Mongomapper Foreign Key?

[Stuart Harrison]

Hi,

I'm currently using Mongomapper within a Padrino project where I'm importing data from an external source. The main object (Application) has two associated document types, Activity and Notice.

However, I'd like to specify the foreign key myself, rather than use the internal Mongo ID, as the foreign key is in the data export, which I import via a rake task.

I've tried an EmbeddedDocument, but this causes issues as I have to delete all the associated data, rather than updating it, which isn't ideal.

I've tried the following, but without any luck:

class Application

  include MongoMapper::Document

  ensure_index [[:latlng, '2d']]

  key :refval, String

  key :pkeyval, String

  key :applicantname, String

  key :latlng, Array

  key :address, String

  key :occupier, String

  key :type, String

  key :casetype, String

  key :tradingname, String

  key :closingdate, Date

  key :recieveddate, Date

  key :details, String

  key :usetype, String

  key :status, String

  key :validfrom, Date

  timestamps!

  many :activities, :foreign_key => :pkeyval

  many :notices, :foreign_key => :pkeyval

end

class Activity

  include MongoMapper::Document

  key :keyval, String

  key :pkeyval, String

  key :type, String  

  key :cycle, String

  key :open, String

  key :close, String

  belongs_to :application, :foreign_key => :pkeyval

end

class Notice

  include MongoMapper::Document

  key :keyval, String

  key :pkeyval, String

  key :recieveddate, Date

  key :startdate, Date

  key :enddate, Date

  key :days, String  

  key :hours, String

  key :activities, Array

  belongs_to :application, :foreign_key => :pkeyval

end

Any ideas where I'm going wrong?

[Jon Kern]

just talking out loud without deep thinking or trying anything... or
looking at your code, so it might be total bunk...

have you noticed that an association has an object_id on the single side?

and, on the many side, you could even simply use an array of object IDs.

i think if you play around with a simple example classes and
associations, you will see some opportunity to do whatever you need.

if you still need help, ping the list.

sorry for being short, but i wanted to drop this idea your way sooner
rather than later so that you can act on it.

jon

blog: http://technicaldebt.com
twitter: http://twitter.com/JonKernPA

Stuart Harrison said the following on 8/29/12 11:02 AM:

> --
> You received this message because you are subscribed to the Google
> Groups "MongoMapper" group.
> For more options, visit this group at
> http://groups.google.com/group/mongomapper?hl=en?hl=en

[Stuart Harrison]

Cool, thanks for that. Appreciated. I shall continue to have a play with that in mind :)

[Jon Kern]

Stuart, here are some examples
https://github.com/JonKernPA/mongo_examples/tree/master/user_event

look at the user class

jon

blog: http://technicaldebt.com
twitter: http://twitter.com/JonKernPA

Stuart Harrison said the following on 8/29/12 11:24 AM:

[Jon Kern]

i mean, look at the event class

jon

blog: http://technicaldebt.com
twitter: http://twitter.com/JonKernPA

Jon Kern said the following on 8/29/12 11:27 AM:

[Stuart Harrison]

Brilliant. Thanks.

[Stuart Harrison]

Just to pick up on this again, I think I've got this nailed now. I didn't need to specify the foreign key in the many part, and also had to override the primary key in my Activities object with the following:

key :_id, String

Cheers

Stuart

[Jon Kern]

glad you worked it out!

jon

blog: http://technicaldebt.com
twitter: http://twitter.com/JonKernPA

Stuart Harrison said the following on 8/30/12 5:00 AM: