Understanding REST API Routing in Payload CMS

zed0547last year

13

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  diorculalast year

  Oeh thanks man!!

• 

  zed0547last year

  My pleasure

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  diorculalast year

  would this be a correct component diagram of payload and payload core?
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  zed0547last year

  Kind of yeah, the local api and the rest api use the same operations under the hood, it's just the routing that is slightly different

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  diorculalast year

  @654031862146007055

  cool cool, but what i can't wrap my head around is

  how

  actually data is send to the database for example, i have it now as a content manager, but basically that would be Nextjs/Payload core utility combined with the schema definition of collections to check?

• 

  zed0547last year

  All operations eventually get to a

  db

  call. Take the

  create

  operation for example, it does some processing, calls some hooks, does some more processing, then it gets to this line:

  https://github.com/payloadcms/payload/blob/main/packages/payload/src/collections/operations/create.ts#L269
  
  

  This is a call to the underlying db adapter directly. DB adapters, as the name suggests, use the adapter pattern to map these calls to actual db operations - in the case of

  create

  , it calls the adapters own

  create

  method. Let's say we are using

  db-postgres

  , then at this point the data that we passed up to now gets transformed for writing (to better represent the actual columns we are writing), and then a special function called

  upsertRow

  is called that updates or inserts this row in the actual database:

  https://github.com/payloadcms/payload/blob/main/packages/drizzle/src/create.ts#L19
  
  

  How do we even get the

  db

  object though? The

  db

  object gets assigned to

  payload

  (The

  BasePayload

  instance) via initialization by using the config you passed with your chosen adapter, simple as that. Whenever you get a

  payload

  instance, for example from a

  req

  , we are always referring to the same cached

  BasePayload

  object.

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  diorculalast year

  ah ah i see, let me work that out real quick!

  
  
  @654031862146007055

  would this be a better component representation?
• 

  zed0547last year

  It's better, in your case the Database Adapter will be mongoose (db-mongodb) but if you want something more representative of the actual flow then it would look a little more linear I think:

  
  
  

  Admin ui -----
  |            |
  |            |
  v            |
  API Handler  | 
  |            |
  |            |
  v            v
  Core Operations / Local API
  |
  |
  v
  DB Adapter
  ...

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  diorculalast year

  ah so the admin ui skips the api handler (like the local api goes straight to the database)

  
  
  

  thanks btw for the time man, when i am finished i will be happy to share my project 🙂

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  zed0547last year

  Yes, at the end of the day the REST API basically just calls the same operations as the Local API

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  diorculalast year

  @654031862146007055

  i know it is quite late (where i live) but i am confused still a bit. There is a Payload Core utility that handles requests received through the Nextjs endpoints. sort of.

  
  
  

  But then there is also Node.js? How does this fit in everything?

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  zed0547last year

  Nodejs is a Javascript runtime environment, Next.js needs a runtime environment outside of the browser for certain processes, for example running an endpoint from the context of a server happens in Nodejs

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  diorculalast year

  copy that captain, my thanks