I'm using redis for the first time, and I can't quite figure out why my middleware 'cache' function is breaking my code? It works great without it, displays in the browser, if I go to my terminal and check for a key value pair it works great.
Here is my setup:
const express = require("express");
const redis = require("redis");
const axios = require("axios").default;
const PORT = process.env.PORT || 5000;
const REDIS_PORT = process.env.PORT || 6379;
const client = redis.createClient(REDIS_PORT);
client.connect();
const app = express();
function setResponse(username, repos) {
return `<h2>${username} has ${repos} Github repos</h2>`;
}
// make req to github
async function getRepos(req, res, next) {
try {
console.log("fetching data...");
const { username } = req.params;
const response = await axios.get(
`https://api.github.com/users/${username}`
);
const data = response.data;
const repos = data.public_repos;
// set to redis
client.set(username, repos);
res.send(setResponse(username, repos));
} catch (err) {
console.log(err);
res.status(500);
}
}
// Cache middleware
function cache(req, res, next) {
const { username } = req.params;
client.get(username, (err, data) => {
if (err) throw err;
if (data !== null) {
res.send(setResponse(username, data));
} else {
next();
}
});
}
app.get("/repos/:username", cache, getRepos);
app.listen(5000, () => {
console.log(`App listening on port ${PORT}`);
});
Any advice would be much appreciated!
Your cache function
function cache(req, res, next) {
const { username } = req.params;
client.get(username, (err, data) => {
if (err) throw err;
if (data !== null) {
res.send(setResponse(username, data));
} else {
next();
}
});
}
uses node redis 3 "logic" so it's hanging
redis 4 is promise led, so you need to use async/await or .then/.catch
So something like this should work for the .then/.catch approach
// Cache middleware
function cache(req, res, next) {
console.log('caching for', req.params);
const { username } = req.params;
client.get(username)
.then((data) => {
if (data !== null) {
res.send(setResponse(username, data));
} else {
next();
}
})
.catch(err => {
if (err) throw err;
});
}
This will solve your initial problem of "why it's getting stuck"
Related
I have built and API with Express to POST a new job in a project I am currently working on. The GET requests work fine, also the DEL, but the POST one is not working. I am connected to a POSTGRES database.
I have defined the following path for the API:
app.use('/api/jobs', jobRoutes);
so when I send a POST request like below:
localhost:4000/api/jobs/createjob
it should work. What is also weird, is that the code was working perfectly before, but now I can't seem to figure it out anymore. I tried looking elsewhere, but I couldn't find any solution when getting this kind of error with APIs.
My API looks like the following:
router.post("/createjob", async (req, res) => {
try {
const {job} = req.body;
const newJob = await pool.query("INSERT INTO job(job_title, job_department, country_id, description, expiration_date) VALUES($1, $2, $3, $4, $5) RETURNING *", [job.job_title, job.job_department, job.country_id, job.description, job.expiration_date]);
res.json(newJob.rows);
} catch (error) {
console.error(error.message);
}
})
I am making the POST request with Postman, and the body looks like this:
{
"description": "job_description",
"job_title": "Back End Developer"
}
When I send the requests, in the terminal shows this error:
Cannot read properties of undefined (reading 'job_title')
Full code of the Routes:
const express = require("express");
const router = express.Router();
const pool = require("../db");
// routes
// get all jobs
router.get('/alljobs', async (req, res) => {
try {
const allJobs = await pool.query("SELECT * FROM job");
res.json(allJobs.rows)
} catch (error) {
console.error(error.message);
}
})
// GET a single job
router.get('/job/:id', async (req, res) => {
try {
const {id} = req.params;
const job = await pool.query("SELECT * FROM job WHERE job_id = $1 ", [id]);
res.json(job.rows)
} catch (error) {
console.error(error.message);
}
})
// create a job
router.post("/createjob", async (req, res) => {
try {
const {job} = req.body;
const newJob = await pool.query("INSERT INTO job(job_title, job_department, country_id, description, expiration_date) VALUES($1, $2, $3, $4, $5) RETURNING *", [job.job_title, job.job_department, job.country_id, job.description, job.expiration_date]);
res.json(newJob.rows);
} catch (error) {
console.error(error.message);
}
})
// update a job
router.patch("/updatejob/:id", async (req, res) => {
try {
const {id} = req.params;
const {description} = req.body;
const updateJob = await pool.query("UPDATE job SET description = $1 WHERE job_id = $2", [description, id]);
res.json(updateJob.rows);
} catch (error) {
console.error(error.message);
}
})
// delete a job
router.delete("/deletejob/:id", async (req, res) => {
try {
const {id} = req.params;
const deleteJob = await pool.query("DELETE FROM job WHERE job_id = $1", [id]);
res.json(deleteJob.rows);
} catch (error) {
console.error(error.message);
}
})
// get all countries
router.get("/countries", async (req, res) => {
try {
const allCountries = await pool.query("SELECT * FROM countries");
res.json(allCountries.rows)
} catch (error) {
console.error(error.message);
}
})
// //create new user
// router.post("/newuser", async (req, res) => {
// try {
// const {user} = req.body;
// const newUser = await pool.query("INSERT INTO users(user_name, email, password, is_candidate, is_recruiter) VALUES($1, $2, $3, $4, $5) RETURNING *", [user.user_name, user.email, user.password, user.candidate, user.recruiter]);
// res.json(newUser.rows);
// } catch (error) {
// console.error(error.message);
// }
// })
module.exports = router;
Full code of my server.js file:
const express = require("express");
const router = require("./routes/jobRoutes");
const jobRoutes = require("./routes/jobRoutes");
const cors = require("cors");
//creates express app
const app = express();
app.use(express.json());
app.use(cors());
//middleware
app.use((req,res,next) => {
console.log("req.path", req.method);
next();
})
app.get("/status", (req, res, next) => {
res.send("connected");
});
// for every other request
app.use('/api/jobs', jobRoutes);
// more middleware
app.use((err, req, res, next) => {
let status = err.status || 500;
let message = err.message;
console.error(err);
return res.status(status).json({
error: { message, status },
});
});
//listen for requests
app.listen(4000, () => {
console.log("listening on port 4000")
});
I tried looking elsewhere, but I couldn't find any solution when getting this kind of error with APIs. The GET and the DEL requests work as expected.
I am trying to call [https://jsonplaceholder.typicode.com/albums/1/photos] in my node codes so that i create an end-point that is dynamic...like if i change 1 in url i get the relevant photos.
here are my codes
const request = require('request');
const callExtrenalApiUsingRequest = async (callback, req, res) => {
try {
let id = req.params.id
await request(`https://jsonplaceholder.typicode.com/albums/${id}/photos`, { json: true }, (err, res, body) => {
if (err) {
return callback(err);
}
return callback(body)
})
}
catch (error){
console.log(error)
}
}
module.exports.callApi = callExtrenalApiUsingRequest;
request.js
const apiCallFromRequest = require( './request.js');
const http = require('http')
http.createServer((req, res) => {
try {
if (req.url === "/request/photos/:id") {
apiCallFromRequest.callApi(function (response) {
res.write(JSON.stringify(response));
res.end();
})
}
}
catch (err) {
console.log(err)
}
}).listen(3000)
console.log("service running on port 3000...")
Sorry if the title if confusing, I wasn't too sure how to word it. I have a PATCH request to update a value in my database, but even though it is "working" (200 status), it's not actually.
I have a .route('/:movie_id/:user_id').all() handler to trigger for all my methods, where it pulls a movie from the database by movie_id and user_id. This works. Then I move on to my PATCH request, but it seems like the PATCH request isn't actually running. I am getting the correct response from the .all() handler, but no update is happening. Even if I completely comment out the code for my PATCH, I am still getting a 200 status.
Here is my .all() handler with my PATCH request:
movieRouter
.route('/:movie_id/:user_id')
.all(requireAuth)
.get((req, res, next) => {
const db = req.app.get('db')
MovieService.getById(db, req.params.movie_id, req.params.user_id)
.then(movie => {
if(!movie) { // this runs fine
return res.status(404).json({ error: `Movie doesn't exist`})
}
// res.json({movie : movie}); --> old code
// solution:
res.movie = movie;
next();
return movie;
})
.catch(next)
})
.patch(requireAuth, (req, res, next) => {
const db = req.app.get('db')
const { watched } = req.body
const updatedMovie = { watched }
// this doesn't run
const numVal = Object.values(updatedMovie).filter(Boolean).length
if(numVal === 0) {
return res.status(400).json({ error: `Must not be blank`})
}
MovieService.updateMovie(db, req.params.movie_id, req.params.user_id, updatedMovie)
.then(movie => {
res.status(200).json(updatedMovie)
})
.catch(next)
})
Here is my MovieService:
updateMovie(db, movie_id, newMovie) {
return db('your_movie_list').where('id', movie_id).where('user_id', user_id).update(newMovie).returning('*')
}
It should be the problem of the 2nd .all(), .all() will catch all request, no matter it is GET, POST, PATCH, DELETE. So even when you comment out PATCH code, it will return 200.
Change the 2nd .all to .get like below
app.use(express.json())
movieRouter
.route('/:movie_id/:user_id')
.all(requireAuth)
.get((req, res, next) => { // use .get instead of .all to avoid catching all requests
const db = req.app.get('db')
MovieService.getById(db, req.params.movie_id, req.params.user_id)
.then(movie => {
if(!movie) { // this runs fine
return res.status(404).json({ error: `Movie doesn't exist`})
}
res.json({movie : movie});
})
.catch((e) => {
console.log("From getMovie", e);
res.status(400).json({ error: e.message })
})
})
.patch((req, res, next) => {
try {
const db = req.app.get('db')
const { watched } = req.body
const updatedMovie = { watched }
// this doesn't run
const numVal = Object.values(updatedMovie).filter(Boolean).length
if(numVal === 0) {
return res.status(400).json({ error: `Must not be blank`})
}
MovieService.updateMovie(db, req.params.movie_id, req.params.user_id, updatedMovie)
.then(movie => {
console.log(movie) // nothing logs
res.status(200).json(movie[0])
})
.catch((e) => {
console.log("From updateMovie", e);
res.status(400).json({ error: e.message })
})
}catch(e) {
console.log("From try/catch", e);
res.status(400).json({ error: e.message })
}
})
A little working example for cross-checking
const express = require("express");
const app = express();
const PORT = process.env.PORT || 8080;
app.use(express.json())
const movieRouter = express.Router()
movieRouter
.route('/:movie_id/:user_id')
// .all(requireAuth)
.get((req, res, next) => {
res.json({"movie:get" : 1});
})
.patch((req, res, next) => {
res.json({"movie:patch" : 1});
})
app.use(movieRouter)
app.listen(PORT, function (err) {
if (err) console.log(err);
console.log("Server listening on PORT", PORT);
});
My /chat route works well through Post method with validation with Joi schema but when I send request through Get method, it show Sending Request and continue loading...
My index.js file:
const express = require('express');
const cors = require('cors');
const bodyParser = require('body-parser');
const morgan = require('morgan');
const chat = require('./db/ChatModel');
const app = express();
app.use(bodyParser.json());
app.get('/chat', (req, res) => {
chat.getAllMessages().then( (messages) => {
res.json(messages);
});
});
app.post('/chat', (req, res) => {
console.log(req.dody);
chat.createMessages(req.body).then((message) => {
res.json(message);
}).catch( (error) => {
res.status(500);
res.json(error);
});
});
const port = process.env.PORT || 8888;
app.listen(port, () => {
console.log(`Listening on port ${port}...`);
});
In connection.js I coded this
const monk = require('monk');
const connectionString = 'localhost/chatboard';
const db = monk(connectionString);
module.exports = db;
And ChatModal.js has the following code
const Joi = require('joi');
const db = require('./connection');
const schema = Joi.object().keys({
username: Joi.string().alphanum().min(4).max(16).required(),
subject: Joi.string().required(),
message:Joi.string().max(300).required(),
imgUrl: Joi.string().uri({
scheme: [ // https://github.com/hapijs/joi/blob/v14.3.1/API.md#stringurioptions
/https?/
]
})
});
const chat = db.get('chat');
function getAllMessages() {
return chat.find();
};
function createMessages(message) {
const result = Joi.validate(message, schema);
if (result.error == null) {
message.created = new Date();
return chat.insert(message);
} else {
return Promise.reject(result.error);
}
}
module.exports = {
createMessages,
getAllMessages
};
I can't understand why getAllMessages() doesn't work and postman continue loading when Get request applied like this http://prntscr.com/s0d9c5
ChatModal.js
function getAllMessages() {
try {
return chat.find();
} catch (err) {
return next(err);
}
index.js
app.get('/chat', (req, res, next) => {
try{
data = chat.getAllMessages()
} catch (err) {
return next(error);
}
res.json(data);
});
User try-catch in the ChatModal.js and also index.js then you can understand what is actual error, like bellow:
ChatModal.js
function getAllMessages() {
try {
chat.find();
} catch (err) {
return next(err);
}
I think, may be your data, i mean message list data so weight, in this case you get all message,res.json(messages); json method have long time to parse messages data
I am building a REST API but every second time I load my site I get a MongoError: Topology was destroyed. Can someone help me fixing this? I have a feeling that there is something wrong with the asynchronous running.
const client = new MongoClient(apiconfig.mongoUrl, {
useNewUrlParser: true
});
app.get("/api/:object", (req, res) => {
mongodb(req.params["object"], async (collection: Collection) => {
if (collection !== undefined) {
let result = await collection.find().toArray();
res.send(result);
}
else {
res.sendStatus(404);
}
});
});
const mongodb = (coll: string, operation: (collection: Collection) => Promise<void>) => {
client.connect((err) => {
const db = client.db("VaorraJS");
db.collections().then((collections) => {
operation(collections.find((collection) => collection.collectionName === coll)).then(() => {
client.close();
});
}).catch((error) => {
console.log("ERROR: " + error);
});
});
}
app.listen(5000);
I would suggest the use Mongoose
you are creating DB connection for every request, which is not the correct way
const MongoClient = require('mongodb').MongoClient;
// Connection URL
const url = 'mongodb://localhost:27017';
// Database Name
const dbName = '<some db>';
// Use connect method to connect to the server
let db;
MongoClient.connect(url, function (err, client) {
assert.equal(null, err);
console.log("Connected successfully to server");
db = client.db(dbName);
});
app.get("/api/:object", async(req, res) => {
const collection = db.collection(req.params["object"]);
let result = await collection.find().toArray();
res.send(result);
});