v1.0.0

README.md

@@ -13,7 +13,7 @@ Makes communication between a client and service worker super easy...
 - Simple API: send anonymous data-only messages _or_ a typed message with data
 - Register handlers for typed messages and anonymous messages
 - Easily respond to any message by calling `respond()` in the handler
-- Register response handlers for anonymous and typed messages using the familiar `then()` method
+- Receive a response for a message using the familiar Promise `then()` method
 
 ## Table of Contents
 
@@ -200,8 +200,6 @@ Register a handler to receive the response to a message.
 
 - __handler__ {Function} Response handler
 
-Note: a message can only have one `then` handler. Registering more than one will throw an error.
-
 Example:
 
 ```js

index.js

@@ -68,9 +68,9 @@ function Channel (handlers, worker) {
   // Handlers for unknown message types
   this.receiveHandlers = []
 
-  // ID/response handlers use for handling `responds()`s
-  // key = id string, value = function
-  this.responseHandlers = {}
+  // Deferreds for sent messages so we can resolve
+  // the promise if they receive a response
+  this.promises = {}
 
   if (this.isClient) {
     this.open.resolve()
@@ -110,11 +110,11 @@ Channel.prototype._handleMessage = function (event) {
   if (request.type in this.handlers) {
     // Known message type, invoke registered handler
     this.handlers[request.type](request.data, responder)
-  } else if (id && id in this.responseHandlers) {
+  } else if (id && id in this.promises) {
     // Response to a message, invoke registered response handler
-    var handler = this.responseHandlers[id]
-    handler(request.data)
-    this.responseHandlers[id] = null
+    var promise = this.promises[id]
+    promise.resolve()
+    this.promises[id] = null
   } else {
     // Unknown message type, invoke receive handlers
     this.receiveHandlers.forEach(function (handler) {
@@ -145,9 +145,7 @@ Channel.prototype.receive = function (handler) {
  * @returns {Object}
  */
 Channel.prototype.send = function (type, data, _id) {
-  _id = _id || shortid.generate()
-
-  var _this = this
+  var id = _id || shortid.generate()
 
   if (!data) {
     data = type
@@ -156,11 +154,13 @@ Channel.prototype.send = function (type, data, _id) {
     }
   }
 
+  var deferred = defer()
+
   var payload = JSON.stringify({
     __msgr: true,
+    id: id,
     type: type,
-    data: data,
-    id: _id
+    data: data
   })
 
   var args = [payload]
@@ -173,18 +173,9 @@ Channel.prototype.send = function (type, data, _id) {
     this.recipient.postMessage.apply(this.recipient, args)
   }.bind(this))
 
-  return {
-    /**
-     * Register a one-off response handler for a message.
-     * @param {Function} handler
-     */
-    then: function (handler) {
-      if (_this.responseHandlers[_id]) {
-        throw new Error('msgr: you can register only one response handler')
-      }
-      _this.responseHandlers[_id] = handler
-    }
-  }
+  this.promises[id] = deferred
+
+  return deferred.promise
 }
 
 // ---

package.json

@@ -1,6 +1,6 @@
 {
   "name": "msgr",
-  "version": "0.5.1",
+  "version": "1.0.0",
   "description": "Nifty worker/client postMessage utility",
   "main": "index.js",
   "scripts": {

test.js

@@ -110,17 +110,6 @@ test('Client sends known message, worker responds', function (t) {
   })
 })
 
-test('Registering multiple response handlers throws', function (t) {
-  resetStubs()
-  var message = client.send('WORKER_KNOWN_MESSAGE_TYPE', 'data')
-  message.then(function () {})
-  try {
-    message.then(function () {})
-  } catch (err) {
-    t.end()
-  }
-})
-
 test('Worker sends known message, client responds', function (t) {
   resetStubs()
   var message = worker.send('CLIENT_KNOWN_MESSAGE_TYPE', 'data')