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https://github.com/hokaccha/node-chain-tiny
A simple control flow library.
https://github.com/hokaccha/node-chain-tiny
Last synced: about 2 months ago
JSON representation
A simple control flow library.
- Host: GitHub
- URL: https://github.com/hokaccha/node-chain-tiny
- Owner: hokaccha
- License: mit
- Created: 2011-10-10T06:53:59.000Z (about 13 years ago)
- Default Branch: master
- Last Pushed: 2013-08-30T08:09:08.000Z (over 11 years ago)
- Last Synced: 2024-11-01T05:16:24.078Z (about 2 months ago)
- Language: JavaScript
- Homepage:
- Size: 118 KB
- Stars: 7
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: History.md
- License: LICENSE
Awesome Lists containing this project
README
# node-chain-tiny
A simple control flow library.
The problem which this library solves is the nest and error handling of callback.
For exsample.
asyncFunc1(function(err, result1) {
if (err) return callback(err);
// do something
asyncFunc2(function(err, result2) {
if (err) return callback(err);
// do something
asyncFunc3(function(err, result3) {
if (err) return callback(err);
// do something
callback(null, result);
});
});
});
This code becomes like this by using chain-tiny.
chain(function(next) {
asyncFunc1(next);
})
.chain(function(result1, next) {
// do something
asyncFunc2(next);
})
.chain(function(result2, next) {
// do something
asyncFunc3(next);
})
.end(function(err, result3) {
// do something
callback(err, result);
});
## Install
$ npm install chain-tiny
## Usage
### simple
var chain = require('chain-tiny');
chain(function(next) {
setTimeout(function() {
next(null, 'foo');
}, 100);
})
.chain(function(foo, next) {
console.log(foo); // => foo
setTimeout(function() {
next(null, 'bar', 'baz');
}, 1);
})
.end(function(err, bar, baz) {
console.log(bar); // => bar
console.log(baz); // => baz
});
### using this.next
var chain = require('chain-tiny');
chain(function() {
var next = this.next;
setTimeout(function() {
next(null, 'foo');
}, 100);
})
.chain(function(foo) {
var next = this.next;
console.log(foo); // => foo
setTimeout(function() {
next(null, 'bar', 'baz');
}, 1);
})
.end(function(err, bar, baz) {
console.log(bar); // => bar
console.log(baz); // => baz
});
### error handling
var chain = require('chain-tiny');
chain(function(next) {
next('Error!');
})
.chain(function(next) {
// not pass here
next(null, 'foo');
})
.end(function(err, foo) {
console.log(foo); // => undefined
console.log(err); // => Error!
});
### parallel
var chain = require('chain-tiny');
var results = [];
chain.parallel({
foo: function(next) {
setTimeout(function() {
results.push(1);
next(null, 1);
}, 100);
},
bar: function(next) {
setTimeout(function() {
results.push(2);
next(null, 2);
}, 1)
}
})
.end(function(err, res) {
console.log(res); // => { foo: 1, bar: 2 }
console.log(results); // => [2, 1]
});
chain:
var chain = require('chain-tiny');
var results = [];
chain(function(next) {
// do something
next();
})
.parallel({
foo: function(next) {
setTimeout(function() {
results.push(1);
next(null, 1);
}, 100);
},
bar: function(next) {
setTimeout(function() {
results.push(2);
next(null, 2);
}, 1)
}
})
.end(function(err, res) {
console.log(res); // => { foo: 1, bar: 2 }
console.log(results); // => [2, 1]
});
### each
var chain = require('chain-tiny');
chain.each({ foo: 'bar', hoge: 'fuga'}, function(val, key, next) {
setTimeout(function() {
next(null, key + ':' + val);
}, 1);
})
.end(function(err, results) { // or .chain(results, next)
console.log(results); // => { foo: 'foo:bar', hoge: 'hoge:fuga' }
});
chain:
var chain = require('chain-tiny');
chain(function(next) {
next(null, { foo: 'bar', hoge: 'fuga'});
})
.each(function(val, key, next) {
setTimeout(function() {
next(null, key + ':' + val);
}, 1);
})
.end(function(err, results) { // or .chain(results, next)
console.log(results); // => { foo: 'foo:bar', hoge: 'hoge:fuga' }
});
or,
var chain = require('chain-tiny');
chain(function(next) {
next(null);
})
.each({ foo: 'bar', hoge: 'fuga'}, function(val, key, next) {
setTimeout(function() {
next(null, key + ':' + val);
}, 1);
})
.end(function(err, results) { // or .chain(results, next)
console.log(results); // => { foo: 'foo:bar', hoge: 'hoge:fuga' }
});
parallel:
var chain = require('chain-tiny');
chain.eachParallel({ foo: 'bar', hoge: 'fuga'}, function(val, key, next) {
setTimeout(function() {
next(null, key + ':' + val);
}, 1);
})
.end(function(err, results) { // or .chain(results, next)
console.log(results); // => { foo: 'foo:bar', hoge: 'hoge:fuga' }
});
Array:
var chain = require('chain-tiny');
chain.eachParallel(['foo', 'bar'], function(val, key, next) {
setTimeout(function() {
next(null, key + ':' + val);
}, 1);
})
.end(function(err, results) { // or .chain(results, next)
console.log(results); // => [ '0:foo', '1:bar' ]
});