Only pass .less files through the gulp stream if they or their dependencies have changed
npm install gulp-less-changedgulp-less-changed> A Gulp plugin to pass through LESS files only if they or their dependencies have changed
Analyses LESS files and their dependencies, i.e., imports and files included using data-uri, to save wasting time
regenerating output.
``
$ npm install gulp-less-changed --save-dev
`js
const gulp = require('gulp');
const lessChanged = require('gulp-less-changed');
const less = require('gulp-less');
gulp.task('default', () => {
return gulp.src('src/*.less')
.pipe(lessChanged())
.pipe(less())
.pipe(gulp.dest('src'));
});
`
`js
const gulp = require('gulp');
const lessChanged = require('gulp-less-changed');
const rename = require('rename');
const less = require('gulp-less');
const cleanCss = require('gulp-clean-css');
const gulpRename = require('gulp-rename');
const OutputPath = 'dest';
const MinifiedExtension = '.min.css';
gulp.task('default', () => {
return gulp.src('src/*.less')
.pipe(lessChanged({
getOutputFileName: file => rename(file, { dirname: OutputPath, extname: MinifiedExtension })
}))
.pipe(less())
.pipe(cleanCss())
.pipe(gulpRename({ extname: MinifiedExtension }))
.pipe(gulp.dest(OutputPath));
});
`$3
`js
const gulp = require('gulp');
const lessChanged = require('gulp-less-changed');
const rename = require('rename');
const less = require('gulp-less');
const cleanCss = require('gulp-clean-css');
const gulpRename = require('gulp-rename');
const OutputPath = 'dest';
const MinifiedExtension = '.min.css';
gulp.task('css', () => {
return gulp.src('src/*.less')
.pipe(lessChanged({
getOutputFileName: file => rename(file, { dirname: OutputPath, extname: MinifiedExtension })
}))
.pipe(less())
.pipe(cleanCss())
.pipe(gulpRename({ extname: MinifiedExtension }))
.pipe(gulp.dest(OutputPath));
});
gulp.task('default', () => {
return gulp.watch('src/*.less', ['css']);
});
`
As an optimisation, the import list for each file is kept in memory and on disk. If all of the imports for a particular file have the same timestamp,
the import list for that file is assumed to be the same. This helps to speed up incremental builds.
For each input LESS file in the Gulp stream, looks for the corresponding CSS file. If the LESS file has a later timestamp than its
corresponding CSS file, or if any of the LESS file's imports has a later timestamp than the CSS file, the LESS file is emitted to the stream.
If no options are specified, looks for a CSS file in the same path as the LESS file with a .css extension. Otherwise:
* options.getOutputFileName - function Map source paths to destination pathsfunction(path) { return rename(path, { extname: 'min.css' }); }
(e.g. )string[]
Overrides the default behaviour of looking for .css files in the input path.
* options.paths - Search paths for @imports and files referenced using data-uri. Thispaths
works in the same way as the option for gulp-less.globalVars` can also be used: internally, less is used to discover imports. This means that
Additional less options such as
paths can be evaluated using less syntax.
Copyright (c) 2016-2018 David Chandler
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