Polling Request

jQuery helper object for AJAX polling a progress-aware endpoint.

Usage

req = new PollingRequest
  url: "/states.csv"
  interval: 1000   # polling interval in milliseconds
  progress: (n)->
    console.log "Progress: #{n} percent"
  success: (res)->
    console.log "Response body: #{res}"
  error: (status, response)->
    console.log("Status: #{status}, Body: #{response}")
  complete: (status, response)->
    console.log("This is called after everything else")

req.status   # 'pending'
req.start()
req.status   # 'running'
req.progress # 0

# sometime later
req.status   # 'running'
req.progress # 50

# much later
req.status   # 'success'
req.progress # 100

# example of setting a hard timeout
setTimeout ->
  req.stop()
, 5000

Progress Aware Endpoint

PollingRequests will have a header X-POLLING-REQUEST set. It expects an HTTP endpoint to respond with a 202 Accepted status code when there is more processing to be done. The JSON response body can optionally include a progress property whose value is an integer 0..100 inclusive to indicate the percentage of processing completed.

$ curl -i http://localhost/endpoint
HTTP/1.1 202 Accepted
{ progress: 0 }

$ curl -i http://localhost/endpoint
HTTP/1.1 202 Accepted
{ progress: 50 }

$ curl -i http://localhost/endpoint
HTTP/1.1 200 Success
Content-Type: text/plain
Successful responses can be any content type

Rails

To access PollingRequest from the asset pipeline, add the following to your Gemfile:

gem 'polling_request'

And this to your asset manifest:

//= require polling_request

Bower

PollingRequest is in the Bower registry. JavaScript and CoffeeScript sources are included.

$ bower install polling-request

Development

Dependencies are managed by npm and Bower.

$ npm install

$ bower install

Tests are written with QUnit and can be run in a browser by opening test/test.html. Continuous integration is run with phantomjs:

$ ./node_modules/phantomjs/lib/phantom/bin/phantomjs test/runner.js test/test.html

Wish List

• Better docs for building and installing project

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Added some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request