https://github.com/printercu/flow-coffee

Easy way to control async flow
https://github.com/printercu/flow-coffee

Last synced: 27 days ago
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Easy way to control async flow

• Host: GitHub
• URL: https://github.com/printercu/flow-coffee
• Owner: printercu
• License: other
• Created: 2013-01-28T22:23:28.000Z (almost 12 years ago)
• Default Branch: master
• Last Pushed: 2014-01-08T18:44:44.000Z (almost 11 years ago)
• Last Synced: 2024-09-15T17:56:34.093Z (about 2 months ago)
• Language: CoffeeScript
• Homepage:
• Size: 254 KB
• Stars: 2
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Flow-coffee

Original idea: [flow-js](https://github.com/willconant/flow-js).

You can read about the concept there.

This version is rewritten in coffee using prototypes.

It contains some extra features mostly needed for

[costa](https://github.com/printercu/costa).

## No js version

There is no js version. Just `require('coffee-script')` before

`require('flow-coffee')`.

## Extra features

### Custom context

```coffee

obj =

  someMethod: -> # ...

do new flow(

  context: obj

  blocks: [

    # If context is specified last argument is always a flow instance

    (cb) ->

      @ == obj # true

      cb() # It's callback

    (cb) ->

      do (cb_multi = cb.multi()) -> # multi is also available

        setImmediate -> cb_multi()

    (err, results, cb) -> # ...

    'someMethod' # calls method from context

    (err, cb) -> # other callback

  ]

)

```

### downcase

`REWIND`, `MULTI`, `TIMEOUT` are now `rewind`, `multi` & `setTitmeout`.

Old names are left for compatibility.

### `#define()` returns just function

```coffee

f = flow.define( -> )

f.exec()  # removed. no one used i think

f()       # keep it simple

```

### prototype's aftermath

This version works only on engines that support `__proto__` (v8 & rhino do).

Now it does mater what context you call `multi`, `setTimeout` and other methods.

```coffee

flow.exec(

  ->

    multi = @multi

    ... ->

      func multi() # wrong

  ->

    state = @

    ... ->

      func state.multi() # ok

)

```

### Multiple results are stored in the order the `@multi()` is called, not callbacks

```coffee

nt = proccess.nextTick

it 'should preserve results order', (cb) ->

  run = []

  flow.exec(

    ->

      do (cb = @multi()) -> nt -> nt -> run.push 1; cb 1

      # this will be ready first:

      do (cb = @multi()) -> nt ->       run.push 2; cb 2

    (err, results)->

      assert.deepEqual run, [2, 1]

      assert.deepEqual (x[0] for x in results), [1, 2]

      @()

    cb

  )

```

### Function after `@multi` is called with 2 arguments

It's incompatible with original flow, but I've found it very convenient.

First argument is set to the first error passed to any `@multi()`. Second is the original results array.

### Callback on any error

```coffee

flow.exec(

  -> @ null, 'test'

  (arg) ->

    # strips first (error) arguments for usual callbacks

    assert.equal arg, 'test'

    setImmediate => @ 'error'

  -> # this won't run

).error (err) ->

  # this will run

  # resume flow with @()

```

### Take a look at tests for examples & undocumented features