Moved the HTML5 placeholder attribute emulation in ext.vector.simpleSearch into it's own jQuery plugin called jquery.placeholder.

resources/Resources.php

@@ -48,6 +48,9 @@ return array(
 	'jquery.highlightText' => new ResourceLoaderFileModule(
 		array( 'scripts' => 'resources/jquery/jquery.highlightText.js' )
 	),
+	'jquery.placeholder' => new ResourceLoaderFileModule(
+		array( 'scripts' => 'resources/jquery/jquery.placeholder.js' )
+	),
 	'jquery.suggestions' => new ResourceLoaderFileModule(
 		array(
 			'scripts' => 'resources/jquery/jquery.suggestions.js',

resources/jquery/jquery.placeholder.js

@@ -0,0 +1,48 @@
+/**
+ * HTML5 placeholder emulation for jQuery plugin
+ * 
+ * This will automatically use the HTML5 placeholder attribute if supported, or emulate this behavior if not.
+ * 
+ * @author Trevor Parscal <tparscal@wikimedia.org>
+ * @version 0.1.0
+ * @license GPL v2
+ */
+
+jQuery.fn.placeholder = function( text ) {
+	// If the HTML5 placeholder attribute is supported, use it
+	if ( 'placeholder' in document.createElement( 'input' ) ) {
+		jQuery(this).attr( 'placeholder', text );
+	}
+	// Otherwise, use a combination of blur and focus event handlers and a placeholder class
+	else {
+		jQuery(this).each( function() {
+			$input = jQuery(this);
+			$input
+				// Show on blur if empty
+				.bind( 'blur', function() {
+					if ( $input.val().length == 0 ) {
+						$input
+							.val( text )
+							.addClass( 'placeholder' );
+						}
+					} )
+				// Hide on focus
+				.bind( 'focus', function() {
+					if ( $input.hasClass( 'placeholder' ) ) {
+						$input
+							.val( '' )
+							.removeClass( 'placeholder' );
+					}
+				} )
+				// Blank on submit -- prevents submitting with unintended value
+				.parents( 'form' )
+					.bind( 'submit', function() {
+						$input.trigger( 'focus' );
+					} );
+			// Show initially, if empty
+			if ( $input.val() == '' ) {
+				$input.trigger( 'blur' );
+			}
+		} );
+	}
+};