如何将设置添加到“后台选项”页面？
Answers:
自定义背景的页面内容是在中创建的wp-admin/custom-background.php。没有可用于打印字段的操作。
要添加新字段，我们必须将JavaScript打印到页面页脚中。动作是'admin_footer-appearance_page_custom-background'。
要保存这些字段值，我们必须挂钩'load-appearance_page_custom-background'。
以下示例为添加了一个新选项background-origin-如果body在样式表中设置了边框，则很有用。
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>";
}
}
谢谢您这么详细的回答。并不是我需要做的事情，但它无疑为我指明了正确的方向。
—
Jacob Rambo 2012年
感谢您发布此信息，即使20个月后它仍然有用。
—
David Gard 2014年
我发现@toscho提供的答案非常有用，但是由于要添加的选项不止一个，因此我对代码进行了一些修改，因此我要做的就是创建一个带有几个选项的简单扩展类。
我还发现将选项简单地添加到列表的末尾很不方便，所以我添加了一个“ position”参数，允许您选择这些选项中的任何一个-
'first'-在第一个设置之前（当前为位置）'last'-最后一次设置后（当前背景色）Integer position-插入设置之前的行号（必须为整数）
这是代码-
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
}
}