Improve fields API and escaping.

src/Fields/DateField.php

@@ -17,29 +17,21 @@
  */
 class DateField extends Field {
 	/**
-	 * Get HTML attributes.
-	 *
-	 * @return array<string, string>
+	 * Get element.
+	 * 
+	 * @return Element|null
 	 */
-	protected function get_html_attributes(): array {
-		$attributes = parent::get_html_attributes();
-
-		$attributes['type'] = 'date';
-		$attributes['id']   = $this->get_id();
-		$attributes['name'] = $this->get_id();
-
-		return $attributes;
-	}
-
-	/**
-	 * Render field.
-	 *
-	 * @return string
-	 */
-	public function render(): string {
-		$element = new Element( 'input', $this->get_html_attributes() );
-
-		return $element->render();
+	protected function get_element() {
+		$element = new Element(
+			'input',
+			[
+				'type' => 'date',
+				'id'   => $this->get_id(),
+				'name' => $this->get_id(),
+			]
+		);
+
+		return $element;
 	}
 
 	/**

src/Fields/Field.php

@@ -11,6 +11,7 @@
 namespace Pronamic\WordPress\Pay\Fields;
 
 use JsonSerializable;
+use Pronamic\WordPress\Html\Element;
 
 /**
  * Field class
@@ -109,12 +110,12 @@ public function is_required(): bool {
 	}
 
 	/**
-	 * Get HTML attributes.
-	 *
-	 * @return array<string, string>
+	 * Get element.
+	 * 
+	 * @return Element|null
 	 */
-	protected function get_html_attributes() {
-		return [];
+	protected function get_element() {
+		return null;
 	}
 
 	/**
@@ -123,16 +124,28 @@ protected function get_html_attributes() {
 	 * @return string
 	 */
 	public function render() {
-		return '';
+		$element = $this->get_element();
+
+		if ( null === $element ) {
+			return '';
+		}
+
+		return $element->render();
 	}
 
 	/**
-	 * Print output.
+	 * Output.
 	 *
 	 * @return int
 	 */
 	public function output() {
-		return print $this->render();
+		$element = $this->get_element();
+
+		if ( null === $element ) {
+			return 0;
+		}
+
+		return $element->output();
 	}
 
 	/**

src/Fields/IDealIssuerSelectField.php

@@ -27,20 +27,6 @@ protected function setup() {
 		$this->set_label( \__( 'Bank', 'pronamic_ideal' ) );
 	}
 
-	/**
-	 * Get HTML attributes.
-	 *
-	 * @return array<string, string>
-	 */
-	protected function get_html_attributes() {
-		$attributes = parent::get_html_attributes();
-
-		$attributes['id']   = $this->get_id();
-		$attributes['name'] = $this->get_id();
-
-		return $attributes;
-	}
-
 	/**
 	 * Get options.
 	 *

src/Fields/SelectField.php

@@ -19,20 +19,6 @@
  * @link https://github.com/WordPress/gutenberg/tree/trunk/packages/components/src/select-control
  */
 class SelectField extends Field {
-	/**
-	 * Get HTML attributes.
-	 *
-	 * @return array<string, string>
-	 */
-	protected function get_html_attributes() {
-		$attributes = parent::get_html_attributes();
-
-		$attributes['id']   = $this->get_id();
-		$attributes['name'] = $this->get_id();
-
-		return $attributes;
-	}
-
 	/**
 	 * Options.
 	 *
@@ -83,18 +69,24 @@ public function get_flat_options() {
 	}
 
 	/**
-	 * Render field.
-	 *
-	 * @return string
+	 * Get element.
+	 * 
+	 * @return Element|null
 	 */
-	public function render() {
-		$element = new Element( 'select', $this->get_html_attributes() );
+	protected function get_element() {
+		$element = new Element(
+			'select',
+			[
+				'id'   => $this->get_id(),
+				'name' => $this->get_id(),
+			]
+		);
 
 		foreach ( $this->get_options() as $child ) {
-			$element->children[] = $child->render();
+			$element->children[] = $child->get_element()->render();
 		}
 
-		return $element->render();
+		return $element;
 	}
 
 	/**

src/Fields/SelectFieldOption.php

@@ -46,11 +46,11 @@ public function __construct( string $value, string $label ) {
 	}
 
 	/**
-	 * Render field.
+	 * Get element.
 	 *
-	 * @return string
+	 * @return Element
 	 */
-	public function render(): string {
+	public function get_element() {
 		$element = new Element(
 			'option',
 			[
@@ -60,7 +60,7 @@ public function render(): string {
 
 		$element->children[] = $this->label;
 
-		return $element->render();
+		return $element;
 	}
 
 	/**

src/Fields/SelectFieldOptionGroup.php

@@ -40,11 +40,11 @@ public function __construct( $label ) {
 	}
 
 	/**
-	 * Render.
+	 * Get element.
 	 *
-	 * @return string
+	 * @return Element
 	 */
-	public function render() {
+	public function get_element() {
 		$element = new Element(
 			'optgroup',
 			[
@@ -53,9 +53,9 @@ public function render() {
 		);
 
 		foreach ( $this->options as $option ) {
-			$element->children[] = $option->render();
+			$element->children[] = $option->get_element()->render();
 		}
 
-		return $element->render();
+		return $element;
 	}
 }

src/Fields/TextField.php

@@ -17,29 +17,21 @@
  */
 class TextField extends Field {
 	/**
-	 * Get HTML attributes.
-	 *
-	 * @return array<string, string>
+	 * Get element.
+	 * 
+	 * @return Element|null
 	 */
-	protected function get_html_attributes(): array {
-		$attributes = parent::get_html_attributes();
-
-		$attributes['type'] = 'text';
-		$attributes['id']   = $this->get_id();
-		$attributes['name'] = $this->get_id();
-
-		return $attributes;
-	}
-
-	/**
-	 * Render field.
-	 *
-	 * @return string
-	 */
-	public function render(): string {
-		$element = new Element( 'input', $this->get_html_attributes() );
-
-		return $element->render();
+	protected function get_element() {
+		$element = new Element(
+			'input',
+			[
+				'type' => 'text',
+				'id'   => $this->get_id(),
+				'name' => $this->get_id(),
+			]
+		);
+
+		return $element;
 	}
 
 	/**