Help using available variables.

Hello,

This issue is related to the JSON in issue #1149902

I'm trying to find a way to use variables into my field.

I tried many kind of formats:

• ?($geometry)
• ?(@geometry)
• ?(['geometry'])
• ?(geometry)
• etc etc etc...

But none of them returns the correct value.

Can you help me by providing a good example or just explain how to use it in Drupal ?

Thanks.