CODEWITHSUNDEEP
ruby-on-railsrubystrong-parameters
Martin Greenaway
Martin Greenaway

Reputation: 574

Rails Strong Parameters - what if one of my fields is optional?

I'd not claim myself to be an expert in Rails by any stretch. One of the things that confuses me is Strong Parameters, and I've not found any really straightforward tutorials on it, with the majority of the search results dominated by hits on the rails documentation which, whilst normally accurate, I don't find in any way easy to read and can't be considered a tutorial. The github for strong params also doesn't appear to cover this.

Say I have an entity called "Resource".

class ResourcesController < ApplicationController
  ...
  def create
    @resource = Resource.new(resource_params)
    if @resource.save
      ...
      respond_with(@resource.level)
    else
      ...
    end
  end

  def update
    if @resource.update(resource_params)
      ...
      respond_with(@resource.level)
    else
      ...
    end
  end
  ...
  def resource_params
    params.require(:resource).permit(:name, :url, :description, :level_id)
  end
end

Assume I have a scaffolded form which displays the fields for name, url, description and level_id. All of the fields are mandatory. I don't know how to amend the resource_params function to ensure that name, url and level_id are mandatory when updating (or creating) a resource, but that description is optional (but should still be permitted).

I've tried removing description from the require line, and adding it on a separate line as params.permit(:description) but that has not made any difference, the field is still mandatory in the form.

Any assistance on this would be welcomed!

Upvotes: 3

Views: 2181

Answers (3)

Pavan
Pavan

Reputation: 33542

As I said, this is nothing to do with strong parameters. You just need to remove required: true for that field to make it optional.

Upvotes: 4

Nermin
Nermin

Reputation: 6100

Strong parameters are used to ensure that no other data can pass into your object, that no1 can insert not wanted data. For example if you have entity User and it has field admin that if it is true, the user has admin role, it can not be set using the create or update method inside your controller, because some1 can send any kind of parameters to your controller, and you want to filter them (Allow only specific parameters).

This does not mean if you put something inside strong parameters that it is required for create, update or whatever. Strong parameters only are there to filter the data, and allow only certain parts of your entity to be settable through this service or REST. If you send parameters that are not in strong params defined, in your server console/log there will be unpermited parameters: list of the parameters.

Upvotes: 1

Evgeniy B
Evgeniy B

Reputation: 184

I think you should think about :on http://guides.rubyonrails.org/active_record_validations.html#on

validates :email, uniqueness: true, on: :create

It enables validations only on specified action.

Upvotes: 2

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