rails, simple_form, how to update the radio buttons with the selected option after saving?

Question

I'm pretty new to rails and this is also my first post, but I'm trying to create a simple_form on a view page which should be a Settings page for some User and I've already searched for 2 days now for an answer and I can't find it anywhere.

<%= f.input :gender, label: 'What is your gender?', collection: [ ['M', 'Male' ], ['F', 'Female'] ], as: :radio_buttons, label_method: :last, value_method: :first, checked: 'M', item_wrapper_class: 'inline'%>

This is my input label and the only option so far is to set :checked => 'M', so that after saving the users settings the radio button will be selected (but this won't be correct if I'm selecting the 'Female' gender, because after saving the Settings page, the 'Male' radio button will be selected by default).

So is there any way to use radio buttons in simple form (or even a dropdown list) so that after saving the page the gender will remain selected?

Answer 1

Try using the user gender attribute instead of "M" fo checked:

<%= f.input :gender, label: 'What is your gender?', collection: [ ['M', 'Male' ], ['F', 'Female'] ], as: :radio_buttons, label_method: :last, value_method: :first, checked: @user.gender, item_wrapper_class: 'inline'%>