[RAILS] I seriously summarized MVC
Introduction
I'm using Rails as a matter of course, When asked "By the way, what is MVC?", I felt that it was unexpectedly difficult to explain ... I tried to summarize it once again in order to make it my own language.
- The MVC used here is the so-called "MVC2" used in Rails.
What is MVC
Abbreviation for Model View Controller This is a web application design pattern that divides the entire program into three elements: data display, data processing, and database management.
In the case of Rails, MVC processing is roughly performed according to the flow shown in the figure below (self-made…: sweat_smile :).
Each function of MVC will be explained in order according to the processing flow.
Before entering MVC ... What is routing?
First receive the request from the client. ** It has a role like "correspondence table" ** that specifies the destination from the request contents to the controller that has the corresponding processing.
C: Controller
This is the part that controls the processing of ** requests from clients **. Executes the action corresponding to the request and returns the aligned contents to the client as a response.
To gather the information needed for the response
--Tell the model and prepare the necessary data --Pass the data required for screen display to the view
It has a role like "bridging" with other functions.
M: Model
It has a function like ** "window" that interacts with the database **. Access the database based on the instructions from the controller, This is the part that acquires the necessary data and processes (inserts / updates / deletes) the data.
It also plays a role in making detailed settings for the data stored in the database, such as ** data validation (validation) and association between tables **.
V: View
This is the part that sets the final ** appearance of the web page **. The data passed from the controller is formatted with HTML etc. and displayed on the screen as a response.
You may also ** get the data from the input form and pass it to the controller **.
Benefits of MVC
The following two points are major merits.
--Separated by function, easy division of labor ――It is less affected by changes in other functional parts, and maintainability is improved.
At the end/impression
I thought I knew MVC through personal development, I feel that I was able to deepen my understanding again by putting it together in an article.
This is a poor article for beginners, but I hope it will be of some help to you. Thank you for reading to the end.
Development environment
Ruby 2.6.5 Rails 6.0.3.4 MySQL Visual Studio Code (GoogleChrome)
Reference articles / books
[Book] Ruby on Rails6 Super Introduction/Yano Palm Tatsu [Official] Rails Document [Qiita] A summary for a quick understanding of the concept of MVC. [Qiita] About MVC model [Qiita] Let's summarize Rails MVC [Pikawaka] Carefully explain the MVC framework from 1!