Wordpress snippets

functions.php

<?php
// --- Create a shortcode
// @Usage: [shortcode_name count="1"]
function theme_shortcode_add_name($args) {
    $html = '';
    $count = !empty($args['count']) ? $args['count'] : 5;
    return $html;
}
add_shortcode( 'shortcode_name', 'theme_shortcode_add_name' );

// --- Add a menu
function theme_add_nav_menu() {
    register_nav_menus(
        array(
            'main-menu' => __( 'Main Menu', 'themename' )
        )
    );
}
add_action( 'after_setup_theme', 'theme_add_nav_menu' );

// --- Add a widget
function theme_widgets_init() {
	register_sidebar( array (
		'name' => __( 'Homepage Widget Area', 'theme' ),
		'id' => 'homepage-widget-area',
		'before_widget' => '',
		'after_widget' => '',
		'before_title' => '',
		'after_title' => '',
	) );
}
add_action( 'widgets_init', 'theme_widgets_init' );

// -- Remove WP Emoji
remove_action('wp_head', 'print_emoji_detection_script', 7);
remove_action('wp_print_styles', 'print_emoji_styles');

remove_action( 'admin_print_scripts', 'print_emoji_detection_script' );
remove_action( 'admin_print_styles', 'print_emoji_styles' );

// -- REST
// Disable unauthenticated REST requests
add_filter( 'rest_authentication_errors', function( $result ) {
	if ( ! empty( $result ) ) {
		return $result;
	}
	if ( ! is_user_logged_in() ) {
		return new WP_Error( 'rest_not_logged_in', 'You are not currently logged in.', array( 'status' => 401 ) );
	}

	return $result;
});

// --- Add a custom post type to REST
function theme_add_events_to_json_api() {
    $types = get_post_types(array('public' => true, '_builtin' => false));
    global $wp_post_types;
    foreach ($types as $type) {
        $wp_post_types[$type]->show_in_rest = true;
        $wp_post_types[$type]->rest_base = $type;
        $wp_post_types[$type]->rest_controller_class = 'WP_REST_Posts_Controller';
    }
}
add_action( 'init', 'theme_add_events_to_json_api', 30 );


// --- Gravity Forms
/**
 * Adds an option to have an Australian address type with a state dropdown
 */
function theme_gravityforms_add_australian_address( $address_types, $form_id ) {
	$address_types['australia'] = array(
		'label' => 'Australian',
		'country' => 'Australia',
		'zip_label' => 'Postcode',
		'state_label' => 'State',
		'states' => array(
			'' => '-- Select a State --',
			'ACT' => 'Australian Capital Territory',
			'NSW' => 'New South Wales',
			'NT' => 'Northern Territory',
			'QLD' => 'Queensland',
			'SA' => 'South Australia',
			'TAS' => 'Tasmania',
			'VIC' => 'Victoria',
			'WA' => 'Western Australia',
		),
	);
	return $address_types;
}
add_filter( 'gform_address_types', 'theme_gravityforms_add_australian_address', 10, 2 );

function theme_set_default_country( $default_address_type, $form_id ) {
	return 'australian';
}
add_filter( 'gform_default_address_type', 'theme_set_default_country',  10, 2 );

// --- Updated login link text when logged in
function theme_update_login_text( $sorted_menu_items, $args ) {
    $logged_in_text = 'My Account';
    $logged_out_text = 'Member Login';
    foreach ( $sorted_menu_items as &$menu_item ) {
        if ( $menu_item->title === $logged_out_text && is_user_logged_in() ) {
            $menu_item->title = $logged_in_text;
	}
    }
    return $sorted_menu_items;
}
add_filter( 'wp_nav_menu_objects', 'theme_update_login_text', 10, 2 );

// --- Remove unwanted Wordpress admin menu items (items added by themes for example)
function theme_admin_remove_unwanted_admin_menu_items() {
    global $menu;
    $remove_menu_titles = array(
        __('Courses', 'theme'),
	__('Teachers', 'theme')
    );
    foreach ($menu as $menu_index => $menu_item) {
	$title_parts = explode(' ', $menu_item[0]);

	$title = !empty( $title_parts[0] ) ? $title_parts[0] : '';
	if ( in_array( $title, $remove_menu_titles ) ) {
	    unset ( $menu[$menu_index] );
	}
    }
}
add_action( 'admin_menu', 'theme_admin_remove_unwanted_admin_menu_items' );

// Add a new ACF toolbar
function theme_add_toolbar( $toolbars ) {
    $toolbars['Very Simple' ] = array(
        1 => array(
            'bold' , 'italic' , 'underline'
        )
    );
    return $toolbars;
}
add_filter( 'acf/fields/wysiwyg/toolbars', 'theme_add_toolbar' );


// Show a warning when a menu is trashed

/**
 * @return array
 */
function theme_admin_get_menu_page_post_ids( $menu_name ) {
    $menu_page_post_ids = array();
    if ( empty( $menu_name ) ) {
        return $menu_page_post_ids;
    }
    $locations = get_nav_menu_locations();
    if ( !isset( $locations[$menu_name] ) ) {
        return $menu_page_post_ids;
    }
    $menu = wp_get_nav_menu_object( $locations[ $menu_name ] );
    $menu_items = wp_get_nav_menu_items( $menu->term_id );
    foreach ( $menu_items as $item ) {
        $menu_page_post_ids[] = get_post_meta( $item->ID, '_menu_item_object_id', true );
    }
    return $menu_page_post_ids;
}

/**
 * @return array
 */
function theme_admin_get_woocommerce_page_post_ids() {
    global $wpdb;
    $post_ids = array();
    $query = 'SELECT ID from wp_posts WHERE post_content LIKE "[woocommerce_%"';

    $records = $wpdb->get_results( $query );
    foreach ( $records as $record ) {
	$post_ids[] = $record->ID;
    }

    return $post_ids;
}

/**
 * Prevent certain pages from being trashed
 *
 * @param $post_ID
 */
function theme_admin_restrict_post_deletion($post_ID){
    $menu_pages = theme_admin_get_menu_page_post_ids( 'main-menu' );

    // Disallow main menu page deletions
    if ( in_array( $post_ID, $menu_pages ) ){
	wp_die( 'The page you\'re trying to delete is used in the "main-menu" menu. Deleting it will break the menu.<br><br>If you wish to delete it, please delete <a href="/wp-admin/nav-menus.php">the menu item</a> first.', 'Warning' );
    }

    // Disallow WooCommerce page deletions
    $woocommerce_page_post_ids = theme_admin_get_woocommerce_page_post_ids();
    if ( in_array( $post_ID, $woocommerce_page_post_ids ) ) {
	wp_die( 'You cannot delete a WooCommerce template page.', 'Disallowed' );
    }

    // Disallow required theme pages - update post IDs
    $theme_post_ids = array(1, 2, 3);
    if ( in_array( $post_ID, $theme_post_ids ) ) {
        wp_die( 'You cannot delete this page. It is required by the theme.', 'Disallowed' );
    }
}
add_action('wp_trash_post', 'theme_admin_restrict_post_deletion', 10, 1);
add_action('before_delete_post', 'theme_admin_restrict_post_deletion', 10, 1);