Imagine I have the following incoming request with query parameters
https://api.myawesomeapi.com/v1/facebook/group_app_install_hook?hub.mode=subscribe&hub.challenge=1409653872&hub.verify_token=myToken
then I have my express function as below to handle the incoming request above
static async appInstallOnGroupHookHandler(req, res) {
let hubChallenge = req.query["hub.challenge"]; //This is always undefined
console.log(`Hub Challenge ${hubChallenge}`);
let verificationToken = req.query["hub.verify_token"];
console.log(`Hub Verification Token=${verificationToken}`);
return res.status(200).send(hubChallenge ?? 'success');
}
When I tried accessing the hub.challenge query parameter using
let hubChallenge = req.query["hub.challenge"];
hubChallenge keeps coming back as undefined.
Is there a better way to access query parameters that has the dot character in them?
Thanks
Related
I am working on building a blog API for a practice project, but am using the data from an external API. (There is no authorization required, I am using the JSON data at permission of the developer)
The idea is that the user can enter multiple topic parameters into my API. Then, I make individual requests to the external API for the requested info.
For each topic query, I would like to:
Get the appropriate data from the external API based on the params entered (using a GET request to the URL)
Add the response data to my own array that will be displayed at the end.
Check if each object already exists in the array (to avoid duplicates).
res.send the array.
My main problem I think has to do with understanding the scope and also promises in Axios. I have tried to read up on the concept of promise based requests but I can't seem to understand how to apply this to my code.
I know my code is an overall mess, but if anybody could explain how I can extract the data from the Axios function, I think it could help me get the ball rolling again.
Sorry if this is a super low-level or obvious question - I am self-taught and am still very much a newbie!~ (my code is a pretty big mess right now haha)
Here is a screenshot of the bit of code I need to fix:
router.get('/:tagQuery', function(req, res){
const tagString = req.params.tagQuery;
const tagArray = tagString.split(',');
router.get('/:tag', function(req, res){
const tagString = req.params.tag;
const tagArray = queryString.split(',');
const displayPosts = tagArray.map(function(topic){
const baseUrl = "https://info.io/api/blog/posts";
return axios
.get(baseUrl, {
params: {
tag: tag
}
})
.then(function(response) {
const responseData = response.data.posts;
if (tag === (tagArray[0])){
const responseData = response.data.posts;
displayPosts.push(responseData);
} else {
responseData.forEach(function(post){
// I will write function to check if post already exists in responseData array. Else, add to array
}); // End if/then
})
.catch(function(err) {
console.log(err.message);
}); // End Axios
}); // End Map Function
res.send(displayPosts);
});
Node.js is a single thread non-blocking, and according to your code you will respond with the result before you fetching the data.
you are using .map which will fetch n queries.
use Promise.all to fetch all the requests || Promise.allsettled.
after that inside the .then of Promise.all || promise.allsettled, map your result.
after that respond with the mapped data to the user
router.get('/:tag', function (req, res) {
const tagString = req.params.tag;
const tagArray = queryString.split(',');
const baseUrl = "https://info.io/api/blog/posts";
const topicsPromises=tagArray.map((tobic)=>{
return axios
.get(baseUrl, {
params: {
tag: tag
}
})
});
Promise.all(topicsPromises).then(topicsArr=>{
//all the data have been fetched successfully
// loop through the array and handle your business logic for each topic
//send the required data to the user using res.send()
}).catch(err=>{
// error while fetching the data
});
});
your code will be something like this.
note: read first in promise.all and how it is working.
I am trying to hit the URL http://localhost:3000/analyze/imageurl=https://www.google.com/ from my browser.
However, due to the presence of //, it does not correctly hit the URL, and gives me an error message, Cannot GET /analyze/imageurl=https://www.google.com/
If I get rid of the backquotes as follows, http://localhost:3000/analyze/imageurl=httpswww.google.com/, it does work correctly.
My backend API looks like this
app.get('/analyze/:imageurl', function (req, res) {
console.log('printing image url:' + req.params.imageurl);
}
Is there a way I can pass in the imageurl with backquotes as a query parameter?
You need to encode your URL before pass it on query string, using encodeURIComponent. For example:
var urlParam = encodeURIComponent('https://www.google.com/');
console.log(urlParam); // https%3A%2F%2Fwww.google.com%2F
var url = 'http://localhost:3000/analyze/' + urlParam;
console.log(url); // http://localhost:3000/analyze/https%3A%2F%2Fwww.google.com%2F
// Decode it in API handler
console.log(decodeURIComponent(urlParam)); // https://www.google.com/
encodeURIComponent
One approach could be to use Express' req.query in your route. It would look something like this:
// Client makes a request to server
fetch('http://localhost:3000/analyze?imageurl=https://google.com')
// You are able to receive the value of specified parameter
// from req.query.<your_parameter>
app.get('/analyze', (req, res, next) => {
res.json(req.query.imageurl)
})
I want to access the query parameter in nock reply callback.
The request object that is exposed contains the path that has them as a string. But I would like to access them as a map so that I will not have to deal with parsing the string
const scope = nock('http://www.google.com')
.get('/cat-poems')
.reply(function(uri, requestBody) {
console.log('path:', this.req.path)
console.log('headers:', this.req.headers)
// ...
})
I would expect the query params to be a separate map that I can access
Does anyone know of a way to achieve this?
The value of this.req inside a reply function is an instance of a ClientRequest that has been slightly modified.
Unfortunately for your use case, ClientRequest does not provide an easy way to access just the query params. But you do have access to the full path, from which you can parse the query params out.
const nock = require('nock')
const http = require('http')
const url = require('url')
const scope = nock('http://www.google.com')
.get('/cat-poems')
.query(true)
.reply(function(uri, requestBody) {
const parsed = new url.URL(this.req.path, 'http://example.com')
console.log('query params:', parsed.searchParams)
return [200, 'OK']
})
const req = http.get('http://www.google.com/cat-poems?page=12')
// output >> query params: URLSearchParams { 'page' => '12' }
The object being logged is a URLSearchParams instance.
Using the URL constructor is the preferred method over url.parse now, so I've used that for the example. Keep in mind that URL won't parse relative paths alone, it requires an origin, but since you don't care about the host in the end it can be a dummy value (hence the use of "example.com").
Нello! I am looking to call a function which has been passed to an expressRouter.post(...) call.
This expressRouter.post(...) call is occurring in a file which I am unable to modify. The code has already been distributed to many clients and there is no procedure for me to modify their versions of the file. While I have no ability to update this file for remote clients, other developers are able to. I therefore face the issue of this POST endpoint's behaviour changing in the future.
I am also dealing with performance concerns. This POST endpoint expects req.body to be a parsed JSON object, and that JSON object can be excessively large.
My goal is to write a GET endpoint which internally activates this POST endpoint. The GET endpoint will need to call the POST endpoint with a very large JSON value, which has had URL query params inserted into it. The GET's functionality should always mirror the POST's functionality, including if the POST's functionality is updated in the future. For this reason I cannot copy/paste the POST's logic. Note also that the JSON format will never change.
I understand that the issue of calling an expressjs endpoint internally has conventionally been solved by either 1) extracting the router function into an accessible scope, or 2) generating an HTTP request to localhost.
Unfortunately in my case neither of these options are viable:
I can't move the function into an accessible scope as I can't modify the source, nor can I copy-paste the function as the original version may change
Avoiding the HTTP request is a high priority due to performance considerations. The HTTP request will require serializing+deserializing an excessively large JSON body, re-visiting a number of authentication middlewares (which require waiting for further HTTP requests + database queries to complete), etc
Here is my (contrived) POST endpoint:
expressRouter.post('/my/post/endpoint', (req, res) => {
if (!req.body.hasOwnProperty('val'))
return res.status(400).send('Missing "val"');
return res.status(200).send(`Your val: ${req.body.val}`);
});
If I make a POST request to localhost:<port>/my/post/endpoint I get the expected error or response based on whether I included "val" in the JSON body.
Now, I want to have exactly the same functionality available, but via GET, and with "val" supplied in the URL instead of in any JSON body. I have attempted the following:
expressRouter.get('/my/get/endpoint/:val', (req, res) => {
// Make it seem as if "val" occurred inside the JSON body
let fakeReq = {
body: {
val: req.params.val
}
};
// Now call the POST endpoint
// Pass the fake request, and the real response
// This should enable the POST endpoint to write data to the
// response, and it will seem like THIS endpoint wrote to the
// response.
manuallyCallExpressEndpoint(expressRouter, 'POST', '/my/post/endpoint', fakeReq, res);
});
Unfortunately I don't know how to implement manuallyCallExpressEndpoint.
Is there a solution to this problem which excludes both extracting the function into an accessible scope, and generating an HTTP request?
This seems possible, but it may make more sense to modify req and pass it, rather than create a whole new fakeReq object. The thing which enables this looks to be the router.handle(req, res, next) function. I'm not sure this is the smartest way to go about this, but it will certainly avoid the large overhead of a separate http request!
app.get('/my/get/endpoint/:val', (req, res) => {
// Modify `req`, don't create a whole new `fakeReq`
req.body = {
val: req.params.val
};
manuallyCallExpressEndpoint(app, 'POST', '/my/post/endpoint', req, res);
});
let manuallyCallExpressEndpoint = (router, method, url, req, res) => {
req.method = method;
req.url = url;
router.handle(req, res, () => {});
};
How about a simple middleware?
function checkVal(req, res, next) {
const val = req.params.val || req.body.val
if (!val) {
return res.status(400).send('Missing "val"');
}
return res.status(200).send(`Your val: ${val}`);
}
app.get('/my/get/endpoint/:val', checkVal)
app.post('/my/post/endpoint', checkVal)
This code isn't tested but gives you rough idea on how you can have the same code run in both places.
The checkVal function serves as a Express handler, with request, response and next. It checks for params first then the body.
I need a way to parse my JSONP object on server side to save it, due to cross domain origin issue I have shifted my way of communication from JSON to JSONP but not finding any suitable way to parse JSONP on server side to save it to the database.
Following is the Model,
define(['backbone'],function(Backbone){
'use strict';
return Backbone.Model.extend({
url:"http://crossdomain:9847/page",
defaults: {
type:'text',
position:0,
align:'left',
text:{"en":""},
color:"#000",
weight:'normal',
size:"14px",
font:"Verdana",
pageid:'askdkasdkgaskdgks'
},
idAttribute:'_id',
sync: function(method, collections, options) {
options.dataType = "jsonp";
return Backbone.sync(method, collections, options);
}
});
});
Express Server,
var express = require('/root/node_modules/express');
var page = require('./routes/page.js');
var app = express();
app.configure(function () {
app.use(express.json());
app.use(express.urlencoded());
app.set("jsonp callback", true);
})
app.get('/page', page.updatePage);
app.listen(9847);
exports.updatePage = function(req, res) {
console.log(req.query);
// Here how I can parse the req is my problem
// so I can save object to database?
}
URL is generating like,
http://crossdomain:9847/page?callback=jQuery203010156283635587138_1384408493698&{%22text%22:{%22en%22:%22Text%22},%22type%22:%22text%22,%22position%22:0,%22align%22:%22left%22,%22color%22:%22#000%22,%22weight%22:%22normal%22,%22size%22:%2214px%22,%22font%22:%22Verdana%22,%22pageid%22:%22askdkasdkgaskdgks%22}&_=1384408493700
and I am able to receive,
{ callback: 'jQuery203010156283635587138_1384408493698',
'{"text":{"en":"Text"},"type":"text","position":0,"align":"left","color":"': '' }
Now how can I parse this ? I can get callback from callback parameter, but how to get actual data ?
You can't parse the result because it's not valid JSON. Your problem is probably in this line:
app.set("jsonp callback", true);
This is where you set the JSONP callback variable, for example changing it from the default of callback to instead be callbackVariable.
Just comment out that line, and the JSONP you get back will hopefully be parseable. Or, you might also have to fix how Backbone is constructing the JSONP URL. If you instead used a URL like http://crossdomain:9847/page?callback=jQuery203010156283635587138_1384408493698&type=text&position=0&align=left&color=%23000&weight=normal&size=14px&font=Verdana&pageid=askdkasdkgaskdgks I believe it would work. Backbone seems to be adding additional encoding into the values in the URL, which makes parsing harder.
Finally, if you need help easily picking specific values out of a (valid) JSON string that has been parsed into a Javascript object, take a look at the many useful function in lodash.