Calling methods in RequireJs modules from HTML ele

问题:

I'm changing a project from an "old" browser-style module structure to a "new" browser-or-server-side-javascript module structure with require.js.

On the client I'm using an offsite hosted jQuery, so I started from the example they give in the "use priority config" technique of the README:

<title>My Page</title>
<script src="scripts/require.js"></script>
<script>
require({
    baseUrl: 'scripts',
    paths: {
        jquery: 'http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min',
        jqueryui: ...,
        ...
        ... // bunch more paths here
    },
    priority: ['jquery']
}, [ 'main' ]);
</script>

This is actually working all right. But I'd like to export functionality from main to the HTML webpage itself. For instance:

<a class="button" href="#" onclick="MyApi.foo();">
    <img src="foo.png" alt="foo" />Click for: <b>Foo!</b>
</a>

Before fitting into the AMD module pattern, I'd exposed functionality from my various files by creating a dictionary object in the global space:

// main.js

var MyApi = {};

jQuery(document).ready(function($) {
    // ...unexported code goes here...

    // export function via MyApi
    MyApi.foo = function() {
        alert("Foo!");
    };
});

But I don't know what the right approach in require.js is. Is it okay to put in the HTML more require statements inside of <script> tags, and then name modules so that it can be used from within the webpage? Or should this always be done dynamically inside of main.js, like $('#foobutton').click(...)?

回答1:

One benefit from using AMD is to drop the need for namespaces. Trying to create them again with RequireJS will go against the patterns AMD promotes.

With regard to using main.js, this is only really appropriate when you have a single page app and all your code be reference from one place. You're free to make additional calls to require and load other modules as you need them.

Using your example from above, you could approach it this way:

foo.js

define(['jquery'], function($) {

    // Some set up 
    // code here

    // Return module with methods
    return {
        bar: function() {

        }
    }


});

page.js

require(['foo'], function(foo) {

    // jQuery loaded by foo module so free to use it
    $('.button').on('click', function(e) {
        foo.bar();
        e.preventDefault();
    });

});

Then in your page request the page.js file with require.

Using your example above:

require({
    // config stuff here
}, [ 'page' ]);

Or loading it in the page further down:

<script>
    require(['page']);
</script>

Some additional points

• Using the pattern above, page.js could easily require many other modules to load other page related functionality.

• Where before you would attach members to your global namespace, you now split that code into separate modules that can be re-used on any page. All without reliance on a global object.

• Using require this way to attach events to your DOM elements will most likely rely on the DOM Ready module provided by RequireJS

回答2:

You can also set the reference on javascript's window class.

At the bottom of the application module window.MyApi = MyApi;

<a class="button" href="#" onclick="MyApi.foo();"></a>

回答3:

putting onclick="" inside your markup feels dirty -- mixing presentation with content. I'd recommend you add a <script> block and put the require in it, and once inside the callback, and inside another inner $(document).ready() if necessary then wire up your event handlers in the normal way: $('#node').click(...). If you can do this generically enough that it's applicable to multiple pages, then put it inside an external file that is minified, combined, and cached. But typically these things end up being page-specific, so a <script> tag at the bottom of the page is a good solution to avoid yet another external resource request.

回答4:

Another solution is just use code like that (of course requirejs must be added to the page):

<input type="button" onclick="(function() { require('mymodule').do_work() })()"/>