Switching from Vagrant to Docker for WordPress Development

These past few weeks I’ve been experimenting with Docker as an alternative to Vagrant (and VVV) for WordPress development.

I had looked into Docker in the past, but given how easy Vagrant and VVV were, I was in no hurry to switch. VVV still is awesome (there is an excellent getting started guide here), but since settling on Vagrant, the tools and ecosystem around Docker have significantly improved.

Mainly to satisfy my own curiosity, but also hoping to use less system resources (since I currently code on a Macbook Air) I finally gave Docker a fair chance. I wanted to share some of the things I’ve learned over the past week whilst switching.


Building a cross-browser compatible, multi-handle range slider

Range Inputs are HTML elements which let users select a numeric value between a specified minimum and maximum value. They support single values by default.

As part of the WooCommerce Blocks project we’ve been working on converting WooCommerce widgets to Gutenberg blocks. One of those happens to be a price slider which currently uses jQuery UI. For blocks we’re using React.

Rather than use a library, we were really keen to use native range inputs to keep our dependencies to a minimum, and so the range inputs were semantic and keyboard accessible. Our idea was to overlay 2 range sliders to form a single component.

After working on this, I’d like to share some of my findings. Spoiler alert, the final slider looks like this:

The finished slider

I made a Super Mario Themed Nursery

Last year, before the birth of my first son, I was able to get creative and decorate the nursery. Being a huge fan of video games (and retro style graphics!) logically I chose a Super Mario theme for the room and set about making plans to create a large wall mural and other themed objects (as well as doing the boring adult stuff like flooring and painting the walls).

It took approximately 2 months to get everything completed, and a lot of that was lead time on the custom things I needed to order. I do wish I took more shots during the build, but alas I didn’t think I’d be blogging about it. Maybe next time!


How we’re tackling GDPR in WooCommerce core

What we’re up to in WooCommerce land right now.


Debugging “unexpected token” in WooCommerce 2.4+

When the WooCommerce checkout is processed it requires that gateways return an array (which is then converted into JSON) telling the checkout whether or not it was successful. It’s been this way since v1. Here is a basic example from the PayPal gateway:

return array(
    'result'   => 'success',
    'redirect' => $paypal_request->get_request_url( $order, $this->testmode )

The above for example returns a successful response and tells the checkout to redirect the user to the URL provided.

In 2.4+ this was made more strict in that the response must be valid JSON. Anything else in the response (such as HTML, notices or whitespace) will invalidate this JSON and you may see an error along the lines of:

SyntaxError: Unexpected token

WooThemes own gateways have all been tested for 2.4, however, we’ve seen some less-supported gateways break due to returning invalid content.

I’ve seen a few vocal users complaining about this recently on the forums (some even feeling the need to attack me personally, thanks guys) and thought it best to post a few steps on how you can narrow down the issue.

First off its always best to rule out your plugins and theme by disabling them, even though a lot of users seem to ignore this step. It is only temporary and helps narrow down the issue. Much better than shouting at me on

Lets assume this does not narrow down the issue for a moment. How would you know if content is being output? The answer is in your browser console.

Lets simulate an error. In the paypal gateway, just before the array is returned I’ll add:

trigger_error( 'Uh oh' );

This triggers the error as expected:

2015-11-12 at 16.29

Now lets try to debug this like someone who does not know where the error is coming from.

In Chrome, go to View > Developer > Javascript Console whilst viewing the checkout.

Now trigger the error again.

After the error is shown, in the console go to the Network tab and click XHR:

2015-11-12 at 16.31

In the list you’re see one which looks like this: ?wc-ajax=checkout. Click on that and go to the response tab:

2015-11-12 at 16.32

Notice in my above example, there is the notice. This invalidates the JSON.

A valid JSON response {starts and ends with a bracket} – if there is an error, white space or content before or after those brackets, that is your issue.

In some cases the error will be obvious and allow you to patch or disable the cause.

Hopefully that helps.


User onboarding for WordPress plugins slides #WCNL

Today I did a talk at WordCamp Netherlands on user onboarding for WordPress plugins. This was my first ever WordCamp talk and it was an interesting, but nerve-wracking, experience. My slides for the presentation are below. Thanks to everyone who attended, and I hope it was useful.!

User onboarding for WordPress plugins from mikejolley86