How to use Ajax within Sonata Admin forms?

Question

I have a Merchant entity with the following fields and associations:-

/**
 * @ORM\\ManyToMany(targetEntity=\"Category\", inversedBy=\"merchants\")
 */
public         


        

Answer 1

At step 1 of Amit and Lumbendil answer you should change

{% extends base_template %}

into

{% extends 'SonataAdminBundle::standard_layout.html.twig' %}

if you get an error like

Unable to find template "" in YourBundle:YourObject:base_edit.html.twig at line 34.