Can get older messages of a conversation

RestControllers/ConversationsController.php

@@ -388,6 +388,40 @@ class ConversationsController{
 		
 	}
 
+	/**
+	 * Get older messages of a conversation
+	 * 
+	 * @url POST /conversations/get_older_messages
+	 */
+	public function getOlderMessages(){
+
+		user_login_required();
+
+		//Get the ID of the conversation to refresh
+		$conversationID = $this->getSafePostConversationID("conversationID");
+
+		//Get the ID of the oldest message ID
+		$maxID = postInt("oldest_message_id") - 1;
+
+		//Get the limit
+		$limit = postInt("limit");
+
+		//Security
+		if($limit < 1)
+			$limit = 1;
+		if($limit > 30)
+			$limit = 30;
+		
+		//Retrieve the list of messages in the database
+		$messages = components()->conversations->getOlderMessages($conversationID, $maxID, $limit);
+
+		//Process the list of messages
+		foreach($messages as $num => $process)
+			$messages[$num] = self::ConvMessageToAPI($process);
+		
+		return $messages;
+	}
+
 	/**
 	 * Get the number of unread conversations of the user
 	 * 
@@ -459,6 +493,29 @@ class ConversationsController{
 		return array("success" => "The conversation has been deleted");
 	}
 
+	/**
+	 * Get and return safely a conversation ID specified in a $_POST Request
+	 * 
+	 * This methods check the existence of the conversation, but also check if the
+	 * user is a member or not of the conversation
+	 * 
+	 * @param string $name The name of the $_POST field containing the conversation ID
+	 * @return int The ID of the conversation
+	 */
+	private function getSafePostConversationID(string $name) : int {
+
+		user_login_required();
+
+		//Get the ID of the conversation
+		$conversationID = getPostConversationID("conversationID");
+
+		//Check if the user belongs to the conversation
+		if(!components()->conversations->userBelongsTo(userID, $conversationID))
+			Rest_fatal_error(401, "Specified user doesn't belongs to the conversation number ".$conversationID." !");
+
+		return $conversationID;
+	}
+
 	/**
 	 * Turn a ConversationInfo object into a valid API entry
 	 * 

classes/components/Conversations.php

@@ -600,6 +600,34 @@ class Conversations {
 		return $messages;
 	}
 
+	/**
+	 * Get the older messages of a conversation
+	 * 
+	 * @param int $conversationID The ID of the target conversation
+	 * @param int $startID The ID from which the research should start
+	 * @param int $limit The maximum number of message to get (positive number)
+	 * @return array The list of messages found
+	 */
+	public function getOlderMessages(int $conversationID, int $startID, int $limit) : array {
+
+		//Define conditions
+		$conditions = "WHERE ID_".$this->conversationsListTable." = ? AND ID < ? ORDER BY ID DESC LIMIT ".($limit);
+		$condVals = array(
+			$conversationID,
+			$startID + 1
+		);
+
+		//Perform request
+		$messages = $this->getMessages($conditions, $condVals);
+
+		//Revert messages order
+		$messages = array_reverse($messages);
+
+		//Return messages
+		return $messages;
+
+	}
+
 	/**
 	 * Check whether a conversation exists or not
 	 * 

functions/requests.php

@@ -82,7 +82,7 @@ function postString(string $name, int $minLength = 1) : string {
 
 /**
  * Get a boolean given in a $_POST request safely.
- * This function make a REST_Error if an error occur while
+ * This function makes a REST_Error if an error occurr while
  * processing the value
  * 
  * @param string $name The name of the $_POST field
@@ -97,6 +97,22 @@ function postBool(string $name) : bool {
 	return $_POST[$name] == "true";
 }
 
+/**
+ * Get an integer given in a $_POST request safely
+ * This function makes a REST_Error in case of error
+ * 
+ * @param string $name The name of the $_POST field
+ * @return int The integer
+ */
+function postInt(string $name) : int {
+	
+	//Check the variable
+	if(!isset($_POST[$name]))
+		Rest_fatal_error(400, "Please add a POST integer named '".$name."' in the request !");
+
+	return (int)$_POST[$name];
+}
+
 /**
  * Securely transform user given number (mixed) to integer (int)
  *