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")

score 10 · Answer 1 · answered Jan 05 '16 at 21:00

10

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")

answered Jan 05 '16 at 21:00

Simone Carletti

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Any idea how to merge into a nested model parameters? – W.M. Mar 18 '17 at 18:04
3

@W.M. sort of `params[:nested_params] = params[:nested_params].merge(...)` – Aleksandr K. Jun 25 '17 at 21:57

Vaibhav · Answer 2 · 2017-02-23T16:21:48.733

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/

edited Feb 23 '17 at 16:21

answered Feb 23 '17 at 14:21

Vaibhav

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score 0 · Answer 3 · answered Apr 02 '16 at 06:12

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")

score -2 · Answer 4 · answered Aug 22 '16 at 21:08

-2

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

answered Aug 22 '16 at 21:08

Weston Ganger

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Please add some explanation to your answer. Code-only answers are discouraged on SO. Thank you. – Gennadii Saprykin Aug 22 '16 at 22:29
This only works when (all or some) parameters have been permitted – Mosselman Nov 24 '17 at 14:14
It returns another error instead: undefined method `to_h' for # Did you mean? to_s – Alexander Gorg Dec 05 '17 at 11:25

Merge ActionController::Parameters with rails 5

4 Answers4