There are many great functions built into WordPress that you might not use as a developer, depending on how you build your sites and what your client requirements are. The Customizer API is one of them.
Starting out as a blogging tool, it sometimes amazes me how far WordPress has developed as a content management system. Ten years ago, it seemed like most discussions about new features in the forums were met with a “that’s not what WordPress is meant for” response by many users.
These days, while the aim is still to keep core WordPress functionality relatively lean, there are a lot of exciting possibilities built-in and ready to be switched on when needed. We tend to build quite bespoke sites with functionality particular to a specific client. Hence it has only been recently that I have started working with the Customizer.
The customizer API “is a framework for live-previewing any change to WordPress”. Rather than having to make changes in the admin, save, check the frontend, adjust, re-save, check again, the customizer allows a developer to add options to an interface, where the user can adjust and see the changes in real-time, but before publishing them.
This is especially useful for theme developers, where a lot of non-technical users will need to customise their site without having to modify theme files or have direct access to their server environment. But it can also be very useful when building custom themes for a particular client, as it’s a way of logically grouping many theme options together, plus many core functions can simply be activated and you don’t have to re-build them from scratch.
Options can be extremely diverse and specific, but some of the common ones are the tagline, header, background image, navigations and colours. Some of these are accessible in other parts of the admin, some will be specific to the customizer.