I'm bringing a template across from an old version of Joomla into Wordpress and got quite a few javascript files that I have to use with the main referring out to functions in the others. All of these files use jQuery left right and centre and given Wordpress uses noconflict by default I thought it would be straightforward to wrap each js file up like this:
(function($){
....my code...
})(jQuery);
The problem I get is with the scope of functions that are called across files, so for example:
File 1
(function($){
$(document).ready(function(){
mainmenu();
});
})(jQuery);
File 2
(function($){
function mainmenu(){
alert("hello");
}
})(jQuery);
Here is the problem I get the error "uncaught ReferenceError: mainmenu is not defined", I know it will be something simple to reference the function, but I can't see it, probably be a "Doh" moment.
Any help is most appreciated. Yes I know I could just find and replace the '$' with 'jQuery' but I just thought that there must be a way to do it?
it is because the mainmenu is a closure function within the anonymous function in the second file.. so it is not available in file1.
One possible solution is to make it a global function, so that it will be available in the global scope.
(function($){
window.mainmenu = function (){
alert("hello");
}
})(jQuery);
Related
my code in JS is getting very large right now and so I wanted to outsource sections to other files, for clarity.
In my main file I use
jQuery(document).ready(function ($) {
$.getScript("/wp-content/plugins/file2.js",function(){
console.log("loaded 2");
});
$.getScript("/wp-content/plugins/file3.js",function(){
console.log("loaded 3");
});
This works.
In file 2 and 3 I use jQuery with functions like:
function getData(){
$.("#foo").on("click", function(){});
}
So I am getting the error
$ is undefined
because I do not declare $.
But if I wrap around the $.ready function I can't access the functions inside file 2 which are used by the other files.
How can I 'declare' the $ separately without loosing the global scope of the function. Or is there even a better way?
I only include in html:
<script src="/wp-content/plugins/file1.js" type="text/javascript"></script>
Thanks for helping!
A copy of jQuery is assigned to $ by default.
It will only be undefined if you:
Overwrite it
Mask it
Call $.noConflict()
… so don't do any of those.
I often start my JavaScript apps like this:
jQuery(function($) {
... code for the app ...
});
I'm just starting to use RequireJS, and will start the app like this:
define(['jquery'], function($) {
... code for the app ...
});
Now, as I don't want the app to start processing until all the HTML has been loaded, I've combined the two like this:
require(['jquery'], function($) {
$(function($) {
... code for the app ...
});
});
Is that the way to do it?
The RequireJS documentation touches on this and offers has a slightly more convenient option:
require(['domReady!'], function (doc) {
//This function is called once the DOM is ready,
//notice the value for 'domReady!' is the current
//document.
});
Note that you will need to download the domReady plugin, and if you have a very complex page you may wish to use the "explicit function call" method that they also show... Although then it looks an awful lot like what you're already doing with jQuery.
So the main diferences between define and require in this scenario is, one declare a module and the second one call this defined module, then if it is not loaded, the browser download the js library.
To take control about when your require files will download, you need to use the domReady plugin.
You need to put the js library at you require.config, I usually put at the same directory as declared at the baseUrl property, for example:
require.config({
baseUrl: "js/lib",
paths:{
filter:"../src/filter",
addPanel: "../src/edit-panel"
}
}
I put the domReady.js at the js/lib/ folder.
So, then you can use the require method at any place of you html file:
require(['jquery!'], function ($) {
});
Note that I use the symbol ! to indicate that this library is load after the completely page load.
As the box at the top of the page, my question is answered here:
Requirejs domReady plugin vs Jquery $(document).ready()?
The other answers here essential repeat what's in the above link. But, thanks!
I am not too familiar with jQuery.noConflict. I have tried to implement it a couple times, but I feel I am doing it wrong.
Is there a way to set a noConflict with "jquery-1.7.1.min.js"? Do I put it in the actual file, or in the header of my index or both? I have tried to follow examples but I know I am doing it wrong.
Any guidance or quick examples would help me tremendously!
var foo = $.noconflict();
foo('body').addClass('bar');
You can either assign it a new alias (as shown above) or call $.noConflict and only have jQuery available for use. If you chose an alias though you must use that new alias every time you want to reference jQuery.
Keep in mind though that you can enable noConflict, but still have it available when necessary using an anonymous function:
// disable $ and force use of myJQ
var myJQ = jQuery.noConflict();
(function($){
//
// be able to use $ within this block and have it mean jQuery
//
$('body').addClass('foo');
})(myJQ);
// we're outside the block, now we're back to myJQ
myJQ('body').removeClass('foo');
No conflict mode is easy to use. Include this shortly after loading jQuery and any jQuery-dependent libraries:
var $j = jQuery.noConflict();
Then, instead of using $ for everything, use $j:
var elements = $j('.class-name');
Have you tried the following examples:
http://api.jquery.com/jQuery.noConflict/
I think it says all about it. Check your browser console to see any errors.
I'd recommend using a noConflict call, as well as wrapping your jQuery code with an anonymous function, so you can call jQuery by $:
jQuery.noConflict();
(function ($) {
// Now you can use $ to call jQuery
}(jQuery));
Suppose we need to embed a widget in third party page. This widget might use jquery for instance so widget carries a jquery library with itself.
Suppose third party page also uses jquery but a different version.
How to prevent clash between them when embedding widgets? jquery.noConflict is not an option because it's required to call this method for the first jquery library which is loaded in the page and this means that third party website should call it. The idea is that third party site should not amend or do anything aside putting tag with a src to the widget in order to use it.
Also this is not the problem with jquery in particular - google closure library (even compiled) might be taken as an example.
What solutions are exist to isolate different javascript libraries aside from obvious iframe?
Maybe loading javascript as string and then eval (by using Function('code to eval'), not the eval('code to eval')) it in anonymous function might do the trick?
Actually, I think jQuery.noConflict is precisely what you want to use. If I understand its implementation correctly, your code should look like this:
(function () {
var my$;
// your copy of the minified jQuery source
my$ = jQuery.noConflict(true);
// your widget code, which should use my$ instead of $
}());
The call to noConflict will restore the global jQuery and $ objects to their former values.
Function(...) makes an eval inside your function, it isn't any better.
Why not use the iframe they provide a default sandboxing for third party content.
And for friendly ones you can share text data, between them and your page, using parent.postMessage for modern browser or the window.name hack for the olders.
I built a library to solve this very problem. I am not sure if it will help you of course, because the code still has to be aware of the problem and use the library in the first place, so it will help only if you are able to change your code to use the library.
The library in question is called Packages JS and can be downloaded and used for free as it is Open Source under a Creative Commons license.
It basically works by packaging code inside functions. From those functions you export those objects you want to expose to other packages. In the consumer packages you import these objects into your local namespace. It doesn't matter if someone else or indeed even you yourself use the same name multiple times because you can resolve the ambiguity.
Here is an example:
(file example/greeting.js)
Package("example.greeting", function() {
// Create a function hello...
function hello() {
return "Hello world!";
};
// ...then export it for use by other packages
Export(hello);
// You need to supply a name for anonymous functions...
Export("goodbye", function() {
return "Goodbye cruel world!";
});
});
(file example/ambiguity.js)
Package("example.ambiguity", function() {
// functions hello and goodbye are also in example.greeting, making it ambiguous which
// one is intended when using the unqualified name.
function hello() {
return "Hello ambiguity!";
};
function goodbye() {
return "Goodbye ambiguity!";
};
// export for use by other packages
Export(hello);
Export(goodbye);
});
(file example/ambiguitytest.js)
Package("example.ambiguitytest", ["example.ambiguity", "example.greeting"], function(hello, log) {
// Which hello did we get? The one from example.ambiguity or from example.greeting?
log().info(hello());
// We will get the first one found, so the one from example.ambiguity in this case.
// Use fully qualified names to resolve any ambiguities.
var goodbye1 = Import("example.greeting.goodbye");
var goodbye2 = Import("example.ambiguity.goodbye");
log().info(goodbye1());
log().info(goodbye2());
});
example/ambiguitytest.js uses two libraries that both export a function goodbye, but it can explicitly import the correct ones and assign them to local aliases to disambiguate between them.
To use jQuery in this way would mean 'packaging' jQuery by wrapping it's code in a call to Package and Exporting the objects that it now exposes to the global scope. It means changing the library a bit which may not be what you want but alas there is no way around that that I can see without resorting to iframes.
I am planning on including 'packaged' versions of popular libraries along in the download and jQuery is definitely on the list, but at the moment I only have a packaged version of Sizzle, jQuery's selector engine.
Instead of looking for methods like no conflict, you can very well call full URL of the Google API on jQuery so that it can work in the application.
<script src="myjquery.min.js"></script>
<script>window.myjQuery = window.jQuery.noConflict();</script>
...
<script src='...'></script> //another widget using an old versioned jquery
<script>
(function($){
//...
//now you can access your own jquery here, without conflict
})(window.myjQuery);
delete window.myjQuery;
</script>
Most important points:
call jQuery.noConflict() method IMMEDIATELY AFTER your own jquery and related plugins tags
store the result jquery to a global variable, with a name that has little chance to conflict or confuse
load your widget using the old versioned jquery;
followed up is your logic codes. using a closure to obtain a private $ for convience. The private $ will not conflict with other jquerys.
You'd better not forget to delete the global temp var.
I'm trying to integrate a javascript library for drag&drop on tables into one page of my custom Drupal module. I've included the js file using drupal_add_js, but I don't know how to initialize it.
The documentation for that library states that an init function should be called like
<body onload="REDIPS.drag.init()">
How would I do that in Drupal? Or has Drupal some better way of initializing the script?
Drupal has its own mechanism for this, involving adding a property to Drupal.behaviors. See this page: http://drupal.org/node/205296
Drupal.behaviors.redipsDragBehavior = function() {
REDIPS.drag.init();
};
From the linked page:
Any function defined as a property of
Drupal.behaviors will get called when
the DOM has loaded.
You could try adding another drupal_add_js call in the same function as your other add_js:
drupal_add_js('REDIPS.drag.init();','inline','header',true);
The last param "true" is to defer the execution of the script.
I hope that helps in some way!