add initial publish implementation

src/index.coffee

@@ -13,6 +13,18 @@ class Subscription
     @lease_seconds = parseInt(@lease_seconds) || 0
     @bad_params    = null
 
+  publish: (items, options, cb) ->
+    format   = Subscription.formatters[options.format]
+    data     = format items
+    data_len = data.length
+    client   = ScopedClient.create(@callback).
+      headers(
+        "content-type":    format.content_type
+        "content-length":  data_len.toString()
+      )
+    client.post(data) (err, resp) =>
+      @check_response_for_success err, resp, cb
+
   # Public: Checks verification of the Subscription by passing a challenge 
   # string and checking for the response.  
   #
@@ -26,10 +38,8 @@ class Subscription
     client.get() (err, resp, body) =>
       if body != client.options.query['hub.challenge']
         cb {error: "bad challenge"}, resp
-      else if resp.statusCode.toString().match(/^2\d\d/)
-        cb null, resp
       else
-        cb {error: "bad status"}, resp
+        @check_response_for_success err, resp, cb
 
   # Public: Checks whether this Subscription is valid according to the PSHb 
   # spec.  If the Subscription is invalid, check @bad_params for an Array of
@@ -98,6 +108,13 @@ class Subscription
     else
       @bad_params["hub.#{key}"] = true
 
+  check_response_for_success: (err, resp, cb) ->
+    if resp.statusCode.toString().match(/^2\d\d/)
+      cb null, resp
+    else
+      cb {error: "bad status"}, resp
+
+Subscription.formatters    = {}
 Subscription.valid_proto   = /^https?:$/
 Subscription.valid_modes   = ['subscribe', 'unsubscribe']
 Subscription.required_keys = ['callback', 'mode', 'topic', 'verify']
@@ -106,6 +123,10 @@ Subscription.allowed_keys  = [
     'lease_seconds', 'secret', 'verify_token'
   ]
 
+Subscription.formatters.json = (items) ->
+  JSON.stringify items
+Subscription.formatters.json.content_type = 'application/json'
+
 # Public: Points to a Subscription object.  You can change this if you want 
 # to subclass Subscription with custom logic.
 exports.Subscription = Subscription

test/publish_test.coffee

@@ -0,0 +1,52 @@
+assert = require 'assert'
+http   = require 'http'
+url    = require 'url'
+query  = require 'querystring'
+nub    = require '../src'
+
+port   = 9999
+server = http.createServer (req, resp) ->
+  body    = ''
+  req.on 'data', (chunk) -> body += chunk
+
+  req.on 'end', ->
+    req_url = url.parse req.url, true
+
+    switch req_url.query.testing
+      when 'json'
+        assert.equal "[{\"abc\":1}]", body
+        resp.writeHead 200
+        resp.end "ok"
+      when 'error'
+        resp.writeHead 500
+        resp.end()
+
+req = 
+  'hub.callback':      'http://localhost:9999?testing=json'
+  'hub.mode':          'subscribe'
+  'hub.topic':         'http://server.com/foo'
+  'hub.verify':        'sync'
+  'hub.lease_seconds': '1000'
+sub = nub.subscribe(query.stringify(req))
+
+server.listen(port)
+
+calls = 2
+
+# successful publishing
+sub.publish [{abc: 1}], {format: 'json'}, (err, resp) ->
+  assert.equal null, err
+  done()
+
+# errored
+sub.callback = sub.callback.replace(/json/, 'error')
+sub.publish [{abc: 1}], {format: 'json'}, (err, resp) ->
+  assert.equal 'bad status', err.error
+  done()
+
+done = ->
+  calls -= 1
+  if calls == 0
+    server.close()
+
+process.on 'exit', -> console.log 'done'