I usually develop only use the model layer, I ask these two layers are dry what use? I spent the relevant content, are directly according to the official manual copy, and did not specifically say clearly, can you give an example to illustrate?
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Speaking of my own understanding, the traditional MVC three layer in the face of the system is getting larger and more complex business logic, the beginning appears to be "not enough".
Not enough to do, and then abstract and then layered chant.
The business logic processing part is abstracted out as a layer, above m, C, called Logic.
Abstract as a layer of services that can be used as a public, this layer is not coupled with any layer, but only provides its own services, called service.
Give me a chestnut:
A large website, or now more popular interface, microservices what what,
It's impossible to just send a request, read and write data, return data so simple,
Requests need to be processed after the request is accepted, and data needs to be processed after reading and writing the data.
After all the processing has been done, you'll find it's weird to put it on the C-level.
The C layer is getting bloated.；
It doesn't feel right to put it on the M layer,
The m layer should be dealing with the database., the processing of business logic should not be put here;
On the logic layer is the best, the business changed, C and M layers do not need to change, just need to change the middle of Logic.
What does the Service layer put? That's a lot,
Small to file upload, download, image processing, storage
Big to log, error handling, mail, authorization, queue, scheduled task, payment, verification, encryption, SMS, Balabala, beep, PA pa
We can use them in many places as a service.
Just Jiangzi ~ thought to add,
remember to praise.~ Uninvited, no invitation.
Phone simple answer under
It is often sufficient to develop a simple project with MVC layering. As the project grows larger and bigger. A clear architecture is needed to reduce the complexity of the code.
The easiest to think of is 2 points to improve
13-party service. This type of code belongs to the public code. In fact, it has little to do with business logic. such as logs. Mail. SMS.
2 coupling between model and model. Model is usually based on the domain model abstraction later encapsulated by a single-accused class or function set. Many business logic that needs to be combined with multiple model implementations. It can also be put in the model layer or other way in other standalone file implementations. But it's going to be a lot more expensive to maintain. Abstract the logic layer between M and C deals with these in order to facilitate the follow-up service of the invitation
It's useless, I don't know.
Personal understanding: In order to precisely define C-and M-layers, reduce the logic in which the split function introduces other hierarchical concepts
