ميدياويكي:Gadget-BiDiEditing.js

function bidiSwitchSetup() {
	var editform = document.getElementById('editform');
	if ( editform == null ) {
		return;
	}

	bidiAddButton( editform, 'Default', function( style ) {
		style.direction = 'inherit';
		style.unicodeBidi = 'inherit';
	});
	bidiAddButton( editform, 'dir=ltr', function( style ) {
		style.direction = 'ltr';
	});
	bidiAddButton( editform, 'dir=rtl', function( style ) {
		style.direction = 'rtl';
	});
	bidiAddButton( editform, 'bidi=normal', function( style ) {
		style.unicodeBidi = 'normal';
	});
	bidiAddButton( editform, 'bidi=override', function( style ) {
		style.unicodeBidi = 'bidi-override';
	});
}

function bidiAddButton( before, label, action ) {
	var button = document.createElement( 'input' );
	button.type = 'button';
	button.value = label;
	button.onclick = function( event ) {
		var box = document.getElementById( 'wpTextbox1' );
		if ( box == null ) {
			alert( 'Broken! Edit box missing.' );
		} else {
			//var style = document.getOverrideStyle( box, null );
			var style = box.style;
			action( style );
		}
	}
	before.parentNode.insertBefore( button, before );
}

$( bidiSwitchSetup );