Conditionally run a task
A ternary gulp plugin: conditionally control the flow of vinyl objects.
Note: Badly behaved plugins can often get worse when used with gulp-if. Typically the fix is not in gulp-if.
Note: Works great with lazypipe, see below
1: Conditionally filter content
var gulpif = require'gulp-if';var uglify = require'gulp-uglify';var condition = true; // TODO: add business logicgulptask'task'gulpsrc'./src/*.js'pipegulpifcondition uglifypipegulpdest'./dist/';;
Only uglify the content if the condition is true, but send all the files to the dist folder
2: Ternary filter
var gulpif = require'gulp-if';var uglify = require'gulp-uglify';var beautify = require'gulp-beautify';var// TODO: add business logicreturn true;gulptask'task'gulpsrc'./src/*.js'pipegulpifcondition uglify beautifypipegulpdest'./dist/';;
If condition returns true, uglify else beautify, then send everything to the dist folder
3: Remove things from the stream
Remove from here on
var gulpIgnore = require'gulp-ignore';var uglify = require'gulp-uglify';var jshint = require'gulp-jshint';var condition = './gulpfile.js';gulptask'task'gulpsrc'./*.js'pipejshintpipegulpIgnoreexcludeconditionpipeuglifypipegulpdest'./dist/';;
Run JSHint on everything, remove gulpfile from the stream, then uglify and write everything else.
4: Exclude things from the stream
Exclude things from entering the stream
var uglify = require'gulp-uglify';gulptask'task'gulpsrc'./*.js' '!./node_modules/**'pipeuglifypipegulpdest'./dist/';;
This is fastest because nothing in node_modules ever leaves
Lazypipe creates a function that initializes the pipe chain on use. This allows you to create a chain of events inside the gulp-if condition. This scenario will run jshint analysis and reporter only if the linting flag is true.
var gulpif = require'gulp-if';var jshint = require'gulp-jshint';var uglify = require'gulp-uglify';var linting = false;var compressing = false;var jshintChannel = lazypipe// adding a pipeline steppipejshint // notice the stream function has not been called!pipejshintreporter// adding a step with an argumentpipejshintreporter 'fail';gulptask'scripts'return gulpsrcpathsscriptssrcpipegulpiflinting jshintChannelpipegulpifcompressing uglifypipegulpdestpathsscriptsdest;;
Lazypipe assumes that all function parameters are static, gulp-if arguments need to be instantiated inside each lazypipe. This difference can be easily solved by passing a function on the lazypipe step
var gulpif = require'gulp-if';var jshint = require'gulp-jshint';var uglify = require'gulp-uglify';var compressing = false;var jsChannel = lazypipe// adding a pipeline steppipejshint // notice the stream function has not been called!pipejshintreporter// adding a step with an argumentpipejshintreporter 'fail'// you can't say: .pipe(gulpif, compressing, uglify)// because uglify needs to be instantiated separately in each lazypipe instance// you can say this instead:pipereturn gulpifcompressing uglify;;// why does this work? lazypipe calls the function, passing in the no arguments to it,// it instantiates a new gulp-if pipe and returns it to lazypipe.gulptask'scripts'return gulpsrcpathsscriptssrcpipejsChannelpipegulpdestpathsscriptsdest;;
gulp-if will pipe data to
condition is truthy.
condition is falsey and
elseStream is passed, data will pipe to
After data is piped to
elseStream or neither, data is piped down-stream.
stat object or
function that takes in a vinyl file and returns a boolean or
RegularExpression that works on the
The condition parameter is any of the conditions supported by gulp-match. The
file.path is passed into
If a function is given, then the function is passed a vinyl
file. The function should return a
Stream for gulp-if to pipe data into when conditon is truthy.
Optional, Stream for gulp-if to pipe data into when condition is falsey.
Copyright (c) 2014 Richardson & Sons, LLC
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