I had to move some scripts to synchronious load through bundle, and I want to set those scripts as already defined, so require.js would not ask server for them in next calls.
Let me explain:
I had some scripts that were required everywhere, e.g. i18n, and jquery. So I have hundreeds if calls all around the project such as
require(['jquery', 'i18n', 'commonjs', ...
I bundled 'jquery', 'i18n', 'commonjs' into one script core.js which now is inserted in layout <script src="/core.js"></script>
All functions from jquer, i18n now can be accesses globally, without need of requiring them. I want to specifically say to reuire.js that those scripts are already loaded, something wich bundles should do.
I've read article about using bundles and tryied to put
bundle in my config file
bundles: {
'core': ['jquery', 'i18n', 'commonjs']
}
but it doesnt work, there lots of mistakes fallen and as I understood th only way to use bundle is to use r.js which optimizes js and folders.
Actually, all I want is to set some scripts as already loaded for require.js. Is ther a dirty way to do it?
There's no configuration option to mark a script as already defined. What you can do is to call define yourself with a module name and an appropriate return value. For instance, if you load jQuery with a script element before you start loading any module through RequireJS, you can do:
define("jquery", [], function () {
return $;
});
The code above makes it so that whenever any module requires the module jquery, they get the value of $. I normally place such modules like the one just before my call to require.config. It's just a convenient place for them.
Basically I want to be able to load some module first before other. For example, I want bootstrap to load first before backbone. Can I declare dependencies like so?
shim: {
'backbone': {deps: ['bootstrap']}
}
Yes, that is the way to do it (in the require.config({ ... block of course.) It is also recommended to add an exports key and set it to Backbone. This will allow you to use Backbone inside a require or define block, as though it were a real AMD module:
define(['backbone'], function (Backbone) {
// Backbone here is the function parameter instead of the global reference
});
Read more here. In fact they even reference Backbone as their example!
I am using requirejs. My main.js content is like following.
requirejs.config({
async: true,
parseOnLoad: true,
packages: [],
paths: {
jquery: 'https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min'
}
});
require(["login"], function (loginService) {
loginService.login('validUser');
});
Now, my config elements are little. But later, I will add packages, paths and others, so the require.config lines will increase.
I wanna separate require.config as a different file and use it?
If jquery load delays, does the error occurs? My other javascript files are using it.
Yes you can, require your config before you require anything else, like this:
config example:
require.config({
baseUrl: '/Public/js',
paths: {
jquery: '../../Scripts/jquery-1.10.2.min',
jqueryui: '../../Scripts/jquery-ui-1.10.2.min',
},
shim: {
jqueryui: {
deps: ['jquery']
},
}
waitSeconds: 3
});
and, then I load it:
require(['/Public/js/config.js'], function() {
require(['home/index'], function() {
});
});
Just remember that you reference the config.js by path in the first require-statement because require.js can not resolve by baseUrl since it has not been loaded. When you get to the inner require()-statement, its loaded and you can reference dependencies relative to baseUrl.
You can put the config into a separate JS file, that's not a problem. Just make sure that file is loaded prior to the require() call in your main code.
If you're using jQuery for other scripts that are not loaded via requireJS, you will get errors if they happen to load sooner than jQuery. What you need to do is convert all those static files into requireJS modules and load them all via requireJS. By using a define() function in each of the modules, you can set up dependencies, so all modules will wait for jQuery to load prior to executing their own code.
This is an example of a multipage requirejs based project where the requirejs.config call is in a separate file
https://github.com/requirejs/example-multipage/tree/master/www
So in my TODO applications i used Backbone and require.js. All is cool. I separated all models, views, collections to single files and use require.js to load them. After i tried to join all files to one using console require.js optimizer r.js. As i result i get one file with all my libs and classes. But when i tryed to run i met error that Backbone undefined. I checked the file and see that r.js generated next thing:
1. First it added backbone sources to app-built.js file and after placed next string
define("lib/backbone", function(){});
So as result i have Backbone variable in the window but in my modules i use it in require.js way
define('models/todo',['jquery','underscore','lib/backbone'],function ($, _, Backbone) {
No as global and as result in my modules Backbone local variable is undefined.
And the same problem with underscore.js. R.js imported it in the same way.
So question. How to avoid this problem with othew libs in future or how to fix this now? SOme technics?
You might need to use a shim since Backbone according to the RequireJS expects Backbone to be in the base url directory. In your case, it appears to be in the /lib instead. Config Shim. Depending on the RequireJS version that you're using, you just have to make sure as well that the library that you're using is AMD compatible.
In your requireJS configuration:
shim: {
backbone: {
deps: ["underscore", "jquery"],
attach: "Backbone"
},
underscore: {
attach: "_"
}
}
Let's assume this is my config.js or main.js:
require.config({
// paths are analogous to old-school <script> tags, in order to reference js scripts
paths: {
jquery: "libs/jquery-1.7.2.min",
underscore: "libs/underscore-min",
backbone: "libs/backbone-min",
jquerymobile: "libs/jquery.mobile-1.1.0.min",
jquerymobilerouter: "libs/jquery.mobile.router.min"
},
// configure dependencies and export value aliases for old-school js scripts
shim: {
jquery: ["require"],
underscore: {
deps: ["jquery"],
exports: "_"
},
backbone: {
deps: ["underscore", "jquery"],
exports: "Backbone"
},
jquerymobilerouter: ["jquery", "backbone", "underscore"],
jquerymobile: ["jquery", "jquerymobilerouter", "backbone", "underscore"]
}
});
require(["jquery", "backbone", "underscore", "app/app.min", "jquerymobilerouter", "jquerymobile"], function ($, Backbone, _, App) {
console.log($);
console.log(Backbone);
console.log(_);
$("body").fadeIn(function () {
App.init();
});
});
If I understand correctly, the paths config option allows you to reference scripts, a-la the <script> tag within HTML. Assuming this is the case, do I still need to alias scripts like jQuery with a $ or underscore with a _ in my actual require statement below? It seems strange that I'd have to, given that if you reference jQuery with a standard <script> tag, $ can be used throughout your script automatically. Shouldn't it be the same using the paths?
I'm new to the shim config option, which I understand has replaced the deprecated order! plugin. What does the exports property actually DO? It doesn't seem to create an alias for a script; for example, if I set the exports for underscore to "whatever", and then try to console.log(whatever), it's undefined. So what's the point?
How would scripts like jQuery be properly used "globally?" That is, what's the proper way to be able to use the $ alias within my App.js module, or any other module in my "app" folder? Do I have to require jQuery within every individual module and alias $ every single time? Or is the way I've done it here the proper way?
I'd greatly appreciate any other criticisms of this particular script as well; the documentation for Require.js, in my opinion, leaves much to be desired; things I'd really like to know more about seem to get glossed over and leave me scratching my head.
Just to clear up any confusion around exports, it's assumed that any shim library attaches a property to the global context (window or root), or modifies an already-existing global property (e.g. a jQuery plugin). When requireJS gets the command to load a shimmed dependency, it examines the global context for a property matching the exports value of that shim config, and if it finds it, returns it as the value of that module. If it doesn't find it, then it loads the associated script, waits for it to execute, then finds the global symbol and returns it.
An important fact to remember is that unless the shim config contains an exports value, any init method on that config will NOT be executed. The dependency loader must locate a value for the module (which is what exports specifies) before that module can be initialized, which is why the property is required if there is a shim init for that module.
update: I also need to point out that if the module in question calls define anywhere, any shim config you have for that module will be ignored. This actually caused me some headaches because I wanted to use the shim config to call jQuery's jQuery.noConflict(true) method to un-globify jQuery and keep it scoped to just the modules that require it, but couldn't manage to get it working. (See update at bottom for info on how to easily do this using map config instead of shim config.)
update 2: A recent question on the requireJS google group made me realize that my explanation might be slightly misleading, so I'd like to clarify. RequireJS will only re-use a shimmed dependency if it was loaded via requireJS at least once. That is to say, if you simply have a <script> tag on the hosting page (say, for example, underscore), like this:
<script src='lib/underscore.js'></script>
<script src='lib/require.js' data-main='main.js'></script>
...and you have something like this in your requireJS config:
paths: {
'underscore': 'lib/underscore'
},
shim: {
'underscore': {
exports: '_'
}
}
Then the first time you do define(['underscore'], function (_) {}); or var _ = require('underscore');, RequireJS will re-load the underscore library rather than re-using the previously defined window._, because as far as requireJS knows, you never loaded underscore before. Sure, it can check to see if _ is already defined on the root scope, but it has no way of verifying that the _ that's already there is the same as the one defined in your paths config. For example, both prototype and jquery assign themselves to window.$ by default, and if requireJS assumes that 'window.$' is jQuery when it is in fact prototype, you're going to be in a bad situation.
All of that means that if you mix-and-match script loading styles like that, your page will wind up with something like this:
<script src='lib/underscore.js'></script>
<script src='lib/require.js' data-main='main.js'></script>
<script src='lib/underscore.js'></script>
Where the second underscore instance is the one loaded by requireJS.
Basically, a library has to be loaded via requireJS for requireJS to have knowledge of it. However, the next time you require underscore, requireJS will go "hey, I already loaded that, so just hand back whatever the exports value is and don't worry about loading another script."
This means you have two real options. One is what I would consider an anti-pattern: simply don't use requireJS to express dependencies for global scripts. That is, as long as a library attaches a global to the root context, you'll be able to access it, event if that dependency isn't explicitly required. You can see why this is an anti-pattern - you've basically just eliminated most of the advantages to using an AMD loader (explicit dependency listing and portability).
The other, better option is using requireJS to load everything, to the degree that the only actual script tag you should create yourself is the one that initially loads requireJS. You can use shims, but 95% of the time it's really not that difficult to add an AMD wrapper to the script instead. It might take a little more work to convert all of your non-AMD libraries to be AMD compatible, but once you've done one or two it gets a lot easier - I can take any generic jQuery plugin and convert it to an AMD module in less than a minute. It's usually just a matter of adding
define(['jquery'], function (jQuery) {
at the top, and
return jQuery;
});
at the bottom. The reason I have 'jquery' mapping to jQuery rather than $ is that I've noticed most plugins these days are wrapped in a closure like this:
(function ($) {
// plugin code here
})(jQuery);
And it's a good idea to pay attention to the intended scope. You can certainly map 'jquery' to $ directly though, assuming the plugin isn't expecting to find jQuery instead of $. That's just the basic AMD wrapper - more complex ones generally try to detect what kind of loader is being used (commonJS vs AMD vs regular ol' globals) and use a different loading method depending on the result. You can find examples of this pretty easily with a few seconds on google.
Update: The workaround I used to support using jQuery.noConflict(true) with RequireJS worked, but it required a very small modification to the jQuery source, and I have since figured out a much better way to accomplish the same thing without modifying jQuery. Luckily enough, so has James Burke, the author of RequireJS, who has added it to the RequireJS documentation: http://requirejs.org/docs/jquery.html#noconflictmap
Paths tell require.js where to look when you require that dependency.
For example i have things configured like this:
"paths": {
"jquery": "require_jquery"
},
"shim": {
"jquery-cookie" : ["jquery"],
"bootstrap-tab" : ["jquery"],
"bootstrap-modal": ["jquery"],
"bootstrap-alert": ["jquery"]
},
this means that every time in a module I do
define( ['jquery']
requirejs loads the file require_jquery from the main path instead of trying to load jquery.js. In your case it would load the jQuery source file, which would then be globally available. I personally don't like that approach and for that reason in the require_jquery.js file I do:
define( ["jquery_1.7.2"], function() {
// Raw jQuery does not return anything, so return it explicitly here.
return jQuery.noConflict( true );
} );
which means that jQuery will be defined only inside my modules. (This is because i write Wordpress plugins and so I can include my own version of jQuery without touching the outside version)
Exports (reading from the docs simply should be the name of the module you are using so that it can be detected if loading went correctly. Here is explained. So if you want to set an export for underscore it should be _
jQuery should be global as I explained, if you simply import it the file is executed and jQuery is global
EDIT - to answer the comments.
yes i mean that, you must export $ or jQuery for jQuery and _ for backbone. From what i got from the docs this is needed only in some edge cases and would not be necessary for libraries that declare themselves in the global namespace as jQuery.
I think that requirejs needs them when it has to fallback from loading jQuery from a CDN. i think that requirejs first tries to load jQuery from the CDN, then makes a check to verify that it was loaded correctly by checking that the "exported" variable exists, and if it doesn't it loads it form the local filesystem (if you had configured fallbacks, of course). This is something that it's needed when requirejs can't see a 404 coming back.
jQuery is globally available because it's declared global. If you simply load and execute the jQuery script, you will end up with two globals, $ and jQuery (or you can do as i did and avoid that). Inside the define() function you can alias jQuery to be whatever you want.
define( [ 'jquery' ], function( jq ) {
// jq is jquery inside this function. if you declared it
// globally it will be also available as $ and jQuery
} );