Ruby on Rails:Scaffold Rails

What is Scaffolding?

Scaffolding is a tool in Ruby on Rails that automatically generates code for new resources like models, views, and controllers. It helps in quickly creating basic pieces of an application that can be modified later.

How to use the Rails Scaffold Command

1. Open the terminal
2. Navigate to the root directory of our Rails application
3. Run the following command

Here, we need to replace ResourceName with the name of the resource to be created, and attribute1:type with the name and data type of the attribute to be included in the resource.

For example, to create a Product resource with name and price attributes, one can use the following command:

Now, rails will generate all the necessary code for the Product resource, including the model, view, and controller component and The generated code can be used to perform CRUD (Create, Read, Update, Delete) operations on the Product resource.

Run the migration to create the resource's database table by using the following command:

This will create the necessary table(s) in our database. The files generated by the 'scaffold' command are:

• Controller
• Model
• Views for every standard controller action (index, edit, show, new)
• A new route
• Migration to prepare our database

Scaffold Rails with Extra Fields

Now the above code will generate a boilerplate code for a model, view, and controller. But sometimes when using scaffolding, some extra fields may be needed in the model that is not included in the default scaffold. Default fields are the attributes of the table that are auto-generated timestamps, such as the created_at and updated_at fields. To add extra fields, we can simply add extra fields when generating the scaffold.

For example, to create a new Task resource with extra fields like description, title, and completed in addition to default fields like timestamps, one can use the following command:

The above command will generate a model with three attributes/fields:

• Title
• completed
• description

Now we may migrate the database to include the new fields, and also views and controllers will be updated to reflect the new fields.

Specific Component Generation

The Scaffold command generates code for all three components - model, view, and controller. But, sometimes only specific components for the resource needed to be generated. A specific component using scaffold can be generated by using the --no- option followed by the name of the component to be excluded.

For example, to generate a 'Post' model and view components, without the controller, one can use the following command:

The above command generates a Post model and view, without creating the controller component.

Creating an Empty Rails Web Application

To create an empty rails web application, open the terminal and navigate to the directory where the project will be created. Let's say we are in the required directory.

Now create an empty rails project by using the following command:

Replace mywebapp with the name of our application. The above command creates a new directory called mywebapp, which contains all the files and directories that are required for a new Rails application - basically an empty Rails project.

Now navigate to the newly created folder mywebapp which will contain the following file structure:

• Database Setting: Rails provide multiple environments such as development mode, test mode, or production mode, using different databases. We can edit the configuration file mywebapp\config\database.yml to let the rails application know the database of our application:

• Scaffolding Code Generation: Now we can create some boilerplate code using the rails scaffold command which will create all necessary resources and let us focus on the main requirements of our application:

This will generate the following files and will also edit routes for the post resource created:

• Controller Setup: Rails scaffold has already created the controller for post which consists of different methods like new, show, edit, and destroy for implementing the CRUD logic to our post page:

• Model Enhancement: Rails provide many error-handling options to help enhance the Model such as validations. The following validations can help the model take data according to the requirement without any chance of error:

• Another command for Creating Rails Scaffolding: We can create the boilerplate code with all the migrations, models, controllers, and also the routes with another command:

Here, g stands for 'generate'.