40 lines
1.7 KiB
Markdown
40 lines
1.7 KiB
Markdown
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### Usage
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```javascript
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import * as gulp from 'gulp';
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import gulpFunction from 'gulp-function' // default ES6 export
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// import {forFirst, forEach, atEnd} from 'gulp-function'
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let Q = require("q");
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let myFunction = function (file, enc) { // file and enc are optional in case you want to modify the file object
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let done = Q.defer();
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console.log("Hello World!")
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// NOTE:
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// you can use done.resolve as callback function
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// of any async tasks within this function
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done.resolve();
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return done.promise;
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}
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gulp.task('gulpTest',function() {
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let stream = gulp.src('./mydir/*.something')
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.pipe(gulpFunction(myFunction,'forEach')) //read the notes below
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// .pipe(forEach(myFunction)) // if imported as >> import { forEach } from 'gulp-function' <<
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.pipe(gulp.dest("./build/"));
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return stream; // by returning the stream gulp knows when our task has finished.
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});
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```
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### Notes:
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* The first argument of gulpFunction can also be an **array of multiple functionnames**.
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Each function can return a promise. The pipe stop will finish when every promise is fullfilled.
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When providing an array of functions be careful with modifying the file object -> race condition
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* The second argument can be empty, it defaults to "forEach"
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* The following options are available:
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* "forFirst" - executes when first chunk/vinylfile of the stream reaches the pipestop.
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file is pushed further down the line when function's returned promise is fullfilled.
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* "forEach" - executes like "forFirst" but with every chunk/vinylfile in the stream;
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* "atEnd" - executes after all chunks have passed and are processed in full.
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That means the stream's "finish" event fires **before "atLast" is executed**!!!
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