Allow widgets to save their current play state so a play can be resumed later.

fuel/app/classes/controller/widgets.php

@@ -343,14 +343,15 @@ protected function _play_widget($inst_id = false, $demo=false, $is_embedded=fals
 
 		// create the play
 		$play_id = \Materia\Api::session_play_create($inst_id, $context_id);
+		$play_state = \Materia\Session_Play::get_play_state($play_id) ?: '';
 
 		if ($play_id instanceof \Materia\Msg)
 		{
 			\Log::warning('session_play_create failed!');
 			throw new HttpServerErrorException;
 		}
 
-		$this->display_widget($inst, $play_id, $is_embedded);
+		$this->display_widget($inst, $play_id, $is_embedded, $play_state);
 	}
 
 	/**
@@ -456,7 +457,7 @@ protected function build_widget_login_messages($inst)
 		return [$summary, $desc, $status['open']];
 	}
 
-	protected function display_widget(\Materia\Widget_Instance $inst, $play_id=false, $is_embedded=false)
+	protected function display_widget(\Materia\Widget_Instance $inst, $play_id=false, $is_embedded=false, $play_state=null)
 	{
 		Css::push_group(['core', 'widget_play']);
 		Js::push_group(['angular', 'materia', 'student']);
@@ -467,6 +468,7 @@ protected function display_widget(\Materia\Widget_Instance $inst, $play_id=false
 		}
 
 		Js::push_inline('var PLAY_ID = "'.$play_id.'";');
+		Js::push_inline("var PLAY_STATE = '".$play_state."';");
 		$this->add_s3_config_to_response();
 		$this->theme->get_template()
 			->set('title', $inst->name.' '.$inst->widget->name)

fuel/app/classes/materia/api/v1.php

@@ -385,6 +385,7 @@ static public function play_activity_get($start = 0, $range = 6)
 		// but we don't want to include that in the results
 		$play  = new Session_Play();
 		$plays = $play->get_plays_by_user_id(\Model_User::find_current_id(), $start, $range + 1);
+		trace($plays);
 		$count = count($plays);
 		if ($count > $range) $plays = array_slice($plays, 0, $range);
 		return [
@@ -393,6 +394,20 @@ static public function play_activity_get($start = 0, $range = 6)
 		];
 	}
 
+	static public function play_state_save($play_id, $state)
+	{
+		$inst = self::_get_instance_for_play_id($play_id);
+		if ( ! $inst->playable_by_current_user()) return Msg::no_login();
+		if ($inst->guest_access) return;
+
+		$encoded_state = base64_encode(json_encode($state));
+
+		\DB::update('log_play')
+			->value('last_state', $encoded_state)
+			->where('id', $play_id)
+			->execute();
+	}
+
 	static public function play_logs_save($play_id, $logs, $preview_inst_id = null)
 	{
 		if ( ! $preview_inst_id)

fuel/app/classes/materia/session/play.php

@@ -31,6 +31,7 @@ class Session_Play
 	public $referrer_url;
 	public $score;
 	public $user_id;
+	public $last_state;
 
 	/**
 	 * NEEDS DOCUMENTAION
@@ -60,6 +61,7 @@ public function start($user_id=0, $inst_id=0, $context_id=false, $is_preview=fal
 				'ip_address' => \Input::ip(),
 				'referrer'   => \Input::referrer(),
 			];
+			$this->last_state = $this->unfinished_play_state() ?: '';
 
 			// @TODO: This is a hack - assuming 'lti_message_type' in POST or 'token' in GET implies an LTI.
 			// Essentially true but fragile.
@@ -104,6 +106,32 @@ protected static function set_user_is_playing()
 		\Session::set('user_is_playing', true);
 	}
 
+	public static function get_play_state($play_id)
+	{
+		$last_state = \DB::select('last_state')
+			->from('log_play')
+			->where('id', $play_id)
+			->execute();
+		if ( ! empty($last_state[0])) return base64_decode($last_state[0]['last_state']);
+		return false;
+	}
+
+	//used to grab the most recent saved state from an unfinished play of this instance by this user
+	protected function unfinished_play_state()
+	{
+		$last_state = \DB::select('last_state')
+			->from('log_play')
+			->where('inst_id', $this->inst_id)
+			->where('user_id', $this->user_id)
+			->where('is_complete', '0')
+			->where('last_state', '!=', '')
+			->order_by('created_at', 'desc')
+			->limit(1)
+			->execute();
+		if ( ! empty($last_state[0])) return $last_state[0]['last_state'];
+		return false;
+	}
+
 	protected static function start_preview($inst_id)
 	{
 		$previews = \Session::get('widgetPreviews', [0 => '']);
@@ -154,7 +182,8 @@ protected function insert_play($hash)
 				'auth'             => $this->auth,
 				'referrer_url'     => $this->referrer_url,
 				'context_id'       => $this->context_id,
-				'semester'         => $this->semester
+				'semester'         => $this->semester,
+				'last_state'       => $this->last_state
 			])
 			->execute();
 
@@ -427,7 +456,8 @@ public function get_plays_by_user_id($user_id, $start, $range)
 				'p.is_complete',
 				'p.inst_id',
 				['w.name', 'widget_name'],
-				['i.name', 'inst_name']
+				['i.name', 'inst_name'],
+				'p.last_state'
 			)
 			->from( ['log_play', 'p'])
 			->join( ['widget_instance', 'i'], 'LEFT')

fuel/app/migrations/040_add_play_state_to_log_play.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace Fuel\Migrations;
+
+class Add_Play_State_To_Log_Play
+{
+	public function up()
+	{
+		\DBUtil::add_fields(
+			'log_play',
+			[
+				'last_state' => ['type' => 'longblob'],
+			]
+		);
+	}
+
+	public function down()
+	{
+		\DBUtil::drop_fields('log_play', ['last_state']);
+	}
+}