使用gulp压缩js详细步骤笔记

先要安装nodejs，初始化项目配置文件package.json，根据情况输入配置参数

npm init

 test command:
 git repository:
 keywords:
 author:
 license: (ISC)
 About to write to E:\temp\\test03\package.json:

 {
   "name": "test03",
   "version": "1.0.0",
   "description": "",
   "main": "index.js",
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1"
   },
   "author": "",
   "license": "ISC"
 }

npm init

安装gulp

npm install gulp -g   (global环境)

npm install gulp --save-dev (项目环境)

在项目中install需要的gulp插件，一般只压缩的话需要npm install gulp-minify-css gulp-concat gulp-uglify gulp-rename del --save-dev更多插件可以在这个链接中找到 http://gratimax.net/search-gulp-plugins/

在项目的根目录新建gulpfile.js，require需要的module

var gulp = require('gulp'),
   uglify = require('gulp-uglify');  

    gulp.task("default",function()
    {
        gulp.src("src/*.js").pipe(uglify()).pipe(gulp.dest("dist/js"));
    })

执行gulp命令进行js压缩

E:\temp\\test03>gulp
[::] Using gulpfile E:\temp\\test03\gulpfile.js
[::] Starting 'default'...
[::] Finished 'default' after  ms

监控文件修改自动执行任务

 gulp.task("file_change",function()
     {
        gulp.src("src/*.js").pipe(uglify()).pipe(gulp.dest("dist/js"));
         console.log("uglifyed");
     })

     gulp.task("auto",function()
     {
         gulp.watch("src/*.js",["file_change"]);
     })

执行gulp auto，文件修改是自动执行压缩任务

E:\temp\\test03>gulp auto
[::] Using gulpfile E:\temp\\test03\gulpfile.js
[::] Starting 'auto'...
[::] Finished 'auto' after  ms
[::] Starting 'file_change'...
uglifyed
[::] Finished 'file_change' after  ms
[::] Starting 'file_change'...
uglifyed
[::] Finished 'file_change' after 4.75 ms
[::] Starting 'file_change'...
uglifyed