MediaWiki:Gadget-FDCodeEditor.js: Difference between revisions

← Older edit

@@ Line 57: / Line 57: @@
 		var cm6 = require( 'ext.CodeMirror.v6.lib' );
 		var $textarea = $( textarea );
-		var cm = new CodeMirror( textarea );
 		var previewTimer = null;
+		var cm;
+		// Never attach twice to the same textarea. CodeMirror's initialize() calls
+		// $.fn.textSelection( 'register', ... ), which THROWS "Another textSelection
+		// API was already registered" the second time - and because that throw
+		// happens inside a promise callback it is easy for it to disappear
+		// silently, leaving a plain textarea and no explanation.
+		if ( $textarea.data( 'fdCodeEditorAttached' ) ) {
+			return;
+		}
+		$textarea.data( 'fdCodeEditorAttached', true );
+		cm = new CodeMirror( textarea );
 		cm.initialize( [
@@ Line 112: / Line 124: @@
 				attach( require, textarea );
 			} );
-		}, function ( err ) {
+		} ).catch( function ( err ) {
-			// Never fail silently: a guard that bails without saying so is
+			// .catch(), NOT then()'s second argument: a rejection handler passed to
-			// indistinguishable from the gadget not being installed at all.
+			// then() does not see errors THROWN INSIDE its own success callback, so
-			mw.log.warn( '[FDCodeEditor] CodeMirror failed to load; the diagram ' +
+			// anything attach() threw used to vanish without trace - the editor just
+			// stayed a plain textarea with every module reporting "ready".
+			// Never fail silently.
+			mw.log.warn( '[FDCodeEditor] could not attach CodeMirror; the diagram ' +
 				'editor stays a plain textarea.', err );
 		} );
 	} );
 }() );