simple-barrier
A very minimalist, callback-based implementation of the Barrier flow control pattern in Javascript. Happy in Node.js or the browser.
This is useful for when you want to wait for several things to execute in parallel, then handle the results together.
For people too lazy to learn async.
Installing
The usual.
npm install --save simple-barrier
Waiting for several async tasks
var simpleBarrier = fs = ; // create a barrier instancevar barrier = ; // load some files, let the barrier handle the callbacks:fs;fs;fs; // add a callback for when all files are loadedbarrier;
Actioning results one-by-one
// in this example we fetch two JSON files from the web,// extracting just the part that we want: var simpleBarrier = request = ; var barrier = ; { // err, data are the standard arguments from request if !err // the value we return will be added to the result array passed to the .endWith // callback. Here, we extract one small part of the whole JSON: return JSONusefulBit; return null;} ;; barrier;
In the browser
Simple-barrier was written for node but it is happy in the browser as well:
var barrier = ; // barrier expects the data to be the second argument (as per Node's errback convention)// so we explicitly return the data param.{ return data;} $ ; $ ; barrier;