我正在开发一个主题，并为其创建了一个自定义小部件。
当我打开调试模式时，我得到以下注意：，
NOTICE: wp-content/themes/integral/inc/widgets/feature_widget.php:92 - Undefined variable: title
wp_list_widgets, call_user_func_array, wp_widget_control, call_user_func_array, WP_Widget->form_callback, Integral_Feature_Widget->form
NOTICE: wp-content/themes/integral/inc/widgets/feature_widget.php:97 - Undefined variable: text
wp_list_widgets, call_user_func_array, wp_widget_control, call_user_func_array, WP_Widget->form_callback, Integral_Feature_Widget->form
NOTICE: wp-content/themes/integral/inc/widgets/feature_widget.php:110 - Undefined variable: textarea
wp_list_widgets, call_user_func_array, wp_widget_control, call_user_func_array, WP_Widget->form_callback, Integral_Feature_Widget->form
这是小部件文件的内容，
<?php
/**
* new WordPress Widget format
* Wordpress 2.8 and above
* @see http://codex.wordpress.org/Widgets_API#Developing_Widgets
*/
class Integral_Feature_Widget extends WP_Widget {
/**
* Constructor
*
* @return void
**/
function __construct() {
$widget_ops = array( \'classname\' => \'wcp_image\', \'description\' => \'Add a feature to the homepage features section.\' );
parent::__construct( \'Integral_feature\', \'Integral - Feature Widget\', $widget_ops );
}
/**
* Outputs the HTML for this widget.
*
* @param array An array of standard parameters for widgets in this theme
* @param array An array of settings for this widget instance
* @return void Echoes it\'s output
**/
function widget( $args, $instance ) {
extract( $args, EXTR_SKIP );
// these are the widget options
$title = apply_filters(\'widget_title\', $instance[\'title\']);
$text = $instance[\'text\'];
$image_url = $instance[\'image_url\'];
$textarea = apply_filters( \'widget_textarea\', empty( $instance[\'textarea\'] ) ? \'\' : $instance[\'textarea\'], $instance );
echo $before_widget;
// Display the widget
echo \'\';
// Check if text is set
if( $text ) {
echo \'<i class="fa \'.$text.\' pull-left featureicon"></i>\';
}
if( !$text && $image_url) {
echo \'<img src="\'.$image_url.\'" class="fimage">\';
}
// Check if title is set
if ( $title ) {
echo $before_title . $title . $after_title;
}
// Check if textarea is set
if( $textarea ) { echo wpautop($textarea); }
echo \'\';
echo $after_widget;
}
/**
* Deals with the settings when they are saved by the admin. Here is
* where any validation should be dealt with.
*
* @param array An array of new settings as submitted by the admin
* @param array An array of the previous settings
* @return array The validated and (if necessary) amended settings
**/
function update( $new_instance, $old_instance ) {
// update logic goes here
$instance = $old_instance;
// Fields
$instance[\'title\'] = strip_tags($new_instance[\'title\']);
$instance[\'text\'] = strip_tags($new_instance[\'text\']);
$instance[\'image_url\'] = strip_tags($new_instance[\'image_url\']);
if ( current_user_can(\'unfiltered_html\') )
$instance[\'textarea\'] = $new_instance[\'textarea\'];
else $instance[\'textarea\'] = stripslashes( wp_filter_post_kses( addslashes($new_instance[\'textarea\']) ) );
return $instance;
}
/**
* Displays the form for this widget on the Widgets page of the WP Admin area.
*
* @param array An array of the current settings for this widget
* @return void Echoes it\'s output
**/
function form( $instance ) {
extract($instance);
?>
<p>
<label for="<?php echo $this->get_field_id(\'title\'); ?>"><?php _e(\'Feature Title\', \'integral\'); ?></label>
<input class="widefat" id="<?php echo $this->get_field_id(\'title\'); ?>" name="<?php echo $this->get_field_name(\'title\'); ?>" type="text" value="<?php echo $title; ?>" />
</p>
<p>
<label for="<?php echo $this->get_field_id(\'text\'); ?>"><?php _e(\'Feature Icon Class\', \'integral\'); ?></label>
<input class="widefat" id="<?php echo $this->get_field_id(\'text\'); ?>" name="<?php echo $this->get_field_name(\'text\'); ?>" type="text" value="<?php echo $text; ?>" />
<small>Copy and paste the required icon class from the <a href="https://fortawesome.github.io/Font-Awesome/cheatsheet/" target="_blank">Fontawesome Icons List</a> and choose from 600+ icons.</small>
</p>
<p><label for="<?php echo $this->get_field_id(\'image_url\'); ?>"><?php _e(\'Feature Image\', \'integral\'); ?></label>
<br /><small>Or instead of using an icon you can upload an image.</small>
<input id="<?php echo $this->get_field_id(\'image_url\'); ?>" type="text" class="image-url" name="<?php echo $this->get_field_name(\'image_url\'); ?>" value="<?php if (isset($image_url)) echo esc_attr($image_url); ?>" style="width: 100%;" />
<input data-title="Image in Widget" data-btntext="Select it" class="button upload_image_button" type="button" value="<?php _e(\'Upload\',\'integral\') ?>" /> <input data-title="Image in Widget" data-btntext="Select it" class="button clear_image_button" type="button" value="<?php _e(\'Clear\',\'integral\') ?>" />
</p>
<p class="img-prev">
<?php if (isset($image_url) && $image_url) { echo \'<img src="\'.$image_url.\'" style="max-width: 100%;">\';} ?>
</p>
<p>
<label for="<?php echo $this->get_field_id(\'textarea\'); ?>"><?php _e(\'Feature Description\', \'integral\'); ?></label>
<textarea class="widefat" rows="5" id="<?php echo $this->get_field_id(\'textarea\'); ?>" name="<?php echo $this->get_field_name(\'textarea\'); ?>"><?php echo $textarea; ?></textarea>
<small>No limit on the amount of text and HTML is allowed.</small>
</p>
<?php
}
}
// End of Widget Class
add_action( \'widgets_init\', create_function( \'\', "register_widget( \'Integral_Feature_Widget\' );" ) );
?>
我想我必须为这些字段设置一个默认变量，但我不知道怎么做？有什么想法吗？
