Rails Select 2 does not work - ajax

Question

I use select2 to call an ajax search on my form. The form is unable to get response with my ajax, I tested at postman my Brand method, and it is able to return json, so I wonder if it is something wrong with my apllication.js or input? Previously I test with:
Sample input
<%= f.select :brand_id, Brand.all.collect {|x| [x.name, x.id]}, {include_hidden: false} %>
it is able search all data inside brand table.
products_controller.rb
def brand
#brands = Brand.select(:id, :name).where("name like :q", q: "%#{params[:q]}%")
respond_to do |format|
format.json { render json: {brands: #brands.map { |e| {id: e.id, name: e.name} }}
}
end end
input form
<%= f.hidden_field :brand_id, class: "brand-select", data: { source: dashboard_brand_path, placeholder: 'Search for a name' } %>
application.js
$( ".brand-select" ).select2({
minimumInputLength: 1,
placeholder: "Brand search",
theme: "bootstrap",
tags: [],
ajax: {
url: "/dashboard/brand",
dataType: 'json',
type: "GET",
quietMillis: 50,
id: function(obj) {
return obj.id;
},
data: function (term) {
return {
q: params.term, // search term
page: params.page
};
},
results: function (data) {
return {
results: $.map(data, function (item) {
return {
name: item.name,
id: item.id
}
})
};
}
},
});
Thank for helping

Answer 1

<%= f.hidden_field :brand_id, class: "brand-select", data: { source: dashboard_brand_path, placeholder: 'Search for a name' } %>
You have Used hidden_field. I guess you should use
<%= f.select :brand_id, Brand.all.collect {|x| [x.name, x.id]}, {include_hidden: false}, class: 'brand-select', placeholder: 'Search for a name' %>