Maximize the use of the Code Snippets plugin by sharing some useful code snippets that can be readily used

How to use the Code Snippets plugin

The use of the Code Snippets plugin is very simple. After installation and activation, click “Add New”, then fill in the title of the code snippet, fill in the code in the middle “Code”, and then click “Save Changes and Activate” to save and activate.

Code Snippets

https://wordpress.org/plugins/code-snippets/

Code Snippets sharing

Next, I will share a few code snippets that I often use. If necessary, you can directly copy and add the following code to the Code Snippets plugin.

Code 1: wordpress switches back to classic widgets

This code turns your wordpress block widget into a classic widget.

// This code turns your wordpress block widget into a classic widget.
add_filter( 'gutenberg_use_widgets_block_editor', '__return_false' );
add_filter( 'use_widgets_block_editor', '__return_false' );

Code 2: Redirect author link

This code can redirect the author’s link, and the link can be modified arbitrarily.

//This code can redirect the author's link, and the link can be modified arbitrarily.
add_filter( 'author_link', 'fanly_author_link' );
function fanly_author_link() {
  return home_url( '/' );//This means redirect to the home page, you can also fill other pages
}

Code 3: Automatically add alt and title attributes to the article image

This code can automatically add ALT and TITLE attributes to the picture of the article, which can help you do a good job in picture SEO, and is good for the SEO optimization of the whole site.

//Automatically add alt and title attributes to the article image
function image_alt_tag($content){
global $post;preg_match_all('/<img (.*?)\>/', $content, $images);
if(!is_null($images)) {foreach($images[1] as $index => $value)
{$new_img = str_replace('<img', '<img 99999);

Code 4: Admin quick switch

After this code is added, you can quickly switch between multiple administrators, without logging out and logging in again, and without re-entering the password.

//Admin quick switch
add_filter('user_row_actions', function($actions, $user){
    $capability = (is_multisite())?'manage_site':'manage_options';
    if(current_user_can($capability)){
        $actions['login_as']    = '<a title="log in as" href="'.wp_nonce_url("users.php?action=login_as&users=$user->ID", 'bulk-users').'">log in as</a>';
    }
    return $actions;
}, 10, 2);

add_filter('handle_bulk_actions-users', function($sendback, $action, $user_ids){
    if($action == 'login_as'){
        wp_set_auth_cookie($user_ids, true);
        wp_set_current_user($user_ids);
    }
    return admin_url();
},10,3);

Code 5: Add article copying function

This code can add a quick copy function to the article, and the same article can be published, and then you only need to modify it on this basis.

//Function creates post duplicate as a draft and redirects then to the edit post screen
function rd_duplicate_post_as_draft(){
    global $wpdb;
    if (! ( isset( $_GET['post']) || isset( $_POST['post'])  || ( isset($_REQUEST['action']) && 'rd_duplicate_post_as_draft' == $_REQUEST['action'] ) ) ) {
        wp_die('No post to duplicate has been supplied!');
    }
    /*
     * Nonce verification
     */
    if ( !isset( $_GET['duplicate_nonce'] ) || !wp_verify_nonce( $_GET['duplicate_nonce'], basename( __FILE__ ) ) )
        return;
    /*
     * get the original post id
     */
    $post_id = (isset($_GET['post']) ? absint( $_GET['post'] ) : absint( $_POST['post'] ) );
    /*
     * and all the original post data then
     */
    $post = get_post( $post_id );
    /*
     * if you don't want current user to be the new post author,
     * then change next couple of lines to this: $new_post_author = $post->post_author;
     */
    $current_user = wp_get_current_user();
    $new_post_author = $current_user->ID;
    /*
     * if post data exists, create the post duplicate
     */
    if (isset( $post ) && $post != null) {
        /*
         * new post data array
         */
        $args = array(
            'comment_status' => $post->comment_status,
            'ping_status'    => $post->ping_status,
            'post_author'    => $new_post_author,
            'post_content'   => $post->post_content,
            'post_excerpt'   => $post->post_excerpt,
            'post_name'      => $post->post_name,
            'post_parent'    => $post->post_parent,
            'post_password'  => $post->post_password,
            'post_status'    => 'draft',
            'post_title'     => $post->post_title,
            'post_type'      => $post->post_type,
            'to_ping'        => $post->to_ping,
            'menu_order'     => $post->menu_order
        );
        /*
         * insert the post by wp_insert_post() function
         */
        $new_post_id = wp_insert_post( $args );
        /*
         * get all current post terms ad set them to the new post draft
         */
        $taxonomies = get_object_taxonomies($post->post_type); // returns array of taxonomy names for post type, ex array("category", "post_tag");
        foreach ($taxonomies as $taxonomy) {
            $post_terms = wp_get_object_terms($post_id, $taxonomy, array('fields' => 'slugs'));
            wp_set_object_terms($new_post_id, $post_terms, $taxonomy, false);
        }
        /*
         * duplicate all post meta just in two SQL queries
         */
        $post_meta_infos = $wpdb->get_results("SELECT meta_key, meta_value FROM $wpdb->postmeta WHERE post_id=$post_id");
        if (count($post_meta_infos)!=0) {
            $sql_query = "INSERT INTO $wpdb->postmeta (post_id, meta_key, meta_value) ";
            foreach ($post_meta_infos as $meta_info) {
                $meta_key = $meta_info->meta_key;
                if( $meta_key == '_wp_old_slug' ) continue;
                $meta_value = addslashes($meta_info->meta_value);
                $sql_query_sel[]= "SELECT $new_post_id, '$meta_key', '$meta_value'";
            }
            $sql_query.= implode(" UNION ALL ", $sql_query_sel);
            $wpdb->query($sql_query);
        }
        /*
         * finally, redirect to the edit post screen for the new draft
         */
        wp_redirect( admin_url( 'post.php?action=edit&post=' . $new_post_id ) );
        exit;
    } else {
        wp_die('Post creation failed, could not find original post: ' . $post_id);
    }
}
add_action( 'admin_action_rd_duplicate_post_as_draft', 'rd_duplicate_post_as_draft' ); 
/*
 * Add the duplicate link to action list for post_row_actions
 */
function rd_duplicate_post_link( $actions, $post ) {
    if (current_user_can('edit_posts')) {
        $actions['duplicate'] = '<a href="' . wp_nonce_url('admin.php?action=rd_duplicate_post_as_draft&post=' . $post->ID, basename(__FILE__), 'duplicate_nonce' ) . '" title="Duplicate this item" rel="permalink">Duplicate</a>';
    }
    return $actions;
}
add_filter( 'post_row_actions', 'rd_duplicate_post_link', 10, 2 );

Code 6: Hide the category classification mark

The use of this code is to hide the category mark in the URL, which can shorten the link, which is a little bit good for SEO.

//Hide the category classification mark
add_action( 'load-themes.php',  'no_category_base_refresh_rules');
add_action('created_category', 'no_category_base_refresh_rules');
add_action('edited_category', 'no_category_base_refresh_rules');
add_action('delete_category', 'no_category_base_refresh_rules');
function no_category_base_refresh_rules() {
    global $wp_rewrite;
    $wp_rewrite -> flush_rules();
}
// register_deactivation_hook(__FILE__, 'no_category_base_deactivate');
// function no_category_base_deactivate() {
//  remove_filter('category_rewrite_rules', 'no_category_base_rewrite_rules');
//  // We don't want to insert our custom rules again
//  no_category_base_refresh_rules();
// }
// Remove category base
add_action('init', 'no_category_base_permastruct');
function no_category_base_permastruct() {
    global $wp_rewrite, $wp_version;
    if (version_compare($wp_version, '3.4', '<')) {
        // For pre-3.4 support
        $wp_rewrite -> extra_permastructs['category'][0] = '%category%';
    } else {
        $wp_rewrite -> extra_permastructs['category']['struct'] = '%category%';
    }
}
// Add our custom category rewrite rules
add_filter('category_rewrite_rules', 'no_category_base_rewrite_rules');
function no_category_base_rewrite_rules($category_rewrite) {
    //var_dump($category_rewrite); // For Debugging
    $category_rewrite = array();
    $categories = get_categories(array('hide_empty' => false));
    foreach ($categories as $category) {
        $category_nicename = $category -> slug;
        if ($category -> parent == $category -> cat_ID)// recursive recursion
            $category -> parent = 0;
        elseif ($category -> parent != 0)
            $category_nicename = get_category_parents($category -> parent, false, '/', true) . $category_nicename;
        $category_rewrite['(' . $category_nicename . ')/(?:feed/)?(feed|rdf|rss|rss2|atom)/?$'] = 'index.php?category_name=$matches[1]&feed=$matches[2]';
        $category_rewrite['(' . $category_nicename . ')/page/?([0-9]{1,})/?$'] = 'index.php?category_name=$matches[1]&paged=$matches[2]';
        $category_rewrite['(' . $category_nicename . ')/?$'] = 'index.php?category_name=$matches[1]';
    }
    // Redirect support from Old Category Base
    global $wp_rewrite;
    $old_category_base = get_option('category_base') ? get_option('category_base') : 'category';
    $old_category_base = trim($old_category_base, '/');
    $category_rewrite[$old_category_base . '/(.*)$'] = 'index.php?category_redirect=$matches[1]';
    //var_dump($category_rewrite); // For Debugging
    return $category_rewrite;
}
// Add 'category_redirect' query variable
add_filter('query_vars', 'no_category_base_query_vars');
function no_category_base_query_vars($public_query_vars) {
    $public_query_vars[] = 'category_redirect';
    return $public_query_vars;
}
// Redirect if 'category_redirect' is set
add_filter('request', 'no_category_base_request');
function no_category_base_request($query_vars) {
    //print_r($query_vars); // For Debugging
    if (isset($query_vars['category_redirect'])) {
        $catlink = trailingslashit(get_option('home')) . user_trailingslashit($query_vars['category_redirect'], 'category');
        status_header(301);
        header("Location: $catlink");
        exit();
    }
    return $query_vars;
}