Merge ActionController::Parameters with rails 5

Question

In rails 4, I can merge! StrongParams, but since rails 5 (beta1) merge! is not available. Which is the best way to do that in a controller

  params = ActionController::Parameters.new({
             name: 'Francesco',
             age:  22,
             role: 'admin'
         })
         params.merge!(city: "Los Angeles")

Answer 1

As far as I can see from the source code , you have merge not merge! . In other words, it doesn't seem to be possible to modify the hash in place.

The following code will work:

params = ActionController::Parameters.new({
             name: 'Francesco',
             age:  22,
             role: 'admin'
         })
params = params.merge(city: "Los Angeles")

Answer 2

params.merge!(city: "Los Angeles") works with Rails5.0.1

In Rails 5: ActionController::Parameters Now Returns an Object Instead of a Hash.

so you must use params.permit(:city).to_h to access city.

For more details how ActionController::Parameters works in Rails5?

Ref: http://www.rortuts.com/ruby-on-rails/rails5-actioncontrollerparameters/

Answer 3

Hope this helps to anyone.

def comment_params
  params.require(:comment).permit(:title, :user_id, :color)
end

I want to merge color attribute with my custom color code or name. so to merge color attribute dynamically

Ininitialize params in rails 5 like this,

params = ActionController::Parameters.new(comment_params)
params = params.merge(color: "green")

Answer 4

new_params = params.to_h.merge(city: "Los Angeles")