async-state

Parse state across async callbacks.

Installation

npm install async-state

Usage

var asyncState = require('async-state')()
 
asyncState.foo = 'foo'
 
setTimeout(function () {
  console.log(asyncState.foo) // => foo
}, 2000)
 
asyncState.foo = 'bar'

This also works between files. For a more complex example, see the example folder.

Gotchas

Only object references are copied across async bounderies. The content of the object is shared! I.e. the following will get you into trouble:

var asyncState = require('async-state')()
 
asyncState.obj = { foo: 'foo' }
 
setTimeout(function () {
  console.log(asyncState.obj.foo) // => bar
}, 2000)
 
// THIS IS BAD!
asyncState.obj.foo = 'bar'

To solve that issue, implement your own cloning logic:

var asyncState = require('async-state')()
 
asyncState.obj = { foo: 'foo' }
 
setTimeout(function () {
  console.log(asyncState.obj.foo) // => foo
}, 2000)
 
// THIS IS GOOD :)
asyncState.obj = { foo: 'bar' }

Credits

Thanks to Andreas Madsen for pointing me towards the async_wrap API.

License

MIT