Filter params with strong parameters

rubyonrails-talk
1

Hi

I have an hstore field in my database where I store a lot of different fields.

I still want getters, setters and validations for my fields so I’ve created an array with the fields like this:

DOCUMENT_FIELDS = %w[foo bar baz]

Then I do some meta programming to create getters and setters:

DOCUMENT_FIELDS.each do |field|

define_method(field) do

…

end

define_method(“#{field}=”) do |value|

…

end

end

Now I would like to pass all fields to strong parameters to properly filter it. I tried like this:

params.require(:foo).permit(Foo::DOCUMENT_FIELDS.map(&:to_sym))

But this doesn’t work. It removes all values anyway. I guess it is because Foo::DOCUMENT_FIELDS.map(&:to_sym) creates an array that is passed to strong parameters (and it seems to not work with arrays).

How can I get around this?

Cheers,

Linus

2

`params.require(:foo).permit(*Foo::DOCUMENT_FIELDS.map(&:to_sym))` Though if I'm honest I probably would expect you to not take the long trip with map and to_sym, might as well just leave them as string keys because params has indifferent access with default keys being all string keys for security.

3

I forgot to say what * does. It will expand the array into args.

4

Got it myself! Splat operator to the rescue :slight_smile:

params.require(:foo).permit(*Foo::DOCUMENT_FIELDS.map(&:to_sym))

5

Thank you. I thought strong params needed symbols.

Cheers,

Linus