I am using a library that (very selfishly, IMHO) assumes that the baseUrl will point to the company's CDN:
baseUrl: "[http protocol slash slash]cdn.wijmo.com/amd-js/"
At first I thought that I would just copy the contents of the above Url to my own folder (such as /scripts/wijmo/amd-js), but that doesn't work because the good folks at Wijmo hardcoded path references in their AMD define statements, such as this:
define(["./wijmo.widget"], function () { ... });
What the above means (if I understand things properly) is that if you have any other non-Wijmo AMD modules then you must either:
(a) place them under the amd-js path, perhaps in a sub-folder named "myScripts"
(b) use hard-coded RequireJS path references to your own AMDs, like this:
paths: {
"myAMD_1": "http://www.example.com/scripts/myScripts/myAMD_1",
"myAMD_2": "/scripts/myScripts/myAMD_2.js"
}
(a) works, but it means that the baseUrl cannot point to the Wijmo CDN because I don't have access to the Wijmo CDN site so I must move the files published under amd-js to my own server.
(b) sort of work, and here is my problem: If I use syntax myAMD_1 then all is well. But that doesn't let me test on my local development machine, which uses localhost. (I don't want to get into detecting which server I'm running on and customize the paths value... I want the path to remain the same before and after I publish to my http server.)
Now, according to the RequireJS documentation:
There may be times when you do want to reference a script directly and not conform to the "baseUrl + paths" rules for finding it. If a module ID has one of the following characteristics, the ID will not be passed through the "baseUrl + paths" configuration, and just be treated like a regular URL that is relative to the document:
* Ends in ".js".
* Starts with a "/".
* Contains an URL protocol, like "http:" or "https:".
When I try to end (terminate) my path reference with .js (as shown in AMD_2 above), RequireJS doesn't find my AMD and because it ends up looking for myAMD_2.js.js (notice the two .js suffixes). So it looks like RequireJS is no longer honoring what the docs say it employs as a path-resolution algorithm. With the .js suffix not working properly, I can't easily fix references to my own AMDs because I don't know for sure what server name or physical path structure they'll be published to--I really want to use relative paths.
Finally, I don't want to change Wijmo's AMD modules not only because they're are dozens of them, but also because I would need to re-apply my customizations each time they issue a Wijmo update.
So if my baseUrl has to point to a hard-coded Wijmo path then how can I use my own AMDs without placing them in a subfolder under the Wijmo path and without making any fixed-path or Url assumptions about where my own AMDs are published?
I can suggest a couple of approaches to consider here--both have some drawbacks, but can work.
The first approach is to provide a path for each and every Wijmo module that needs to be loaded. This will work, but you have touched on the obvious drawbacks of this approach in the description of the question: Wijmo has many modules that will need to be referenced, and maintaining the module list across updates in the future may be problematic.
If you can live with those drawbacks, here is what the RequireJS config would look like:
require.config({
paths: {
'wijmo.wijgrid': 'http://cdn.wijmo.com/amd-js/wijmo.wijgrid',
'wijmo.widget': 'http://cdn.wijmo.com/amd-js/wijmo.widget',
'wijmo.wijutil': 'http://cdn.wijmo.com/amd-js/wijmo.wijutil',
// ... List all relevant Wijmo modules here
}
});
require(['wijmo.wijgrid'], function() { /* ... */ });
The second approach is to initially configure the RequireJS baseUrl to load the Wijmo modules. Then once Wijmo modules have been loaded, re-configure RequireJS to be able to load your local app modules. The drawback of this approach is that all the Wijmo modules will need to be loaded up front, so you lose the ability to require Wijmo modules as needed within your own modules. This drawback will need to be balanced against the nastiness of listing out explicit paths for all the Wijmo modules as done in the first approach.
For example:
require.config({
baseUrl: 'http://cdn.wijmo.com/amd-js',
paths: {
// ... List minimal modules such as Jquery and Globalize as per Wijmo documentation
}
});
require(['wijmo.wijgrid'], function() {
require.config({
baseUrl: '.'
});
require(['main'], function() {
/* ... */
});
});
Related
Lets say i have a bunch of js view scripts defined as AMD modules in directory 'views'.
Rather than listing them all out in the requirejs config, i could just do this:
require = {
baseUrl: 'js',
packages: [
{ name:'views',location:'app/views' }
...
],
...
}
I then require them as ['views/sunset', 'views/ocean'] (or './ocean' if from another view) etc.
This saves me a whopping 20 seconds or so versus listing them all out individually in the require config, and arguably makes my define() calls more expressive (i.e it's clear which scripts are components, which are utilities etc)
Essentially i'm treating the directory as a package, but there is no main script, so require(['views']) would return a 404. Is there any reason why this approach might be considered bad practice? Are there issues with this that i'm not seeing?
In my previous job we did not have main.js file because each page had different modules so they were loaded dynamically based on the content of the page. I didn't notice any issues with that.
Your solution seems to be similar. If you do not have any errors, it's fine :)
main.js is not required but it is recommended by RequireJS from what I remember
I am building a modular single page application which consumes multiple require config files from different sources. I would like a way in my application to be able to consume a list of all modules of a specific type. something like this:
define('module-type/an-implementation',...)
define('module-type/another-implementation',...)
require('module-type/*', function(modules){
$.each(modules,function(m){ m.doStuff(); });
})
This is similar patterns dependency injectors use with multiple dependency injection (eg. https://github.com/ninject/ninject/wiki/Multi-injection)
Is there a way to do this (or something similar) with require?
RequireJS doesn't know which modules exist until something requires them. Once a module is required / depended upon RequireJS will figure out where to request the module from based on module's name and RequireJS's configuration. Once the module is loaded it can be examined / executed to find out its dependencies and handle them in turn, until all dependencies are loaded and all module bodies are executed.
In order to be able to "consume a list of all modules of a specific type" something would need to be able to find all such modules. RequireJS doesn't have any means to know which modules exist, so it alone wouldn't be enough to implement "Multi Injection".
Speculation
Some kind of module registry could be created and populated with help of the build system: e.g. a file (say module-registry.js) could be generated each time a file in the source directory is added / removed or renamed, then multi inject could be possible like:
multiRequire('module-type/*', function(modules){
$.each(modules,function(m){ m.doStuff(); });
})
which in turn would call
require(findModules(pattern), function() {
callback(Array.prototype.slice.call(arguments, 0));
});
(where multiRequire and findModules are provided by the module registry).
A am relatively new to JamJS, and struggle to make it work properly.
I've got a very simple project based on Backbone and RequireJS, where I use JamJS to manage dependencies, namely: Backbone, _, Less, $, modernizr, underscore, bootstrap.
I tend to follow the method used by Backbone Boilerplate.
This is the code I use to get the Jam-compiled requireJS config file, together with my application-specific require config:
in html:
< script data-main="/assets/js/app/config" src="/assets/js/jam/compiled.min.js"> < /script>
'Compiled.min.js' is obviously the 600kb minified file generated by Jam.
The '/app/config' file is my Require.js configuration file where I'm planning to include all my project-specific code, not managed by the dependency manager.
Here's app/config.js:
require.config({
baseUrl:'/assets/js/',
deps: ['less','modernizer','bootstrap-jam','app/main'],
paths: {
'homeView': 'app/views/homeView'
// Use the underscore build of Lo-Dash to minimize incompatibilities.
,'lodash': '../jam/lodash/dist/lodash.underscore.min'
},
map: {
},
shim: {
}
});
(the files in deps are the ones I need on every page + my main.js - kind of a router.
The problem is that, in my homeView (which is initialized by main.js), I do this sort of thing:
define(['backbone'], function (Backbone) {
return Backbone.View.extend({
el:$('#homepageWrapper'),
initialize: function () {
this.$('#subTitle').text('This text is generated by homeView - the default Backbone View.');
}
})
});
As you can see I want Backbone to be available in this view. I assume that it's available through the compiled Jam code, however when I look in the Network panel in the Web Inspector, I see that this dependency is pulled in separately- this happens to any resource I try to use, not just Backbone.
I suspect that it might be something to do with the error I get as well, which I haven't been able to figure out. When using the compiled jam config, I get:
Uncaught Error: Module name "underscore" has not been loaded yet for
context: _. Use require([])
I'd really appreciate help with this
Thanks.
Good evening,
im new with requireJs and hope my questions are not stupid, its my first :).
Why the guy is using in the code above require and requirejs, whats the difference?
require(["config"], function(config){
requirejs.config(config);
require(["App", "ember"], function(App, Ember){
var app_name = config.app_name || "App";
root[app_name] = App = Ember.Application.create(App);
App.deferUntilDOMReady();
});
});
Is there a differences beetween the different code spellings?
Will the script ressources are loaded asynchon or synchron in both cases?
If i use requirejs-jquery are jquery (the $) than global or only local scope (amd scope)?
require(['script1','script2'], function() {}
require(function(require) {
require('script1');
require('script2');
}
Is it possible to have several require configs?
For example i have a bunch of nested structures like /modules/helper/example/js/example.
At the moment i have all required shims,paths inside the main.js config.
I want to place a main.js or config.js inside each helper module, which configer the required shims, pathes, etc.
Than i no longer need places all configs, pathes inside the main.
1.1
RequireJS registers TWO instances of itself in global scope - require and requirejs - really just for one reason - if one (most likely require) is overriden with another require that is different in scope or implementation, you still have requirejs - usually always a global. This separation is important when you plan to consume resources that are relative to the module you are in now.
// contents of 'a/b/c.js' module file
define(['require'], function(require){
// "local scope" require call
// resolves to 'a/b/d.js' file
require(['./d'], function(d){})
// "global scope" require call
// resolves to 'd.js' file
requirejs(['./d'], function(d){})
})
Note that asking for local require only makes sense in define calls. As define call is what establishes the "module" and it's ID. The above is equivalent to this named define:
// contents of whatever file
define('a/b/c', ['require'], function(require){
// "local scope" require call
// resolves to 'a/b/d.js' file
require(['./d'], function(d){})
// "global scope" require call
// resolves to 'd.js' file
requirejs(['./d'], function(d){})
})
The other, secret, reason why James put requirejs in there is to force you to keep using require in local scope because his build tool looks for that specific string require to find the require calls. You do this, and r.js suddenly cannot follow you dependency tree because myLocalRequire is not what r.js expects:
// contents of 'a/b/c.js' module file
define(['require'], function(myLocalRequire){
// "local scope" require call
// resolves to 'a/b/d.js' file
myLocalRequire(['./d'], function(d){})
// "global scope" require call
// resolves to 'd.js' file
require(['./d'], function(d){})
})
1.2 RequireJS does NOT do sync loading at all. The only place where you think that "it must be sync!" - the CommonJS style call like var a = require('a') it's still not. It yanks the resource out of cache. In other words, it never loads anything sync.
1.3 Don't use bundled RequireJS+jQuery. It makes an already huge jQuery more huge and interferes with browser cache. (Instead of using cached jQuery from CDN you force user to download same jQuery again - 100k of trash).
See this instead: Use jQuery as a dependency without loading jQuery with RequireJS?
2.0 Don't. separate configs is a trap. It's hell that you willingly enter once you start "building" your apps. I dare you to give me one example of a separate sane config that I cannot express as either named defines group or "packages" where main module loads relative resource.
The only thing that must be in your RequireJS config is 'baseUrl' and 2-5 globally-used 'paths' definitions. That's it.
I have my main initialization script which calls require() and one of the dependencies is a utilities framework, but some of the other modules that I'm specifying via require() also themselves have defined this framework as a dependency.
For example (init.js):
require(['module-a', 'module-b', 'module-c'], function(a, b, c){
// where module-c is the framework
});
And then in 'module-a' I have:
define(['module-c'], function(c){
// utilize module-c framework
});
So how does AMD/RequireJs handle this scenario, does it load the same framework twice?
Any help appreciated.
Kind regards,
Mark
It will only be loaded once, both of the above modules will get the same module value for 'module-c'.
Incase its useful to others - Here's a situation I came across where a module was loaded twice:
For the following project structure:
~/prj/js/app/fileA.js
~/prj/js/app/util/fileB.js
~/prj/js/ext/publisher.js
where the RequireJs baseurl is ~/prj/js/app
fileA.js refers to the external (ext) dependancy publisher.js as:
//fileA:
define(['../ext/publisher'], function(){});
But fileB.js refers to the same dependancy with a different path:
//fileB:
define(['../../ext/publisher'], function(){});
In short, for both files, the dependency paths are different although the dependancy is in the same location. In this case, publisher.js gets loaded twice.
Use Firebug's Net tab to see it loading twice:
This is easily fixed using paths to configure the external folder path (as explained in the require_js docs):
requirejs.config({
paths: {ext: '../ext'}
});
After setting paths, the dependency is loaded just once with fileA.js and fileB.js both using the same dependency path as follows:
//fileA:
define(['ext/publisher'], function(){});
and
//fileB:
define(['ext/publisher'], function(){});