Controllers making guide

1. getItem by id
   • Case when we get correct id
     • in route means router.get('/:id', controller.getById);
     • in controller that parameters are in req.params object
     • so in controller f.e. use method find

       See the Pen 5 - get Item by id by Andrii (@imitator) on CodePen.

       Remember about id in databases, ofter set  ̲ id, so method find will be

       const oneProduct = products.find(item => item._id === id);
   • If we get incorrect id

     • See the Pen 6 - get Item by Id (check if id incorrect) by Andrii (@imitator) on CodePen.

2. POST (We make it in cash without real db/rewrite in to file)
   • Make route
     • routes/products.js

       router.post('/', products.add);

   • Create controller
     • controllers/products/add.js

       Firstly for testing what "req.body" is, we get it in console

       For converting body req we should use "express.json()" middleware. In our example it used for all requests by setting it in server.js by app.use(express.json());.

       But for optimizing our server we may use it only for body requests, that's mean in routes/products.js

       router.post('/', express.json(), products.add);

       Before express.json() developers used another middleware building in node.js, called body-parser , in server.js we may use it.
     • Make request via postman
     • For testing use UUID to generate id-s

       npm i uuid

   • To sum up, first version of add.js controller (in this case we add product in cash, NOT to data/products.js file)

     See the Pen 9 - POST controller by Andrii (@imitator) on CodePen.

3. UPDATE (We make it in cash without real db/rewrite in to file)
   • Create route

     router.put('/:id', express.json(), products.update);

     P.S. express.json - middleware for body, could be use in server.js, like app.use(express.json()); for all requests, the same explanation was in POST method

   • Create controller

     See the Pen 10 - UPDATE controller by Andrii (@imitator) on CodePen.

4. DELETE (We make it in cash without real db/rewrite in to file)

   P.S. It is impossible to create "delete" controller name, b/c it is reserved word.

   • Create route

     router.delete('/:id', products.remove);

   • Create controller

     See the Pen 11 - DELETE controller by Andrii (@imitator) on CodePen.