JSON in WordPress block theme development

Introduction - use the power of JSON to develop a WordPress theme

Developing and designing a WordPress block theme is a relatively new feature of WordPress that basically, enabled WordPress core system to become a web builder of sorts, while using more front-end technologies like React and JavaScript in general. Developers can use these technologies to build custom blocks, that can then be used by any WordPress user to build posts and pages. For example, a developer can develop a custom banner block that consists of some text and a cover image. Everything in this block can be made customizable, fonts, colors, image. Now, we can use our Gutenberg editor to insert this block into our page template (we can build custom page templates also in block themes). In developing block themes the central role is delegated to theme.json file. In simple terms, theme.json is a configuration file that allows you to control the appearance and behavior of your WordPress theme. It replaces the need for multiple add_theme_support() calls in your functions.php file in order to setup different theme options and variances. Basically, this is the central point of WordPress block theme, like a central office in a factory that has control over all the processes in a factory. Let us now look at some of the major features of using a well configured theme.json file in block theme WordPress development.

Global settings

When you define a theme.json file, you can define global settings for your overall look and feel with it, such as color palettes, font sizes or layout options. So you as a WordPress / PHP developer use theme.json file in order to configure all these variables for the whole app. This means you can set default values that apply across your entire site, ensuring a consistent look and feel, for example you can set a base font color for the whole website.

Block-Level Customization

Oppose to Global settings, Block-level customization with theme.json means that you override the global styles of your theme by a block-level configuration. A developer will specify settings for individual blocks in theme.json, and by that achieve more flexibility in your theme development. You (a developer) can enable custom color options for image blocks, while restricting them for paragraph blocks, as an example of this feature. This is amazing. You can practically do whatever you want with your theme during the development process.

CSS Variables support

The theme.json file also supports CSS variables, which can be used to create a more modern and dynamic stylesheet. This is useful for defining color schemes and typography that can be easily updated on a global scale. By using theme.json we centralize styles and settings and consolidate them into a single file, and this helps reduce the amount of CSS that needs to be loaded on page load. This leads to faster page load times and a more efficient website.

Example - Global settings

{
  "version": 1,
  "settings": {
    "color": {
      "palette": [
        {
          "name": "Primary",
          "slug": "primary",
          "color": "#0000ff"
        },
        {
          "name": "Secondary",
          "slug": "secondary",
          "color": "#669999"
        },
        {
          "name": "Danger",
          "slug": "danger",
          "color": "#ff0000"
        }
      ]
    },
    "typography": {
      "fontSizes": [
        {
          "name": "Medium",
          "slug": "medium",
          "size": "16px"
        },
        {
          "name": "Large",
          "slug": "large",
          "size": "24px"
        }
      ]
    }
  }
}

We see the settings key in this theme.json, under this key we can configure all the Global settings of our theme. So in this example, we define a color palette with primary, secondary and danger colors. We also define font sizes for medium and large text. This configuration will be applied globally across your theme (we can override it tough, with the Block level settings if we want).

Example - Block level settings

{
  "version": 1,
  "settings": {
    "color": {
      "defaultPalette": false
    },
    "blocks": {
      "core/site-title": {
        "color": {
          "defaultPalette": true
        }
      }
    }
  }
}

In the second Example, we disable the default color picker for the website, and transfer that responsibility on individual blocks. Specifically, we set the default color picker for a specific core WordPress block that is called and designated core/site-title. This is a default block that allows us to arrange the main site title, we could set the specific color for this title, or do something else, but here we just chose to set the default color picker that let's us set the color of this title in the Gutenberg editor.

Why WordPress block themes matter and why theme.json matters

Block themes in WordPress marked a new era of WordPress theme development that is advancing day by day. The theme.json file and JSON itself as a data format marks a significant shift in how WordPress themes are created and configured. It simplifies the process of managing theme settings and styles, making it easier for developers to create cohesive and customizable themes. This file enhances the user experience by providing more control over the appearance of their site without needing to delve into code, effectively serving as a web builder with a lot of possible customizations. To conclude, theme.json offers a centralized way to manage global settings and styles, reduces CSS bloat, and provides block-level customization. Whether you’re a seasoned WordPress or PHP developer, or just starting out, incorporating theme.json into your workflow will greatly enhance the efficiency and flexibility of your theme development process. Happy coding!