Rails, DataMapper & JSON issue

Question

I've some trouble with a really simple Rails setup using DataMapper. This is my model:

class Capture
  include DataMapper::Resource
  property :id, Serial
  property :identifier, String
  property :caption, Text
 end

Now I add a new capture in Rails console by:

Capture.create(:identifier => '12345', :caption => 'Foo bar foo')

If I try to get all captures by

Capture.all

... i get a

[#<Capture @id=1 @identifier="12345" @caption=<not loaded>>]

First question: what does the "not loaded" mean in this case? But the trouble I have is I cannot convert the result to JSON:

Capture.all.to_json

NoMethodError: undefined method `encode_json' for #<Capture @id=1 @identifier="12345" @caption=<not loaded>>

Is it a DM issue? How to encapsulate such a result into JSON? Many thanks in advance ;-) Chris.

OK, found it out: to use to_json in DataMapper I need dm-serializer as Gem. Works fine now ;-) — ctp
– ctp, Commented May 8, 2011 at 1:26
@Simon's right, instead of adding [SOLVED] to the title of your answer, just answer your own question and accept it. — Matt Ball
– Matt Ball, Commented May 8, 2011 at 1:31

ujifgc · Accepted Answer · 2011-05-09 07:52:49Z

1

The answer for the first question: not loaded means that data loading is delayed until actually needed because Text property is lazy by default. http://datamapper.org/articles/spotlight_on_laziness.html

answered May 9, 2011 at 7:52

ujifgc

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