I have the following Rails code in my conversations_controller:
A user may be : master or rookie.
@conversations = current_user.master.conversations.all
@conversations = @conversations.sort_by { |c| c.messages.last.created_at }.reverse
But on running this I'm getting a no method error for created_at.
If I do a puts like this:
puts "Sorted: #{@conversations.map { |c| c.messages.last}}"
this gives me the following response:
Sorted: [#<Message id: 9, content: "some content", user_id: 3, conversation_id: 1, created_at: "2017-03-01 00:00:36", updated_at: "2017-03-01 00:00:36", attachment_url: []>, nil, #<Message id: 11, content: "new message", user_id: 3, conversation_id: 6, created_at: "2017-03-01 15:15:58", updated_at: "2017-03-01 15:15:58", attachment_url: []>]
If I'm getting created_at then why can't I extract the last messages created_At to compare and sort?
On doing a simple
puts "The conversations sorted are: #{@conversations.map { |c| c.messages}}"
Gives me the following response:
The conversations sorted are: [#<ActiveRecord::Associations::CollectionProxy [#<Message id: 1, content: "Hey there! This is my first message.", user_id: 1, conversation_id: 1, created_at: "2017-02-28 23:57:46", updated_at: "2017-02-28 23:57:46", attachment_url: []>, #<Message id: 2, content: "Thank you for your message. I am a coach.", user_id: 3, conversation_id: 1, created_at: "2017-02-28 23:57:46", updated_at: "2017-02-28 23:57:46", attachment_url: []>, #<Message id: 9, content: "adsdadasd", user_id: 3, conversation_id: 1, created_at: "2017-03-01 00:00:36", updated_at: "2017-03-01 00:00:36", attachment_url: ["https://ace-up-www.s3.amazonaws.com/message-attachments%2Fbd450b1e-f85c-47ec-94c7-c539809f8d68%2Frecommendation-bg.jpg"]>]>, #<ActiveRecord::Associations::CollectionProxy []>, #<ActiveRecord::Associations::CollectionProxy [#<Message id: 10, content: "Add a new message", user_id: 8, conversation_id: 6, created_at: "2017-03-01 14:58:29", updated_at: "2017-03-01 14:58:29", attachment_url: []>, #<Message id: 11, content: "new message", user_id: 3, conversation_id: 6, created_at: "2017-03-01 15:15:58", updated_at: "2017-03-01 15:15:58", attachment_url: []>]>]
As you can see there is an empty #<ActiveRecord::Associations::CollectionProxy []> which is probably getting translated to nil.
Any help in debugging this?
The error occured when you tried to get the created at attribute of the converstions last message which actually dont have any messages with it.
@conversations = current_user.master.conversations.joins(:messages)
@conversations = @conversations.sort_by { |c| c.messages.last.created_at }.reverse
By joining the messages with the conversations only the conversation with atleast one message will be retrieved so by that i think the issue get fixed.