Faciilitate creation of settings page.

settings.php

<?php

/**
 * This class facilitates creation of settings field to the theme options
 * through, default pre-made boxes
 * 
 * @todo example usage
 * 
 * @author Rafal Gicgier <[email protected]>
 */
class Skeleton_Settings {

	private $options = array( );

	function __construct($args = array( )) {

		$this->options = $args;

		$args = array_merge(
				array(
			'config_file' => TEMPLATEPATH . DIRECTORY_SEPARATOR . 'skeleton/config.php',
				), $args
		);

		add_action( 'admin_init', array( $this, 'admin_init' ) );
		add_action( 'admin_menu', array( $this, 'options_page' ) );
	}

	/**
	 * Generates Backend Page for options
	 * 
	 * @hook add_theme_page
	 */
	public function do_options_page() {
		?>

		<div class="wrap">
			<?php
			if ( isset( $_GET['settings-updated'] ) ) {
				echo "<div class='updated'><p>Theme settings updated successfully.</p></div>";
			}
			?>

			<?php
			// @todo http://codex.wordpress.org/Function_Reference/get_settings_errors
			$errors = get_settings_errors();

			if ( $errors ) {
				echo "<div class='error'>";
				foreach ( $errors as $error ) {
					echo $error['message'];
				}
				echo "</div>";
			}
			?>

			<form action="options.php" method="post">
				<?php
				settings_fields( 'skeleton_options' );
				do_settings_sections( 'skeleton_settings' );
				?>
				<br />
				<input name="skeleton_options[submit]" type="submit" class="button-primary" value="<?php esc_attr_e( 'Save Settings', 'skeleton' ); ?>" />
			</form>
		</div>

		<?php
	}

	/**
	 * Utility that registers setting, adds setting section and adds field for each
	 * field provided through config array
	 * 
	 * @hook admin_init
	 */
	function admin_init() {

		register_setting( 'skeleton_options', 'skeleton_options', array( $this, 'options_validate' ) );

		add_settings_section( 'skeleton_main', 'Main Settings', array( $this, 'options_text' ), 'skeleton_settings' );

		foreach ( $this->options as $option ) {
			add_settings_field( $option['name'], $option['desc'], array( $this, 'options_generate_fields' ), 'skeleton_settings', 'skeleton_main', $option );
		}
	}

	/**
	 * Generate section's text 
	 */
	function options_text() {
		echo '<p>Change the footer about text here.</p>';
	}

	/**
	 * Generates fields for each option specified
	 * 
	 * @param {array of strings} $option 
	 */
	function options_generate_fields($option) {

		if ( $option['type'] == 'text' ) {
			$this->generate_text_field( $option );
		} else if ( $option['type'] == 'dropdown_pages' ) {
			$this->generate_dropdown_pages_field( $option );
		} else if ( $option['type'] == 'wp_editor' ) {
			$this->generate_wp_editor( $option );
		} else {
			// @todo throw an error?
		}
	}

	/**
	 * Generates text field
	 * 
	 * @param {array of strings} $option 
	 */
	function generate_text_field($option) {
		$options = get_option( 'skeleton_options' );
		if ( !empty( $options[$option['name']] ) ) {
			echo "<input id='{$option['name']}' name='skeleton_options[{$option['name']}]' size='80' type='text' value='{$options[$option['name']]}' />";
		}
		else
			echo "<input id='{$option['name']}' name='skeleton_options[{$option['name']}]' size='80' type='text' value='' />";
	}

	/**
	 * Generates dropdown of all listed pages
	 * 
	 * @param {array of strings} $option 
	 */
	function generate_dropdown_pages_field($option) {
		$options = get_option( 'skeleton_options' );

		if ( !empty( $options[$option['name']] ) ) {
			$args = array(
				'selected' => $options[$option['name']],
				'name' => "skeleton_options[{$option['name']}]",
			);
			wp_dropdown_pages( $args );
		} else {
			$args = array(
				'name' => "skeleton_options[{$option['name']}]",
			);
			wp_dropdown_pages( $args );
		}
	}

	/**
	 * Generates wp_editor textarea
	 * 
	 * @param {array of strings} $option 
	 */
	function generate_wp_editor($option) {
		$options = get_option( 'skeleton_options' );

		$settings = array( 'textarea_name' => "skeleton_options[{$option['name']}]", 'media_buttons' => false, 'wpautop' => true );

		if ( !empty( $options[$option['name']] ) ) {
			wp_editor( $options[$option['name']], $option['name'], $settings );
		}
		else
			wp_editor( '', $option['name'], $settings );
	}

	/**
	 * Validates the input 
	 * 
	 * @param {mixed} $input
	 * @return {mixed}
	 */
	function options_validate($input) {
		$valid = array( );

		foreach ( $this->options as $option ) {
			if ( $option['type'] == 'text' )
				$valid[$option['name']] = sanitize_text_field( $input[$option['name']] );
			else if ( $option['type'] == 'dropdown_pages' ) {
				$valid[$option['name']] = $input[$option['name']];
			}
			else if ( $option['type'] == 'wp_editor' ) {
				$valid[$option['name']] = $input[$option['name']];
			}
			// @todo if
		}



		// add_settings_error( 'secreta_about', 'settings_updated', 'error fucker' );
		return $valid;
	}

	/**
	 * Adds theme options page
	 * 
	 * @hook admin_menu
	 */
	function options_page() {
		add_theme_page( 'Theme Options', 'Theme Options', 'manage_options', 'skeleton_settings', array( $this, 'do_options_page' ) );
	}

}