sh-navid / Archive.Learn.WordPress

Learn-WordPress

Hook

• Action
• Filter

Plugin

• Make my-plugin folder in wp-content/plugins
• Make a index.php file in my-plugin and fill these contents

  •   <?php
      /**
      * Plugin Name: my-plugin
      * Plugin URI: https://www.my-site.com/
      * Description: My Plugin
      * Version: 0.1
      * Author: my-name
      * Author URI: https://www.my-site.com/
      **/
    
      add_filter( 'preprocess_comment' , 'my_func' );
    
      function my_func( $commentdata ) {
          $commentdata['comment_content'] = strtoupper( $commentdata['comment_content'] );
          return $commentdata;
      }

• Go to Plugins tab on wordpress and activate this plugin
• Plugin Menu

  •   add_menu_page(
          string $page_title,
          string $menu_title,
          string $capability,
          string $menu_slug,
          callable $function = '',
          string $icon_url = '',
          int $position = null
      );

ShortCode

• You can use it inside posts, pages, and widgets
• You can also register this shortcode inside plugin

  •   add_shortcode('myshortcode', 'my_short_code');
    
      function my_short_code( $atts = [], $content = null) {
          $content="<h1>My Shortcode Content</h1>";
          return $content;
      }

• Then you can put [myshortcode] inside for example post content

Meta Data

Custom Post Type

Taxonomy

Cron

Plugin example

Disclaimer: this is a bad practice and its not secure; its just for testing

• index.php

<?php
/**
 * Plugin Name: my-plugin
 * Plugin URI: https://www.my-site.com/
 * Description: My Plugin
 * Version: 0.1
 * Author: my-name
 * Author URI: https://www.my-site.com/
 **/


function get_local_file_contents($file_path)
{
    ob_start();
    include $file_path;
    $contents = ob_get_clean();
    return $contents;
}


add_filter('preprocess_comment', 'my_func');
function my_func($commentdata)
{
    if (get_local_file_contents("options.txt") == "lower") {
        $commentdata['comment_content'] = strtolower($commentdata['comment_content']);
    } else {
        $commentdata['comment_content'] = strtoupper($commentdata['comment_content']);
    }
    return $commentdata;
}


add_shortcode('myshortcode', 'my_short_code');
function my_short_code($atts = [], $content = null)
{
    $content = "<h1>My Shortcode Content</h1>";
    return $content;
}


function myplugin_page()
{
    echo "Option: ";
    echo get_local_file_contents("options.txt");


    echo "<h1>" . esc_html(get_admin_page_title()) . "</h1>";
    echo '<form action="' . esc_attr(plugin_dir_url(__FILE__)) . 'save.php?type=upper" method="post">';
    submit_button(__('Save Upper'));
    echo '</form>';
    echo '<form action="' . esc_attr(plugin_dir_url(__FILE__)) . 'save.php?type=lower" method="post">';
    submit_button(__('Save Lower'));
    echo '</form>';
}


add_action('admin_menu', 'myplugin_options_page');
function myplugin_options_page()
{
    add_menu_page(
        'My Plugin', // Page Title
        'My Plugin Options', // Menu title
        'manage_options', // Capability
        'myplugin', // Menu Slug
        'myplugin_page', // Function
        plugin_dir_url(__FILE__) . 'icon.png', // Icon
        20 // Position
    );
}

• save.php

<?php
$myfile = fopen("options.txt", "w") or die("Unable to open file!");
fwrite($myfile, $_GET["type"]);
fclose($myfile);

header("Location: http://localhost:8000/wp-admin/admin.php?page=myplugin");
exit();