Retrieving checkbox input (Groovy Html MarkupBuilder + SpringBoot) - forms

Question

I'm a newbie in Groovy and SpringBoot, but have to use these technologies in my work.
I have a User and Role classes, they don't have any relations inside classes. In Get-action in Controller I pass User and List of all possible roles to the form.
Controller class:
#GetMapping
public String edit(Model model){
model.addAttribute("user", new User());
model.addAttribute("roles", roleRepository.findAll());
return "edit";
}
My edit.tpl file:
...
form(..., method:'post'){
label(for:'username', 'Username: ')
input(type:'text', id:'username', name:'username', value:user.username)
label("Add roles: ")br()
roles.each {role ->
label(for:role.name, role.name)
input(type:'checkbox', id:role.name, name:role.name, value:role.name)
br()
}
input(type:'hidden', id:'_method', name:'_method', value:'put')
input(type:'submit', class:'btn btn-info', value:'Save')
}
I want to retrieve all the checked Roles.
Like that:
role_1 unchecked
role_2 checked
role_3 checked
List = [role_2, role_3];
I get the User like that:
#PutMapping("{id}")
public String update(#Valid User user, #PathVariable Long id){
user.setId(id);
userRepository.save(user);
return "redirect:/users";
}
And also in future I want to somehow check the current active Roles when passing them to the form.
Like that:
Current active roles are: role_2, role_3.
When I make a Get-request to show the form for editing, i have role_1 unchecked, and role_2 and role_3 checked.
My classes are as follows:
public class Role{
private String name;
//getters, setters, etc.
}
public class User{
#NotBlank(message="Please enter username")
private String username;
//getters, setters, etc.
}
Thanks for any help!! :)

Answer 1

I've found a way to get necessary information from the checkbox inputs:
use the #RequestParam annotation the following way:
Controller.java
public String update(#Valid User user, #RequestParam("roleIDs") List<Long> roles, #PathVariable Long id){
System.out.println(roles); //-the checked roles
return "redirect: /users";
}
Groovy .tpl file:
roles.each {role ->
label(for:role.name, role.name)
input(type:'checkbox', id:role.name, name:'roleIDs', value:role.id)
br()
}
Seems like I haven't googled the right question :)