I am relatively new to NodeJS, but I'm porting an existing API server written in PHP to use NodeJS. I started out looking at Express, but realised that with all the layout-rendering and templating stuff in Express, it wasn't suited for the task. Then I looked at Restify, but realised it's REST-ness wouldn't work with the model of this API.
I don't want anything that is tied to a database, or any specific way of setting out the API endpoints. Is the best solution to fully roll my own server, without the help of any libraries?
EDIT: Sorry, it seems I was unclear. I am trying to recreate the PHP API as close as possible, and the PHP version does not use REST. It has a few different PHP scripts which take some POST parameters.
If you just want a simple JSON API, Express is still an option. Layouts, temptating and middleware are optional, and you can just use simpler functions.
var express = require('express');
var app = express();
app.use(express.bodyParser());
app.post('/', function(req, res) {
// req.body is an object with POST parameters
// respond with JSON
res.json(200, { data: 'payload' })
// or show an error
res.json(500, { error: 'message' });
});
app.listen(80);
That is one of the simplest solutions available. Unless you want to do request body parsing, checking the HTTP request method, other things yourself, then you can create your own server. That would look more like this:
var http = require('http');
http.createServer(function(request, response) {
if (request.method === 'POST') {
var data = '';
request.on('data', function(chunk) {
data += chunk;
});
request.on('end', function() {
// parse the data
});
}
}).listen(80);
A method like so would also require checking the path as well as other things that would be handled automatically in Express.
Related
I have a NestJS route which sends back in response, a JSON not well formatted (like minified),
I want to make this JSON easier to read, like a JSON prettier or JSON formatted,
Do someone knows how to do it in NestJS ? I accept answers for other NodeJS frameworks like Express, maybe it will work in NestJS too...
Prettifying the JSON response should be the responsibility of the client, not the server. Otherwise you could be sending a lot of white space which will bloat the response size and could lead to a crash due to having a response too large. If you are using something like Postman, it should be easy to prettify it, I think Postman might do it by default. If you are looking at the response in some web browser, you could use JSON.parse() on the response and it should make the response an actual JSON which console.log() would then print in a pretty way.
You should try https://www.postman.com or https://insomnia.rest/. It can save you a lot of time when it comes to testing an API.
While you shouldn't do it in prod as mentioned above, there's number of cases where it makes a lot of sense (e.g. in dev env). You can achieve this in a bit hacky way:
Access express instance inside nest through breaking abstraction. It's not exposed on INest interface, so you'll need to cast it to any type to bypass Typescript check
Set undocumented express property "json spaces", which will set formatting for all JSON responses over the app
const app = await NestFactory.create(AppModule);
if (process.env.NODE_ENV === 'development') {
(app as any).httpAdapter.instance.set('json spaces', 2);
}
await app.listen(3000);
It works for me:
// src/main.ts
async function bootstrap() {
const app = await NestFactory.create(AppModule);
if (process.env.NODE_ENV !== 'production') {
app.getHttpAdapter().getInstance().set('json spaces', 2);
}
await app.listen(process.env.PORT);
}
Define return type string on your controller
Set the Content-Type: application/json response header
Use JSON.stringify to format your object with whitespace
Example controller code:
import { Controller, Get, Header } from '#nestjs/common';
#Controller('diagnostics')
export class DiagnosticsController {
#Get()
#Header('Content-Type', 'application/json')
findAll(): string {
const statusCode = 200;
const statusText = 'OK';
const info = {
self: 'NestJS Diagnostics Report',
status: {
statusCode,
statusText,
},
};
return JSON.stringify(info, null, 2);
}
}
I am writing a private plugin for nodebb (open forum software). In the nodebb's webserver.js file there is a line that seems to be hogging all incoming json data.
app.use(bodyParser.json(jsonOpts));
I am trying to convert all incoming json data for one of my end-points into raw data. However the challenge is I cannot remove or modify the line above.
The following code works ONLY if I temporarily remove the line above.
var rawBodySaver = function (req, res, buf, encoding) {
if (buf && buf.length) {
req.rawBody = buf.toString(encoding || 'utf8');
}
}
app.use(bodyParser.json({ verify: rawBodySaver }));
However as soon as I put the app.use(bodyParser.json(jsonOpts)); middleware back into the webserver.js file it stops working. So it seems like body-parser only processes the first parser that matches the incoming data type and then skips all the rest?
How can I get around that? I could not find any information in their official documentation.
Any help is greatly appreciated.
** Update **
The problem I am trying to solve is to correctly handle an incoming stripe webhook event. In the official stripe documentation they suggested I do the following:
// Match the raw body to content type application/json
app.post('/webhook', bodyParser.raw({type: 'application/json'}),
(request, response) => {
const sig = request.headers['stripe-signature'];
let event;
try {
event = stripe.webhooks.constructEvent(request.body, sig,
endpointSecret);
} catch (err) {
return response.status(400).send(Webhook Error:
${err.message});
}
Both methods, the original at the top of this post and the official stripe recommended way, construct the stripe event correctly but only if I remove the middleware in webserver. So my understanding now is that you cannot have multiple middleware to handle the same incoming data. I don't have much wiggle room when it comes to the first middleware except for being able to modify the argument (jsonOpts) that is being passed to it and comes from a .json file. I tried adding a verify field but I couldn't figure out how to add a function as its value. I hope this makes sense and sorry for not stating what problem I am trying to solve initially.
The only solution I can find without modifying the NodeBB code is to insert your middleware in a convenient hook (that will be later than you want) and then hack into the layer list in the app router to move that middleware earlier in the app layer list to get it in front of the things you want to be in front of.
This is a hack so if Express changes their internal implementation at some future time, then this could break. But, if they ever changed this part of the implementation, it would likely only be in a major revision (as in Express 4 ==> Express 5) and you could just adapt the code to fit the new scheme or perhaps NodeBB will have given you an appropriate hook by then.
The basic concept is as follows:
Get the router you need to modify. It appears it's the app router you want for NodeBB.
Insert your middleware/route as you normally would to allow Express to do all the normal setup for your middleware/route and insert it in the internal Layer list in the app router.
Then, reach into the list, take it off the end of the list (where it was just added) and insert it earlier in the list.
Figure out where to put it earlier in the list. You probably don't want it at the very start of the list because that would put it after some helpful system middleware that makes things like query parameter parsing work. So, the code looks for the first middleware that has a name we don't recognize from the built-in names we know and insert it right after that.
Here's the code for a function to insert your middleware.
function getAppRouter(app) {
// History:
// Express 4.x throws when accessing app.router and the router is on app._router
// But, the router is lazy initialized with app.lazyrouter()
// Express 5.x again supports app.router
// And, it handles the lazy construction of the router for you
let router;
try {
router = app.router; // Works for Express 5.x, Express 4.x will throw when accessing
} catch(e) {}
if (!router) {
// Express 4.x
if (typeof app.lazyrouter === "function") {
// make sure router has been created
app.lazyrouter();
}
router = app._router;
}
if (!router) {
throw new Error("Couldn't find app router");
}
return router;
}
// insert a method on the app router near the front of the list
function insertAppMethod(app, method, path, fn) {
let router = getAppRouter(app);
let stack = router.stack;
// allow function to be called with no path
// as insertAppMethod(app, metod, fn);
if (typeof path === "function") {
fn = path;
path = null;
}
// add the handler to the end of the list
if (path) {
app[method](path, fn);
} else {
app[method](fn);
}
// now remove it from the stack
let layerObj = stack.pop();
// now insert it near the front of the stack,
// but after a couple pre-built middleware's installed by Express itself
let skips = new Set(["query", "expressInit"]);
for (let i = 0; i < stack.length; i++) {
if (!skips.has(stack[i].name)) {
// insert it here before this item
stack.splice(i, 0, layerObj);
break;
}
}
}
You would then use this to insert your method like this from any NodeBB hook that provides you the app object sometime during startup. It will create your /webhook route handler and then insert it earlier in the layer list (before the other body-parser middleware).
let rawMiddleware = bodyParser.raw({type: 'application/json'});
insertAppMethod(app, 'post', '/webhook', (request, response, next) => {
rawMiddleware(request, response, (err) => {
if (err) {
next(err);
return;
}
const sig = request.headers['stripe-signature'];
let event;
try {
event = stripe.webhooks.constructEvent(request.body, sig, endpointSecret);
// you need to either call next() or send a response here
} catch (err) {
return response.status(400).send(`Webhook Error: ${err.message}`);
}
});
});
The bodyParser.json() middleware does the following:
Check the response type of an incoming request to see if it is application/json.
If it is that type, then read the body from the incoming stream to get all the data from the stream.
When it has all the data from the stream, parse it as JSON and put the result into req.body so follow-on request handlers can access the already-read and already-parsed data there.
Because it reads the data from the stream, there is no longer any more data in the stream. Unless it saves the raw data somewhere (I haven't looked to see if it does), then the original RAW data is gone - it's been read from the stream already. This is why you can't have multiple different middleware all trying to process the same request body. Whichever one goes first reads the data from the incoming stream and then the original data is no longer there in the stream.
To help you find a solution, we need to know what end-problem you're really trying to solve? You will not be able to have two middlewares both looking for the same content-type and both reading the request body. You could replace bodyParser.json() that does both what it does now and does something else for your purpose in the same middleware, but not in separate middleware.
Disclaimer: I'm new to NoSQL databases, if something is not clear, appreciate comments and questions to clear things up.
I'm calling some 3rd party web services to get JSON response but need a way to cache the response to avoid repeated calling since each response is constant across remote entities.
Question.
I've selected mongodb, is it the right tool for the job, the response entities have lengthy schemas and mongoose is forcing me to define one, is there a way to avoid having to define schema and just save the response by some id and read it later. if someone can kindly help with condition for checking the A. cache and B. saving.
var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/test');
if() { // A. condition to check if cached response is available
} else { // call web service
http.request({}, function (response) {
var buffers = [];
response.on('data', function (chunk) {
buffers.push(chunk)
});
response.on('end', function () {
var data = Buffer.concat(buffers).toString();
// B. how to save data to a mongoose db
});
})
}
If approach is not right, and I should be using something else then please also enlighten.
If you don't have a schema available then don't use mongoose. Just store the json as mongo documents directly.
https://docs.mongodb.com/getting-started/node/client/
https://docs.mongodb.com/getting-started/node/update/
I have a loopback 2.x app, in which I have a model Conversation and a model Message, with a relationship "Conversation has many messages". I want to customize the response for POST conversations/:id/messages with a json response different than the default, say {status: 'success'}. I tried to use remote hook for the method __create__messages, but it did not work:
Conversation.afterRemote('__create__messages', function(ctx, next) {
ctx.result.data = {
success: 'yes'
};
next();
});
This still returns the default response. How can I return a custom json for a remote method? I have seen examples only for all models, or for all methods: multiple models, multiple methods
Maybe you can try a version of following code below. Also, I think you are meaning to to manipulate data before the method finishes, not after. If you wait, the response will already be created, preventing your intended goal. Let me know if this works (replace with methods that will work for your use case).
Conversation.observe('before save', function(context, next) {
var instance = context.instance || context.data;
if (!instance) return next();
// Your code here
next();
});
I have a simple Backbone.js/Bootstrap front end in HTML5 with a Node.js/Restify backend. I am setting cookies in a header response from the server as below:
res.setHeader("Set-Cookie", ["token=ninja", "language=javascript"]);
On the client side, I am making a REST call as
var response = this.model.fetch().success(function(data){
//success
}).error(function(data){
//error
}).complete(function(data){
//complete
});
that callsback a parse method in the model.
How can I read the cookie value in the model?
Include Cookie.js.
You can then reference individual cookies like this:
var token = Cookie.get('token')
# token == 'ninja'
Here is what I figured out. My application has two components - the HTML/js from one domain that talks to a REST sevice on another domain (and therefore is cross-domain.) Because the cookie is set from REST, it appears is not readable across domains. So the web page will not store the cookie even though the server is sending it. One alternative is to use local cookies or use the technique illustrated by http://backbonetutorials.com/cross-domain-sessions/.
Assuming you are using jQuery with Backbone, you can get the headers by defining the parse function in your model by calling getAllResponseHeaders or getResponseHeader:
var model = Backbone.Model.extend({
// the rest of your model
parse: function(resp, xhr) {
var allHeaders = xhr. getAllResponseHeaders();
var cookieHeader = xhr. getResponseHeader("Set-Cookie");
// do something with the headers
return resp;
}
});