API Server

Reading Materials

• Express router.params Middleware
• Mongoose Middleware

Express router.params middleware

The router.params() function adds callback triggers to route parameters. Primarily, the use case that I found interesting was the example of a user id being provided in the URL path. A call to router.params is able to intercept the user id and to translate that into a user model (from the DB) and attach that information to the request object.

Mongoose Middleware

Background on Documents and Collections in Mongoose:

• Documents
  • ‘Documents’ in MongoDB are equivalent to records or rows of data in SQL. While an SQL row can reference data in other tables, Mongo documents usually combine that in a single document.
• Collections
  • ‘Collections’ in Mongo are equivalent to tables in relational databases. They can hold multiple JSON documents.

Mongoose has 4 types of middleware:

• Document Middleware
  • validate
  • save
  • remove
  • init
• Collection Middleware
  • count
  • deleteMany, deleteOne
  • find, findOne, findOneAndDelete, findOneAndRemove, findOneAndUpdate
  • remove
  • update, updateOne, updateMany
• Aggregate middleware
  • This middleware is for MyModel.aggregate(). Aggregate middleware executes when you call exec() on an aggregate object.
  • aggregate
• Model middleware
  • insertMany