webchat: refactor to rpc

1 files changed, 99 insertions, 0 deletions

diff --git a/webchat/public/rpc.js b/webchat/public/rpc.js
new file mode 100644
index 00000000..8e911e1d
--- /dev/null
+++ b/webchat/public/rpc.js
@@ -0,0 +1,99 @@
+try {
+  module.exports = RPC
+}
+catch(e){
+}
+
+function RPC (transport) {
+  this._id = 0
+  this._waiting_callbacks = {}
+  this._methods = {}
+  this._transport = transport
+
+  transport.onmessage = this.onmessage.bind(this)
+}
+
+RPC.prototype.register = function (method, params, callback) {
+  this._methods[method] = callback
+}
+
+RPC.prototype.send = function (method, params, callback) {
+  var message = {
+    method: method,
+    params: params,
+  }
+  if (callback) {
+    var id = ++this._id
+    this._waiting_callbacks[id] = callback
+    message.id = id
+  }
+  return this._transport.send(message)
+}
+
+function _is_request (message) {
+  return typeof message.method === 'string'
+}
+
+function _is_response (message) {
+  return message.hasOwnProperty('result')
+      || message.hasOwnProperty('error')
+}
+
+RPC.prototype.onmessage = function (message) {
+  console.log('RPC message:', message)
+  if (_is_request(message)) {
+    return this._on_request(message)
+  }
+  if (_is_response(message)) {
+    return this._on_response(message)
+  }
+  return this._on_bad_message(message)
+}
+
+RPC.prototype._on_request = function (request) {
+  var method = this._methods[request.method] || function(){
+    console.log('method not found', request.method)
+  }
+  var params = request.params
+  var id = request.id
+
+  var transport = this._transport
+
+  if (typeof id === 'string' || typeof id === 'number' || id === null) {
+    return method(params, function (error, result) {
+      var response = {
+        id: id,
+      }
+      if (error) {
+        response.error = error
+      } else {
+        response.result = result
+      }
+      console.log('request:', request, '->', response)
+      return transport.send(response)
+    })
+  } else {
+    return method(params, function (error, result) {
+      var response = {
+        id: id,
+      }
+      if (error) {
+        response.error = error
+      } else {
+        response.result = result
+      }
+      console.log('notification:', request, '->', response)
+    })
+  }
+}
+
+RPC.prototype._on_response = function (response) {
+  var result = response.result
+  var error = response.error
+  var id = response.id
+
+  var callback = this._waiting_callbacks[id]
+  delete this._waiting_callbacks[id]
+
+  return callback(result, error)
+}