Standard record validations are fine in most applications. However, if you find that standard validations are not working, you can create your own custom validations in Ruby on Rails 4 applications. This training shows you how to create custom validations and what to watch out for to avoid validations that fail. You will also learn to recognize errors and what to do about them.
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…I think that you'll find the standard set of active record…validations will meet most of your needs, most of the time.…However, it is also possible to write your own custom validations.…You do that by using validate, followed by the name…of the method that should be run with the validations.…So, for example, validate custom method.…Notice that it's validate singular, not plural.…The plural version's is what we were using in the last movie, for sexy validations.…This is just validate, singular.…When the validations are run, my custom method will be called and it…will be up to that custom method to pass or fail my validations.…
Now validations fail, because errors are present in the errors array.…That's all that valid question mark does when we use it.…It runs the validations.…Let's those validations add any errors to the errors array, and then…returns true or false, based on whether that errors array is empty.…So in our own validation method, all we have to do is…add an error to make the object invalid and therefore fail validations.…
- Why use Ruby on Rails?
- Installing Ruby on Rails on Mac and Windows
- Rendering templates and redirecting requests
- Generating and running database migrations
- Creating, updating, and deleting records
- Understanding association types
- Using layouts, partials, and view helpers
- Incorporating assets using asset pipeline
- Validating form data
- Authenticating users and managing user access
- Architecting RESTful applications
- Debugging and error handing
Skill Level Beginner
1. What Is Ruby on Rails?
2. Installing Ruby on Rails on a Mac
3. Installing Ruby on Rails on a Windows Machine
4. Getting Started
5. Controllers, Views, and Dynamic Content
6. Databases and Migrations
7. Models, ActiveRecord, and ActiveRelation
9. Controllers and CRUD
10. Layouts, Partials, and View Helpers
13. Data Validation
14. User Authentication
15. Improving the Simple CMS
16. REST and RESTful Routes
17. Debugging and Error Handling
18. Introducing More Advanced Topics
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