Handy Wordpress Snippets

Base Plugin Script.php

global $wpdb;

if (!class_exists("[class name]")) {
	class [class name] {

		public function ignite(){
			add_action('admin_init', array(&$this, 'adminInit'));
        	add_action('admin_menu', array(&$this, 'addMenu'));
        	add_action('admin_head', array(&$this, 'adminStyles'));
		}

		public function adminInit(){
			// register your plugin's settings
		}

		public function adminStyles(){
			echo '<link rel="stylesheet" type="text/css" href="'.plugins_url('[file]').'">';
		}

		public function addMenu(){
			
			add_menu_page([Refer to wordpress.org]);

			// Add a page to manage this plugin's settings
        	add_options_page([Refer to wordpress.org]);
		}

		public function pluginAdmin(){
        	if(!current_user_can('manage_options')){
        		wp_die(__('You do not have sufficient permissions to access this page.'));
        	}
        	// Render the settings template
        	include(sprintf("%s/[file]", dirname(__FILE__)));
        } // END public function pluginAdmin()

		public function pluginSettings(){
        	if(!current_user_can('manage_options')){
        		wp_die(__('You do not have sufficient permissions to access this page.'));
        	}
        	// Render the settings template
        	include(sprintf("%s/[file]", dirname(__FILE__)));
        } // END public function pluginSettings()



		/** Activate the plugin */ 
		public static function activate() { 
      // Do nothing
		} // END public static function activate 


		/** Deactivate the plugin */ 
		public static function deactivate() { 
			// Do nothing 
		} // END public static function deactivate

		public function init_settings() { 
			// register the settings for this plugin 
			register_setting('wp_plugin_template-group', 'setting_a'); 
			register_setting('wp_plugin_template-group', 'setting_b'); 
		} // END public function init_custom_settings())
	}
}

if(class_exists([class name])){

	register_activation_hook(__FILE__, array('[class name]', 'activate')); 
	register_deactivation_hook(__FILE__, array('[class name]', 'deactivate'));

	$[class name] = new [class name];

	$[class name]->ignite();
}

Check if table exists.php

global $wpdb;
$table_name = "your-table-name-here";
if($wpdb->get_var("SHOW TABLES LIKE '$table_name'") != $table_name) {
    //table is not created. you may create the table here.
}