gulp-task-builder/index.js

/*
* Gulp task builder version 0.0.3
*/
var gulp = require('gulp'),
	async = require('async'),
  plugins = require("gulp-load-plugins")({
	pattern: ['gulp-*', 'gulp.*', 'main-bower-files', 'run-sequence'],
	replaceString: /\bgulp[\-.]/
});




var builder = function(){
	this.activeTasksList = [];
};

/* Utils Start */
builder.prototype.getTasks = function(){ return this.activeTasksList; };
builder.prototype.runTask = function(tasks, callback){
	callback = callback || function(){};
	plugins.runSequence(tasks, callback);
};

builder.prototype.runTasks = function(arr){
	var _self = this;
	var tasks = (arr && _self.isArray(arr)) ? arr : _self.activeTasksList;
	for(var i in tasks) _self.runTask(tasks[i]);
};

builder.prototype._isObject = function(obj){ return (typeof obj === 'object' && obj !== null );};
builder.prototype.isArray = Array.isArray || function(arr){ return (arr instanceof Array && arr.constructor.toString().indexOf("Array") > -1); };
/* Utils End */

builder.prototype.initTask = function(name, taskObj){
	var _self = this;
	/* Validate and sone other options like taskObj.preRun */
	taskObj.name = taskObj.name || name;
	if(taskObj.preRun){
		taskObj.preRun = _self.isArray(taskObj.preRun) ? taskObj.preRun : [taskObj.preRun];
		_self.runTask(taskObj.preRun, function(){
			// gulp.task(name,taskObj.preRun, _self.buildTask(taskObj));
			gulp.task(name, _self.buildTask(taskObj));
		});
	}
	else gulp.task(name, _self.buildTask(taskObj));
	_self.activeTasksList.push(name);
	if(taskObj.watch) gulp.watch(taskObj.src, [name]);

};

builder.prototype.buildTasks = function(tasks){
	var _self = this;
	if(!_self.isArray(tasks) && !_self._isObject(tasks)){ console.log('Invalid tasks list...!'); return; }
	for(var i in tasks) _self.initTask(tasks[i].name || i, tasks[i]);
};

builder.prototype.buildTask = function(task){ 
	var _self = this;
	return function(){
		var gulpTask = gulp.src(task.src).on('error', console.log);
		if(task.filter) gulpTask = gulpTask.pipe(plugins.filter(task.filter))
		if(task.preLog) gulpTask = log(gulpTask, task.preLog)
		if(task.debug){
			switch(task.ext){
				case '.js': gulpTask = gulpTask.pipe(plugins.plumber())/*.pipe(plugins.plumber().stop())*/; break;
			}
		}
		if(task.concat){
			var fileName;
			if(_self._isObject(task.concat)){
				fileName = task.concat.name || '';
				if(task.concat.ext) fileName += (task.concat.ext.indexOf('.') != -1) ? task.concat.ext : ('.'+task.concat.ext);
				if(! ~fileName.indexOf('.') && task.ext) fileName+= task.ext;
			}else if( typeof task.concat === 'string'){
				fileName = task.concat;
				if(fileName.indexOf('.') == -1 && task.ext) fileName += task.ext;
			}
			gulpTask = gulpTask.pipe(plugins.concat(fileName));
		}
		if(task.compress && !_self._isObject(task.compress) ) gulpTask = compress(gulpTask, task.ext);
		if(task.replace){
			if(_self.isArray(task.replace)){
				for(var i in task.replace){
					var repCrit = task.replace[i];
					if(repCrit.target && repCrit.src ) gulpTask = gulpTask.pipe(plugins.replace(repCrit.target, repCrit.src));
					if(repCrit.options && _self._isObject(repCrit.options) && task.ext =='.html') gulpTask = gulpTask.pipe(plugins.htmlReplace(repCrit.options));
				}
			}else if(_self._isObject(task.replace)){
				if(task.replace.target && task.replace.src ) gulpTask = gulpTask.pipe(plugins.replace(task.replace.target, task.replace.src));
				if(task.replace.options && _self._isObject(task.replace.options) && task.ext =='.html') gulpTask = gulpTask.pipe(plugins.htmlReplace(task.replace.options));
			}else console.log('replace skip of task'+name);
		}
		if(task.rename){ 
			if(_self._isObject(task.rename) || typeof(task.rename) === 'function') gulpTask = gulpTask.pipe(plugins.rename(task.rename));
			else console.log('rename skip of task '+name); 
		}

		if(task.wrapper && _self._isObject(task.wrapper) ){
			var obj = {};
			if(task.wrapper.header) obj.header = task.wrapper.header
			if(task.wrapper.footer) obj.footer = task.wrapper.footer
			gulpTask = gulpTask.pipe( plugins.wrapper(obj) );
		}

		if(task.compress && _self._isObject(task.compress) && task.compress.post) gulpTask = compress(gulpTask, task.ext);

		if(task.postLog) gulpTask = log(gulpTask, task.preLog)
		if(task.save) gulpTask = gulpTask.pipe( gulp.dest(task.dest) );
		console.log(task.name, ' job done');
	}
};

function log(stream, opt) {
	return stream.pipe(plugins.intercept(function(file){
		opt = (typeof opt === 'string' && file[opt] ) ? opt : "contents";
		console.log(file[opt].toString()); return file;
	}));
}

function compress(stream, ext) {
	switch(ext){
		case '.js': return stream.pipe(plugins.uglify())/*.pipe(plugins.plumber().stop())*/;
		case '.html': return stream.pipe(plugins.htmlmin({collapseWhitespace: true})/*minifyHtml({conditionals: true,spare:true})*/);
		case '.css': return stream.pipe(plugins.cleanCss({compatibility: 'ie8'}));
	}
}


module.exports = builder;