Rails 6, has added a new utility method each_value on ActionController::Parameters.

This method as the name suggests iterates over and yields each value of the ActionController::Parameters just like Hash#each_value.

Hash#each_value vs ActionController::Parameters#each_value

It’s different from Hash#each_value in that it converts all the hashes in values to ActionController::Parameters object before yielding the values to block, instead of simply returning the value.

Example

Consider the example below, we define a ActionController::Parameters with user profile details

params = ActionController::Parameters.new({
  name: {
    first: "Narendra",
    last: "Rajput"
  },
  gender: "Male",
})

=> <ActionController::Parameters {"name"=>{"first"=>"Narendra", "last"=>"Rajput"}, "gender"=>"Male"} permitted: false>

Now lets add another regular hash object to params

params[:social_profiles] = {
  twitter: "https://twitter.com/HiSaeloun",
  github: "https://github.com/saeloun"
}

=> {:twitter=>"https://twitter.com/HiSaeloun", :github=>"https://github.com/saeloun"}

Now if we iterate over the params with ActionController::Parameters#each_value

params.each_value do |value|
  puts value.inspect
end

<ActionController::Parameters {"first"=>"Narendra", "last"=>"Rajput"} permitted: false>
"Male"
<ActionController::Parameters {"twitter"=>"https://twitter.com/HiSaeloun", "github"=>"https://github.com/saeloun"} permitted: false>

As you can see the social_profiles in the params is a Hash. But in the each_value block its converted to ActionController::Parameters.

This is helpful for consistent parameters object access.