Generators and scaffolds (scaffolds and generators)

GENERATOR

A generator is a program (script) that writes programs (or code fragments) according to given input parameters. Since the absolute majority of ROR application fragments are maximally unified (consistent with ROR standards), we have the opportunity to create programs that will independently generate beautiful working code for some fragments of our application.

So, for example, most of the actions taking place on the site fall into the category of CRUD (Create, Read, Update, Delete). Let's take a user profile - there must be functions for it - create, read (view), update, delete. It's the same with site pages, each should be able to be created, read, updated and deleted. These actions have a completely similar algorithm, the only difference is the name of the object class to which the algorithm is applied (Profile and Page).

Generators are known that, according to the given object names, create completely ready-to-execute logic files (functions, request handlers), display types, and so on. So we can in a matter of seconds, using the generator, create very simple, but full-fledged administrative web interfaces.

Scaffold, scaffolding (scaffold, scaffold generator)

The scaffold is a generator that creates a completely ready-to-use administrative interface for managing database objects through a web browser.
As input data, it takes the name of the Model (object class) and a list of database table fields with the corresponding data types (in order to create a corresponding input element inside the html form for each data type). Provides a complete set of CRUD actions.

The scaffold generator embodies one of the RAILS ideologies - DRY (DON't REPEAT YOURSELF) - i.e. don't repeat yourself (don't rewrite your code). Indeed, by creating a generator to create files with similar functionality for different fragments of the application, we largely save ourselves from having to write the same code repeatedly.

Scaffold (scaffold) - in translation means scaffolding or scaffolding. Those. creates something that allows you to quickly build an interface.

 

Use javascript scaffolding to quickly build a React project

1. Project construction

create-react-app is a framework officially launched by Facebook that can basically create a webpack-based React development environment with zero configuration.
Steps:
Open the console
Enter the directory file where you want to create the project.

Run the following commands in sequence

npm install -g create-response-app 
 
 create-response-app my-demo 
 
npm start

Once done, you can quickly create a React development environment.
You can view the project at http://localhost:3000/

2. Problems encountered

After executing npm install -g create-response-app the following error occurred:

Solution: Just replace npm with cnpm, but cnpm has the following error:

The above permission denied issue has been resolved. This is because there is no permission, so add sudo in front of it like below: (Author's protest is valid 😯), after doing the following steps it's very smooth hahahaha😁 .

 

 Scaffold (programming)

Code Generation Method or Project Generation Method

Scaffolding used in calculations refers to one of two methods: the first is the code generation method associated with database access in some model-view-controller frameworks; the second is a project generation method supported by various tools.

Code generation

Templating is a technique supported by some model-view-controller frameworks, in which the programmer can specify how the application's database can be used. Compiler platforms uses this specification along with predefined code templates to generate final code that an application can use to create, read, update, and delete database entries, effectively treating the templates as a " framework " on which a more powerful application can be built.

Scaffolding is an evolution of database code generators from earlier development environments such as Oracle CASE Generator and many other 4GL client-server software development products.

Scaffolding has become popular with the Ruby on Rails framework. It has been adapted to other software frameworks including OutSystems Platform, Express Framework, Play framework, Django, web2py, MonoRail, Brail, Symfony, Laravel, CodeIgniter, Yii, CakePHP, Phalcon PHP, Model-Glue, PRADO, Grails, Catalyst, Mojolicious, Seam Framework, Spring Roo, JHipster, ASP.NET Dynamic Data, KumbiaPHP, and ASP.NET MVC framework metadata template helpers 

Scaffolding can occur at two different stages in the program life cycle: design time and run time. Design-time templating creates code files that can later be modified by the programmer to customize how the application's database is used. However, for large-scale applications, this approach can be difficult to maintain due to the sheer number of files created and the fact that the design of the files was largely fixed when they were created or copied. from the original templates. Alternatively, runtime scaffolding creates code on the fly. This allows you to immediately reflect changes in the design of the templates throughout the application. But redesigning templates can be more difficult or impractical in the case of scaffolding at runtime.

Scaffolding in Ruby on Rails

When a string scaffold: model_name is added to a controller, Rails will automatically generate all the relevant given interfaces at runtime. Since the API is created on the fly, the programmer cannot easily change the interfaces created in this way. Such a simple framework is often used for prototyping applications and entering test data into a database.

The programmer can also run an external command to pre-generate the Ruby code for the framework: rails генерируют каркас model_name The script generate will create Ruby code files that the application can use to interact with the database. This is somewhat less convenient than dynamic scaffolding but gives the programmer the flexibility to change and customize the generated APIs.

Note. As of Rails 2.0, dynamic scaffoldings are no longer stored.