tiny

tiny makes asynchronous JavaScript be graceful and easy.

Language Translations:

• 简体中文 (zh_CN)

Quick Start

var tiny = require('tiny-control');
var ctrl = new tiny.Controller();
ctrl.go(function() {
  // do something
});
ctrl.go(fs.readdir, './path', function(files) {
  // do something
});
ctrl.go(promise, function(data) {
  // do something
});
ctrl.onError(function(err) {
  // handle err
});
ctrl.run(); // these go atom tasks will be run one by one

Atom task

Most of tiny.Controller method accept the same arguments to make an atom task, such as 'go', 'parallel', 'do', 'onFinish'. The atom task looks like:

var ctrl = new tiny.Controller();

// a single function task
ctrl.go(function() {
  // do something here
});

// a async function task, such as node.js api functions
ctrl.go(fs.readdir, path, function(files) {
  // do something
});

// a promise task, the callback will accept promise success data
ctrl.go(promise, function(data) {
  // do something
});

It will be used 'atomArgs' instead of arguments of atom task below, such as ctrl.go(atomArgs).

Sequence

tiny makes async sequence be simple.

var ctrl = new tiny.Controller();
ctrl.go(atomArgs);
ctrl.go(atomArgs);
ctrl.run(); // these go atom tasks will be run one by one

Break

var ctrl = new tiny.Controller();
ctrl.go(atomArgs);
ctrl.go(function() {
  return tiny.break;
});
ctrl.go(atomArgs); // this task will not run
ctrl.run();

Parallel tasks

tiny also support parallel tasks.

var ctrl = new tiny.Controller();
ctrl.parallel(atomArgs);
ctrl.parallel(atomArgs);
ctrl.onFinish(atomArgs); // run this task when all parallel tasks have finished
ctrl.run(); // these parallel atom tasks will be run parallelly if they are async tasks

While-do or do-while

tiny make async loop control be simple.

var ctrl = new tiny.Controller();
var i = 0;
ctrl.while(function() { return i < 2; });
ctrl.do(fs.readdir, './path', function(files) {
  i++;
}); // ctrl.do(atomArgs), the method 'do' can be called only once.
ctrl.onFinish(function() {
  i.should.equal(2);
});
ctrl.run();

If the method 'do' will be called first, the controller will run as do-while:

var ctrl = new tiny.Controller();
var i = 0;
ctrl.do(fs.readdir, './path', function(files) {
  i++; // this task will run at least once.
});
ctrl.while(function() { return i < 2; });
ctrl.onFinish(function() {
  i.should.equal(2);
});
ctrl.run();

each and map

tiny provide two methods for iterate, the each iter task will run one by one, the map iter task will run parallelly.

each:

var arr = ['cat', 'dog', 'sheep'];
var ctrl = new tiny.Controller();
ctrl.each(arr).iter(function(item, index) {
  // item is arr[index]
  // this task is also a atom task, you could return a tiny.Controller here
});
ctrl.run();

map:

var arr = ['cat', 'dog', 'sheep'];
var ctrl = new tiny.Controller();
ctrl.map(arr).iter(function(item, index) {});
ctrl.run();

Chain style

You could do this:

var ctrl = new tiny.Controller();
ctrl.go(atomArgs).go(atomArgs).go(atomArgs).onError(function(err) {}).onFinish(atomArgs).run();

Shotcut functions

tiny provide shotcut functions for all tasks:

tiny.go(atomArgs).go(atomArgs).onFinish(atomArgs).onError(function(err) {}).run();
tiny.parallel(atomArgs).parallel(atomArgs).run();
tiny.while(cond).do(atomArgs).run();
tiny.do(atomArgs).while(cond).run();
tiny.each(arr).iter(atomArgs).run();
tiny.map(arr).iter(atomArgs).run();

Nested controller

tiny.Controller could be nested! You could return a tiny.Controller in a atom task function.

var ctrl = new tiny.Controller();
ctrl.go(function() {
  console.log(1);
});
ctrl.go(function() {
  console.log(2);
  var subCtrl = new tiny.Controller();
  subCtrl.go(atomArgs);
  subCtrl.go(atomArgs);
  subCtrl.go(function() {
    console.log(3);
  });
  return subCtrl; // don't call method 'run' here, just return
});
ctrl.go(function() {
  console.log(4);
});
ctrl.go(atomArgs);
ctrl.run(); // console.log output: 1, 2, 3, 4

Error handle

You could handle all error in one place. The tiny.Controller will catch all exception that throw by atom task.

var ctrl = new tiny.Controller();
ctrl.go(function() {
  throw new Error('aa');
});
ctrl.onError(function(err) {
  // err.message will be 'aa'
});
ctrl.run();

The parent controller can catch exception that throw by it's children.

var ctrl = new tiny.Controller();
ctrl.go(function() {
  var subCtrl = new tiny.Controller();
  subCtrl.go(function() {
    throw new Error('child error');
  });
  return subCtrl;
});
ctrl.onError(function(err) {
  // err.message should be 'child error'
});
ctrl.run();

If the child controller has called method 'onError', the parent controller could not catch exception any more.

var ctrl = new tiny.Controller();
ctrl.go(function () {
  var subCtrl = new tiny.Controller();
  subCtrl.go(function () {
    throw new Error('child error');
  });
  subCtrl.onError(function (err) {
    // err.message should be 'child error'
  });
  return subCtrl;
});
ctrl.onError(function (err) {
  // could not catch error 'child error' here
});
ctrl.run();

If you want to handle the error in both parent and children controllers, just return tiny.bubble in child error handler.

var arr = ['dog', 'cat', 'sheep', 'monkey'];
var ctrl = new tiny.Controller();
ctrl.map(arr).iter(function(item, index) {
  var subCtrl = new tiny.Controller();
  subCtrl.go(function() {
    throw new Error('bubble');
  });
  subCtrl.onError(function(err) {
    err.message.should.equal('bubble');
    return tiny.bubble;
  });
  return subCtrl;
});
ctrl.onError(function(err) {
  err.message.should.equal('bubble');
});
ctrl.run();

onFinish

Every task type has onFinish event when all the task has finished.

var ctrl = new tiny.Controller();
ctrl.go(atomArgs).go(atomArgs).onFinish(atomArgs).onError(function(err) {}).run();

Notice: Each controller onFinish or onError event will be fire only once.

License

MIT