Editing JSON

This article describes how to edit JSON in MapTiler Customize. The JSON editor in MapTiler Customize allows the writing or adjustment of any style.json code. Cartographers and other advanced users can leverage this to manipulate complex data expressions that are not editable on the UI.

Important notice

To use MapTiler Customize, you need to set up a MapTiler Cloud account. If you don't have one yet, don't hesitate to sign up for free!

JSON editor

JSON editor can be accessed after clicking on a specific layer. Either navigate to the bottom of the page and click the { } symbol or use the Alt+E shortcut.

After opening the JSON editor, you will see the JSON syntax of the selected layer. You can directly type or paste into the editor, and in case of a syntax error, you will be notified with code marked in red. After hovering a mouse over it, you will get suggestions for fixes. MapTiler Customize is compliant with MapLibre style specification. 

Search functions

When working with complex JSON layers, the search functions might come in handy. You can use the search dialogue directly in the JSON editor to look for specific text sequences or use focus functionality.

With the search, it is possible to use find & replace based on match case, whole words, or regular expressions. Search is available through the magnifier icon.

With the focus, you can have only specific JSON properties visible in the editor: layout, paint, metadata, or filter. Focus is a drop-down menu atop the JSON field.

Fallback on complex expressions

MapTiler Customize UI currently does not support the editing of complex data expressions (such as  "match", "case" or "get") or nested ones. If such an expression is used in a map style, Customize will let you know by the "Set by expression" button that will switch to JSON editor with a click. There, it is possible to edit or write any expression compliant with JSON syntax.

Conclusion

With the JSON editor in MapTiler Customize, it is possible to do advanced editing or writing style JSON codes by hand. If there is a complex or nested expression used in a map style, UI will switch to the JSON editor, where you can edit any part of your code.

Useful links

MapLibre Style Spec