"this" is undefined when running via grunt. about node-sass-import-once

[mcsagittarius]

Hmm... after a nights rest I've come up with a better solution.

I also had issues with grunt-watch. Since the "localObj" cache was set on the first run, it would simply not include any files on subsequent runs, since the files were already in the cache.

So, my solution for getting this to work with grunt and grunt-contrib-watch is:

1. Require module as normal.
2. Setup an options object e.g. importOnce: { options: {} } somewhere in the grunt.config tree.
3. Create anonymous function as importer in your "node-sass" task options.
4. Call the required importOnce with your options object passed as scope.
5. Setup an event listener for the "watch" event and reset the options object to empty (or whatever options you initially had).

Simplified example of Gruntfile.js:

var importOnce = require("node-sass-import-once");
grunt.initConfig({
    importOnce: { options: {} },
    sass: {
        options: {
            ...,
            importer: function (uri, prev, done) {
                importOnce.call(grunt.config.data.importOnce, uri, prev, done);
            },
            ...
        },
        ...
    },
    watch: {
        scss: {
            files: ["/scss/**/*.scss"],
            tasks: ["sass"],
            options: {
                ...
            }
        }
    }
    grunt.event.on("watch", function (action, filepath) {
        grunt.config(["importOnce"], { options: {} });
    });
});

I hope this will help others who are having trouble getting this to work with grunt.

Cheers.

[mcsagittarius]

I'm closing this as it can be resolved externally. Please consider updating the readme with some of my findings (or something better?).

[Snugug]

The error you're getting is most likely because you're not using the Node Sass >= v3.0.0-alpha.5, which is explicitly required in order to use the importer.

[Snugug]

That, or grunt-sass is doing something super crazy weird with the way it passes options to Node Sass

[mcsagittarius]

I'm using the latest version of grunt-sass which requires "node-sass": "^3.0.0-", so that's probably it.

Other grunt-users will likely be in the same situation until it's updated though.

Thanks.

EDIT:

Hmm... just checked the version of node-sass that grunt-sass installs and it's @2.1.1, but the node-sass repo says:

"importer (>= v2.0.0) - experimental"

So, node-sass 2.1.1 still supports this feature (experimentally) which, I suppose, is why I can still get it to work.