Gulp文件运行任务并通知两次

Question

我刚刚开始使用gulp,需要我想要使用的所有插件并编写第一个用于sass编译的任务.它似乎工作,但有两个问题,首先当我在命令行上输入gulp时,似乎需要3或4秒才能启动,这似乎比grunt慢(我开始使用gulp,因为我知道它更快).这是正常的吗？

但主要的问题是我有一个调用sass任务的默认任务.命令行输出似乎表明两者都在运行,这意味着sass被编译两次.它也输出我的两次gulp-notify通知,这似乎不对.

这是命令行输出...

? gulp default
[00:53:40] Using gulpfile ~\Desktop\jon\gulpfile.js
[00:53:40] Starting 'sass'...
[00:53:40] Finished 'sass' after 10 ms
[00:53:40] Starting 'default'...
[00:53:40] Finished 'default' after 7.93 ?s
[00:53:41] gulp-notify: [Gulp notification] Css created
[00:53:41] gulp-notify: [Gulp notification] Css created

这是我的gulp文件全部...

var gulp = require('gulp'),
    gutil = require('gulp-util'),
    compass = require('gulp-compass'),
    rename = require('gulp-rename'),
    uglify = require('gulp-uglify'),
    watch = require('gulp-watch'),
    concat = require('gulp-concat'),
    notify = require('gulp-notify'),
    jshint = require('gulp-jshint'),
    autoprefixer = require('gulp-autoprefixer'),
    minifyCSS = require('gulp-minify-css'),
    traceur = require('gulp-traceur'),
    svgmin = require('gulp-svgmin'),
    imagemin = require('gulp-imagemin'),
    ngAnnotate = require('gulp-ng-annotate'),
    expect = require('gulp-expect-file'),
    sourcemaps = require('gulp-sourcemaps');

var paths = {
    src: "src",
    css: "stylesheets",
    img: "images",
    js:  "js"
}


// Compile Our Sass
gulp.task('sass', function() {

    gulp.src(paths.src + '/sass/*.scss')
        .pipe(sourcemaps.init())
        .pipe(compass({
            sass: 'src/sass',
            environment: 'development',
            outputStyle: 'expanded',
            debugInfo: false,
            noLineComments: true
        }))
        .pipe(autoprefixer('> 5%', 'last 2 version', 'ie 9'))
        .pipe(sourcemaps.write('./'))
        .pipe(gulp.dest(paths.css))
        .pipe(notify({ message: 'Css created' }));

});


// Dev Task
gulp.task('default', ['sass']);

谁知道这里发生了什么？我误解了Gulp任务是如何工作的吗？

Answer 1

onLast如果您只需要每个流的单个通知,请使用gulp-notify选项:

//...
.pipe(notify({message: 'Css created', onLast: true}));