PHP NumberInputWidget for OOUI

NumberInputWidget.patch

diff --git a/demos/demos.php b/demos/demos.php
index ab8ba742..6a232d95 100644
--- a/demos/demos.php
+++ b/demos/demos.php
@@ -157,6 +157,7 @@
 	<script src="node_modules/jquery/dist/jquery.js"></script>
 	<script src="node_modules/oojs/dist/oojs.jquery.js"></script>
 	<script src="dist/oojs-ui-core.js"></script>
+	<script src="dist/oojs-ui-widgets.js"></script>
 	<script src="dist/oojs-ui-<?php echo $theme; ?>.js"></script>
 	<script>window.Demo = {};</script>
 	<script src="classes/ButtonStyleShowcaseWidget.js"></script>
diff --git a/demos/pages/widgets.php b/demos/pages/widgets.php
index 04a5bb76..5b70d6fd 100644
--- a/demos/pages/widgets.php
+++ b/demos/pages/widgets.php
@@ -436,6 +436,41 @@ $demoContainer->appendContent( new OOUI\FieldsetLayout( [
 				'label' => "MultilineTextInputWidget (icon, indicator)\xE2\x80\x8E",
 				'align' => 'top'
 			]
+		),
+		new OOUI\FieldLayout(
+			new OOUI\NumberInputWidget(),
+			[
+				'label' => "NumberInputWidget\xE2\x80\x8E",
+				'align' => 'top'
+			]
+		),
+		new OOUI\FieldLayout(
+			new OOUI\NumberInputWidget( [ 'disabled' => true ] ),
+			[
+				'label' => "NumberInputWidget (disabled)\xE2\x80\x8E",
+				'align' => 'top'
+			]
+		),
+		new OOUI\FieldLayout(
+			new OOUI\NumberInputWidget( [ 'min' => 0, 'max' => 5, 'isInteger' => true ] ),
+			[
+				'label' => "NumberInputWidget (1-5, ints only)\xE2\x80\x8E",
+				'align' => 'top'
+			]
+		),
+		new OOUI\FieldLayout(
+			new OOUI\NumberInputWidget( [ 'min' => 0, 'max' => 1, 'step' => 0.1, 'pageStep' => 0.25 ] ),
+			[
+				'label' => "NumberInputWidget (0–1, step by .1, page by .25)\xE2\x80\x8E",
+				'align' => 'top'
+			]
+		),
+		new OOUI\FieldLayout(
+			new OOUI\NumberInputWidget( [ 'showButtons' => false ] ),
+			[
+				'label' => "NumberInputWidget (no buttons)\xE2\x80\x8E",
+				'align' => 'top'
+			]
 		)
 	]
 ] ) );
diff --git a/php/widgets/NumberInputWidget.php b/php/widgets/NumberInputWidget.php
new file mode 100644
index 00000000..d1d5e0c9
--- /dev/null
+++ b/php/widgets/NumberInputWidget.php
@@ -0,0 +1,111 @@
+<?php
+
+namespace OOUI;
+
+/**
+ * Input widget with a number field.
+ */
+class NumberInputWidget extends TextInputWidget {
+
+	/**
+	 * @param array $config Configuration options
+	 * @param int $config['placeholder'] Placeholder number
+	 * @param bool $config['autofocus'] Ask the browser to focus this widget, using the 'autofocus'
+	 *   HTML attribute (default: false)
+	 * @param bool $config['readOnly'] Prevent changes (default: false)
+	 * @param number $config['min'] Minimum input allowed
+	 * @param number $config['max'] Maximum input allowed
+	 * @param number $config['step'] Stepping delta (default: any)
+	 * @param number $config['pageStep'] Stepping delta (page-up and page-down) (default: step * 10)
+	 * @param number $config['isInteger'] Only integers are allowed
+	 * @param number $config['showButtons'] Show increment and decrement buttons (default: true)
+	 * @param bool $config['required'] Mark the field as required.
+	 *   Implies `indicator: 'required'`. Note that `false` & setting `indicator: 'required'
+	 */
+	public function __construct( array $config = [] ) {
+		// Config initialization
+		$config = array_merge( [
+			'step' => 'any',
+			'showButtons' => true
+		], $config );
+
+		$config['type'] = 'number';
+		$config['multiline'] = false;
+
+		if ( $config['step'] !== 'any' && !isset( $config['pageStep'] )
+		) {
+			$config['pageStep'] = $config['step'] * 10;
+		}
+
+		// Parent constructor
+		parent::__construct( $config );
+
+		if ( isset( $config['min'] ) ) {
+			$this->input->setAttributes( [ 'min' => $config['min'] ] );
+		}
+
+		if ( isset( $config['max'] ) ) {
+			$this->input->setAttributes( [ 'max' => $config['max'] ] );
+		}
+
+		$this->input->setAttributes( [ 'step' => $config['step'] ] );
+		if ( isset( $config['pageStep'] ) ) {
+			$this->input->setAttributes( [ 'pageStep' => $config['pageStep'] ] );
+		}
+
+		if ( isset( $config['isInteger'] ) ) {
+			$this->input->setAttributes( [ 'isInteger' => $config['isInteger'] ] );
+		}
+
+		if ( !$config['showButtons'] ) {
+			$this->setAttributes( [ 'showButtons' => false ] );
+		}
+
+		$this->addClasses( [
+			'oo-ui-numberInputWidget',
+			'oo-ui-numberInputWidget-php',
+		] );
+	}
+
+	public function getConfig( &$config ) {
+		$min = $this->input->getAttribute( 'min' );
+		if ( $min !== null ) {
+			$config['min'] = $min;
+		}
+		$max = $this->input->getAttribute( 'max' );
+		if ( $max !== null ) {
+			$config['max'] = $max;
+		}
+		$config['step'] = $this->input->getAttribute( 'step' );
+		$pageStep = $this->input->getAttribute( 'pageStep' );
+		if ( $pageStep !== null ) {
+			$config['pageStep'] = $pageStep;
+		}
+		$isInteger = $this->input->getAttribute( 'isInteger' );
+		if ( $isInteger !== null ) {
+			$config['isInteger'] = $isInteger;
+		}
+		$showButtons = $this->input->getAttribute( 'showButtons' );
+		if ( $showButtons !== null ) {
+			$config['showButtons'] = $showButtons;
+		}
+		return parent::getConfig( $config );
+	}
+
+	protected function getInputElement( $config ) {
+		$attributes = [
+			'step' => $config['step'],
+			'type' => 'number',
+		];
+
+		if ( isset( $config['min'] ) ) {
+			$attributes['min'] = $config['min'];
+		}
+
+		if ( isset( $config['max'] ) ) {
+			$attributes['max'] = $config['max'];
+		}
+
+		return ( new Tag( 'input' ) )->setAttributes( $attributes );
+	}
+}