# pull-postmsg

[pull-stream][] for bidirectional communication between frames using
[window.postMessage][]

```js
var Postmsg = require('pull-postsg')
```

```
var duplex = Postmsg(win, origin)
```

- `duplex`: duplex-stream for communication between `win` and the current
    window
- `win`: window object to post messages to. If not specified, the source
    window for the first message received on the current window will be used.
- `origin`: origin URL or path. defaults to `'*'`. This value is used when
    [posting messages to `win`](window.postMessage) and is used to filter
    messages received on the current window.

Note that the stream does not propagate backpressure or errors, so if you need
those, you have to emulate them at a higher level.

[pull-stream]: https://github.com/dominictarr/pull-stream/
[window.postMessage]: https://developer.mozilla.org/en-US/docs/Web/API/Window/postMessage

## See also

- [mmckegg's window-stream](https://github.com/mmckegg/window-stream)
- https://steveliles.github.io/cross_domain_inter_frame_communication_in_javascript.html

## License

Copyright (c) 2016 Charles Lehner

Usage of the works is permitted provided that this instrument is
retained with the works, so that any entity that uses the works is
notified of this instrument.

DISCLAIMER: THE WORKS ARE WITHOUT WARRANTY.