Ticket #18285: test-settings.php

<?php
/*
Plugin Name: Settings API Test
Description: Plugin to test the settings api
Author: prettyboymp
License: GPLv2 or later
*/
class Test_Settings_1 {
        
        private $settings_page_key;

        public function  __construct() {
                $this->settings_page_key = 'test-settings-page';
        }

        public function initialize() {
                add_action('admin_menu', array($this, '_admin_menu'));
                add_action('admin_init', array($this, '_admin_init'));
        }

        public function _admin_init() {
        }

        public function _admin_menu() {
                $hook = add_menu_page('Test Settings', 'Test', 'manage_options', $this->settings_page_key, array($this, '_print_test_settings_page'));

                add_action('load-'.$hook, array($this, '_on_load_settings_page_1'));
        }

        public function _on_load_settings_page_1() {
                global $current_screen;

                add_contextual_help( $current_screen, '<p>' . __( 'Lorem ipsum dolor sit amet, consectetur adipiscing elit.' ) . '</p>' );

                add_settings_section( 'section-a', 'Section A', '', $this->settings_page_key );
                add_settings_field( 'foo', 'Foo', array( $this, 'display_generic_select_field' ), $this->settings_page_key, 'section-a', array( 'options' => array( 1 => 'Foo', 2 => 'Bar', 3 => 'Quasi' ) ), array( $this, 'sanitize_generic_select_field' ), 'foobar' );
                add_settings_field( 'bar', 'Bar', array( $this, 'display_generic_text_field' ), $this->settings_page_key, 'section-a', array( ), array( $this, 'sanitize_generic_text_field' ), 'foobar' );
                add_settings_field( 'someint', 'Some Int', array( $this, 'display_generic_text_field' ), $this->settings_page_key, 'section-a', array( ), array( $this, 'sanitize_generic_int_field' ), 'foobar' );

                add_settings_section( 'section-b', 'Section B', '', $this->settings_page_key );
                add_settings_field( 'cheese', 'Cheese', array( $this, 'display_generic_text_field' ), $this->settings_page_key, 'section-b', array( ), array( $this, 'sanitize_generic_text_field' ) );
                add_settings_field( 'wine', 'Wine', array( $this, 'display_generic_text_field' ), $this->settings_page_key, 'section-b', array( ), array( $this, 'sanitize_generic_text_field' ) );

                add_settings_section( 'section-c', 'Section C', '', $this->settings_page_key );
                add_settings_field( 'mayo', 'mayo', array( $this, 'display_generic_text_field' ), $this->settings_page_key, 'section-c', array( ), array( $this, 'sanitize_generic_text_field' ) );
                add_settings_field( 'mustard', 'Mustard', array( $this, 'display_generic_text_field' ), $this->settings_page_key, 'section-c', array( ), array( $this, 'sanitize_generic_text_field' ) );

                if( isset( $_REQUEST[ 'action' ] ) ) {
                        check_admin_referer( $this->settings_page_key . '-options' );
                        save_settings_page( $this->settings_page_key );
                }

        }

        public function display_generic_text_field( $args, $current_value, $field, $section_id, $page_id ) {
                ?>
                <input type="text" name="<?php echo esc_attr( $field[ 'id' ] );?>" value="<?php echo esc_attr( $current_value );?>" />
                <?php
        }

        public function display_generic_integer_field( $args, $current_value, $field, $section_id, $page_id ) {
                ?>
                <input type="text" id="<?php echo esc_attr( $field[ 'id' ] )?>" name="<?php echo esc_attr( $field[ 'id' ] );?>" value="<?php echo esc_attr( $current_value );?>" />
                <?php
        }

        public function display_generic_select_field( $args, $current_value, $field, $section_id, $page_id ) {
                if( isset( $args[ 'options' ] ) && is_array( $args[ 'options' ] ) ) {
                        ?>
                        <select id="<?php echo esc_attr( $field[ 'id' ] )?>" name="<?php echo esc_attr( $field[ 'id' ] );?>">
                                <?php foreach( $args[ 'options' ] as $key => $name ) :?>
                                        <option value="<?php echo esc_attr( $key )?>"<?php selected( $key, $current_value )?>><?php echo esc_html( $name )?></option>
                                <?php endforeach;?>
                        </select>
                        <?php
                }
        }

        public function sanitize_generic_text_field( $new_value, $old_value ) {
                return strip_tags($new_value);
        }

        public function sanitize_generic_select_field( $new_value, $old_value, $field ) {
                if( isset( $field[ 'args' ][ 'options' ] ) && in_array( $new_value, array_keys( $field[ 'args' ][ 'options' ] ) ) )
                        return $new_value;

                add_settings_error( $field[ 'id' ], 'invalid-option', sprintf( 'An invalid option was selected for %s', $field[ 'title' ] ) );
                return $old_value;
        }

        public function sanitize_generic_int_field( $new_value ) {
                return intval( $new_value );
        }


        public function _print_test_settings_page() {
                $title = __( 'Test Settings' );
                $page_key = $this->settings_page_key;
                $description = __( 'Some description text' );
                ?>
                <div class="wrap">
                        <?php screen_icon();?>
                        <h2><?php echo $title?></h2>
                        <?php settings_errors( $page_key );?>
                        <?php if( $description )
                                echo "<p>{$description}</p>";?>
                        <form action="" method="post">
                                <?php settings_fields( $this->settings_page_key ); //would like to rename this function ?>
                                <?php do_settings_sections( $this->settings_page_key );?>
                                <p class="submit">
                                        <input type="submit" value="Save Changes" class="button-primary" name="Submit">
                                </p>
                        </form>
                </div>
                <?php
        }
}
add_action( 'init', array( new Test_Settings_1(), 'initialize' ) );
add_action( 'init', array( new Test_Settings_1(), 'initialize' ) ); //kicking off two instances to be sure that multiple registrations don't interfer