Hi Please let me know when we should use reader and writer classes as per spryker standards.

U03TXRYL7U7

Hi
Please let me know when we should use reader and writer classes as per spryker standards.

fsmeier

Hey, can you maybe elaborate more on what exactly you need to know?

U03TXRYL7U7

In Some vendor modules, reader and writer classes are written when we are fetching data and saving data.
So I just need to know if there is formatting required while saving or fetching then whether we should use reader or writer classes.
or is there any further use cases for these classes.

fsmeier

It is mostly about separating different logic

U03TXRYL7U7

Can you please provide some usecase for that with examples

fsmeier

Ideally you should follow some kind of the following structure:

/Business
    /EntityA
        /Writer
            EntityAWriterInterface
            EntityAWriter
        /Reader
            EntityAReaderInterface
            EntityAReader
        /Expander
            EntityAExpanderInterface
            EntityAExpander

    /EntityB
        /Writer
        /Reader
        /Expander

Reader: reads and optionally hydrates the corresponding entity or entities

Writer: saves and/or creates and/or deletes the corresponding entity or entities

fsmeier

Does this help?

fsmeier

But please have in mind that you dont need these interfaces on project level in most of the cases

U03TXRYL7U7

ok, it means if while saving and fetching any business logic is there then reader and writer comes into picture.
Ok thanks for clearing out the confusion.

fsmeier

Yeah, it is in the end just a logical separation between read & write, similar to Repository and Entitymanager

U03TXRYL7U7

so before entering to repository , reader is there and and before entering to entity manager , writer is there for any business logic, Please confirm.

fsmeier

reader and writer are both there for business logic (since they are in the business layer) - If you would just forward the EntityManager or Repository inside the reader and writer you can also use the EntityManager or Repository directly in the Facade. But as soon as you need to do additional operations you should introduce a reader and/or a writer class to put the logic there.

U03TXRYL7U7

ok thanks

U03TXRYL7U7

it helps🙂