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Rails 3 - How to Create a JSON Object to store in the database

Answer 1

A:

Take a look at this: http://github.com/laserlemon/vestal_versions

If it's not what you're looking for, it will at least show you it's done.

Coderama 2010-09-30 21:56:01

The auditlog is just an example to make the question easier to digest... Thanks though.

AnApprentice 2010-09-30 22:00:11

Answer 2

+1 A:

First, definitely check out ActiveRecord serialize and see if it does what you need: http://api.rubyonrails.org/classes/ActiveRecord/Base.html#method-c-serialize

However, if you need JSON specifically (serialize uses YAML by default), then you can always fake it by hand.

You can simply build a hash in Ruby and then call to_json on it before assigning it to your model attribute.

data = { 'photoid' => 123, 'photoname' => "asdasd", 'creator_id' => "asdasd" }
myrecord.stored_data = data.to_json
myrecord.save

tfe 2010-09-30 21:59:48

Thanks, I'll try this out.

AnApprentice 2010-09-30 22:00:33

Is to_json safe? I've seen some posts on Google Searches that mention it sometimes fails? Any thoughts on that?

AnApprentice 2010-09-30 22:08:22

There are some wrinkles when you're using `to_json` on an activerecord object (you're supposed to use `as_json` or something), but for serializing a simple hash it's really straightforward JSON encoding... not much to go wrong. What did you find with Google?

tfe 2010-10-01 01:22:13

What is the myrecord.stored_data all about ? (stored_data)?

AnApprentice 2010-10-01 01:46:07

Turns out the above doesn't work...getting errors on "stored_data" does not exist... Also, should the observer be in the CONTROLLERS or MODELS Directory? bec running the generator put it in the models dir.

AnApprentice 2010-10-01 01:48:43

"undefined method `save' for nil:NilClass"

AnApprentice 2010-10-01 01:49:27

Getting: "undefined method `data=' for nil:NilClass" when I try this: data = { 'photoid' => 123, 'photoname' => "This is my photo", 'creator_id' => "1" } @AuditLog.data = data.to_json @AuditLog.save

AnApprentice 2010-10-01 01:58:05

`stored_data` is an example attribute name. It can be anything you want. It also has to be backed by a text column in your database... it's not magic. Create a migration to add it.

tfe 2010-10-01 03:46:45

Answer 3

+1 A:

Just today I answered a similar (if not same) question - http://stackoverflow.com/questions/3827851/raisl-3-howto-storing-unstructured-data-in-a-database-column-field-data/3833003#3833003

pawien 2010-09-30 22:39:37

@pawien thanks, that's interesting but not sure if it solves wanting to save a @AuditLog record in the observer after_create?

AnApprentice 2010-10-01 01:58:39

well, I'm little bit lost on that comment. In the example it is used in the after save callback. It would be dead simple to change it to after_create. Or into the generic (shared) observer: http://guides.rubyonrails.org/active_record_validations_callbacks.html#sharing-observers. The AuditLog.audit method is generic and you can pass any model to it.

pawien 2010-10-01 08:07:56

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Rails 3 - How to Create a JSON Object to store in the database

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