mincer
Version:
Web assets processor. Native JavaScript port of Sprockets.
87 lines (64 loc) • 1.76 kB
JavaScript
/** internal
* class Processor
*
* Used to create custom processors without need to extend [[Template]] by
* simply providing a function to the processor registration methods:
*
* var name = 'my-pre-processor';
* var func = function (context, data, callback) {
* callback(null, data.toLowerCase());
* };
*
* // register custom pre-processor
* environment.registerPreProcessor('text/css', name, func);
*
* // unregister custom pre-processor
* environment.unregisterPreProcessor('text/css', name);
*
*
* ##### See Also:
*
* - [[Context]]
* - [[Processing]]
*
*
* ##### SUBCLASS OF
*
* [[Template]]
**/
;
// stdlib
var inherits = require('util').inherits;
// 3rd-party
var _ = require('lodash');
// internal
var Template = require('./template');
var prop = require('./common').prop;
// Class constructor
var Processor = module.exports = function Processor() {
Template.apply(this, arguments);
};
inherits(Processor, Template);
// Run processor
Processor.prototype.evaluate = function (context) {
if (Processor === this.constructor) {
throw new Error('Processor can\'t be used directly. Use `Processor.create()`.');
}
return this.constructor.__func__(context, this.data);
};
/**
* Processor.create(name, func) -> Function
*
* Returns new `Processor` subclass.
**/
Processor.create = function (name, func) {
var Klass;
if (!_.isFunction(func)) {
throw new Error('Processor#create() expects second argument to be a function.');
}
Klass = function () { Processor.apply(this, arguments); };
inherits(Klass, Processor);
prop(Klass, '__name__', 'Processor(' + name + ')');
prop(Klass, '__func__', func);
return Klass;
};