backend library now complete

server/api/controllers/controller.js

@@ -0,0 +1,18 @@
+import mongoose from 'mongoose';
+import Example from './../models/model.js';
+
+export const getExamples = (request, response, next) =>
+  Example.find() // what is .find() ???   --->   https://mongoosejs.com/docs/queries.html
+    .then((data) => response.status(200).json(data))
+    .catch((error) => response.status(500).json(error));
+
+export const uploadExample = (request, response, next) =>
+  new Example({
+    _id: mongoose.Types.ObjectId(), // _id is set by default, (you can remove this line)
+    name: request.body.fieldName, // fieldName === name used on client side
+  })
+    .save() // what is .save() ???   --->   https://mongoosejs.com/docs/api.html#document_Document-save
+    .then.then((data) => response.status(201).json(data))
+    .catch((error) => response.status(500).json(error));
+
+// more about response status codes   --->   https://restapitutorial.com/httpstatuscodes.html