How to set the default plugin for a module in require.js?

Question

I am using require.js to load some JS libraries and want to run some common code before and after load. I have made a simple loader plug-in named plug.js to do so:

define([], function () {
    return {
        load: function (name, req, onload, config) {

            // Pre-load code...

            req([name], function (value) {
                // Post-load code...

                onload(value);
            });
        }
    };
});

When I use it from other modules like this, it works as expected:

define(['plug!lib1'], function (lib1) {
    // Use lib1
}

But I want to prevent the library to be accidentally loaded with the default loader, so I tried to add the following mapping:

require.config({
    // ...
    map: {
        '*': {
            'lib1': 'plug!lib1'
        }
    },
    // ...
}

Then I required the library in my modules without specifying the plug-in by define(['lib1'], ...) and the pre-load code of the plug-in runs as expected, but the post-load code never runs and I get load timeout errors. I also tried to apply mapping to specific modules rather than to * , but got the same error.

Is it something wrong with my loader plug-in code? Is it ever possible to have the default loader plug-in associated with a module (a global plug-in would also be acceptable)?

As an alternative I see making custom modules with pre-load code and setting them as dependencies in shim configuration, but this looks even less convenient than specifying the plug-in name everywhere.

Answer 1

Looks like require.js tries to prevent circular dependency. app module requests lib1 , which resolves to plug!lib1 , and plug requests lib1 again, which require.js refuses to load despite that this time it would be loaded directly rather than plug would be called recursively.

I renamed the original library, and the problem gone away:

require.config({
    // ...
    paths: {
        'lib1-core': 'lib1'
    },
    map: {
        '*': {
            'lib1': 'plug!lib1-core'
        }
    },
    // ...
});