Is it possible to 'get' data using POST with json-server?

[vsharma2266]

Hi,

I am trying to get response using POST. My POST body has some key-value pairs which determine what needs to be responded.
Is it possible to get data back from POST method ?

Thanks

[sanserna]

It would be helpful if they answered this issue... i'am facing the same problem

[typicode]

Hi @vsharma2266 @sanserna,

Out of the box it's not possible, sorry. With REST, making a POST usually mean that you request a change and if you want to query GET is the right verb.

That said, using the project as a module, you can fake it:

// server.js
var jsonServer = require('json-server')
var server = jsonServer.create()
var router = jsonServer.router('db.json')
var middlewares = jsonServer.defaults()

server.use(middlewares)

server.use(jsonServer.bodyParser)
server.use(function (req, res, next) {
  if (req.method === 'POST') {
    // Converts POST to GET and move payload to query params
    // This way it will make JSON Server that it's GET request
    req.method = 'GET'
    req.query = req.body
  }
  // Continue to JSON Server router
  next()
})

// If you need to scope this behaviour to a particular route, use this
server.post('/comments', function (req, res, next) {
  req.method = 'GET'
  req.query = req.body
  next()
})

server.use(router)
server.listen(3000, function () {
  console.log('JSON Server is running')
})

I would suggest checking https://expressjs.com/ docs and https://github.com/typicode/json-server#module

And if you need to customize more, you can also access router's lowdb instance using router.db.

Hope this helps :)

[hopkinson]

@typicode i tried pasted above code ,but i found that i failed to get data
in routes.json,
'/api/product/stocks_index/list': '/referenceList/:id'
I want '/api/product/stocks_index/list' this api‘s request value is {id:1},and want to turn '/referenceList/:id' into '/referenceList/1' but ,/api/product/stocks_index/list can not change such as/api/product/stocks_index/list?id=1` ..
Or,what can i solve this problem?

[vsharma2266]

Closing as this question is answered.

[appsparkler]

This is what worked for me:

Instead of writing the server.js file from scratch and executing it; I created a middleware file. The contents of the middleware file are from @typicode's response above:

// middleware-1.js
module.exports = function (req, res, next) {
  if (req.method === 'POST') {
    // Converts POST to GET and move payload to query params
    // This way it will make JSON Server that it's GET request
    req.method = 'GET'
    req.query = req.body
  }
  // Continue to JSON Server router
  next()
}

Next, this is in my json-server.json file:

{
    //...
    "middlewares": ["middleware-1.js"],
    //..
}

The db.json file is as usual with all the data, and finally, executed the code:

json-server db.json

Good Luck.

[mircolac]

@appsparkler thanks a lot for your answer, it helped me fixing a problem in the project i'm working at the moment.

Moreover, while writing the middleware and testing your solution, I discovered a weird behaviour when the query result cointained a field with the same name of a field contained in the POST original body.

I'll explain it better, using an example from the code I wrote

HTTP request

(variable's names are voluntarily changed)

this.http.post<OutputFormat>(EndpointUrl('URL'),
      {
        'foo': foo,
        'bar': bar,
        'baz': 'baz',
        'qux': 'qux'
    })
      .subscribe(
      res => {
        console.log("res is  ",res);
       ...

MIDDLEWARE

module.exports = (req, res, next) => {
...
                req.method ='GET';
                req.query = req.body
                next();
...
}

RESULT:
Everything works fine UNLESS the json at the endpoint contains a field that has the same label of the fields in the req.body ( 'foo', 'bar', 'baz' or 'qux' ).

example:

"endpointYouAskedFor": [
    {
      "foo": {...},
      "someOtherThing": {...}
}

In this case, the result will be an empty res object.
If there was no 'foo' field in the endpoint, everything would have been fine.

I hope this will be useful and spare some hours to someone :)

[appsparkler]

hi @mircolac

i'm not sure if this would work but another thing that we can include in the middleware is to make the req.body into an empty object before :

// ...
    req.query = req.body;
    delete req.body; //or null (if that works)
// ...

this might avoid the req.body reaching the json-server logic without missing out on the query...

[mircolac]

Hey @appsparkler
That was certainly worth a try, but unfortunately didn't fix the problem!

Thanks anyway :)

[leohxj]

@typicode
I use POST method to make some change, but want to get some response (not the insert resource).

Is there another way which not to make the method to 'get' ?

Thanks.

[leotm]

@leohxj Is there an issue with setting your method to get, like so?

server.post('/some/url', (req, res) => {
  req.method = 'GET'
  res.jsonp({ some: "response" })
})

As you can still POST to your server, .then use the response.

[m-e-conroy]

I needed to reroute the URL but resetting req.url wasn't working so I did the following.

const jsonServer = require('json-server');
const server = jsonServer.create();
const router = jsonServer.router('db.json');
const request = require('request');
const middlewares = jsonServer.defaults();

server.use(middlewares);
server.use(jsonServer.bodyParser);

server.post('/login',(req,res,next) => {
  // We don't care if we don't check the password we just want to receive a user back for testing
  let url = 'http://localhost:3000/user?login.username=' + req.body.username;
  request({url: url, json: true},(err, response, body) => {
    res.send(body);
  });
}); // post(/login)

server.use(router);

server.listen(3000, ()=>{
  console.log('http://localhost:3000 Running...');
});

[MickL]

It seems like the only way is write a middleware that changes requests from POST to GET:

server.use((req, res, next) => {
  if (req.method === 'POST') {
    req.method = 'GET';
  }
  next();
});

You can still have and react to POST requests if you do this BEFORE the middleware:

server.post('/addUser', (req, next) => {
  res.jsonp(myResponse);
});

server.use((req, res, next) => {
  if (req.method === 'POST') {
    req.method = 'GET';
  }
  next();
});