MongoClient Server Code

.eslintrc.js

module.exports = {
  env: {
    browser: true,
    es6: true,
    node: true,
  },
  extends: ["eslint:recommended", "prettier"],
  parserOptions: {
    ecmaVersion: "latest",
    sourceType: "module",
    ecmaFeatures: {
      jsx: true,
    },
  },
  rules: {
    indent: ["error", 2, { SwitchCase: 1 }],
    "linebreak-style": ["error", "unix"],
    quotes: ["error", "double"],
    semi: ["error", "always"],
    "no-console": 0,
  },
};

.gitignore

.DS_Store
node_modules/**

README

Boilerplate code for helping connecting to Mongo locally from Observable, as detailed on this Notebook https://observablehq.com/@kasivisu4/mongodb-local

mongoDBClient.js

import { MongoClient } from "mongodb";

function MyMongoDB() {
  const myDB = {};
  let client;
  myDB.init = async (url) => {
    try {
      client = new MongoClient(url);
      await client.connect();
      return { success: true };
    } catch (err) {
      console.log(err);
      return { success: false };
    }
  };

  myDB.find = async (dbName, collectionName, query = {}) => {
    try {
      const db = client.db(dbName);
      const collection = db.collection(collectionName);
      let res = await collection.find(query).toArray();
      return res;
    } catch (err) {
      console.error(err);
      return err;
    }
  };

  myDB.insert = async (dbName, collectionName, data = {}) => {
    try {
      const db = client.db(dbName);

      const collection = await db.collection(collectionName);
      console.log(data);
      let res = await collection.insertMany(data);
      return res;
    } catch (err) {
      console.error(err);
      return err;
    }
  };

  myDB.delete = async (dbName, collectionName, query = {}) => {
    try {
      const db = client.db(dbName);
      const collection = db.collection(collectionName);
      let res = await collection.deleteMany(query);
      return res;
    } catch (err) {
      console.error(err);
      return err;
    }
  };

  myDB.closeConnection = async () => {
    client.close();
  };

  return myDB;
}

export const databaseManager = MyMongoDB();

package.json

{
  "name": "mongolocal",
  "version": "1.0.0",
  "description": "",
  "main": "mongoDBClient.js",
  "type": "module",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "node ./node_modules/nodemon/bin/nodemon.js server.js"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "cors": "^2.8.5",
    "express": "^4.18.2",
    "mongodb": "^5.2.0",
    "nodemon": "^2.0.22"
  },
  "devDependencies": {
    "eslint": "^8.37.0",
    "eslint-config-prettier": "^8.8.0",
    "prettier": "^2.8.7"
  }
}

server.js

import express from "express";
import { databaseManager } from "./mongoDBClient.js";
import bodyParser from "body-parser";
import cors  from "cors";


const app = express();


let corsOptions = {
  origin: function (origin, callback) {
    // Accept connections from Observable
    if (origin.endsWith("static.observableusercontent.com")) {
      callback(null, true)
    } else {
      callback(new Error('Not allowed by CORS'))
    }
  }
}

app.use(cors(corsOptions));


app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());

const PORT = 5001;

app.post("/api/init", async (req, res) => {
  let body = req.body;
  console.log(body);
  let { url } = body;
  console.log("Received init request", url);
  let result = await databaseManager.init(url);
  res.status(200).json(result);
});

app.post("/api/insert", async (req, res) => {
  let { db, collection, data } = req.body;
  console.log("Received Insert request", db, collection, data);
  let result = await databaseManager.insert(db, collection, data);
  res.status(200).json(result);
});

app.post("/api/find", async (req, res) => {
  let { db, collection, query } = req.body;
  console.log("Received Find request", db, collection, query);
  let result = await databaseManager.find(db, collection, query);
  res.status(200).json(result);
});

app.get("/api/closeConnection", async (req, res) => {
  console.log("Received Close Connection request");
  let result = await databaseManager.closeConnection();
  res.status(200).json(result);
});

app.post("/api/delete", async (req, res) => {
  let { db, collection, query } = req.body;
  console.log("Received Find request", db, collection, query);
  let result = await databaseManager.delete(db, collection, query);
  res.status(200).json(result);
});

// app.get("/api/delete", async (req, res) => {
//   let body = req.body;
//   console.log("Received Delete request", body);
//   let result = await databaseManager.delete();
//   res.status(200).json(result);
// });

app.listen(PORT, console.log(`Mongodb Server running on port ${PORT}`));