ambientlight: Relocate controller creation in start

to use onerror

Change-Id: I04d2e9910d3f4b69dd2eb5fce30c90f5fa3b0462
Signed-off-by: Philippe Coval <p.coval@samsung.com>

lib/ambientlight/index.js

@@ -17,15 +17,15 @@
 
 'use strict';
 
+var console = require('console');
 var BH1750 = require('bh1750');
 
 /**
  * Class inspired by W3C's generic-sensor
  * @related: https://www.w3.org/TR/ambient-light/
  **/
 function AmbientLight(options) {
-  this.state = 'construct';
-
+  this.state = 'idle';
   this.type = 'ambientlight';
   this.illuminance = 0;
 
@@ -42,12 +42,6 @@ function AmbientLight(options) {
   this.options = options || {};
   this.options.frequency = this.options.frequency || 1;
   this.options.controller = this.options.controller || 'bh1750';
-  if (this.options.controller === 'bh1750') {
-    this.sensor = new BH1750(this.options.sensor);
-  } else {
-    throw new Error("TODO: unsupported controller:" + this.options.controller);
-  }
-  this.state = 'idle';
 
   return this;
 }
@@ -80,7 +74,21 @@ AmbientLight.prototype.stop = function stop() {
 
 AmbientLight.prototype.start = function start() {
   var self = this;
-  self.state = 'activating';
+  this.state = 'activating';
+  if (!this.sensor) {
+    try {
+      if (this.options.controller === 'bh1750') {
+        this.sensor = new BH1750(this.options.sensor);
+      } else {
+        throw new Error("TODO: unsupported controller:" + this.options.controller);
+      }
+    } catch (err) {
+      if (this.onerror) {
+        return this.onerror(err)
+      }
+    }
+  }
+
   try {
     if (!self.interval) {
       self.interval = setInterval(function() { self.update(); },
@@ -95,3 +103,12 @@ AmbientLight.prototype.start = function start() {
 
 module.exports = AmbientLight;
 
+
+if (module.parent === null) {
+  var sensor = new AmbientLight();
+  sensor.onreading = function() {
+    console.log('log: ' + this.illuminance)
+    this.stop();
+  }
+  sensor.start();
+}