To make this example as simple as possible, let's say I have the following code in home.html:
<html>
<head>
<!-- ALL DEPENDENCIES FOR ICANHAZ ARE INCLUDED ABOVE -->
<script type="text/html" id="foo" src="js_template.js"></script>
<script>ich.foo({})</script>
</head>
<body></body>
</html>
And in javascript_template.js, I have the following:
Hello world!
As it turns out, icanhaz is not detecting foo, so ich.foo({}) is throwing an error. What exactly is going on here?
ICanHaz.js does not automatically download the contents of src. This behavior can be seen on line 510 of ICH.js's source code, in which it checks for an innerHTML property of the script tag before defining the template.
You must define it inline, or use your own AJAX request. For example, embedded:
<script type="text/html" id="foo">
Hello, world
</script>
Or, if you are using jQuery, you can use AJAX to load the script:
$(function(){
$.get('js_template.js', function(res){
ich.addTemplate('foo', res);
});
});
Keep in mind, ich.foo() will not be available until the AJAX request completes.
Related
I have a layout file where i included Jquery just before closing tag.
//layout.handlebars
<!DOCTYPE html>
<html>
<head></head>
<body>
{{{body}}} // renders the body content
<script src='/js/jquery-2.2.4.min.js'></script>
</body>
</html>
I also have a page specific javascript(helper.js) that makes an Ajax call.
<div>Some sample data</div>
<script src="/js/helper.js"></script>
but the problem here is jquery is loaded at the end of the page but i am referring to it in the external javascript before jquery is loaded. which shows me '$' is not defined and i know that is obvious.
One solution to this will be like adding jquery to the head section but that is not what i want.
Is there any approach that i can apply to make an ajax call from external file without moving Jquery to head section.
Any help is much appreciated!!
Is there any approach that i can apply to make an ajax call from external file without moving Jquery to head section.
Yes, I assume you already understand the cause of the issue. As you see below the final content is ..
<!DOCTYPE html>
<html>
<head></head>
<body>
<div>Some sample data</div>
<script src="/js/helper.js"></script> <!--Jquery is not loaded yet, and hence $ is undefined -->
<script src='/js/jquery-2.2.4.min.js'></script>
</body>
</html>
As you already know one option is to move jquery anywhere in the HTML but make sure its loaded before any other jquery dependent files. Now since you don't want to take this option. we have another option.
Solution:
Our only aim is to make sure the jquery library is loaded prior to any other jquery dependent files.
We can get the files on document.ready using $.getScript()
$(function(){
$.getScript( "/js/helper.js", function( data, textStatus, jqxhr ) {
console.log( "Load was performed." );
});
});
Extras: If you feel this is a overhead and you cannot add this code to all the files in your page (since there can be too many files ), You can write a generic function and a global array variable , This function will check for file paths in the array and execute each one synchronously and remove from the array. Make sure this generic function is called in every document.ready event.
One Solution is that You can put the jquery script at the start of body tag before {{{body}}} section .. In this way your helper script will be rendered after jquery and your problem will be solved .....
Well its not pretty but you could use some kind of test and wait loop something like
<script>
(function test(){
if( window.jQuery ){
//your jQuery code
} else {
setTimeout(function(){ test(); }, 200);
}
})
</script>
In the below code,
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Falback procedure</title>
<script type="text/javascript" src="//ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js">
</script>
<script type="text/javascript">
if(typeof jQuery === 'undefined')
document.write('<script type="text/javascript" src="../localfolder/jquery.js"></script>');
</script>
<script type="text/javascript" src="//cdnjs.cloudflare.com/ajax/libs/angular.js/2.0.0-beta.0/angular2.js">
</script>
</head>
<body>
<p>Hello</p>
</body>
</html>
considering a scenario, where google CDN has reach-ability issues that triggers fallback mechanism of loading local jQuery library(sitting in webserver).
In such scenario, Does angularjs library get loaded? after executing document.write
You have two problems with that code that are likely to be making it not behave as you expect:
You have a literal </script> inside a script block. It doesn't matter that it's inside a string, it terminates the block it's in. You have to break it up so the browser doesn't see it as the end of the block:
<script type="text/javascript">
if(typeof jQuery === 'undefined')
document.write('<script type="text/javascript" src="../localfolder/jquery.js"><\/script>');
// Note the \------------------------------------------------------------------^
</script>
The \ there is meaningless in JavaScript, but prevents the browser from seeing </script> and thus from ending the script block prematurely. Other ways you see it done are '....<' + '/script>' or '...</scr' + 'ipt>', etc.
Your src on the Angular script is incorrect, so it won't work whether jQuery loads or not (or from where). You've made the URL relative to the path of the page, but you need to make it at least protocol-relative by adding //:
<script type="text/javascript" src="//cdnjs.cloudflare.com/ajax/libs/angular.js/2.0.0-beta.0/angular2.js">
</script>
<!-- here --------------------------^ -->
In a comment, you asked
I was wondering, whether document.write was an asynchronous execution
No, it happens immediately when the function is run. In your case, since the function is at the top level of a script tag with no special attributes, the HTML parser has to screech to a halt and run that JavaScript code, processing any tokens the JavaScript code outputs via document.write, and waiting until the JavaScript code finishes before moving on to the Angular part.
The browser may well be able to scan ahead to preload the angular.js file, but it won't execute the contents of that file until the parser has reached that file's script tag, because the order in which scripts execute is well-defined (e.g., in document order) unless you use the async or defer attributes.
I'm trying to understand how to modularize the Backbone ToDo tutorial
Originally everything is inside the same file, but if I try to extract to another file:
var TodoView = Backbone.View.extend({
...
});
then this throws an error:
var view = new TodoView({model: todo});
**Uncaught TypeError: undefined is not a function**
It's probably due to a scope issue, but I don't know how to create a reference inside the $(function() so I can create this new object inside the main function.
Assuming that your first code part is TodoView.js,
and your second code part is app.js.
Write your html file like this,
<html>
<head>
<script type="text/javascript" src="js/TodoView.js"></script>
<script type="text/javascript" src="js/app.js"></script>
</head>
<body>
// your dom
</body>
</html>
(Edited, at 2015-07-27)
sorry for my late reply.
how about this?
<html>
<head></head>
<body>
<!-- your dom -->
<script type="text/javascript" src="js/TodoView.js"></script>
<script type="text/javascript" src="js/app.js"></script>
</body>
</html>
In many case, most javascript codes are appended to just before </body>, so that javascript can use your dom!
You can use something like require.js to load your external files and manage dependancies.
Ok, the solution was to move the script references to the end of the body instead of inside the head tags.
I think that the reason is that TodoView.js is making use of templates that were defined in the body, and since the js file was being loaded before the body, the templates were not yet available.
A simple script tag inside the body tag doesn't seem to work. The alert doesn't get triggered in the code below:
<body>
<script type="text/javascript">
alert('Hello');
</script>
{{>main}}
</body>
Any idea why?
Edit:
Just tried it with a fresh meteor app, no alert tag still:
<head>
<title>test</title>
</head>
<body>
<script type="text/javascript">
alert('Hello');
</script>
{{> hello}}
</body>
<template name="hello">
<h1>Hello World!</h1>
{{greeting}}
<input type="button" value="Click" />
</template>
Weird thing is when I copy paste the source of the html, made a new html page, and the alert will work.
Edit3: I deployed this app here: http://alert-in-body-test.meteor.com/
Do you get an alert box?
This question is still relevant in the current version of Meteor (version 0.5.4) so I wanted to describe how to include script at the end of the body.
To execute javascript at the end of the body, register a Handlebars helper and put the relevant code there, like this:
In client.html:
<body>
{{renderPage}}
{{afterBody}}
</body>
...
In client.js:
if (typeof Handlebars !== 'undefined') {
Handlebars.registerHelper('afterBody', function(name, options) {
$('body').append('AFTER BODY');
});
}
(For a great description of why this is required, see Rahul's answer to a similar question here: https://stackoverflow.com/a/14002991/219238 )
Its working for me
in onrender call this jquery
$.getScript('yours url')
It should work.
I have just pasted this inside one of my projects and it worked.
Your {{>main}} is strange for me tough. Also make sure that <body> is inside <html> tag.
Meteor is constructing the entire DOM from Javascript by rendering your page as a template -- the 'source' for your page as seen by the browser is basically:
<script type="text/javascript" src="/5a8a37bef5095c69bcd3844caf3532e1ba6d49bf.js"></script>
I can't find a definitive page stating that embedding a script tag in a template like this won't cause it to be executed, but it definitely feels against the spirit of what the framework is trying to achieve.
If the point is to achieve a clean separation of your markup and logic then why put it in the template. A better solution would be to use the meteor.startup call
Instead of looking the rendered html at developer tools, try looking the real downloaded html.
You will find a (probably) empty tag, with tons of script tags inside the .
In other words, the body of your meteor application is not the body of the final html, it's just your main template.
Instead, this ton on scripts shipped by Meteor, will load your templates.
So, your code will not run, cause it's been placed there. It's like when you manipulate DOM (with jQuery, for exemple), placing a script tag in DOM, after it's loaded. This script tag will not run.
I'm learning JavaScript for a project, but I am stuck at the very beginning. I boiled it down, to the function in my script not being defined, but as near as I can tell it is defined.
I have a script: "script.js" with the function display result.
function displayResult()
{
document.write("hello world");
}
in the header of index.html I have this line
<script type="text/javascript" href="script.js"></script>
I have this line later
<body onload="displayResult()">
I have no idea why my function will not call. I would appreciate the help.
<script type="text/javascript" href="script.js"></script>
Should be:
<script type="text/javascript" src="script.js"></script>
there is no href attribute to a script block, its included from an external source through the src attribute.
BTW, calling document.write after the document has finished loading will first clear the entire content of the document, then replace it with whatever you pass to the call (in this case, 'hello world', which is not a valid HTML or XML document).