Ruby on Rails: How to validate a model without Active Record?

Question

I'm currently trying to validate fields without having an ActiveRecord::Base inheritance.

My model stores the data on a cache server so I do not need ActiveRecord.

Anyway, I would like to validate the fields of the model like I would if I was using ActiveRecord (e.g validates_numericality_of :quantity, :greater_than => 0) ?

How can I do that?

I believe this is that question: http://stackoverflow.com/questions/315850/rails-model-without-database — Mark Fraser, Mar 22 '12 at 05:23

score 33 · Accepted Answer · answered Mar 22 '12 at 05:38

In Rails 3, Active Model contains the non-database functionality of Active Record.

Basically, you need to include ActiveModel::Validations, define your fields as attr_accessor, use an initialize method to initialize the attributes and make them non-persisted as your model isn’t persisted to a database.

This way you can have validations on the tableless model and your controller the same as if you were using Active Record. There's also a Railscast on this http://railscasts.com/episodes/219-active-model.

[For Rails 4+ follow this SO question](https://stackoverflow.com/questions/16865821/rails-4-validate-model-without-a-database) — notapatch, Jun 12 '21 at 10:59

score 1 · Answer 2 · answered Nov 06 '13 at 21:51

1

Check out our Veto gem instead if you're looking for a standalone validations for ruby objects. It's lightweight, and has no dependencies.. ActiveModel might be overkill.

answered Nov 06 '13 at 21:51

Erik Lott

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Ruby on Rails: How to validate a model without Active Record?

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