How to handle Dynamic Choice Fields that depends on another Field in Symfony EasyAdmin

EasyAdmin makes it incredibly simple to build admin panels in Symfony, but things can get tricky when you need fields to change based on user input.

One common example is when you have an entity with a type field and a value field. Depending on the selected type, the available options in value should differ.

For instance:

• If the type is Color, then value should allow picking from red, blue, green.
• If the type is Size, then value should allow choosing small, medium, large.

Sounds straightforward, but out of the box, EasyAdmin doesn’t handle this dynamic behavior gracefully. You’ll often run into issues where the field renders as a plain multiple select, loses the EasyAdmin styling, or doesn’t play nicely with JSON-backed fields.

I spent some time digging into this and eventually found a way to:

• Keep the EasyAdmin look and feel intact.
• Allow multiple selections (stored as JSON in the database).
• Even make the field work with associations using AJAX (think: selecting multiple users).

The key lies in extending Symfony form behavior in a way EasyAdmin understands. But getting there required a bit of trial and error, since EasyAdmin doesn’t expose an obvious configureFormField() hook.

👉 I documented the full step-by-step solution on my blog. If you’ve been struggling with dynamic dropdowns in EasyAdmin, check it out here.