Changing the Auto-Suggest Behaviour in WooCommerce

A request came in this week from a client with a WooCommerce store:

I just placed an order through our website and had an issue with the state. The customer lives in Oregon, so I typed “O” hoping Oregon would auto populate, but it didn’t. I was stuck having to scroll through all 50 states to find Oregon.

An animated Gif showing WooCommerce's default autosuggest behaviour on select boxes.
Confusing for most people.

I tried it, and it’s true. Typing “o” doesn’t narrow the list down much, and the way it does narrow it down doesn’t make much sense in this context: The autosuggest on the State field matches the search phrase anywhere in one of the options, so typing “o” gets you a list of all states with the letter “o” in the state name, ordered alphabetically by state name. Go ahead and try it out in a WooCommerce demo shop.

Out of the box WooCommerce uses SelectWoo, which is essentially Select2 with more accessibility. Select2’s default behaviour of matching the typed text to any part of an option makes sense in many places, especially when searching a store or for categories, but for selecting states, (and countries, although slightly less), it’s confusing.

Nothing’s filterable, but we can set a default

Select2 lets us set the callback function used for matching, so we can customize the matching behaviour, but there’s a problem, the settings for SelectWoo are set in WooCommerce’s country-select.js file, and there’s no way to filter them, so we can’t change the matching behaviour on initialization. It turns out that once a Select2/SelectWoo instance is initialized there’s no way to change the settings either.

When I got to here I thought we were out of luck – either I’d be creating a child theme and re-implementing the checkout, or we were going to live with SelectWoo’s default filtering behaviour. Luckily, I found one way to change the matching callback: It’s possible to set the default SelectWoo options callback before any instances are initialized. So that’s what we’re going to do.

Server-Side

First we need to add a bit of Javascript to our checkout page, so we enqueue a small script that’s dependent on the selectWoo script.


namespace JB\WooAutosuggest;



function enqueue_frontend_scripts() {
    
    if( function_exists('is_checkout') && is_checkout() ) {

        wp_enqueue_script( 'jb-was-checkout-autosuggest', plugins_url( '../assets/checkout-autosuggest.js', __FILE__), array('selectWoo') );

    }
}

add_action( 'wp_enqueue_scripts', __NAMESPACE__ . '\enqueue_frontend_scripts', 20 );

And that’s all the PHP we need! Because our solution changes the default matching behaviour we are careful to only enqueue this script on the Checkout page using WooCommerce’s is_checkout() function.

Client-Side

The enqueued Javascript file is pretty simple as well:

(function($) {
    // Based on custom matcher here: https://select2.org/searching#customizing-how-results-are-matched
    function start_matcher(params, data ) {
        
        // If there are no search terms, return all of the data
        if ($.trim(params.term) === '') {
          return data;
        }

        // Do not display the item if there is no 'text' property
        if (typeof data.text === 'undefined') {
          return null;
        }

        // `params.term` should be the term that is used for searching
        // `data.text` is the text that is displayed for the data object
        // Make sure to compare in the same case! 
        if ( data.text.toLowerCase().indexOf(params.term.toLowerCase() ) === 0 ) {
            return data;
        }
        // Return `null` if the term should not be displayed
        return null;
    }
    $.fn.select2.defaults.set('matcher', start_matcher );
})(jQuery);

There’s a closure so we don’t pollute the global namespace, then we define a new matcher function that matches the beginning of the phrase, and set it as the default matcher. This code runs as soon as it’s ready – it doesn’t wait for a DOMReady event, because by the time DOMReady fires the SelectWoo boxes have probably been initialized already.

Conclusion

I wish we didn’t have to set the defaults for the whole page, but that’s what we’re stuck with at the moment. We could apply different matching patterns to different pages by adding a few more conditions to the PHP block, and a bit more Javascript. This works to make the checkout page work as expected, though.

All the code is up on Github as a WordPress plugin. If it’s useful let me know!

An animated Gif showing WooCommerce's autosuggest matching the beginning of each option.
This makes more sense!

Adding Custom Fields to WooCommerce Products in 2018

Screenshot showing the Shipping section of WooCommerce's Product Data box.
Look, there’s a Shipping section!

This week a client asked to add estimated ship times to the single-product pages in WooCommerce. Ship times are sometimes different for different products, so adding it as a custom field to each product made sense. As a bonus, there’s a “Shipping” tab in the Product Data metabox that the field can go in. Some Googling led me to Tom McFarlin‘s “Adding Custom Fields to Simple Products with WooCommerce” tutorial on tuts+, which is pretty thorough, but out of date – the actions he’s are no longer in WooCommerce, so it’s time for a new version of that tutorial, my-style. There are three main tasks to accomplish: Add the field to the WordPress back-end, save whatever is in the field, and output the data on the Single Product page. We’ll look at each task separately. The completed plugin is up on GitHub if you want to follow along.

Add the Custom Field to WooCommerce in the WordPress Back-End

WooCommerce provides an incredible number of hooks and filters. We’re going to us woocommerce_product_options_shipping hook, because it runs in the shipping block, but is an equivalent hook for each Product Data tab. Look at the files in the woocommerce/includes/admin/meta-boxes/views directory to understand how the Product Data, (and all the WooCommerce Metaboxes), are created, and what hooks are available.

Now we know what hook we need, it’s time for some code:


function print_admin_field() {
    /**
     * @var \WC_Product
     * @see https://docs.woocommerce.com/wc-apidocs/source-class-WC_Meta_Box_Product_Data.html#42
     */
    global $product_object;

    if( $product_object->get_type() == 'simple' ) {
        $field = [
            'id'            => 'sif_ships_in',
            'label'         => __('Ships In', 'jb-sif'),
            'placeholder'   => __('example: 1-2 days', 'jb-sif'),
            'value'         => get_post_meta( $product_object->get_id(), '_sif_ships_in', true ), // Pre-fill any values that have already been saved.
            'description'   => __( 'Add a "Ships in X" message below the Product Meta on the single-product page.', 'jb-sif'),
            'desc_tip'      => true
        ];

        \woocommerce_wp_text_input( $field );
    }
}

add_action( 'woocommerce_product_options_shipping', 'JB\SIF\print_admin_field');

We make sure we have the $product_object variable available, (it’s set in the WC_Meta_Box_Product_Data class, linked with the @see directive), then we make sure we’re adding the field to a “Simple” product type. Then, instead of writing a bunch of HTML, we set some info in an array, and pass it to the woocommerce_wp_text_input() function, (with a backslash, because the plugin is namespaced). WooCommerce has several of these helper fields available that create a form fields and their associated markup so they fit nicely with the rest of the WooCommerce admin.

Notice we’re already getting a value with get_post_meta(). That’s because the same code gets used every time the field is displayed – so if there’s a value in the database we want to display it. This is all we need to properly display a field in the Shipping section of the Product Data. We could add a name attribute to the $field variable, but it defaults to the value of id, so I left it out. Setting desc_tip to true puts the description in the tooltip that appears when someone hovers the circle with the question mark beside the field.

The last line of the code block above hooks our function into the woocommerce_product_options_shipping action. Because the plugin has its own namespace we need to include the full name of the function in the add_action() call.

A screenshot of the new "Ships In" field in the WooCommerce admin.
Our new “Ships In” field, looking great.

Save Whatever is Entered in the Field

Again, a game of hooks figuring out how to save the data. Tom’s tutorial from last year used a woocommerce_process_product_meta hook which no longer exists. It looks like it’s been replaced by a woocommerce_process_product_meta_* hook for each product type. Since we’re only using a Simple product, we’ll use the woocommerce_process_product_meta_simple hook. Now we know which hook to use, some code:


function save( $post_id ) {

    // check nonce
    if( ! ( isset( $_POST['woocommerce_meta_nonce'], $_POST['sif_ships_in'] ) || wp_verify_nonce( sanitize_key( $_POST['woocommerce_meta_nonce'] ), 'woocommerce_save_data' ) ) ) {
        return false;
    }

    update_post_meta( $post_id, '_sif_ships_in', sanitize_text_field( $_POST['sif_ships_in'] ) );

}
add_action( 'woocommerce_process_product_meta_simple', 'JB\SIF\save' );

In the save() function, (which we can name “save” without collisions because we’re using namespaces), we check the field is part of the $_POST array, check the nonce set by WooCommerce, and save the contents of the field, without forgetting to sanitize the data first.

WooCommerce may already checks the nonce for us, but I am not 100% sure, so I added an extra check.

Output the Data on the Single Product Page

WooCommerce’s plethora of hooks make placing the output relatively simple. I chose to put it right below the “Add to Cart” button on the Single Product page, but if you look through WooCommerce’s templates/content-single-product.php file and the files in the templates/single-product directory you’ll find lots hooks to use – and of course you’re not restricted to the single-product page. If you want to add your output to each product in a list of products take a look in the templates/content-product.php file.


function print_output() {

    global $product;
    $ships_in = get_post_meta( $product->get_id(), '_sif_ships_in', true );


    if( !empty( $ships_in )): ?>
        
< ?php echo sprintf( __( 'Ships in %s.', 'jb-sif' ), $ships_in ); ?>
< ?php endif; } add_action( 'woocommerce_single_product_summary', 'JB\SIF\print_output', 45 );

Our print_output() function is pretty simple: Grab the post_meta, check it’s not empty, and output it mixed in with a “Ships In” string. It’s hooked into the woocommerce_single_product_summary action with a priority of 45, which means it appear after the Add to Cart button and after the Product Meta. WooCommerce’s template files are really good at explaining what functions are hooked to actions, and the priority they’re hooked at, which makes it easy to place things on a page without having to copy templates over to your theme.

A screenshot showing the output of the "Ships In" field on the single-product page.
Here you can see the output of the new “Ships In” field on the single-product page. The product meta was moved elsewhere.

Conclusion

Adding fields to the WooCommerce part of a WordPress admin area is much easier than adding a whole metabox. You can grab the completed plugin on Github. You’ll see there’s a bit more to the plugin: requirements are checked using Mark Jaquith’s method before embarking on a namespaced plugin with shorthand array syntax.

If this is useful let me know, and feel free to open tickets and send pull requests on Github.

Flush Opcache with Varnish: a WordPress Plugin Announcement

Flush Opcache with Varnish is here to rescue you from the constant annoyance of flushing yet another cache!

If, like me, you use PHP’s Opcache to speed up a site, and you have a Varnish cache, and maybe some other server-side caches, you probably want to flush the opcache, Varnish cache, and any other server-side caches at the same time after changing the PHP files on your server, (like, when you update WordPress, plugins, or themes). I don’t want to click a button for each cache type, or worse, have to log in to the command-line for a sudo service restart varnish after doing updates, especially if I’m doing repeated updates. Flush Opcache with Varnish hooks into Mika Epstein’s excellent Varnish HTTP Cache plugin and flushes the PHP Opcache and the WP Super Cache cache, (if you use WP Super Cache), every time you manually flush the Varnish cache, turning the Varnish HTTP Cache “Clear Cache” buttons into a three-for-one deal.

If you also use the plugin WP Opcache to manage your opcache then WP Opcache will be called to do the actual Opcache flushing so you can take advantage of its automatic rebuilding of the opcache.

I’m already using Flush Opcache with Varnish in production and it’s saving me time every time I update a theme or plugin. You can get it in the WordPress.org plugin directory.

Announcing DeadTrees

Today I’m releasing DeadTrees, a WordPress plugin to share the books you read. Get it from wordpress.org or search for DeadTrees in the Plugins > Add section of your WordPress admin.

Features

DeadTrees lets you post the books you read, with or without writing about them, (really, does the internet need to know what you thought of the last mystery you read?). It generates Amazon affiliate links to those books so you, (or I), can make a little money if your readers buy the books, and it auto-fetches the books’ cover art from Amazon so things look cool.

Why?

I have been posting about books that I read for a while now, but ground to a halt when I got lazy & didn’t want to write a whole post about each book, and realized often it doesn’t matter what I think about a book. However, I did want to keep posting at least the te title & author of each book I read, (and so my sister can check to see what I’ve read before giving me a book).

Why write a plugin when there are other plugins to share the books I read? Because the other plugins didn’t do it how I wanted them to. I couldn’t find another plugin that uses WordPress’s Custom Post Types to store books I’ve read, and books are such a perfect use of CPTs that they’re even used as the example in the WordPress documentation!

Support & All That

I’ve put DeadTrees up at GitHub, if you have issues try to submit them there. My contact page is also always available to reach me.

See It Live

DeadTrees is up & running here. Take a look at the books I’ve read.