Gulp-async-func-runner NPM

gulp-async-func-runner

A gulp task for running asynchronous functions.

Usage

This gulp task expects an options object, an asynchronous function and a callback function. The task runs the asynchronous function passing it the options, a chunk of data, and the callback function.

As a gulp task

Use the task to execute an asynchronous function within a gulp pipe.

var asyncPipe = require('gulp-async-func-runner');
gulp.src('test/*')
    .pipe(asyncPipe(
        opts,
        asyncFunc,
        callback)
    );

API

gulp-async-func-runner ⇒ through2

A gulp task for running asynchronous functions. Returns: through2 - readable-stream/transform

Param	Type	Default	Description
opts	Object		optional options. Options to be passed to the task function should be provided in this object.
opts.oneTimeRun	Object	false	flag to run the task only once no matter how many data chunks are passed through the stream
opts.passThrough	Object	false	flag to pass data chunks through without modification. Default behaviour is to stream the data transformed by the asynchronous function. Set to passThrough to true if you only want to use the results of the asynchronous function as part of the `done` callback function.
task	function		the asynchronous task to call and wait for callback to be executed. The task must be a function with the following signature: task(options, chunk, enc, callback) - options {Object} - an options object. This will be passed the opts parameter from this module. - chunk {Object} - the current chunk of data passing through stream. - callback - the callback function to be executed once task complete. The callback function has the following signature: callback(error, data). This will be passed the done parameter from this module which must have a matching signature.
done	function		the callback function called once the asynchronous task has completed. The function must have the following signature: done(error, data).

Example
Usage:

var asyncPipe = require('gulp-async-func-runner');

Given a simple asynchronous function:

var asyncFunc = function (opts, cb) {
    assert.equal(opts.testOpt, "test option");
    cb(false, "test data");
};

When executing the function as part of a gulp pipe:

var opts = {
    oneTimeRun: true,
    passThrough: true,
    testOpt: "test option"
};
gulp.src('test/*')
    .pipe(asyncPipe(
        opts,
        function(opts, chunk, cb) {
            asyncFunc(opts, cb); //wrap in function to match the function signature
        },
        function (error, data) {
            //results of the asynchronous function available on data parameter
            ...
        })
    );

Then the pipe will wait for function to complete before continuing:

gulp.src('test/*')
    .pipe(asyncPipe(
        ...
    )
    .on('finish', function(){
        //pipe will not finish before the results of the asynchronous function are available
        ...
    });

documented by jsdoc-to-markdown.