Handle session loss in the console

If the session data gets lost, the console forgets the content and
previous commands. Detect this situation and handle it.

Change-Id: I82fb5e111c09091d4f9a87d2e1b1c245eced1420

Scribunto.i18n.php

@@ -32,6 +32,7 @@ $1',
 	'scribunto-console-previous-src' => 'previous console input',
 	'scribunto-console-clear' => 'Clear',
 	'scribunto-console-cleared' => 'The console state was cleared because the module was updated.',
+	'scribunto-console-cleared-session-lost' => 'The console state was cleared because the session data was lost.',
 
 
 	'scribunto-common-error-category' => 'Pages with script errors',
@@ -89,6 +90,8 @@ $messages['qqq'] = array(
 	'scribunto-common-timeout' => 'Error message displayed when script execution has passed a threshold.',
 	'scribunto-common-oom' => 'Error message displayed when the script requires more memory than the threshold.',
 	'scribunto-common-backtrace' => 'A backtrace is a list of the function calls that are currently active in a thread. This message is followed by a backtrace.',
+	'scribunto-console-cleared' => 'Message displayed in the console when the module source has been changed.',
+	'scribunto-console-cleared-session-lost' => 'Message displayed in the console when the session has expired.',
 	'scribunto-lua-in-function' => 'Reference to a function name. Parameters:
 * $1 is a function name.',
 	'scribunto-lua-in-main' => 'Part of the backtrace creation routines. Refers to the main part of the code.',

Scribunto.php

@@ -82,6 +82,7 @@ $wgResourceModules['ext.scribunto.edit'] = $sbtpl + array(
 		'scribunto-console-intro',
 		'scribunto-console-clear',
 		'scribunto-console-cleared',
+		'scribunto-console-cleared-session-lost',
 	),
 );
 $wgAPIModules['scribunto-console'] = 'ApiScribuntoConsole';

common/ApiScribuntoConsole.php

@@ -26,11 +26,13 @@ class ApiScribuntoConsole extends ApiBase {
 		$sessionKey = wfMemcKey( 'scribunto-console', $wgUser->getId(), $sessionId );
 		$cache = ObjectCache::getInstance( CACHE_ANYTHING );
 		$session = null;
+		$sessionIsNew = false;
 		if ( $params['session'] ) {
 			$session = $cache->get( $sessionKey );
 		}
 		if ( !isset( $session['version'] ) ) {
 			$session = $this->newSession();
+			$sessionIsNew = true;
 		}
 
 		// Create a variable holding the session which will be stored if there 
@@ -73,6 +75,9 @@ class ApiScribuntoConsole extends ApiBase {
 		$result['session'] = $sessionId;
 		$result['sessionSize'] = $newSession['size'];
 		$result['sessionMaxSize'] = self::SC_MAX_SIZE;
+		if ( $sessionIsNew ) {
+			$result['sessionIsNew'] = '';
+		}
 		foreach ( $result as $key => $value ) {
 			$this->getResult()->addValue( null, $key, $value );
 		}

modules/ext.scribunto.edit.js

@@ -73,7 +73,7 @@
 		}
 
 		if ( getContent() !== sessionContent ) {
-			printClearBar();
+			printClearBar( 'scribunto-console-cleared' );
 			clearNextRequest = true;
 		}
 	}
@@ -128,10 +128,10 @@
 		div.insertBefore( head, div.firstChild );
 	}
 
-	function printClearBar() {
+	function printClearBar( msg ) {
 		$( '<div/>' )
 			.attr( 'class', 'mw-scribunto-clear' )
-			.text( mw.msg( 'scribunto-console-cleared' ) )
+			.text( mw.msg( msg ) )
 			.appendTo( _out );
 	}
 
@@ -251,9 +251,11 @@
 		};
 
 		var content = getContent();
+		var sentContent = false;
 		if ( !sessionKey || sessionContent !== content ) {
 			params.clear = true;
 			params.content = content;
+			sentContent = true;
 		}
 		if ( sessionKey ) {
 			params.session = sessionKey;
@@ -268,6 +270,15 @@
 
 		api.post( params, {
 			ok: function ( result ) {
+				if ( result.sessionIsNew === '' && !sentContent ) {
+					// Session was lost. Resend query, with content
+					printClearBar( 'scribunto-console-cleared-session-lost' );
+					sessionContent = null;
+					clearPending();
+					_in.value = params.question;
+					go();
+					return;
+				}
 				sessionKey = result.session;
 				sessionContent = content;
 				if ( result.type === 'error' ) {