在 WordPress 里 http://localhost/wordpress3.6.1/wp-admin/edit-tags.php?taxonomy=category 这个链接可以显示 WP 里的无限栏目分类,我们来研究一下 WordPress 是如何实现的。
找到 wp-admin/edit-tags.php 这个文件,发现显示栏目的代码很少:
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<form id= "posts-filter" action= "" method= "post" > |
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<input type= "hidden" name= "taxonomy" value= "<?php echo esc_attr($taxonomy); ?>" /> |
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<input type= "hidden" name= "post_type" value= "<?php echo esc_attr($post_type); ?>" /> |
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<?php $wp_list_table ->display(); ?> |
其实关键的是 $wp_list_table->display(); 这一行代码。金殿娱乐城
wordpress 的类库 wp_list_table 自始至终都是用来显示数据,例如用户,插件,评论或是文章,这个类库包含了几乎所有的用于显示、排序、分页和搜索的方法。
我们继续追踪下,打开 wp-admin/includes/class-wp-list-table.php 这个文件,找到 display(); 方法:
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extract( $this ->_args ); |
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$this ->display_tablenav( ‘top‘ ); |
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<table class = "wp-list-table <?php echo implode( ‘ ‘, $this->get_table_classes() ); ?>" cellspacing= "0" > |
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<?php $this ->print_column_headers(); ?> |
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<?php $this ->print_column_headers( false ); ?> |
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<tbody id= "the-list" <?php if ( $singular ) echo " data-wp-lists=‘list:$singular‘" ; ?>> |
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<?php $this ->display_rows_or_placeholder(); ?> |
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$this ->display_tablenav( ‘bottom‘ ); |
我们再着眼于生成栏目分类的下面这几行代码:
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<tbody id= "the-list" <?php if ( $singular ) echo " data-wp-lists=‘list:$singular‘" ; ?>> |
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<?php $this ->display_rows_or_placeholder(); ?> |
display_rows_or_placeholder() 这个函数又是怎么回事呢?
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* Generate the <tbody> part of the table |
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function display_rows_or_placeholder() { |
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if ( $this ->has_items() ) { |
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$this ->display_rows(); |
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list( $columns , $hidden ) = $this ->get_column_info(); |
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echo ‘<tr class="no-items"><td class="colspanchange" colspan="‘ . $this ->get_column_count() . ‘">‘ ; |
接下来是 has_items() 这个函数,这个函数判断有没有数据需要显示:
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* Whether the table has items to display or not |
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function has_items() { |
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return ! empty ( $this ->items ); |
如果有,就 display_rows() :
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* Generate the table rows |
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function display_rows() { |
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foreach ( $this ->items as $item ) |
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$this ->single_row( $item ); |
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* Generates content for a single row of the table |
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* @param object $item The current item |
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function single_row( $item ) { |
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static $row_class = ‘‘ ; |
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$row_class = ( $row_class == ‘‘ ? ‘ class="alternate"‘ : ‘‘ ); |
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echo ‘<tr‘ . $row_class . ‘>‘ ; |
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$this ->single_row_columns( $item ); |
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* Generates the columns for a single row of the table |
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* @param object $item The current item |
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function single_row_columns( $item ) { |
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list( $columns , $hidden ) = $this ->get_column_info(); |
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foreach ( $columns as $column_name => $column_display_name ) { |
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$class = "class=‘$column_name column-$column_name‘" ; |
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if ( in_array( $column_name , $hidden ) ) |
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$style = ‘ style="display:none;"‘ ; |
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$attributes = "$class$style" ; |
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if ( ‘cb‘ == $column_name ) { |
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echo ‘<th scope="row" class="check-column">‘ ; |
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echo $this ->column_cb( $item ); |
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elseif ( method_exists( $this , ‘column_‘ . $column_name ) ) { |
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echo "<td $attributes>" ; |
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echo call_user_func( array ( & $this , ‘column_‘ . $column_name ), $item ); |
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echo "<td $attributes>" ; |
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echo $this ->column_default( $item , $column_name ); |
也就是说,根据是否有子栏目先拼凑好栏目分类的 html,再通过 $wp_list_table->display(); 显示到前台。
时间: 2024-10-12 02:24:31