I'm trying to consolidate a bunch of route usage throughout my Express API, and I'm hoping there's a way I can do something like this:
const app = express()
const get = {
fetchByHostname({
name
}) {
return `hey ${name}`
}
}
const map = {
'/public/hostname/:hostname': get.fetchByHostname
}
app.use((req, res, next) => {
const url = req.originalUrl
const args = { ...req.body, ...req.query }
const method = map[url] // this won't work
const result = method(args)
return res.json({
data: result
})
})
I'm trying to avoid passing round the req and res objects and just handle the response to the client in one place. Is there an Express/Node/.js module or way to match the URL, like my map object above?
I really don't understand what you are trying to achieve, but from what i can see, your fectchByHostname({name})should be fetchByHostname(name) and you might be able to return hey $name. You should be sure you are using ES6 because with you args. Else you have to define the as in es5 args = {body: req.body, query: req.query};. Hope it helps.
Related
I'm trying to make GET request to external API (Rick and Morty API). The objective is setting a GET request for unique character, for example "Character with id=3". At the moment my endpoint is:
Routes file:
import CharacterController from '../controllers/character_controller'
const routes = app.Router()
routes.get('/:id', new CharacterController().get)
export default routes
Controller file:
async get (req, res) {
try {
const { id } = req.params
const oneChar = await axios.get(`https://rickandmortyapi.com/api/character/${id}`)
const filteredOneChar = oneChar.data.results.map((item) => {
return {
name: item.name,
status: item.status,
species: item.species,
origin: item.origin.name
}
})
console.log(filteredOneChar)
return super.Success(res, { message: 'Successfully GET Char request response', data: filteredOneChar })
} catch (err) {
console.log(err)
}
}
The purpose of map function is to retrieve only specific Character data fields.
But the code above doesn't work. Please let me know any suggestions, thanks!
First of all I don't know why your controller is a class. Revert that and export your function like so:
const axios = require('axios');
// getCharacter is more descriptive than "get" I would suggest naming
// your functions with more descriptive text
exports.getCharacter = async (req, res) => {
Then in your routes file you can easily import it and attach it to your route handler:
const { getCharacter } = require('../controllers/character_controller');
index.get('/:id', getCharacter);
Your routes imports also seem off, why are you creating a new Router from app? You should be calling:
const express = require('express');
const routes = express.Router();
next go back to your controller. Your logic was all off, if you checked the api you would notice that the character/:id endpoint responds with 1 character so .results doesnt exist. The following will give you what you're looking for.
exports.getCharacter = async (req, res) => {
try {
const { id } = req.params;
const oneChar = await axios.get(
`https://rickandmortyapi.com/api/character/${id}`
);
console.log(oneChar.data);
// return name, status, species, and origin keys from oneChar
const { name, status, species, origin } = oneChar.data;
const filteredData = Object.assign({}, { name, status, species, origin });
res.send(filteredData);
} catch (err) {
return res.status(400).json({ message: err.message });
}
};
When I paste the endpoint URL with query directly inside the axios.get(), it responds correctly and I can see the json object returned. (i.e axios.get(http://localhost:3000/api/products/product_search?secretKey=${secret}&id=${blabla})). However, if I call the url with the summonerByNameUrl method, it crashes when I make a request. What is the problem in my code?
Crash report:
...
data: '<!DOCTYPE html>\n' +
'<html lang="en">\n' +
'<head>\n' +
'<meta charset="utf-8">\n' +
'<title>Error</title>\n' +
'</head>\n' +
'<body>\n' +
'<pre>Cannot GET /[object%20Object]</pre>\n' +
'</body>\n' +
'</html>\n'
},
isAxiosError: true,
toJSON: [Function: toJSON]
Code:
config.js
const summonerByNameUrl = (summonerName) => `${URL(hidden)}${summonerName}`;
module.exports = {
summonerByNameUrl
}
summoner.js
const config = require('../config');
const axios = require('axios');
const getSummonerByName = async (summonerName) => {
const res = await axios.get(config.summonerByNameUrl(summonerName));
return res.data;
}
const summonerParser = async (req, res) => {
if(!req.query.secretKey)
return res.status(403).json({error: 'missing secret key.'})
let data = await getSummonerByName(req.query)
return res.status(200).json(data);
}
module.exports = {
getSummonerByName,
summonerParser
}
products.js
var express = require('express');
var axios = require('axios')
var router = express.Router();
const summoner = require('../services/summoner');
router.get('/product_search', summoner.summonerParser)
module.exports = router;
app.js
...
app.use('/api/products', productsRouter);
...
You're calling your function with getSummonerByName(req.query) where it is clear from the lines just before that req.query is an object and not a string. When objects are used in a string-context (like your URL), they become "[object Object]", hence the error.
Taking some guesses here but it seems you want to forward some req.query information to the Axios call as query params. Try this instead...
const PRODUCT_SEARCH_URL = "http://localhost:3000/api/products/product_search"
const getSummonerByName = async ({ secretKey, id }) => {
const { data } = await axios.get(PRODUCT_SEARCH_URL, {
params: { secretKey, id }
})
return data
}
If you've got a helper function that returns the base URL (ie http://localhost:3000/api/products/product_search) then by all means, use that instead of a string literal in the Axios call.
The req.query is a Object, not a string.
You can try map the req.query object to make a string. Something like that:
Object.keys(req.query).map(key => {
return key + '=' + req.query[key]
}).join('&')
This code return a string like that: 'id=1&name=test', so you can pass to the endpoint.
I have a Rest API where a user can create a list and then put list items in it (for a quiz). My schema structure is this:
const verbListSchema = {
title: String,
verbs: [{verb: String}]
};
Here are the url endpoints I have so far:
/lists/ (gets back all the lists)
/lists/verbs (gets all the verbs from all the lists)
My question is - I want to get, post, patch and delete a specific list using its id, like /lists?list_id=123/verbs or /lists/123/verbs and then one step further to get individual verbs I want to do something like /lists/123/verbs/124 or /lists?list_id=123/verbs?verb_id=124 the last doesn't work because it counts the last endpoint as a query param.
In terms of best practice what's the best way to do this. I could do something like this (I use express.js)?
app.[request-type]("/lists") {...}
app.[request-type]("/lists/:list_id") {...}
app.[request-type]("/lists/:list_id/verbs") {...}
app.[request-type]("/lists/:list_id/verbs/:verb_id") {...}
and then if I want to retrieve all the lists, not just a specific one I can check if the list_id is "all" like, /lists/all/verbs?
And here is my code so far:
const express = require("express");
const verbRouter = require("./verbRoutes");
const router = express.Router();
const VerbList = require("../../verb-list-db");
const isOriginal = async (req,res,next) => {
const listExists = await VerbList.find({title: req.body.listTitle})
if (listExists.length > 0 ) return res.status(400).json({message: "list already exists"});
next();
};
router.route("/")
.get(async (req,res,next) => {
try {
const listId = req.query.list_id;
if (listId) return res.json(await VerbList.find({_id: listId}));
const lists = await VerbList.find({});
res.json(lists);
} catch(err) {next(err)}
})
.post(isOriginal, async (req,res,next) => {
const newList = new VerbList({ // creates a new list
title: req.body.listTitle
})
newList.save()
.then(() => {return res.send("list successfully added!")})
.catch(err => next(err));
})
.patch(isOriginal, async (req,res,next) => {
try {
const listId = req.query.list_id;
if (!listId) throw new Error("you must have a list_id to patch!")
res.json(await VerbList.updateOne({_id: req.query.list_id}, {title: req.body.listTitle}))
} catch(err) {next(err)}
})
.delete(async (req,res,next) => {
try {
const listId = req.query.list_id;
if (!listId) throw new Error("you must have a list_id to delete!");
res.json(await VerbList.deleteOne({_id: req.query.list_id}))
} catch(err) {next(err)}
})
Any suggestions would be appreciated :)
You can try to modularize your express code by separating your /lists routes from your main server.js (or index.js) file.
index.js
const express = require('express');
const app = express();
//Now lets route all the API requests that start with '/list' to a file called lists.js
app.use('/lists', require('/path/to/lists.js')
app.listen(3000, () => console.log(`\nServer started on port 3000`))
lists.js
const express = require('express');
const router = express.Router();
// now you know all the requests in this file would be for /list so lets implement a router for fetching all the lists
router.get('/', async(req, res) => {
*** add all your logic for /lists endpoints here**
res.status(200).json(lists_json_response); //send a response back to your client
})
//you can create as many endpoints as you want in this file for endpoints that start with '/lists'
router.[request-method]("/lists/:list_id") {...} // endpoint for requesting a specific list
router.[request-method]("/:list_id/verbs") {...} //endpoint for requesting all the verbs for a specific list
router.[request-method]("/lists/all/verbs") {...} // all the verbs in all the lists
module.exports = router;
Also you cant put query parameters in the middle of an endpoint. if it is going to be a variable that you need and its not in the end of the URL, you have to pass it as a param, e.g.:
instead of doing /lists?list_id=123/verbs?verb_id=124, you can do something like /lists/123/verbs/124 to look for the verb with id 124 in a list with id 123.
so to listen to a request to this endpoint, you can design another endpoint in your lists.js file like this:
router[request-method].('/:list_id/verb/:verb_id', async(req, res)=> {
var list_id = req.params.list_id
var verb_id = req.params.verb_id
***
now use the list_id and verb_id to query the requested data and send a response back to the client
***
})
I'm stuck on how to design error handling in an Express.js application.
What are the best design practices to handle errors in Express?
To my understanding, I can handle errors in 2 different ways:
First way would be to use an error middleware and, when an error is thrown in a route, propagate the error to that error middleware. This means that we have to insert the logic of the error handler in the middleware itself (note, the middleware here was purposely kept simple).
app.post('/someapi', (req, res, next) => {
if(req.params.id == undefined) {
let err = new Error('ID is not defined');
return next(err);
}
// do something otherwise
});
app.use((err, req, res, next)=>{
// some error logic
res.status(err.status || 500).send(err);
});
Another option is to deal with the errors on the spot, when the error happens. This means that the logic must be in the route itself
app.post('/someapi', (req, res, next) => {
if(req.params.id == undefined) {
let err = new Error('ID is not defined');
// possibly add some logic
return res.status(ErrorCode).send(err.message);
}
// do something otherwise
});
What is the best approach, and what are the best design practices for this?
Thank you
I think there are much more extensive cases but the main idea is using middleware design. Add your validation logic to this middleware.
yourRouter.post('/message', routerValidator.messageValidator, yourController.saveMessage.bind(yourController));
Below is my sample structure;
// controller
const BaseRoute = require('../infra/base/BaseRoute');
const log = require('./../../utils/log-helper').getLogger('route-web');
const { ErrorTypes } = require('../infra/middlewares/ErrorMiddleware');
const GameService = require('../../service/GameService');
const { SystemMessages } = require('../../statics/default_types');
module.exports = class WebController {
constructor() {
this._logger = log;
this._gameService = new GameService();
}
getGameInfo(req, res) {
var self = this;
try {
const info = self._gameService.getGameInfo(req.body.query);
return BaseRoute.success(res, { info });
} catch (err) {
self._logger.error('Something went wrong while getting game information', err);
return BaseRoute.internalError(res, SystemMessages.GENERIC_ERROR, req.getErrorCode(ErrorTypes.UNHANDLED, 1));
}
}
};
// router index
const express = require('express');
const ErrorMiddleware = require('../infra/middlewares/ErrorMiddleware').ErrorMiddlewarePath;
const baseValidator = require('../infra/validators/BaseRouterValidator');
const AndroidController = require('./AndroidController');
const IosController = require('./IosController');
const WebController = require('./WebController');
const AndroidRouter = express.Router();
const IosRouter = express.Router();
const WebRouter = express.Router();
const androidController = new AndroidController();
const iosController = new IosController();
const webController = new WebController();
AndroidRouter.post('/message', ErrorMiddleware(1), baseValidator.teamQueryValidator, androidController.getGameInfo.bind(androidController));
IosRouter.post('/message', ErrorMiddleware(1), baseValidator.teamQueryValidator, iosController.getGameInfo.bind(iosController));
WebRouter.post('/message', ErrorMiddleware(1), baseValidator.teamQueryValidator, webController.getGameInfo.bind(webController));
module.exports = {
AndroidRouter,
IosRouter,
WebRouter
};
// validator
const log = require('../../../utils/log-helper').getLogger('route-validator-base');
const BaseRoute = require('../base/BaseRoute');
const _ErrorTypes = require('../middlewares/ErrorMiddleware').ErrorTypes;
function teamQueryValidator(req, res, next) {
if (!req.body || !req.body.query) {
const params = req.body ? JSON.stringify(req.body) : 'Empty';
log.error('Invalid Parameters req body', params);
return BaseRoute.httpError(res, 'Bir takım adı giriniz..', 400, req.getErrorCode(_ErrorTypes.VALIDATION, 1));
}
return next();
}
module.exports = {
teamQueryValidator
};
// app.js that assigns to express
this._router = require('./src/route/api/index');
this._ErrorMiddleware = require('./src/route/infra/middlewares/ErrorMiddleware').ErrorMiddlewareRouter;
this.app.use('/api/android', this._ErrorMiddleware(1), this._router.AndroidRouter);
this.app.use('/api/ios', this._ErrorMiddleware(2), this._router.AndroidRouter);
this.app.use('/api/web', this._ErrorMiddleware(3), this._router.WebRouter);
What are the best design practices to handle errors in Express?
There is no best design, it's all subjective.
To my understanding, I can handle errors in 2 different ways:
Correct. You used error middleware for the first and then handled the error directly in the route handler.
To me, it makes sense to separate out the error handling logic from the business logic. It makes for cleaner code. So the former (error middleware) would be better IMO.
You would have a different error handler for different errors.
I know how to get the params for queries like this:
app.get('/sample/:id', routes.sample);
In this case, I can use req.params.id to get the parameter (e.g. 2 in /sample/2).
However, for url like /sample/2?color=red, how can I access the variable color?
I tried req.params.color but it didn't work.
So, after checking out the express reference, I found that req.query.color would return me the value I'm looking for.
req.params refers to items with a ':' in the URL and req.query refers to items associated with the '?'
Example:
GET /something?color1=red&color2=blue
Then in express, the handler:
app.get('/something', (req, res) => {
req.query.color1 === 'red' // true
req.query.color2 === 'blue' // true
})
Use req.query, for getting he value in query string parameter in the route.
Refer req.query.
Say if in a route, http://localhost:3000/?name=satyam you want to get value for name parameter, then your 'Get' route handler will go like this :-
app.get('/', function(req, res){
console.log(req.query.name);
res.send('Response send to client::'+req.query.name);
});
Query string and parameters are different.
You need to use both in single routing url
Please check below example may be useful for you.
app.get('/sample/:id', function(req, res) {
var id = req.params.id; //or use req.param('id')
................
});
Get the link to pass your second segment is your id example: http://localhost:port/sample/123
If you facing problem please use Passing variables as query string using '?' operator
app.get('/sample', function(req, res) {
var id = req.query.id;
................
});
Get link your like this example: http://localhost:port/sample?id=123
Both in a single example
app.get('/sample/:id', function(req, res) {
var id = req.params.id; //or use req.param('id')
var id2 = req.query.id;
................
});
Get link example: http://localhost:port/sample/123?id=123
Update: req.param() is now deprecated, so going forward do not use this answer.
Your answer is the preferred way to do it, however I thought I'd point out that you can also access url, post, and route parameters all with req.param(parameterName, defaultValue).
In your case:
var color = req.param('color');
From the express guide:
lookup is performed in the following order:
req.params
req.body
req.query
Note the guide does state the following:
Direct access to req.body, req.params, and req.query should be
favoured for clarity - unless you truly accept input from each object.
However in practice I've actually found req.param() to be clear enough and makes certain types of refactoring easier.
#Zugwait's answer is correct. req.param() is deprecated. You should use req.params, req.query or req.body.
But just to make it clearer:
req.params will be populated with only the route values. That is, if you have a route like /users/:id, you can access the id either in req.params.id or req.params['id'].
req.query and req.body will be populated with all params, regardless of whether or not they are in the route. Of course, parameters in the query string will be available in req.query and parameters in a post body will be available in req.body.
So, answering your questions, as color is not in the route, you should be able to get it using req.query.color or req.query['color'].
The express manual says that you should use req.query to access the QueryString.
// Requesting /display/post?size=small
app.get('/display/post', function(req, res, next) {
var isSmall = req.query.size === 'small'; // > true
// ...
});
const express = require('express')
const bodyParser = require('body-parser')
const { usersNdJobs, userByJob, addUser , addUserToCompany } = require ('./db/db.js')
const app = express()
app.set('view engine', 'pug')
app.use(express.static('public'))
app.use(bodyParser.urlencoded({ extended: false }))
app.use(bodyParser.json())
app.get('/', (req, res) => {
usersNdJobs()
.then((users) => {
res.render('users', { users })
})
.catch(console.error)
})
app.get('/api/company/users', (req, res) => {
const companyname = req.query.companyName
console.log(companyname)
userByJob(companyname)
.then((users) => {
res.render('job', { users })
}).catch(console.error)
})
app.post('/api/users/add', (req, res) => {
const userName = req.body.userName
const jobName = req.body.jobName
console.log("user name = "+userName+", job name : "+jobName)
addUser(userName, jobName)
.then((result) => {
res.status(200).json(result)
})
.catch((error) => {
res.status(404).json({ 'message': error.toString() })
})
})
app.post('/users/add', (request, response) => {
const { userName, job } = request.body
addTeam(userName, job)
.then((user) => {
response.status(200).json({
"userName": user.name,
"city": user.job
})
.catch((err) => {
request.status(400).json({"message": err})
})
})
app.post('/api/user/company/add', (req, res) => {
const userName = req.body.userName
const companyName = req.body.companyName
console.log(userName, companyName)
addUserToCompany(userName, companyName)
.then((result) => {
res.json(result)
})
.catch(console.error)
})
app.get('/api/company/user', (req, res) => {
const companyname = req.query.companyName
console.log(companyname)
userByJob(companyname)
.then((users) => {
res.render('jobs', { users })
})
})
app.listen(3000, () =>
console.log('Example app listening on port 3000!')
)
you can simply use req.query for get query parameter:
app.get('/', (req, res) => {
let color1 = req.query.color1
let color2 = req.query.color2
})
The url module provides utilities for URL resolution and parsing. URL parse without using Express:
const url = require('url');
const queryString = require('querystring');
let rawUrl = 'https://stackoverflow.com/?page=2&size=3';
let parsedUrl = url.parse(rawUrl);
let parse = queryString.parse(parsedUrl.query);
// parse = { page: '2', size: '3' }
Another way:
const url = require('url');
app.get('/', (req, res) => {
const queryObject = url.parse(req.url,true).query;
});
url.parse(req.url,true).query returns { color1: 'red', color2: 'green' }.
url.parse(req.url,true).host returns 'localhost:8080'.
url.parse(req.url,true).search returns '?color1=red&color2=green'.
Just use the app.get:
app.get('/some/page/here', (req, res) => {
console.log(req.query.color) // Your color value will be displayed
})
You can see it on expressjs.com documentation api:
http://expressjs.com/en/api.html
A nice technique i've started using with some of my apps on express is to create an object which merges the query, params, and body fields of express's request object.
//./express-data.js
const _ = require("lodash");
class ExpressData {
/*
* #param {Object} req - express request object
*/
constructor (req) {
//Merge all data passed by the client in the request
this.props = _.merge(req.body, req.params, req.query);
}
}
module.exports = ExpressData;
Then in your controller body, or anywhere else in scope of the express request chain, you can use something like below:
//./some-controller.js
const ExpressData = require("./express-data.js");
const router = require("express").Router();
router.get("/:some_id", (req, res) => {
let props = new ExpressData(req).props;
//Given the request "/592363122?foo=bar&hello=world"
//the below would log out
// {
// some_id: 592363122,
// foo: 'bar',
// hello: 'world'
// }
console.log(props);
return res.json(props);
});
This makes it nice and handy to just "delve" into all of the "custom data" a user may have sent up with their request.
Note
Why the 'props' field? Because that was a cut-down snippet, I use this technique in a number of my APIs, I also store authentication / authorisation data onto this object, example below.
/*
* #param {Object} req - Request response object
*/
class ExpressData {
/*
* #param {Object} req - express request object
*/
constructor (req) {
//Merge all data passed by the client in the request
this.props = _.merge(req.body, req.params, req.query);
//Store reference to the user
this.user = req.user || null;
//API connected devices (Mobile app..) will send x-client header with requests, web context is implied.
//This is used to determine how the user is connecting to the API
this.client = (req.headers) ? (req.headers["x-client"] || (req.client || "web")) : "web";
}
}