Node.js Flow Control Utility, powerful and easy to use
$ git clone --branch=master git://github.com/enricostara/get-flow.git
$ cd get-flow
$ npm installFunction runSeries(taskList, callback, ...) runs an Array of tasks - and yes, you can mix synchronous
and asynchronous tasks! - in series, calling back when done or immediately if an exception occurs.
-
Each task must be a sync or async
Functionand all the async tasks must have the first argument namedcallbackin order to be recognised as asynchronous. -
Synchronous taskwill be internally executed surrounded by a try/catch statement, any exception stops the flow and it will be passed to the main callback as first argument. -
ASynchronous taskmust manage any exception internally and propagate it to the callback as first argument -
The arguments
callbackandtasksare mandatory (callbackcan be null but in place anyway), the subsequent arguments (if any) will be passed only to the first task .
See the following example where [sync, async, sync] tasks are executed in series:
var flow = require('get-flow');
function multiply(x, y) {
return x * y;
}
function addMillis(callback, x) { // for ASYNC task the first argument must be the callback and be named 'callback'
var start = new Date().getTime();
setTimeout(function () {
var millis = new Date().getTime() - start;
callback(null, x + millis);
}, 100);
}
function sqrt(x) {
return Math.sqrt(x);
}
flow.runSeries(
[ // tasks series
multiply, // sync
addMillis, // async
sqrt // sync again
],
function(ex, result) { // a proper callback when the last task (sqrt) is done
console.log('no exception, (ex == null) = %s ', ex == null);
console.log('result = %s', result);
var assert = require('assert');
assert.equal(result >= 10, true);
},
2, 3 // x and y passed at first task (multiply)
);Function retryUntilIsDone(callback, retriesLimit, task, ...) calls the given async task until succeeds or the retries limit
has been reached (the default is 10 attempts)
All the arguments are mandatory (callback and retriesLimit can be null but in place anyway),
the subsequent arguments (if any) will be passed to the task.
See the following example
var flow = require('get-flow');
var i = 0;
function task(callback, input) {
setTimeout(function () {
i++;
if (i === 5) {
callback(null, input + i);
} else {
callback('err')
}
}, 10);
}
flow.retryUntilIsDone(
function (ex, result) { // a proper callback
console.log('no exception, (ex == null) = %s ', ex == null);
console.log('result = %s', result);
var assert = require('assert');
assert.equal(result, 15);
},
null, // retries limit will be the default = 10
task, // the async task
10 // argument for the task
);$ npm test- get-log: a Node.js Logging Utility, easy to use and ready for production.
The project is released under the MIT license
React
Typescript
Django
Laravel
Facebook
Microsoft
Google
Alibaba
D3
Tencent