最近これに遭遇し、従来の「widgets.php」インターフェースでは、既存のウィジェット（#widgets-rightdiv 内のもの）に対してjavascriptの初期化を直接実行しwidget-added、新しく追加されたウィジェットに対してイベントを介して間接的に実行する必要があるようです。一方、カスタマイザーの「customize.php」インターフェースでは、既存および新規のすべてのウィジェットにwidget-addedイベントが送信されるため、そこで初期化するだけです。これに基づいて、次のWP_Widget1つの関数をオーバーライドすることにより、ウィジェットのフォームにJavaScriptの初期化を簡単に追加できるクラスの拡張機能がありform_javascript_init()ます。
class WPSE_JS_Widget extends WP_Widget { // For widgets using javascript in form().
var $js_ns = 'wpse'; // Javscript namespace.
var $js_init_func = ''; // Name of javascript init function to call. Initialized in constructor.
var $is_customizer = false; // Whether in customizer or not. Set on 'load-customize.php' action (if any).
public function __construct( $id_base, $name, $widget_options = array(), $control_options = array(), $js_ns = '' ) {
parent::__construct( $id_base, $name, $widget_options, $control_options );
if ( $js_ns ) {
$this->js_ns = $js_ns;
}
$this->js_init_func = $this->js_ns . '.' . $this->id_base . '_init';
add_action( 'load-widgets.php', array( $this, 'load_widgets_php' ) );
add_action( 'load-customize.php', array( $this, 'load_customize_php' ) );
}
// Called on 'load-widgets.php' action added in constructor.
public function load_widgets_php() {
add_action( 'in_widget_form', array( $this, 'form_maybe_call_javascript_init' ) );
add_action( 'admin_print_scripts', array( $this, 'admin_print_scripts' ), PHP_INT_MAX );
}
// Called on 'load-customize.php' action added in constructor.
public function load_customize_php() {
$this->is_customizer = true;
// Don't add 'in_widget_form' action as customizer sends 'widget-added' event to existing widgets too.
add_action( 'admin_print_scripts', array( $this, 'admin_print_scripts' ), PHP_INT_MAX );
}
// Form javascript initialization code here. "widget" and "widget_id" available.
public function form_javascript_init() {
}
// Called on 'in_widget_form' action (ie directly after form()) when in traditional widgets interface.
// Run init directly unless we're newly added.
public function form_maybe_call_javascript_init( $callee_this ) {
if ( $this === $callee_this && '__i__' !== $this->number ) {
?>
<script type="text/javascript">
jQuery(function ($) {
<?php echo $this->js_init_func; ?>(null, $('#widgets-right [id$="<?php echo $this->id; ?>"]'));
});
</script>
<?php
}
}
// Called on 'admin_print_scripts' action added in constructor.
public function admin_print_scripts() {
?>
<script type="text/javascript">
var <?php echo $this->js_ns; ?> = <?php echo $this->js_ns; ?> || {}; // Our namespace.
jQuery(function ($) {
<?php echo $this->js_init_func; ?> = function (e, widget) {
var widget_id = widget.attr('id');
if (widget_id.search(/^widget-[0-9]+_<?php echo $this->id_base; ?>-[0-9]+$/) === -1) { // Check it's our widget.
return;
}
<?php $this->form_javascript_init(); ?>
};
$(document).on('widget-added', <?php echo $this->js_init_func; ?>); // Call init on widget add.
});
</script>
<?php
}
}
これを使用したテストウィジェットの例：
class WPSE_Test_Widget extends WPSE_JS_Widget {
var $defaults; // Form defaults. Initialized in constructor.
function __construct() {
parent::__construct( 'wpse_test_widget', __( 'WPSE: Test Widget' ), array( 'description' => __( 'Test init of javascript.' ) ) );
$this->defaults = array(
'one' => false,
'two' => false,
'color' => '#123456',
);
add_action( 'admin_enqueue_scripts', function ( $hook_suffix ) {
if ( ! in_array( $hook_suffix, array( 'widgets.php', 'customize.php' ) ) ) return;
wp_enqueue_script( 'wp-color-picker' ); wp_enqueue_style( 'wp-color-picker' );
} );
}
function widget( $args, $instance ) {
extract( $args );
extract( wp_parse_args( $instance, $this->defaults ) );
echo $before_widget, '<p style="color:', $color, ';">', $two ? 'Two' : ( $one ? 'One' : 'None' ), '</p>', $after_widget;
}
function update( $new_instance, $old_instance ) {
$new_instance['one'] = isset( $new_instance['one'] ) ? 1 : 0;
$new_instance['two'] = isset( $new_instance['two'] ) ? 1 : 0;
return $new_instance;
}
function form( $instance ) {
extract( wp_parse_args( $instance, $this->defaults ) );
?>
<div class="wpse_test">
<p class="one">
<input class="checkbox" type="checkbox" <?php checked( $one ); disabled( $two ); ?> id="<?php echo $this->get_field_id( 'one' ); ?>" name="<?php echo $this->get_field_name( 'one' ); ?>" />
<label for="<?php echo $this->get_field_id( 'one' ); ?>"><?php _e( 'One?' ); ?></label>
</p>
<p class="two">
<input class="checkbox" type="checkbox" <?php checked( $two ); disabled( $one ); ?> id="<?php echo $this->get_field_id( 'two' ); ?>" name="<?php echo $this->get_field_name( 'two' ); ?>" />
<label for="<?php echo $this->get_field_id( 'two' ); ?>"><?php _e( 'Two?' ); ?></label>
</p>
<p class="color">
<input type="text" value="<?php echo htmlspecialchars( $color ); ?>" id="<?php echo $this->get_field_id( 'color' ); ?>" name="<?php echo $this->get_field_name( 'color' ); ?>" />
</p>
</div>
<?php
}
// Form javascript initialization code here. "widget" and "widget_id" available.
function form_javascript_init() {
?>
$('.one input', widget).change(function (event) { $('.two input', widget).prop('disabled', this.checked); });
$('.two input', widget).change(function (event) { $('.one input', widget).prop('disabled', this.checked); });
$('.color input', widget).wpColorPicker({
<?php if ( $this->is_customizer ) ?> change: _.throttle( function () { $(this).trigger('change'); }, 1000, {leading: false} )
});
<?php
}
}
add_action( 'widgets_init', function () {
register_widget( 'WPSE_Test_Widget' );
} );