Express - push to testing array on post request

Question

I'm creatin CRUD operations in Express, and I want to test this on simply array in the same file. My problem is that everything is working but delete or post request doesn't update that array's items. What am I doing wrong ??

const express = require("express");
const app = express();
const bodyParser = require("body-parser");
const cors = require("cors");
app.use(cors());

app.use(express.json());
app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());
let cats = [
  {
    id: 1,
    title: "Filemon",
    color: "black"
  },
  {
    id: 2,
    title: "Burys",
    color: "fire"
  },
  {
    id: 3,
    title: "Mysia",
    color: "Grey"
  },
  {
    id: 4,
    title: "Niunia",
    color: "Black - grey"
  }
];
app.get("/api/cats", (req, res) => {
  res.send(cats);
});
app.get("/api/cats/:id", (req, res) => {
  res.send(cats.find(t => t.id === parseInt(req.params.id)));
});

app.post("/api/cats", (req, res) => {
  let cat = {
    id: cats[cats.length - 1].id + 1,
    title: req.body.title
  };
  cats.push(req.body);
  res.send(cat);
});

I want to add cat with dynamic id depending of last cat's id. When I add one cat his id is 5 but when I add next his id is undefined because my array is not updated. How to fix this ?

`cats.push(req.body);` why are you doing this here? You should have pushed the newly created object. No? — Rajaprabhu Aravindasamy, Dec 10 '18 at 12:50
Yeah, my mistake... Id is working well now, but It's not saving array, Can I do this ? When I restart server my cat's are gone... — Freestyle09, Dec 10 '18 at 12:52
You have to keep your cats in a DB then. Once the node process is dead, the associated memory will be flushed. — Rajaprabhu Aravindasamy, Dec 10 '18 at 12:53
@Freestyle09 well for that you need to write data of your array to some file and read up from there. — Code Maniac, Dec 10 '18 at 12:54
I've added file cats.json and still it's not updating it :/ How can I do this? — Freestyle09, Dec 10 '18 at 12:59
Ok thank you guys, I followed this link and now it's working well :) You can add this as an answer: https://stackoverflow.com/questions/10685998/how-to-update-a-value-in-a-json-file-and-save-it-through-node-js — Freestyle09, Dec 10 '18 at 13:07

score 1 · Accepted Answer · answered Dec 10 '18 at 14:45

app.post("/api/cats", (req, res) => {
  let cat = {
    id: cats[cats.length - 1].id + 1,
    title: req.body.title
  };
  cats.push(req.body);
  res.send(cat);
});

cats.push(req.body); should read cats.push(cat); you need to be pushing the new object into your cats array. However this is not permanent and any time you restart the server the data will revert to as is laid out in the initial cats declaration. For permanent data you need to store this info in a DB.

Express - push to testing array on post request

1 Answers1