app.get(/\/example\/(.+)/, (req, res) => {
const url=req.params[0]
})
The URL "/example/test.com?a=1" matches the given regex route, but the capture group does not capture the query string. I know I can obtain the query params using req.query.
But the capture group should have captured the entire test.com?a=1, but it only captures test.com.
I don't understand why this is happening. Am I missing something?
Route strings, whether regex or simple, don't capture query strings (after the ?). You use req.query for that, as you know
They capture parts of the URL path. Therefore, if your url were
https://example.com/a/1
you could write a regex path to capture the 1.
Related
i want a route url to be like this
http://localhost:3000/api/uploader/:path
The moment is that path can be '' => http://localhost:3000/uploader/ or string containing slashes like this aaa/bbb/ccc => http://localhost:3000/api/uploader/aaa/bbb/ccc
I wrote something like this for empty case
http://localhost:3000/api/uploader/:path?
How can I write regex for many slashes, so the req.params === /aaa/bbb/ccc ?
I'll assume you're using express and answer below.
What you're looking for is the * wildcard.
Try this and check it out:
router.get('/uploader/?*', function(req, res, next) {
res.send(req.originalUrl);
});
You should see the request url back to you so you can confirm.
Edit: I'm changing the wildcard with the question mark to accept baseUrl too***
Tell me if anything else, but that should do it. I hope this helps you out.
I'm trying to create an endpoint that contains an actual path that I extract and use as a parameter. For instance, in the following path:
/myapi/function/this/is/the/path
I want to match "/myapi/function/" to my function, and pass the parameter "this/is/the/path" as the parameter to that function.
If I try this it obviously doesn't work because it only matches the first element of the path:
app.get("/myapi/function/:mypath")
If I try this it works, but it doesn't show up in req.params, I instead have to parse req.path which is messy because the logic has to know about the whole path, not just the parameter:
app.get("/myapi/function/*")
In addition, the use of wildcard routing seems to be discouraged as bad practice. I'm not sure I understand what alternative the linked article is trying to suggest, and I'm not using the query as part of a database call nor am I uploading any information.
What's the proper way to do this?
You can use wildcard
app.get("/myapi/function/*")
And then get your path
req.params[0]
// Example
//
// For the route "/myapi/function/this/is/my/path"
// You will get output "this/is/my/path"
If I have two REST endpoints:
app.get('/something/:id', ...handlers);
app.get('/something/else', ...handlers);
And I send a request to http://host:port/something/else
Is there a way to make Express router execute the endpoint with absolute path first (/something/else) before executing the one that matches the query params (/something/:id)?
I understand that I can reverse the order of invocation and specify the endpoint with query params last. But logically speaking, absolute path should take priority over query params and I believe that's the default behaviour for Koa.js
Just put the more specific route first and the wildcard route second. Routes are matched in order and the first one that matches handles the request and the others are not then processed. So, put the more specific route for /something/else before the /something/:id and you will see the /something/else route work properly when that's the URL.
// put wildcard route last and more specific route definitions first
// routes are matched in the order they are defined
app.get('/something/else', ...handlers);
app.get('/something/:id', ...handlers);
This does raise the question why you have designed this potential conflict into your URL scheme in the first place. You've essentially overloaded the id namespace and have reserved at least one id value for your own use. This can be managed by careful ordering of the route definitions, but it would generally be better if you didn't have this conflict in your URL design in the first place.
Is there a way to make Express router execute the endpoint with absolute path first ('/something/else') before executing the one that matches the query params ('/something/:id')?
Yes, define the more specific route first.
I understand that I can reverse the order of invocation and specify the endpoint with query params last. But logically speaking, absolute path should take priority over query params and I believe that's the default behaviour for Koa.js
You asked about Express. It matches routes in the order you've defined them. It doesn't try to guess which route it "thinks" you want to match first. It lets you define that exactly via the order of your route definitions.
I don't know Koa.js well, but there is this in the doc for Koa2: Middleware is now always run in the order declared by .use() (or .get(), etc.), which matches Express 4 API.
There are no specific route matching rules for express.js to match the routes.It goes and try to match every registered route with incoming request path and calls route handlers for all matched paths. Thus the following code will work.
app.get('/something/:id', (req, res, next) => {
console.log(`Calling with param ${req.params.id}`);
next(); // if you remove next from here it will not call the rest of the handlers
});
app.get('/something/else', (req, res, next) => {
console.log(`Calling with else`);
next();
});
Output:
Thus the only way to make sure the routes match exactly, define routes in their specific order.
app.get('/something/else', ...handlers);
app.get('/something/:id', ...handlers);
I want to query the yelp api, and have the following route:
app.get("/yelp/term/:term/location/:location", yelp.listPlaces)
When I make a GET request to
http://localhost:3000/yelp?term=food&location=austin,
I get the error
Cannot GET /yelp?term=food&location=austin
What am I doing wrong?
Have you tried calling it like this?
http://localhost:30000/yelp/term/food/location/austin
The URL you need to call usually looks pretty much like the route, you could also change it to:
/yelp/:location/:term
To make it a little prettier:
http://localhost:30000/yelp/austin/food
In the requested url http://localhost:3000/yelp?term=food&location=austin
base url/address is localhost:3000
route used for matching is /yelp
querystring url-encoded data is ?term=food&location=austin i.e. data is everything after ?
Query strings are not considered when peforming these matches, for example "GET /" would match the following route, as would "GET /?name=tobi".
So you should either :
use app.get("/yelp") and extract the term and location from req.query like req.query.term
use app.get("/yelp/term/:term/location/:location") but modify the url accordingly as luto described.
I want to add to #luto's answer. There is no need to define query string parameters in the route. For instance the route /a will handle the request for /a?q=value.
The url parameters is a shortcut to define all the matches for a pattern of route so the route /a/:b will match
/a/b
/a/c
/a/anything
it wont match
/a/b/something or /a
Express 4.18.1 update:
using app.get("/yelp/term/:term/location/:location"), your query string can be yelp/term/food/location/austin
So your request url will look like this:
http://localhost:3000/yelp/term/food/location/austin
I'm attempting to implement permalinks, in the form /2013/02/16/title-with-hyphens. I'd like to use route parameters. If I try the following route:
app.get('/:href', function(req, res) { });
...then I get a 404, presumably because Express is only looking for one parameter, and thinks that there are 4.
I can work around it with /:y/:m/:d/:t, but this forces my permalinks to be of that form permanently.
How do I get route parameters to include slashes?
It seems that app.get("/:href(*)", ...) works fine (at least in Express 4). You will get your parameter value in req.params.href.
It will also be fired by / route, which is probably not what you want. You can avoid it by setting app.get('/', ...) elsewhere in your app or explicitly checking for an empty string.
Use a regular expression instead of a string.
app.get(/^\/(.+)/, function(req, res) {
var href = req.params[0]; // regexp's numbered capture group
});
Note that you cannot use the string syntax (app.get('/:href(.+)')) because Express only allows a small subset of regular expressions in route strings, and it uses those regular expressions as a conditional check for that particular component of the route. It does not capture the matched content in the conditional, nor does it allow you to match across components (parts of the URL separated by slashes).
For example:
app.get('/:compa([0-9])/:compb([a-z]/')
This route only matches if the first component (compa) is a single digit, and the second component (compb) is a single letter a-z.
'/:href(.+)' says "match the first component only if the content is anything", which doesn't make much sense; that's the default behavior anyway. Additionally, if you examine the source, you'll see that Express is actually forcing the dot in that conditional to be literal.
For example, app.get('/:href(.+)') actually compiles into:
/^\/(?:(\.+))\/?$/i
Notice that your . was escaped, so this route will only match one or more periods.
You can do this with regex routing
app.get('/:href(\d+\/\d+\/\d+\/*)', function(req, res) { });
I don't know if the regex is right, but you get the idea
EDIT:
I don't think the above works, but this does
app.get(/^\/(\d+)\/(\d+)\/(\d+)\/(.*)/, function(req, res) { });
Going to http://localhost:3000/2012/08/05/hello-i-must-be yeilds req.params = [ '2012', '08', '05', 'hello-i-must-be' ]
You can use this if your parameters has include slashes in it
app.get('/:href(*)', function(req, res) { ... })
It works for me. In my case, I used parameters like ABC1/12345/6789(10).
Hopefully this useful.