Implemented a simple server-side api to store data

api.php

@@ -0,0 +1,92 @@
+<?php
+/*
+ * api.php handels data storage
+ * Used by Ember Data RESTAdapter to read and write data on server side
+ * 
+ * Returns data back to the client on a GET request on ?/poll/:id or ?/user/:id.
+ * Save new data on a POST request on ?/polls or ?/users and return new id back.
+ * 
+ * There is no need to check for permission because all data stored on server 
+ * is encrypted and could only be read with the correct encryption key. There is
+ * no update oder delete feature yet.
+ */
+
+// load classes
+require_once 'classes/datahandler.php';
+
+// initialize
+$datahandler = new datahandler();
+
+switch ($_SERVER['REQUEST_METHOD']) {
+    // read data
+    case 'GET':
+        // get requested id from uri
+        $query_paramter = split("/",$_SERVER["QUERY_STRING"]);
+        if (isset($query_paramter[2])) {
+            $requested_id = $query_paramter[2];
+        }
+        else {
+            throw new Exception("Requested data but there is no ID in URI");
+        }
+        
+        // read data
+        $data = $datahandler->get($requested_id);
+        if ($data === false) {
+            // there was no data with this id or it could not be readen
+            
+            // set http header
+            header("HTTP/1.0 404 Not Found");
+        }
+        else {
+            // set http header
+            header("HTTP/1.0 200 OK");
+            
+            // forbidde browser to lead javascript from an external location
+            header("Content-Security-Policy: script-src 'self'");
+            
+            // set content-type and charset
+            header('Content-Type: application/x-json-encrypted; charset=utf-8');
+            
+            // send data back
+            echo $data;
+        }
+        
+        break;
+    
+    // write data
+    case 'POST':
+        // get data send with request
+        $data = file_get_contents('php://input');
+        
+        $newId = $datahandler->write($data);
+        if ($newId === false) {
+            header("HTTP/1.0 500 Internal Server Error");
+        }
+        else {
+            // set http header
+            header("HTTP/1.0 200 OK");
+            
+            // forbidde browser to lead javascript from an external location
+            header("Content-Security-Policy: script-src 'self'");
+            
+            // set content-type and charset
+            header('Content-Type: application/x-json-encrypted; charset=utf-8');
+            
+            // extend given data with newId
+            $newData = json_decode($data);
+            $newData->poll->id = $newId;
+            
+            // send back data
+            echo json_encode($newData);
+        }
+        
+        break;
+    
+    // request method is not supported
+    default:
+        // set http header
+        header("HTTP/1.0 400 Bad Request");
+        
+        break;
+}
+?>

classes/datahandler.php

@@ -0,0 +1,80 @@
+<?php
+
+/*
+ * handles the data for api.php
+ */
+class datahandler {
+    // (string) folder to store data in relative to position of api.php
+    // webserver has to have write access to this folder
+    // must end with a slash
+    const DATA_FOLDER = 'data/';
+    
+    // (int) length of ids used to identify data
+    const ID_LENGTH = 10;
+    
+    // (string) characters used to generate a new id
+    const ID_CHARACTERS = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
+    
+    /*
+     * read data with $id
+     * return false, if there is no data with this id or if data could not be read
+     */
+    public function get($id) {
+        // file with absolut path
+        $file = self::DATA_FOLDER . $id;
+        
+        // check if file exists and is readable
+        if (!is_readable($file)) {
+            return false;
+        }
+        
+        return file_get_contents($file);
+    }
+    
+    /*
+     * generates a new Id
+     */
+    protected function generateNewId()
+    {
+        // generate random string
+        $randomString = '';
+        for ($i = 0; $i < self::ID_LENGTH; $i++) {
+            $characters = self::ID_CHARACTERS;
+            $randomString .= $characters[rand(0, strlen($characters) - 1)];
+        }
+        
+        // check if id is already used, generate new one if necessary
+        if (file_exists(self::DATA_FOLDER.$randomString)) {
+            $randomString = $this->generateNewId();
+        }
+        
+        return $randomString;
+    }
+    
+    /*
+     * stores data
+     * returns new id or false on error
+     */
+    public function write ($data) {
+        // get a new id
+        $new_id = $this->generateNewId();
+        
+        $new_file = self::DATA_FOLDER . $new_id;
+        
+        // check if new file could be created
+        if (!is_writeable(self::DATA_FOLDER)) {
+            echo "not writeable";
+            return false;
+        }
+        
+        // write data
+        if (file_put_contents($new_file, $data, LOCK_EX) === false) {
+            echo "error on write";
+            return false;
+        }
+        
+        return $new_id;
+    }
+}
+
+?>

index.html

@@ -108,6 +108,8 @@
     <script src="lib/handlebars-v1.2.0.js"></script>
     <script src="lib/ember.js"></script>
     <script src="lib/ember-data.js"></script>
+    <script src="lib/activemodel-adapter.js"></script>
+    <script src="lib/embedded-records-mixin.js"></script>
     <script src="lib/localstorage_adapter.js"></script>
     
     <!-- EMBER APP CODE -->
@@ -118,7 +120,10 @@
         });
         
         // adapter initialization
-        App.ApplicationAdapter = DS.LSAdapter;
+        App.ApplicationAdapter = DS.RESTAdapter.extend({
+            // set namespace to api.php in same subdirectory
+            namespace: 'api.php?'
+        });
         
         /*
          * models
@@ -137,6 +142,7 @@
         // option model
         // used by poll model
         App.Option = DS.Model.extend({
+            poll : DS.belongsTo('poll', {async: true}),
             title : DS.attr('string')
         });
         
@@ -283,10 +289,10 @@
             actions: {
                 save: function(){
                     // save poll
-                    this.get('model').save();
-                    
-                    // redirect to new poll
-                    this.transitionToRoute('poll', this.get('model'));
+                    this.get('model').save().then(function(){
+                        // redirect to new poll
+                        this.transitionToRoute('poll', this.get('model'));
+                    });
                 }
             }
          });