Develop Reference

Inserting script/div chatbot in GTM

I'm having problems using faqbot.
The normal way of installing it is simple :
before the closing body tag insert this (i changed the keys in this example):
<script type="application/javascript">
var FAQBOT = {
PUBLIC_KEY: "0000000000000000",
AUTO_OPEN: 500
}
</script>
<div id="faqbot-00000000"></div>
<script src="https://faqbot.co/public/js/bundle.js"></script>
This works like a charm.
Now I want to do this using GTM, i'm positive my tag fires (on the DOM Rdy).
I first tried to just put the code inside the custom html tag because that should be a code injector on itself.. this didnt work..
Then I used the DOM Manipulation to achieve it and indeed when i check the source of my page, the tags are right there , BUT the bot doesn't work..
<script>
window.onload = function() {
var s = document.createElement('script');
s.type = 'application/javascript';
var code = 'var FAQBOT = { PUBLIC_KEY:"0000000000000000000",AUTO_OPEN: 500 }';
var d = document.createElement('div');
d.id ='faqbot-00000000';
var s2 = document.createElement('script');
s2.src = 'https://faqbot.co/public/js/bundle.js';
try {
s.appendChild(document.createTextNode(code));
document.body.appendChild(s);
} catch (e) {
s.text = code;
document.body.appendChild(s);
}
document.body.appendChild(d);
document.body.appendChild(s2);
}
</script>
Why is this not working , does it fire too late ?

I tried to put the following code in a custom HTML tag:
<script type="application/javascript">
var FAQBOT = {
PUBLIC_KEY: "0000000000000000",
AUTO_OPEN: 500
}
</script>
<div id="faqbot-00000000"></div>
<script src="https://faqbot.co/public/js/bundle.js"></script>
using this custom event as a trigger:
gtm.dom
and it seems to work properly:
Request URL: https://faqbot.co/public/js/bundle.js
Request Method: GET
Status Code: 200 OK

Load multiple JS files sequently after page load

To speed up the page loading time, I want to load the JS scripts after the page content has loaded.
I found this helpful article which explains how to do this when you have a single JS file: https://varvy.com/pagespeed/defer-loading-javascript.html
The solution goes like this:
<script type="text/javascript">
function downloadJSAtOnload() {
var element = document.createElement("script");
element.src = "yourSingleJSFile.js";
document.body.appendChild(element);
}
if (window.addEventListener)
window.addEventListener("load", downloadJSAtOnload, false);
else if (window.attachEvent)
window.attachEvent("onload", downloadJSAtOnload);
else window.onload = downloadJSAtOnload;
</script>
In my case, I have 4 different js files: jQuery, main.js and index.js that are starting with $(document).ready(...); and define a function initMap(), and maps.googleapis.com. Therefore I changed the code to
function downloadJSAtOnload() {
var element = document.createElement("script");
element.src = "https://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js";
document.body.appendChild(element);
var element = document.createElement("script");
element.src = "/resources/js/main.js";
document.body.appendChild(element);
var element = document.createElement("script");
element.src = "/resources/js/index.js";
document.body.appendChild(element);
var element = document.createElement("script");
element.src = "https://maps.googleapis.com/maps/api/js?key=***mysecetrkey**&callback=initMap";
document.body.appendChild(element);
Each time I load the page, I find a JS error in the console. There are two errors that I spotted so far:
First
ReferenceError: $ is not defined index.js:9:5
I don't understand what is happening here. It seems like index.js was included before jquery was loaded. But how come the error is not thrown in main.js?
Second
validValueError: initMap is not a function
It seems to me that googleapis.com js is already loaded but index.js is missing (since I define function initMap() there).
How can I force the scripts to load sequently after the page content has loaded?

If the scripts have dependencies towards each other you need to make sure that the dependencies loads first. You can nest the script loading like so:
var jqueryElement = document.createElement("script");
jqueryElement.src = "https://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js";
var mainElement = document.createElement("script");
mainElement.src = "/resources/js/main.js";
var indexElement = document.createElement("script");
indexElement.src = "/resources/js/index.js";
var googleApiElement = document.createElement("script");
googleApiElement.src = "https://maps.googleapis.com/maps/api/js?key=***mysecetrkey**&callback=initMap";
// add the first script element
document.body.appendChild(jqueryElement);
jqueryElementElement.onload = function () {
document.body.appendChild(googleApiElement);
}
googleApiElement.onload = function () {
document.body.appendChild(mainElement);
document.body.appendChild(indexElement)
}
I'm just guessing your dependency order.

Dynamically loaded jQuery not defined when using inline script

Situation:
jQuery is dynamically loaded together with other scripts by one file javascripts.js in the <head> section of the html file
Each html file has it's own javascript code executed on jQuery(document).ready() in the <body> section of the html file
Problem:
Error: jQuery is not defined for javascript in the <body> section
Modifying the html file is not an option (+1000 files with same problem)
Example html file:
<html>
<head>
<title>JS test</title>
<script src="javascripts.js" type="text/javascript"></script>
</head>
<body>
<input type="text" class="date">
<script>
jQuery(document).ready(function() { // Error: jQuery not defined
jQuery('.date').datepicker();
});
</script>
</body>
</html>
javascripts.js:
// Load jQuery before any other javascript file
function loadJS(src, callback) {
var s = document.createElement('script');
s.src = src;
s.async = true;
s.onreadystatechange = s.onload = function() {
var state = s.readyState;
console.log("state: "+state);
if (!callback.done && (!state || /loaded|complete/.test(state))) {
callback.done = true;
callback();
}
};
document.getElementsByTagName('head')[0].appendChild(s);
}
loadJS('javascripts/jquery-1.8.3.min.js', function() {
var files = Array(
'javascripts/functions.js',
'javascripts/settings.js'
);
if (document.getElementsByTagName && document.createElement) {
var head = document.getElementsByTagName('head')[0];
for (i = 0; i < files.length; i++) {
var script = document.createElement('script');
script.setAttribute('type', 'text/javascript');
script.setAttribute('src', files[i]);
script.async = true;
head.appendChild(script);
}
}
});

This is happening, as many in the comments have pointed out, because you are loading jQuery asynchronously. Asynchronous means the rest of the code is executed, and so your document-ready handler (DRH) line is running before jQuery is present in the environment.
Here's a really hacky way of resolving this. It involves making a temporary substitute of jQuery whose job is just to log the DRH callbacks until jQuery has arrived. When it does, we pass them in turn to jQuery.
JS:
//temporary jQuery substitute - just log incoming DRH callbacks
function jQuery(func) {
if (func) drh_callbacks.push(func);
return {ready: function(func) { drh_callbacks.push(func); }};
};
var $ = jQuery, drh_callbacks = [];
//asynchronously load jQuery
setTimeout(function() {
var scr = document.createElement('script');
scr.src = '//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js';
document.head.appendChild(scr);
scr.onload = function() {
$.each(drh_callbacks, function(i, func) { $(func); });
};
}, 2000);
HTML:
jQuery(document).ready(function() { alert('jQuery has loaded!'); });
Fiddle: http://jsfiddle.net/y7aE3/
Note in this example drh_callbacks is global, which is obviously bad. Ideally hook it onto a namespace or something, e.g. mynamespace.drh_callbacks.

I believe this simple solution should do the trick. The changed line in the html changes the jquery onload function to a regular function. The jquery onload function will sometimes happen before the jquery is loaded and we can't have that. It's unreliable. We need that function not to execute on page load, but AFTER the jquery has loaded.
To that end, the three lines I've added in the javascript.js are inside the code that is executed immediately after jQuery has finished loading. They test to see if the pageLoaded function has been defined (so you don't have to put one on every page, only the ones that need it) and then execute it if it's there.
Now, because the change to the HTML is simple, you can just do a regex search and replace on those 1000 files to fix them. Tools like Sublime, Eclipse or TextPad are suited for that task.
Cheers!
Example html file:
<html>
<head>
<title>JS test</title>
<script src="javascripts.js" type="text/javascript"></script>
</head>
<body>
<input type="text" class="date">
<script>
function pageLoaded() { // changed
jQuery('.date').datepicker();
} // changed
</script>
</body>
</html>
javascripts.js:
// Load jQuery before any other javascript file
function loadJS(src, callback) {
var s = document.createElement('script');
s.src = src;
s.async = true;
s.onreadystatechange = s.onload = function() {
var state = s.readyState;
console.log("state: "+state);
if (!callback.done && (!state || /loaded|complete/.test(state))) {
callback.done = true;
callback();
}
};
document.getElementsByTagName('head')[0].appendChild(s);
}
loadJS('javascripts/jquery-1.8.3.min.js', function() {
var files = Array(
'javascripts/functions.js',
'javascripts/settings.js'
);
if (document.getElementsByTagName && document.createElement) {
var head = document.getElementsByTagName('head')[0];
for (i = 0; i < files.length; i++) {
var script = document.createElement('script');
script.setAttribute('type', 'text/javascript');
script.setAttribute('src', files[i]);
script.async = true;
head.appendChild(script);
}
}
if( typeof(pageLoaded) == "function" ){ // added
pageLoaded(); // added
} // added
});

You should try following workaround to load scripts synchronously:
function loadJS(src, callback) {
document.write('<scr'+'ipt src="'+src+'"><\/scr'+'ipt>');
callback();
}
IMPORTANT to note: this function should be called always before DOM is fully rendered.

Appending Jquery in HTML dynamically

I am new to jquery. I am trying to append Jquery in an HTML page in java. To include jquery.js file I have written following code:
scriptTag += "var script = document.createElement('script');" +
"script.src = 'http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js'; " +
"script.type = 'text/javascript'; " +
"document.getElementsByTagName('head')[0].appendChild(script);" +
and then I appended following js+jquery code with it
"var script2 = document.createElement('script'); window.onload = function() {" +
"$(document).ready(function() {" +
"$(\"#identity\").hide();});};" +
"script2.type = 'text/javascript'; " +
"document.getElementsByTagName('head')[0].appendChild(script2);";
So basically I am trying to write this :
var script = document.createElement('script');
script.src = 'http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js';
script.type = 'text/javascript';
document.getElementsByTagName('head')[0].appendChild(script);
var script2 = document.createElement('script');
window.onload = function() {
$(document).ready(function() {
$("#identity").hide();
});
};
script2.type = 'text/javascript';
document.getElementsByTagName('head')[0].appendChild(script2);
What I want to do is that I want my function after window load. Somehow, writing $(document).ready(function() { alone does'nt work. I get an error that $ is not defined (looks like jquery.js is not ready yet).
To avoid this problem I have used window.onload = function() {. But now I am getting error: $(document).ready is not a function. I am really confused here on how to write this thing. Is this the correct approach? Any help/guidance is highly appreciated.
[Edit]
Please note that the following code (without jquery) works fine:
window.onload = function() {
document.getElementById('identity').style.visibility='hidden';
};
[Edit]
Actually I am making a web proxy, where I download page and serve them with custom look and field. The pages does not contain any jquery files nor can I include or write HTML. I can only add my Js dynamically using java etc.

Here is some code that shows how to load a script file dynamically and also delay calling of $(document).ready until that file is loaded:
http://jqfaq.com/how-to-load-java-script-files-dynamically/

The code you use to load jquery.min.js file is called asycnhroniously. Probably this file has not been loaded at the moment you try to execute jquery function.
Therefore you should make sure that the file is loaded using a callback function.
In the following link you can find an example on how to this:
http://blog.logiclabz.com/javascript/dynamically-loading-javascript-file-with-callback-event-handlers.aspx
Also here is a working example:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<title>index</title>
<script type="text/javascript">
function loadScript(sScriptSrc, callbackfunction) {
//gets document head element
var oHead = document.getElementsByTagName('head')[0];
if (oHead) {
//creates a new script tag
var oScript = document.createElement('script');
//adds src and type attribute to script tag
oScript.setAttribute('src', sScriptSrc);
oScript.setAttribute('type', 'text/javascript');
//calling a function after the js is loaded (IE)
var loadFunction = function() {
if (this.readyState == 'complete' || this.readyState == 'loaded') {
callbackfunction();
}
};
oScript.onreadystatechange = loadFunction;
//calling a function after the js is loaded (Firefox)
oScript.onload = callbackfunction;
//append the script tag to document head element
oHead.appendChild(oScript);
}
}
var SuccessCallback = function() {
$("#identity").hide();
}
window.onload = function() {
loadScript('http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js', SuccessCallback)
};
</script>
</head>
<body>
<span id="identity"> This text will be hidden after SuccessCallback </span>
</body>
You should use this code in your scriptTag variable and then you can use eval() function to evaluate the script in this variable. Also you can load the second javascript file in the callback function using jquery's getscript function

how can i load <script>'s into an iframe?

I've got the logic working to append into my iframe from the parent
this works:
$('#iframe').load(function() {
$(this).contents().find('#target').append('this text has been inserted into the iframe by jquery');
});
this doesn't
$('#iframe').load(function() {
$(this).contents().find('body').append('<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>');
});
.lf
The problem is something to do with the inserted script tags not being escaped properly.
Half of the javascript is becomes visible in the html, like the first script tag has been abruptly ended.

Maybe the error is with your string, never create a string in javascript with a literal < /script> in it.
$('#iframe').load(function() {
$(this).contents().find('body').append('<scr' + 'ipt type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></scr' + 'ipt>');
});

I'm a bit surprised that isn't working [Edit: No longer surprised at all, see mtrovo's answer.]...but here's what I do, which is mostly non-jQuery per your comment below but still quite brief:
var rawframe = document.getElementById('theframe');
var framedoc = rawframe.contentDocument;
if (!framedoc && rawframe.contentWindow) {
framedoc = rawframe.contentWindow.document;
}
var script = doc.createElement('script');
script.type = "text/javascript";
script.src = "http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js";
framedoc.body.appendChild(script);
Off-topic: I really wouldn't give an iframe (or anything else) the ID "iframe". That just feels like it's asking for trouble (IE has namespace issues, and while I'm not aware of it confusing tag names and IDs, I wouldn't be completely shocked). I've used "theframe" above instead.

Warning: loading script in this manner would make scripts running in main window context
i.e.: if you use window from somescript.js, it would be NOT iframe's window!
$('#iframe').load(function() {
$(this).contents().find('body').append('<scr' + 'ipt type="text/javascript" src="somescript.js"></scr' + 'ipt>');
});
To be able to use iframe context inject script with this:
function insertScript(doc, target, src, callback) {
var s = doc.createElement("script");
s.type = "text/javascript";
if(callback) {
if (s.readyState){ //IE
s.onreadystatechange = function(){
if (s.readyState == "loaded" ||
s.readyState == "complete"){
s.onreadystatechange = null;
callback();
}
};
} else { //Others
s.onload = function(){
callback();
};
}
}
s.src = src;
target.appendChild(s);
}
var elFrame = document.getElementById('#iframe');
$(elFrame).load(function(){
var context = this.contentDocument;
var frameHead = context.getElementsByTagName('head').item(0);
insertScript(context, frameHead, '/js/somescript.js');
}