添加数量和排序选项到标签云小工具WordPress开发教程

今天主题盒子小编为大家分享添加数量和排序选项到标签云小工具WordPress开发教程。

通过钩子全局修改标签云小工具的参数

其实，如果只是简单修改下标签云小工具的选项，我们可以直接通过widget_tag_cloud_args 过滤器钩子来操作，具体代码示例如下：

//cus*** widget tag cloud

add_filter( ‘widget_tag_cloud_args’, ‘theme_tag_cloud_args’ );

function theme_tag_cloud_args( $args ){

$newargs = array(

‘s**llest’    => 8,  //最小字号

‘largest’     => 22, //最大字号

‘unit’        => ‘pt’,   //字号单位，可以是pt、px、em或

‘number’      => 45,     //显示个数

‘for**t’      => ‘flat’,//列表格式，可以是flat、list或array

‘separator’   => “\n”,   //分隔每一项的分隔符

‘orderby’     => ‘n**e’,//排序字段，可以是n**e或count

‘order’       => ‘ASC’, //升序或降序，ASC或DESC

‘exclude’     => null,   //结果中排除某些标签

‘include’     => null,  //结果中只包含这些标签

‘link’        => ‘view’, //taxonomy链接，view或edit

‘taxonomy’    => ‘post_tag’, //调用哪些分类法作为标签云

);

$return = array_merge( $args, $newargs);

return $return;

}

第 5-16 行的代码就是各个参数的设置，根据需要修改即可，将全部代码添加到主题的 functions.php 或插件中即可。

添加选项到WordPress标签云小工具

好了，现在开始我们文本的话题，添加数量和排序选项到WordPress标签云小工具。

WordPress自带的标签云小工具的设置选项是非常简单的：

我们先来看下标签云小工具的注册代码：

<?php

/**

* Widget API: WP_Widget_Tag_Cloud class

*

* @package WordPress

* @subpackage Widgets

* @since 4.4.0

*/

/**

* Core class used to implement a Tag cloud widget.

*

* @since 2.8.0

*

* @see WP_Widget

*/

class WP_Widget_Tag_Cloud extends WP_Widget {

/**

* Sets up a new Tag Cloud widget instance.

*

* @since 2.8.0

*/

public function __construct() {

$widget_ops = array(

‘description’                 => __( ‘A cloud of your most used tags.’ ),

‘cus***ize_selective_refresh’ => true,

);

parent::__construct( ‘tag_cloud’, __( ‘Tag Cloud’ ), $widget_ops );

}

/**

* Outputs the content for the current Tag Cloud widget instance.

*

* @since 2.8.0

*

* @par** array $args     Display arguments including ‘before_title’, ‘after_title’,

*                        ‘before_widget’, and ‘after_widget’.

* @par** array $instance Settings for the current Tag Cloud widget instance.

*/

public function widget( $args, $instance ) {

$current_taxonomy = $this->_get_current_taxonomy( $instance );

if ( ! empty( $instance[‘title’] ) ) {

$title = $instance[‘title’];

} else {

if ( ‘post_tag’ === $current_taxonomy ) {

$title = __( ‘Tags’ );

} else {

$tax   = get_taxonomy( $current_taxonomy );

$title = $tax->labels->n**e;

}

}

$show_count = ! empty( $instance[‘count’] );

$tag_cloud = wp_tag_cloud(

/**

* Filters the taxonomy used in the Tag Cloud widget.

*

* @since 2.8.0

* @since 3.0.0 Added taxonomy drop-down.

* @since 4.9.0 Added the `$instance` par**eter.

*

* @see wp_tag_cloud()

*

* @par** array $args     Args used for the tag cloud widget.

* @par** array $instance Array of settings for the current widget.

*/

apply_filters(

‘widget_tag_cloud_args’,

array(

‘taxonomy’   => $current_taxonomy,

‘echo’       => false,

‘show_count’ => $show_count,

),

$instance

)

);

if ( empty( $tag_cloud ) ) {

return;

}

/** This filter is documented in wp-includes/widgets/class-wp-widget-pages.php */

$title = apply_filters( ‘widget_title’, $title, $instance, $this->id_base );

echo $args[‘before_widget’];

if ( $title ) {

echo $args[‘before_title’] . $title . $args[‘after_title’];

}

echo ‘<div class=”tagcloud”>’;

echo $tag_cloud;

echo “</div>\n”;

echo $args[‘after_widget’];

}

/**

* Handles updating settings for the current Tag Cloud widget instance.

*

* @since 2.8.0

*

* @par** array $new_instance New settings for this instance as input by the user via

*                            WP_Widget::form().

* @par** array $old_instance Old settings for this instance.

* @return array Settings to save or bool false to cancel saving.

*/

public function update( $new_instance, $old_instance ) {

$instance             = array();

$instance[‘title’]    = sanitize_text_field( $new_instance[‘title’] );

$instance[‘count’]    = ! empty( $new_instance[‘count’] ) ? 1 : 0;

$instance[‘taxonomy’] = stripslashes( $new_instance[‘taxonomy’] );

return $instance;

}

/**

* Outputs the Tag Cloud widget settings form.

*

* @since 2.8.0

*

* @par** array $instance Current settings.

*/

public function form( $instance ) {

$title = ! empty( $instance[‘title’] ) ? $instance[‘title’] : ”;

$count = isset( $instance[‘count’] ) ? (bool) $instance[‘count’] : false;

?>

<p>

<label for=”<?php echo $this->get_field_id( ‘title’ ); ?>”><?php _e( ‘Title:’ ); ?></label>

<input type=”text” class=”widefat” id=”<?php echo $this->get_field_id( ‘title’ ); ?>” n**e=”<?php echo $this->get_field_n**e( ‘title’ ); ?>” value=”<?php echo esc_attr( $title ); ?>” />

</p>

<?php

$taxonomies       = get_taxonomies( array( ‘show_tagcloud’ => true ), ‘object’ );

$current_taxonomy = $this->_get_current_taxonomy( $instance );

switch ( count( $taxonomies ) ) {

// No tag cloud supporting taxonomies found, display error message.

case 0:

?>

<input type=”hidden” id=”<?php echo $this->get_field_id( ‘taxonomy’ ); ?>” n**e=”<?php echo $this->get_field_n**e( ‘taxonomy’ ); ?>” value=”” />

<p>

<?php _e( ‘The tag cloud will not be displayed since there are no taxonomies that support the tag cloud widget.’ ); ?>

</p>

<?php

break;

// Just a single tag cloud supporting taxonomy found, no need to display a select.

case 1:

$keys     = array_keys( $taxonomies );

$taxonomy = reset( $keys );

?>

<input type=”hidden” id=”<?php echo $this->get_field_id( ‘taxonomy’ ); ?>” n**e=”<?php echo $this->get_field_n**e( ‘taxonomy’ ); ?>” value=”<?php echo esc_attr( $taxonomy ); ?>” />

<?php

break;

// More than one tag cloud supporting taxonomy found, display a select.

default:

?>

<p>

<label for=”<?php echo $this->get_field_id( ‘taxonomy’ ); ?>”><?php _e( ‘Taxonomy:’ ); ?></label>

<select class=”widefat” id=”<?php echo $this->get_field_id( ‘taxonomy’ ); ?>” n**e=”<?php echo $this->get_field_n**e( ‘taxonomy’ ); ?>”>

<?php foreach ( $taxonomies as $taxonomy => $tax ) : ?>

<option value=”<?php echo esc_attr( $taxonomy ); ?>” <?php selected( $taxonomy, $current_taxonomy ); ?>>

<?php echo esc_html( $tax->labels->n**e ); ?>

</option>

<?php endforeach; ?>

</select>

</p>

<?php

}

if ( count( $taxonomies ) > 0 ) {

?>

<p>

<input type=”checkbox” class=”checkbox” id=”<?php echo $this->get_field_id( ‘count’ ); ?>” n**e=”<?php echo $this->get_field_n**e( ‘count’ ); ?>” <?php checked( $count, true ); ?> />

<label for=”<?php echo $this->get_field_id( ‘count’ ); ?>”><?php _e( ‘Show tag counts’ ); ?></label>

</p>

<?php

}

}

/**

* Retrieves the taxonomy for the current Tag cloud widget instance.

*

* @since 4.4.0

*

* @par** array $instance Current settings.

* @return string N**e of the current taxonomy if set, otherwise ‘post_tag’.

*/

public function _get_current_taxonomy( $instance ) {

if ( ! empty( $instance[‘taxonomy’] ) &**p;&**p; taxonomy_exists( $instance[‘taxonomy’] ) ) {

return $instance[‘taxonomy’];

}

return ‘post_tag’;

}

}

以上代码位于 wp-includes/widgets/class-wp-widget-tag-cloud.php 文件中。我们将57-79行的代码抽出来看一下：

$tag_cloud = wp_tag_cloud(

/**

* Filters the taxonomy used in the Tag Cloud widget.

*

* @since 2.8.0

* @since 3.0.0 Added taxonomy drop-down.

* @since 4.9.0 Added the `$instance` par**eter.

*

* @see wp_tag_cloud()

*

* @par** array $args     Args used for the tag cloud widget.

* @par** array $instance Array of settings for the current widget.

*/

apply_filters(

‘widget_tag_cloud_args’,

array(

‘taxonomy’   => $current_taxonomy,

‘echo’       => false,

‘show_count’ => $show_count,

),

$instance

)

);

代码中有一个函数 wp_tag_cloud() 用于输出标签云的内容，它里面包含了几个参数，并且有一个 widget_tag_cloud_args 过滤器钩子，这就是上文【通过钩子全局修改标签云小工具的参数】所展示的钩子和所有可用参数。

添加设置选项到标签云小工具

/**

* 添加新选项到标签云小工具

* @par**  [type] $widget   [description]

* @par**  [type] $return   [description]

* @par**  [type] $instance [description]

* @return [type]           [description]

*/

function cmhello_tag_cloud_new_options( $widget, $return, $instance ) {

// Are we dealing with a tag_cloud widget?

if ( ‘tag_cloud’ == $widget->id_base ) {

?>

<p>

<label for=”<?php echo $widget->get_field_id(‘tags_number’); ?>”><?php _e( ‘显示数量：’, ‘textdo**in’ ); ?></label>

<input type=”text” class=”widefat” id=”<?php echo $widget->get_field_id(‘tags_number’); ?>” n**e=”<?php echo $widget->get_field_n**e(‘tags_number’); ?>” value=”<?php if (isset ( $instance[‘tags_number’]) &**p;&**p; $instance[‘tags_number’]) echo esc_attr( $instance[‘tags_number’] ); ?>” />

</p>

<p>

<label for=”<?php echo $widget->get_field_id(‘orderbytag’); ?>”><?php _e(‘排序依据：’, ‘textdo**in’ ) ?></label>

<select  class=”widefat” id=”<?php echo $widget->get_field_id(‘orderbytag’); ?>” n**e=”<?php echo $widget->get_field_n**e(‘orderbytag’); ?>”>

<option <?php if ( isset($instance[‘orderbytag’]) &**p;&**p; $instance[‘orderbytag’] == ‘n**e’) echo ‘selected=”SELECTED”‘; else echo ”; ?>  value=”n**e”><?php  echo __(‘名称’,’textdo**in’);?></option>

<option <?php if ( isset($instance[‘orderbytag’]) &**p;&**p; $instance[‘orderbytag’] == ‘count’) echo ‘selected=”SELECTED”‘; else echo ”; ?> value=”count”><?php echo __(‘数量’,’textdo**in’);?></option>

</select>

</p>

<p>

<label for=”<?php echo $widget->get_field_id(‘ordertag’); ?>”><?php _e(‘排序方式：’, ‘textdo**in’ ) ?></label>

<select  class=”widefat” id=”<?php echo $widget->get_field_id(‘ordertag’); ?>” n**e=”<?php echo $widget->get_field_n**e(‘ordertag’); ?>”>

<option <?php if ( isset($instance[‘ordertag’]) &**p;&**p; $instance[‘ordertag’] == ‘ASC’) echo ‘selected=”SELECTED”‘; else echo ”; ?>  value=”ASC”><?php  echo __(‘升序’,’textdo**in’);?></option>

<option <?php if ( isset($instance[‘ordertag’]) &**p;&**p; $instance[‘ordertag’] == ‘DESC’) echo ‘selected=”SELECTED”‘; else echo ”; ?> value=”DESC”><?php echo __(‘降序’,’textdo**in’);?></option>

<option <?php if ( isset($instance[‘ordertag’]) &**p;&**p; $instance[‘ordertag’] == ‘RAND’) echo ‘selected=”SELECTED”‘; else echo ”; ?> value=”RAND”><?php echo __(‘随机’,’textdo**in’);?></option>

</select>

</p>

<?php

}

}

add_filter(‘in_widget_form’, ‘cmhello_tag_cloud_new_options’, 10, 3 );

我们通过 in_widget_form 过滤钩子，并在第 11 行’tag_cloud’ == $widget->id_base确保新选项只适用于标签云小工具，这样我们就可以在标签云小工具中看到新的选项了：

保存标签云新选项的值

/**

* 更新标签云新字段的值

*/

function cmhello_tag_cloud_instance($instance, $new_instance, $old_instance) {

$instance[‘tags_number’] = stripslashes($new_instance[‘tags_number’]);

$instance[‘ordertag’] = stripslashes($new_instance[‘ordertag’]);

$instance[‘orderbytag’] = stripslashes($new_instance[‘orderbytag’]);

return $instance;

}

add_filter(‘widget_update_callback’, ‘cmhello_tag_cloud_instance’, 10, 3);

通过 widget_update_callback 钩子，让小工具保存的时候，可以更新我们新增的选项设置。

　修改标签云的输出

我们的新选项已经添加并可以保存，下面我们就需要将我们的新选项的值应用到标签云的参数中：

/**

* 通过钩子去修改标签云的参数

* @par**  [type] $args     [description]

* @par**  [type] $instance [description]

* @return [type]           [description]

*/

function cmhello_tag_cloud_args( $args, $instance){

if(isset($instance[‘tags_number’])){

$args[‘number’] = $instance[‘tags_number’]; //Limit number of tags

}

if(isset($instance[‘orderbytag’])){

$args[‘orderby’] = $instance[‘orderbytag’];

}

if(isset($instance[‘ordertag’])){

$args[‘order’] = $instance[‘ordertag’];

}

return $args;

}

add_filter(‘widget_tag_cloud_args’, ‘cmhello_tag_cloud_args’, 10, 2);

前文我们已经提到了 widget_tag_cloud_args 钩子，所以我们可以将新的选项通过钩子应用到标签云函数 wp_tag_cloud() 中，达到我们的目的。

完整的示例代码

以下就是我们最终用到的所有代码：

/**

* 添加新选项到标签云小工具

* @par**  [type] $widget   [description]

* @par**  [type] $return   [description]

* @par**  [type] $instance [description]

* @return [type]           [description]

*/

function cmhello_tag_cloud_new_options( $widget, $return, $instance ) {

// Are we dealing with a tag_cloud widget?

if ( ‘tag_cloud’ == $widget->id_base ) {

?>

<p>

<label for=”<?php echo $widget->get_field_id(‘tags_number’); ?>”><?php _e( ‘显示数量：’, ‘textdo**in’ ); ?></label>

<input type=”text” class=”widefat” id=”<?php echo $widget->get_field_id(‘tags_number’); ?>” n**e=”<?php echo $widget->get_field_n**e(‘tags_number’); ?>” value=”<?php if (isset ( $instance[‘tags_number’]) &**p;&**p; $instance[‘tags_number’]) echo esc_attr( $instance[‘tags_number’] ); ?>” />

</p>

<p>

<label for=”<?php echo $widget->get_field_id(‘orderbytag’); ?>”><?php _e(‘排序依据：’, ‘textdo**in’ ) ?></label>

<select  class=”widefat” id=”<?php echo $widget->get_field_id(‘orderbytag’); ?>” n**e=”<?php echo $widget->get_field_n**e(‘orderbytag’); ?>”>

<option <?php if ( isset($instance[‘orderbytag’]) &**p;&**p; $instance[‘orderbytag’] == ‘n**e’) echo ‘selected=”SELECTED”‘; else echo ”; ?>  value=”n**e”><?php  echo __(‘名称’,’textdo**in’);?></option>

<option <?php if ( isset($instance[‘orderbytag’]) &**p;&**p; $instance[‘orderbytag’] == ‘count’) echo ‘selected=”SELECTED”‘; else echo ”; ?> value=”count”><?php echo __(‘数量’,’textdo**in’);?></option>

</select>

</p>

<p>

<label for=”<?php echo $widget->get_field_id(‘ordertag’); ?>”><?php _e(‘排序方式：’, ‘textdo**in’ ) ?></label>

<select  class=”widefat” id=”<?php echo $widget->get_field_id(‘ordertag’); ?>” n**e=”<?php echo $widget->get_field_n**e(‘ordertag’); ?>”>

<option <?php if ( isset($instance[‘ordertag’]) &**p;&**p; $instance[‘ordertag’] == ‘ASC’) echo ‘selected=”SELECTED”‘; else echo ”; ?>  value=”ASC”><?php  echo __(‘升序’,’textdo**in’);?></option>

<option <?php if ( isset($instance[‘ordertag’]) &**p;&**p; $instance[‘ordertag’] == ‘DESC’) echo ‘selected=”SELECTED”‘; else echo ”; ?> value=”DESC”><?php echo __(‘降序’,’textdo**in’);?></option>

<option <?php if ( isset($instance[‘ordertag’]) &**p;&**p; $instance[‘ordertag’] == ‘RAND’) echo ‘selected=”SELECTED”‘; else echo ”; ?> value=”RAND”><?php echo __(‘随机’,’textdo**in’);?></option>

</select>

</p>

<?php

}

}

add_filter(‘in_widget_form’, ‘cmhello_tag_cloud_new_options’, 10, 3 );

/**

* 更新标签云新字段的值

*/

function cmhello_tag_cloud_instance($instance, $new_instance, $old_instance) {

$instance[‘tags_number’] = stripslashes($new_instance[‘tags_number’]);

$instance[‘ordertag’] = stripslashes($new_instance[‘ordertag’]);

$instance[‘orderbytag’] = stripslashes($new_instance[‘orderbytag’]);

return $instance;

}

add_filter(‘widget_update_callback’, ‘cmhello_tag_cloud_instance’, 10, 3);

/**

* 通过钩子去修改标签云的参数

* @par**  [type] $args     [description]

* @par**  [type] $instance [description]

* @return [type]           [description]

*/

function cmhello_tag_cloud_args( $args, $instance){

if(isset($instance[‘tags_number’])){

$args[‘number’] = $instance[‘tags_number’]; //Limit number of tags

}

if(isset($instance[‘orderbytag’])){

$args[‘orderby’] = $instance[‘orderbytag’];

}

if(isset($instance[‘ordertag’])){

$args[‘order’] = $instance[‘ordertag’];

}

return $args;

}

add_filter(‘widget_tag_cloud_args’, ‘cmhello_tag_cloud_args’, 10, 2);