Bagaimana cara menambahkan pengaturan ke Halaman Opsi Latar Belakang?

Saya sedang mengembangkan tema dan saya ingin menambahkan beberapa konten tambahan ke halaman opsi latar belakang bawaan. Saya tahu cara menggunakan pengaturan API untuk membuat opsi dan pengaturan tema baru tapi saya tidak bisa mencari tahu di mana itu sebenarnya memanggil ke halaman latar belakang. Saya telah mencari wp-includes/theme.phpdan masih tidak banyak di sana kecuali untuk panggilan ke fungsi latar belakang dan tidak ada yang benar-benar membuat halaman.

Mungkinkah ini tidak dilakukan dengan tindakan?

Konten halaman untuk latar belakang khusus dibuat di wp-admin/custom-background.php. Tidak ada tindakan yang tersedia di mana bidang dicetak.

Untuk menambahkan bidang baru, kita harus mencetak JavaScript ke footer halaman. Aksinya adalah 'admin_footer-appearance_page_custom-background'.

Untuk menyimpan nilai-nilai bidang itu, kita harus terhubung 'load-appearance_page_custom-background'.

Contoh berikut menambahkan opsi baru untuk background-origin- berguna jika Anda telah menetapkan batas di bodydalam stylesheet Anda.

add_action(
    'load-appearance_page_custom-background',
    array ( 'T5_Background_Origin', 'get_instance' )
);

/**
 * Add a new row to the background options table for 'background-origin'.
 *
 * @author  Thomas Scholz http://toscho.de
 * @version 2012.09.10
 */
class T5_Background_Origin
{
    /**
     * Main instance.
     * @type object|NULL
     */
    protected static $instance = NULL;

    /**
     * The name for the option. Will be saved as theme option.
     *
     * @link http://www.w3.org/TR/css3-background/#the-background-origin
     * @type string
     */
    protected $option = 'background_origin';

    /**
     * Label on the left side of our new option.
     *
     * @type string
     */
    protected $table_header = 'Background Origin';

    /**
     * Return an instance.
     *
     * @wp-hook load-appearance_page_custom-background
     * @return object
     */
    public static function get_instance()
    {
        NULL === self::$instance and self::$instance = new self;
        return self::$instance;
    }

    /**
     * Save our option and register the form.
     *
     * @wp-hook load-appearance_page_custom-background
     */
    public function __construct()
    {
        add_action(
            'admin_footer-appearance_page_custom-background',
            array ( $this, 'form' )
        );

        if ( empty ( $_POST[ $this->option ] ) )
        {
            return;
        }

        check_admin_referer( $this->option, "_t5nonce-$this->option" );
        set_theme_mod( $this->option, $_POST[ $this->option ] );
    }

    /**
     * Create the form elements.
     *
     * @wp-hook admin_footer-appearance_page_custom-background
     * @return void
     */
    public function form()
    {
        $nonce = wp_nonce_field(
            $this->option,
            "_t5nonce-$this->option",
            TRUE, // check referer
            FALSE // do not echo
            );
        $html = $nonce . $this->get_radio_fields();
        $this->print_script( $html );
    }

    /**
     * Create the jQuery function that inserts our form fields.
     *
     * @param  string $html Radio buttons
     * @return void
     */
    protected function print_script( $html )
    {
        $row = "'<tr><th>$this->table_header</th><td>$html</td></tr>'";
        ?>
<script>jQuery( function <?php echo $this->option; ?>($) {
    $('.form-table:last').append(<?php echo $row; ?>);
});</script>
<?php
    }

    /**
     * Helper for form(). Create radio input fields
     *
     * @return string
     */
    protected function get_radio_fields()
    {
        $value  = get_theme_mod( $this->option, 'padding-box' );
        $radios = array ( 'padding-box', 'border-box', 'content-box' );
        $html   = "<p>";

        foreach ( $radios as $radio )
        {
            $html .= sprintf(
                ' <input type="radio" name="%1$s" value="%2$s" id="%3$s"%4$s>'
                . ' <label for="%3$s">%2$s</label> ',
                $this->option,
                $radio,
                "$this->option-$radio",
                // returns ' as value delimiters and has to be escaped
                addslashes( checked( $value, $radio, FALSE ) )
            );
        }

        return "$html</p>";
    }
}

Saya menemukan jawaban yang diberikan oleh @toscho sangat berguna, tetapi karena saya memiliki lebih dari satu opsi untuk ditambahkan, saya telah mengubah sedikit kode sehingga yang harus saya lakukan adalah membuat Kelas tambahan sederhana dengan beberapa opsi.

Saya juga merasa tidak nyaman untuk menambahkan opsi ke bagian akhir daftar, jadi saya telah menambahkan argumen 'posisi' yang memungkinkan Anda memilih salah satu dari opsi ini -

• 'first' - Sebelum pengaturan pertama (Posisi saat ini)
• 'last'- Setelah pengaturan terakhir (Warna Latar Belakang saat ini)
• Integer position - Nomor baris untuk memasukkan pengaturan sebelumnya (harus berupa bilangan bulat)

Ini kodenya -

add_action('load-appearance_page_custom-background', array('PS_Background_Setting_Random', 'get_instance'));
add_action('load-appearance_page_custom-background', array('PS_Background_Setting_Position_Y', 'get_instance'));
add_action('load-appearance_page_custom-background', array('PS_Background_Setting_Size', 'get_instance'));

/**
 * Add a new 'Random Background' setting to the Customise Background admin page
 */
final class PS_Background_Setting_Random extends PS_Background_Setting{

    /**
     * The main instance
     *
     * @var object|null
     */
    protected static $instance = null;

    /**
     * Return an instance of this class
     *
     * @return object   An instance of this class
     */
    public static function get_instance(){

        NULL === self::$instance and self::$instance = new self;
        return self::$instance;

    }

    /**
     * Constructor
     */
    public function __construct(){

        $args = array(
            'mod'       => 'ps_background_random',
            'default'   => 'yes',
            'label'     => __('Random Background', 'djg_photo_show'),
            'position'  => 'first',
            'options'   => array(
                'yes'   => __('Yes', 'djg_photo_show'),
                'no'    => __('No', 'djg_photo_show')
            )
        );

        parent::__construct($args);

    }

}

/**
 * Add a new 'Background Position (Y)' setting to the Customise Background admin page
 */
final class PS_Background_Setting_Position_Y extends PS_Background_Setting{

    /**
     * The main instance
     *
     * @var object|null
     */
    protected static $instance = null;

    /**
     * Return an instance of this class
     *
     * @return object   An instance of this class
     */
    public static function get_instance(){

        NULL === self::$instance and self::$instance = new self;
        return self::$instance;

    }

    /**
     * Constructor
     */
    public function __construct(){

        $args = array(
            'mod'       => 'ps_background_position_y',
            'default'   => 'cover',
            'label'     => __('Position (Y)', 'djg_photo_show'),
            'position'  => 3,
            'options'   => array(
                'top'       => __('Top', 'djg_photo_show'),
                'center'    => __('Centre', 'djg_photo_show'),
                'bottom'    => __('Bottom', 'djg_photo_show')
            )
        );

        parent::__construct($args);

    }

}

/**
 * Add a new 'Background Size' setting to the Customise Background admin page
 */
final class PS_Background_Setting_Size extends PS_Background_Setting{

    /**
     * The main instance
     *
     * @var object|null
     */
    protected static $instance = null;

    /**
     * Return an instance of this class
     *
     * @return object   An instance of this class
     */
    public static function get_instance(){

        NULL === self::$instance and self::$instance = new self;
        return self::$instance;

    }

    /**
     * Constructor
     */
    public function __construct(){

        $args = array(
            'mod'       => 'ps_background_size',
            'default'   => 'cover',
            'label'     => __('Size', 'djg_photo_show'),
            'position'  => 6,
            'options'   => array(
                'auto'      => __('Auto', 'djg_photo_show'),
                'contain'   => __('Contain', 'djg_photo_show'),
                'cover'     => __('Cover', 'djg_photo_show')
            )
        );

        parent::__construct($args);

    }

}

/**
 * Add a new setting to the Customise Background admin page
 */
class PS_Background_Setting{

    /**
     * The name for the theme modification option
     *
     * @var string
     */
    private $mod = '';

    /**
     * The default value to return if $mod is not yet set
     *
     * @var mixed
     */
    private $default = false;

    /**
     * The label for the additional setting
     *
     * @var string
     */
    private $label = '';

    /**
     * The options to use for creating the fields for the additional setting
     *
     * @var array
     */
    private $options = array();

    /**
     * The nonce for the additional setting
     *
     * @var string
     */
    private $nonce;

    /**
     * The HTML fields for all of the options for the additional setting
     *
     * @var string
     */
    private $fields;

    /**
     * The position in which to insert the option
     *
     * @var string
     */
    private $position = 'last';

    /**
     * Constructor
     */
    public function __construct($args = array()){

        /** Map the args to this object */
        foreach($args as $key => $value) :
            $this->$key = $value;
        endforeach;

        /** Ensure that all of the required $args are valid */
        if(!$this->is_valid_args()) :
            return;
        endif;

        add_action('admin_footer-appearance_page_custom-background', array($this, 'output_additional_setting'));

        /** Check to see if there is an option to save */
        if(!empty($_POST[$this->mod])):

            /** Check the nonce is valid and save the updated setting */
            check_admin_referer($this->mod, "_ps_nonce-$this->mod");
            set_theme_mod($this->mod, $_POST[$this->mod]);

        endif;

    }

    /**
     * Ensure that all of the required $args are valid
     */
    private function is_valid_args(){

        return (empty($this->mod) || empty($this->label) || empty($this->options)) ? false : true;

    }

    /**
     * Output the additional custom fields to the custom backgrounds page
     */
    public function output_additional_setting(){

        $this->nonce = wp_nonce_field(  // Create a nonce for each settings so that it can be checked when the user saves
            $this->mod,             // The nonce $action
            "_ps_nonce-$this->mod", // The nonce $name
            true,                   // Also create a referer nonce
            false                   // Do not echo
        );
        $this->set_fields();    // Set up the fields for this setting
        $this->print_script();  // Print the jQuery that will insert the setting into the DOM

    }

    /**
     * Create the HTML fileds for all of the options required for the additional setting
     *
     * @return string   The fields for the additional setting
     */
    private function set_fields(){

        $saved_value = get_theme_mod($this->mod, $this->default);

        foreach($this->options as $value => $description) :

            $checked = ($value === $saved_value) ? 'checked="true"' : false;

            $fields[] = sprintf(
                '<label>'.
                '<input type="radio" id="%1$s" name="%2$s" value="%3$s" %4$s>'.
                '%5$s</label> ',
                "$this->mod-$key",  /** %1$s - The option ID */
                $this->mod,         /** %2$s - The option name */
                $value,             /** %3$s - The option vale */
                $checked,           /** %4$s - Whether or not the option should be checked */
                $description        /** %5$s - The option description */
            );

        endforeach;

        $this->fields = join('', $fields);

    }

    /**
     * Create the $row to insert in to the DOM and the jQuery function to carry out the insertion
     */
    private function print_script(){

        $row = sprintf(
            '<tr>'.
            '<th scope="row">%1$s</th>'.
            '<td><fieldset>'.
            '<legend class="screen-reader-text"><span>Background %1$s</span></legend>'.
            '%2$s%3$s</fieldset></td></tr>',            
            $this->label,   /** %1$s - The setting label */
            $this->nonce,   /** %2$s - The nonce field for this setting */
            $this->fields   /** %3$s - The setting fields */
        );

        if(!is_int($this->position)) :
            $this->position = (in_array($this->position, array('first', 'last'))) ? $this->position : 'last';
        endif;
?>
<script id="custom-background-mod-<?php echo $this->mod; ?>">jQuery(function <?php echo $this->mod; ?>($){

    /** Insert the '<?php echo $this->mod; ?>' setting option in to the Custom Background admin page */
    var row = '<?php echo $row; ?>';
    var rows = $('.form-table:last tr');
<?php if(is_int($this->position)) : ?>
    var position = parseInt('<?php echo $this->position; ?>');
    if(position < 0){
        rows.first().before(row);
    }
    else if(position > rows.length){
        rows.last().after(row);
    }
    else{
        rows.eq(position - 1).before(row);
    }
<?php elseif($this->position === 'first') : ?>
    $('.form-table:last tr:first').before(row);
<?php else : ?>
    $('.form-table:last tr:last').after(row);
<?php endif; ?>

});</script>
<?php
    }

}