getElementById('some-div');
await appendHtml(html, container);
// appendHtml returns a Promise, some_js_file.js is now loaded and executed (note the await)
Find it here: https://www.npmjs.com/package/appendhtml
Just create an element by parsing it with jQuery.
<div id="someElement"></div>
<script>
var code = "<script>alert(123);<\/script>";
$("#someElement").append($(code));
</script>
Working example: https://plnkr.co/edit/V2FE28Q2eBrJoJ6PUEBz
I'm having a very frustrating problem with my javascript files. I have one global namespace that contains a page_data, utilities, modules etc namespace.
My directories look like this:
/utilities/single_utility.js
/modules/module.js etc tec
Anyways, I load the utilities before the modules, (which use the utilities) but keep getting problems.
My loader script looks like this (its wrapped in an SEAF):
for (var index in file_list) {
var url = file_list[index];
var new_script = document.createElement('script');
new_script.setAttribute("type", "text/javascript");
new_script.setAttribute("src", url);
element.appendChild(new_script);
}
Project is my global namespace, that holds all of these other namespaces. But when I try to reference a utility in one of my modules, with Project.utilities.session.exist() etc, it will sometimes throw an error that Project can't be found?
How can I fix this to make sure my files are loading properly or am I doing something else wrong?
Using async = false should protect your load order.
This is a quick snippet I use to load and maintain order.
var loadScript = function( url ) {
if (url) {
var doc = document,
t = doc.createElement("script"),
s = doc.getElementsByTagName("script")[0];
t.type = "text/javascript";
// Keep script order!
t.async = false;
t.src = url;
s.parentNode.insertBefore(t, s);
}
};
Some references backing this logic (and regarding browser support) from MDN and Microsoft
When you add the script tag to the page, the browser has to go out and download those scripts. There's no guarantee that they will download and execute in the same order that you created them.
You will need to add an event listener to new_script for when it loads, either onload or onreadystatechange, depending on the browser. But truly I'd recommend using a script loading library (such as RequireJS) that handles all the nasty details for you.
As an aside, why not just add all your script tags directly to your page? In that case they load sequentially.
It's better if you resolve this problem using a script loader.
As Matt said RequireJS is a good option if you also want to handle script dependencies.
For script loading only, you can take a look into LAB.js, is very small and straightforward:
for (var index in file_list) {
$LAB.script(file_list[index]);
}
If the scripts have dependencies and must be loaded in order, you can use .wait(), to do that keep the chain object returned by script. You can re-write the loop to keep the chain:
var chain;
for (var index in file_list) {
if (!chain) {
chain = $LAB.script(file_list[index]).wait();
} else {
chain.script(file_list[index]).wait();
}
}
Or just forget the file_list array and use $LAB directly:
$LAB.script('file1.js').wait()
.script('file2.js').wait()
/* ... */
I have a Greasemonkey script that works just fine in Firefox and Opera. I struggle with getting it to work in Chrome, however. The problem is injecting a function into the page that can be invoked by code from the page. Here's what I'm doing so far:
First, I get a helper reference to the unsafeWindow for Firefox. This allows me to have the same code for FF and Opera (and Chrome, I thought).
var uw = (this.unsafeWindow) ? this.unsafeWindow : window;
Next, I inject a function into the page. It's really just a very thin wrapper that does nothing but invoking the corresponding function in the context of my GM script:
uw.setConfigOption = function(newValue) {
setTimeout(setConfigOption, 0, newValue);
}
Then, there's the corresponding function right in my script:
setConfigOption = function(newValue) {
// do something with it, e.g. store in localStorage
}
Last, I inject some HTML into the page with a link to invoke the function.
var p = document.createElement('p');
p.innerHTML = 'set config option to 1';
document.getElementById('injection-point').appendChild(p);
To summarize:
In Firefox, when the user clicks that injected link, it will execute the function call on the unsafeWindow, which then triggers a timeout that invokes the corresponding function in the context of my GM script, which then does the actual processing. (Correct me if I'm wrong here.)
In Chrome, I just get a "Uncaught ReferenceError: setConfigOption is not defined" error. And indeed, entering "window.setConfigOption" into the console yields an "undefined". In Firebug and the Opera developer console, the function is there.
Maybe there's another way to do this, but a few of my functions are invoked by a Flash object on the page, which I believe makes it necessary that I have functions in the page context.
I took a quick look at the alternatives to unsafeWindow on the Greasemonkey wiki, but they all look pretty ugly. Am I completely on the wrong track here or should I look more closely into these?
RESOLUTION: I followed Max S.' advice and it works in both Firefox and Chrome now. Because the functions I needed to be available to the page had to call back into the regular ones, I moved my whole script to the page, i.e. it is completely wrapped into the function he called 'main()'.
To make the extra uglyness of that hack a little bit more bearable, I could at least drop the usage of unsafeWindow and wrappedJSObject now.
I still haven't managed to get the content scope runner from the Greasemonkey wiki working. It should do the same and it seems to execute just fine, but my functions are never accessible to <a> elements from the page, for example. I haven't yet figured out why that is.
The only way to communicate with the code running on the page in Chrome is through the DOM, so you'll have to use a hack like inserting a <script> tag with your code. Note that this may prove buggy if your script needs to run before everything else on the page.
EDIT: Here's how the Nice Alert extension does this:
function main () {
// ...
window.alert = function() {/* ... */};
// ...
}
var script = document.createElement('script');
script.appendChild(document.createTextNode('('+ main +')();'));
(document.body || document.head || document.documentElement).appendChild(script);
I have this :
contentscript.js :
function injectJs(link) {
var scr = document.createElement('script');
scr.type="text/javascript";
scr.src=link;
document.getElementsByTagName('head')[0].appendChild(scr)
//document.body.appendChild(scr);
}
injectJs(chrome.extension.getURL('injected.js'));
injected.js :
function main() {
alert('Hello World!');
}
main();
The other answers either force you to use function expressions, import an external additional file or use a long patched hack.
This answer will add the javascript into the page directly from your source code. It will use ECMAScript 6 (ES6) template literals to get the multi-line javascript string effortlessly onto the page.
var script = document.createElement('script');
script.type = "text/javascript";
script.innerHTML = `
function test() {
alert(1);
}
`;
document.getElementsByTagName('head')[0].appendChild(script);
Please note the backticks `` that define the beginning and the end of a multi-line string.
I took a quick look at the alternatives to unsafeWindow on the Greasemonkey wiki, but they all look pretty ugly. Am I completely on the wrong track here or should I look more closely into these?
You should look, because it's only available option. I'd prefer to use location hack.
myscript.user.js:
function myFunc(){
alert('Hello World!');
}
location.href="javascript:(function(){" + myFunc + "})()"
example.com/mypage.html
<script>
myFunc() // Hello World!
</script>
Sure, it's ugly. But it's working well.
Content Scope Runner method, mentioned by Max S. is better than location hack, because its easier to debug.
Any idea why the piece of code below does not add the script element to the DOM?
var code = "<script></script>";
$("#someElement").append(code);
The Good News is:
It's 100% working.
Just add something inside the script tag such as alert('voila!');. The right question you might want to ask perhaps, "Why didn't I see it in the DOM?".
Karl Swedberg has made a nice explanation to visitor's comment in jQuery API site. I don't want to repeat all his words, you can read directly there here (I found it hard to navigate through the comments there).
All of jQuery's insertion methods use
a domManip function internally to
clean/process elements before and
after they are inserted into the DOM.
One of the things the domManip
function does is pull out any script
elements about to be inserted and run
them through an "evalScript routine"
rather than inject them with the rest
of the DOM fragment. It inserts the
scripts separately, evaluates them,
and then removes them from the DOM.
I believe that one of the reasons jQuery
does this is to avoid "Permission
Denied" errors that can occur in
Internet Explorer when inserting
scripts under certain circumstances.
It also avoids repeatedly
inserting/evaluating the same script
(which could potentially cause
problems) if it is within a containing
element that you are inserting and
then moving around the DOM.
The next thing is, I'll summarize what's the bad news by using .append() function to add a script.
And The Bad News is..
You can't debug your code.
I'm not joking, even if you add debugger; keyword between the line you want to set as breakpoint, you'll be end up getting only the call stack of the object without seeing the breakpoint on the source code, (not to mention that this keyword only works in webkit browser, all other major browsers seems to omit this keyword).
If you fully understand what your code does, than this will be a minor drawback. But if you don't, you will end up adding a debugger; keyword all over the place just to find out what's wrong with your (or my) code. Anyway, there's an alternative, don't forget that javascript can natively manipulate HTML DOM.
Workaround.
Use javascript (not jQuery) to manipulate HTML DOM
If you don't want to lose debugging capability, than you can use javascript native HTML DOM manipulation. Consider this example:
var script = document.createElement("script");
script.type = "text/javascript";
script.src = "path/to/your/javascript.js"; // use this for linked script
script.text = "alert('voila!');" // use this for inline script
document.body.appendChild(script);
There it is, just like the old days isn't it. And don't forget to clean things up whether in the DOM or in the memory for all object that's referenced and not needed anymore to prevent memory leaks. You can consider this code to clean things up:
document.body.removechild(document.body.lastChild);
delete UnusedReferencedObjects; // replace UnusedReferencedObject with any object you created in the script you load.
The drawback from this workaround is that you may accidentally add a duplicate script, and that's bad. From here you can slightly mimic .append() function by adding an object verification before adding, and removing the script from the DOM right after it was added. Consider this example:
function AddScript(url, object){
if (object != null){
// add script
var script = document.createElement("script");
script.type = "text/javascript";
script.src = "path/to/your/javascript.js";
document.body.appendChild(script);
// remove from the dom
document.body.removeChild(document.body.lastChild);
return true;
} else {
return false;
};
};
function DeleteObject(UnusedReferencedObjects) {
delete UnusedReferencedObjects;
}
This way, you can add script with debugging capability while safe from script duplicity. This is just a prototype, you can expand for whatever you want it to be. I have been using this approach and quite satisfied with this. Sure enough I will never use jQuery .append() to add a script.
I've seen issues where some browsers don't respect some changes when you do them directly (by which I mean creating the HTML from text like you're trying with the script tag), but when you do them with built-in commands things go better. Try this:
var script = document.createElement( 'script' );
script.type = 'text/javascript';
script.src = url;
$("#someElement").append( script );
From: JSON for jQuery
It is possible to dynamically load a JavaScript file using the jQuery function getScript
$.getScript('http://www.whatever.com/shareprice/shareprice.js', function() {
Display.sharePrice();
});
Now the external script will be called, and if it cannot be loaded it will gracefully degrade.
What do you mean "not working"?
jQuery detects that you're trying to create a SCRIPT element and will automatically run the contents of the element within the global context. Are you telling me that this doesn't work for you? -
$('#someElement').append('<script>alert("WORKING");</script>');
Edit: If you're not seeing the SCRIPT element in the DOM (in Firebug for example) after you run the command that's because jQuery, like I said, will run the code and then will delete the SCRIPT element - I believe that SCRIPT elements are always appended to the body... but anyway - placement has absolutely no bearing on code execution in this situation.
This works:
$('body').append($("<script>alert('Hi!');<\/script>")[0]);
It seems like jQuery is doing something clever with scripts so you need to append the html element rather than jQuery object.
Try this may be helpful:
var fileref=document.createElement('script');
fileref.setAttribute("type","text/javascript");
fileref.setAttribute("src","scriptAnalytics.js");
document.getElementsByTagName("head")[0].appendChild(fileref);
I want to do the same thing but to append a script tag in other frame!
var url = 'library.js';
var script = window.parent.frames[1].document.createElement('script' );
script.type = 'text/javascript';
script.src = url;
$('head',window.parent.frames[1].document).append(script);
<script>
...
...jQuery("<script></script>")...
...
</script>
The </script> within the string literal terminates the entire script, to avoid that "</scr" + "ipt>" can be used instead.
Adding the sourceURL in the script file helped as mentioned in this page:
https://blog.getfirebug.com/2009/08/11/give-your-eval-a-name-with-sourceurl/
In the script file, add a statement with sourceURL like "//# sourceURL=foo.js"
Load the script using jQuery $.getScript() and the script will be available in "sources" tab in chrome dev tools
Your script is executing , you just can't use document.write from it. Use an alert to test it and avoid using document.write. The statements of your js file with document.write will not be executed and the rest of the function will be executed.
This is what I think is the best solution. Google Analytics is injected this way.
var (function(){
var p="https:" == document.location.protocol ? "https://" : "http://";
d=document,
g=d.createElement('script'),
s=d.getElementsByTagName('script')[0];
g.type='text/javascript';
g.src=p+'url-to-your-script.js';
s.parentNode.insertBefore(g,s); })();
You don't need jQuery to create a Script DOM Element. It can be done with vanilla ES6 like so:
const script = "console.log('Did it work?')"
new Promise((resolve, reject) => {
(function(i,s,o,g,r,a,m){
a=s.createElement(o),m=s.getElementsByTagName(o)[0];
a.innerText=g;
a.onload=r;m.parentNode.insertBefore(a,m)}
)(window,document,'script',script, resolve())
}).then(() => console.log('Sure did!'))
It doesn't need to be wrapped in a Promise, but doing so allows you to resolve the promise when the script loads, helping prevent race conditions for long-running scripts.
Append script to body:
$(document).ready(function() {
$("<script>", { src : "bootstrap.min.js", type : "text/javascript" }).appendTo("body");
});
Another way you can do it if you want to append code is using the document.createElement method but then using .innerHTML instead of .src.
var script = document.createElement( 'script' );
script.type = 'text/javascript';
script.innerHTML = 'alert("Hey there... you just appended this script to the body");';
$("body").append( script );
I tried this one and works fine. Just replace the < symbol with that \x3C.
// With Variable
var code = "\x3Cscript>SomeCode\x3C/script>";
$("#someElement").append(code);
or
//Without Variable
$("#someElement").append("\x3Cscript>SomeCode\x3C/script>");
You can test the code here.
Can try like this
var code = "<script></" + "script>";
$("#someElement").append(code);
The only reason you can't do "<script></script>" is because the string isn't allowed inside javascript because the DOM layer can't parse what's js and what's HTML.
I wrote an npm package that lets you take an HTML string, including script tags and append it to a container while executing the scripts
Example:
import appendHtml from 'appendhtml';
const html = '<p>Hello</p><script src="some_js_file.js"></script>';
const container = document.getElementById('some-div');
await appendHtml(html, container);
// appendHtml returns a Promise, some_js_file.js is now loaded and executed (note the await)
Find it here: https://www.npmjs.com/package/appendhtml
Just create an element by parsing it with jQuery.
<div id="someElement"></div>
<script>
var code = "<script>alert(123);<\/script>";
$("#someElement").append($(code));
</script>
Working example: https://plnkr.co/edit/V2FE28Q2eBrJoJ6PUEBz