I am wondering if someone could tell me why I am getting this error "undefined method '[]' for nil:NilClass". This happens when I remove a picture with cocoon and try update. The method works fine for adding pictures to the edited gallery but I am getting this error when removing and updating. I tried using unless @pictures.blank? end I am assuming the problem is when cocoon removes the picture but I am not sure what to do from there. the server error is,
Started PATCH "/galleries/41" for ::1 at 2017-05-07 16:03:02 +1000
Processing by GalleriesController#update as HTML
Parameters: {"utf8"=>"✓", "authenticity_token"=>"cG1UXCvODhYzqqAr++EAn8GvMVk7+t/eASkzDDOoPmJfw3l6ax/F2xXMhvs7FcrJ3LOuTd0sks5+2fb86kQv0Q==", "gallery"=>{"name"=>"Hellooo", "cover"=>"123456", "pictures_attributes"=>{"0"=>{"_destroy"=>"1", "id"=>"47"}, "1"=>{"_destroy"=>"1", "id"=>"48"}}}, "commit"=>"Update Gallery", "id"=>"41"}
Gallery Load (0.0ms) SELECT "galleries".* FROM "galleries" WHERE "galleries"."id" = ? LIMIT ? [["id", 41], ["LIMIT", 1]]
Unpermitted parameter: pictures_attributes
(0.0ms) begin transaction
User Load (0.0ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT ? [["id", 1], ["LIMIT", 1]]
(0.0ms) commit transaction
Completed 500 Internal Server Error in 4ms (ActiveRecord: 0.0ms)
NoMethodError (undefined method `[]' for nil:NilClass):
...
Perhaps if someone could explain this to me would be great!
_form.html.erb
<%= form_for(@gallery, multipart: true) do |f| %>
<div class="field">
<%= f.label :name %>
<%= f.text_field :name %>
</div>
<div class="field">
<%= f.label :cover %>
<%= f.text_field :cover %>
</div>
<div id="pictures">
<%= f.fields_for :pictures do |pic| %>
<%= render 'picture_fields', f: pic %>
</div>
<% end %>
<div class="links">
<%= link_to_add_association 'add picture', f, :pictures %>
<%= f.submit %>
</div>
<% end %>
_picture_fields.html.erb
<div class="nested-fields">
<div class="field">
<%= f.label :picture %>
<%= f.file_field :picture, multiple: true, name: "pictures[picture][]" %>
<%= link_to_remove_association "remove picture", f %>
</div>
</div>
GalleriesController
def update
@gallery = Gallery.find(params[:id])
if @gallery.update(gallery_params)
params[:pictures][:picture].each do |pic|
@pictures = @gallery.pictures.create!(picture: pic)
end
flash[:success] = "Gallery Updated!"
redirect_to root_url
else
render 'edit'
end
end
Edit: Added gallery_params
def gallery_params
params.require(:gallery).permit(:id, :name, :user_id, :cover, picture_attributes: [:id, :gallery_id, :picture, :_destroy])
end
EDIT: Added create action and server log using cocoon
def create
@user = User.first
@gallery = @user.galleries.build(gallery_params)
if @gallery.save
flash[:success] = "Picture created!"
redirect_to root_url
else
render 'new'
end
end
server log
Started POST "/galleries" for ::1 at 2017-05-10 13:18:43 +1000
Processing by GalleriesController#create as HTML
Parameters: {"utf8"=>"✓", "authenticity_token"=>"XU3z2jMdbselPJZ2SdZdGPwiAebiPznt8GWRqmbv8LM/MIxO+sNo1z2NTaDQ3nJNm0qaBJ66ny5254MPpHZaQQ==", "gallery"=>{"name"=>"Hello", "cover"=>"123456", "pictures_attributes"=>{"1494386318553"=>{"picture"=>#<ActionDispatch::Http::UploadedFile:0xac59228 @tempfile=#<Tempfile:C:/Users/Lee/AppData/Local/Temp/RackMultipart20170510-7596-16xlrir.jpg>, @original_filename="Skateboard 1.jpg", @content_type="image/jpeg", @headers="Content-Disposition: form-data; name=\"gallery[pictures_attributes][1494386318553][picture]\"; filename=\"Skateboard 1.jpg\"\r\nContent-Type: image/jpeg\r\n">, "_destroy"=>"false"}, "1494386321001"=>{"picture"=>#<ActionDispatch::Http::UploadedFile:0xac59150 @tempfile=#<Tempfile:C:/Users/Lee/AppData/Local/Temp/RackMultipart20170510-7596-jxo0st.jpg>, @original_filename="Skateboard 2.jpg", @content_type="image/jpeg", @headers="Content-Disposition: form-data; name=\"gallery[pictures_attributes][1494386321001][picture]\"; filename=\"Skateboard 2.jpg\"\r\nContent-Type: image/jpeg\r\n">, "_destroy"=>"false"}}}, "commit"=>"Create Gallery"}
User Load (0.0ms) SELECT "users".* FROM "users" ORDER BY "users"."id" ASC LIMIT ? [["LIMIT", 1]]
(0.0ms) begin transaction
User Load (0.0ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT ? [["id", 1], ["LIMIT", 1]]
(0.0ms) rollback transaction
Rendering galleries/new.html.erb within layouts/application
Rendered galleries/_picture_fields.html.erb (1.0ms)
Rendered galleries/_picture_fields.html.erb (0.5ms)
Rendered galleries/_picture_fields.html.erb (0.5ms)
Rendered galleries/_form.html.erb (42.0ms)
Rendered galleries/new.html.erb within layouts/application (58.5ms)
Completed 200 OK in 157ms (Views: 139.3ms | ActiveRecord: 0.0ms)
Mmmm. Confused. There is no params[:pictures] so that is obviously nil (check the log you posted at the top). So that is causing the error. If you are looking for the pictures posted, you should refer to params[:pictures_attributes], but not even sure what you are trying to do there: create an empty picture (again?) for each posted pictures? The pictures are saved by doing the gallery.update(gallery_params).
Note: iterating over the posted params is imho definitely wrong, because if one is deleted, it will still be posted with the nested parameter _destroy set to true, so it can be deleted correctly from the database, or if a picture already existed, it will also be posted again (and not saved, since it already exists).
[EDIT] Add short solution:
f.fields_for :pictures in your view: this will iterate over the existing pictures a gallery has, and will allow to delete/edit existing, and add new pictures to a gallerygallery_params and allow pictures_attributes (instead of the singular form)(otherwise nothing is saved)@gallery.update_attributes(gallery_params) and do not iterate over params[:pictures] at all (remove that part) and it should just work (because the update_attributes will already have done this, at least if you want to iterate manually use pictures_attributes)