I'm stuck with a stupid problem:
How to work with optional locale parameter?
That's what I mean:
For example, I have frontpage and contacts, here is routes:
app.get('/', frontpage.get);
app.get('/contacts', contacts.get);
Now I'm trying to add localization to my site
app.all('/:lang?*', language.all); -> detect and set locale
app.get('/:lang?', frontpage.get);
app.get('/:lang?/contacts', contacts.get);
The only problem is when I don't use lang-parameter in URL:
mysite.com/contacts
because Express uses 'contacts' as a language parameter.
(+ I don't like this copy-pasted :lang?)
I think, I just took the wrong way.
How to use locale parameter from URL in Express?
PS: I dont want to use subdomains de.mysite.com or querystring mysite.com?lang=de. I want exactly this variant mysite.com/de
Most modules use Accept-Language so I can't find any that use the path like this that you might be able to use. So you'll need to define your own middleware that initializes before everything else. Express's Router doesn't really help for your usecase.
app.use(function(req, res, next){
var match = req.url.match(/^\/([A-Z]{2})([\/\?].*)?$/i);
if (match){
req.lang = match[1];
req.url = match[2] || '/';
}
next();
});
Now you can use req.lang in your routes or other middleware to configure your translation logic and since we have rewritten the URL, later logic will not know that there is a language param.
Related
When I make a GET request with route parameters in express with mongoose like the following code, I sometimes see that the browser tries to load some unexpected files such as favicon.ico, robots.txt, humans.txt, sitemap.xml, ads.txt, etc., and 404 error shows up in the browser console.
app.get("/:userId", ...);
By refering to this Q&A, I figured out that if I don't use the route parameters right after the root route like the following code, it doesn't happen.
app.get("/user/:userId", ...);
In the same Q&A, however, there seem to be another way that uses req.url to ignore those unexpected files to be loaded, but it isn't explained in detail.
How do you do that?
All that's meant in that other answer is that you could examine req.url in your route handler and make sure it is not a known special name. In this specific case, it's probably simpler to use req.params.userId instead of req.url, but you could also use req.url in the same way.
const specials = new Set(["favicon.ico", "robots.txt", "humans.txt", "sitemap.xml", "ads.txt"]);
app.get("/:userId", (res, res, next) => {
// if it's a special URL, then skip it here
if (specials.has(req.params.userId)) {
next();
return;
}
// process your route here
});
Personally, I wouldn't recommend this solution because it presupposes a perfect knowledge of all possible special filenames. I don't use a top level wildcards ever because they ruin the ability to use your server for anything else.
I have a question about routing and urls in general. My question regards parameters or queries in the url before the domain itself. For example:
http://param.example.com/
I ask this question because I am using ExpressJS and you only define your routes after the domain itself like:
http://example.com/yourRoute
Which would be added to the end of the url. What I want is to be able to store parameters inbefore the domain itself.
Thank you in advance!
FYI
I do know how to use parameters and queries, I just don't know how I would go about to insert them before the domain.
You can create an if statement which can look at the sub-domain through the express req.headers.host variable which contains the domain of the request. For example:
-- google.com/anything/another
req.headers.host => "google.com"
-- docs.google.com/anything/
req.headers.host => "docs.google.com"
So working off this in your route you can call Next() if the request doesn't match the form you want.
router.get('/', function(req, res, next) {
if (req.headers.host == "sub.google.com") {
//Code for res goes here
} else {
//Moves on to next route option b/c it didn't match
next();
}
});
This can be expanded on a lot! Including the fact that many packages have been created to accomplish this (eg. subdomain) Disclaimer you may need to account for the use of www. with some urls.
Maybe this vhost middleware is useful for your situation: https://github.com/expressjs/vhost#using-with-connect-for-user-subdomains
Otherwise a similar approach would work: create a middleware function that parses the url and stores the extracted value in an attribute of the request.
So I would use something like
router.get('/myRoute', function(req, res,next) {
req.headers.host == ":param.localhost.com"
//rest of code
}
I think I understand what you are saying, but I will do some testing and some further reading upon the headers of my request.
EDIT: Right now it seems like an unnecessary hassle to continue with this because I am also working with React-router at the moment. So for the time being I am just going to use my params after the /.
I thank you for your time and your answers. Have a nice day!
Currently working on a nodejs express server. And I think I'm doing something in an inefficient way. I have this route set up
app.get('/admin/scanTable/:table', require('./AUTH/ValidateCookie.js'), require('./AUTH/verifyURI.js'), require('./ROUTES/render.js'));
so the url here is /admin/scanTable/:table. I know I can get the whole path with req.route.path. I know I can use req.params.table to collect the table parameter. But the thing I don't know how to get is the first part of the path, in this case admin. I know I could get it by looking for / symbols and slicing the parts I need from req.route.path but I figure with all these functionalities that express has, there's probably a better way of doing this.
I know I can use
app.use('/admin', function(req, res, next){console.log('admin called'), next();});
to check if this part of the uri was called to then execute some code, but it's not really what I want. Can anyone tell me the easiest way to find this? At the moment I have attached a variable to req.string whenever app.use('/admin' is called it will attach the string admin to this variable which then makes it available to all other functions that are called. But even this feels like overkill. Any Ideas?
Both options you describe are valid and straightforward:
Using a regex on req.route.path, a la /^admin/.test(req.route.path)
Using middleware to attach a new property to the req object, a la
app.use('/admin', function(req, res, next){ req.adminRoute = true; next();});
or if you need to do this same thing for all admin routes, do it once:
var adminRouter = require("express").Router();
router.get("/scanTable/:table", require("./AUTH/ValidateCookie.js"), ...);
router.use(function (req, res, next) { req.adminRoute = true; next(); }));
app.use("/admin", adminRouter);
I don't know the context of your application, but I would consider using the last example, and putting anything else that's specific to /admin routes as middleware also.
Hellow I have code in my app.js, looking like that:
app.use('/someurl', require('./middleware/somemodule'));
-app.use instead app.all
and module looks like:
if(process.env.BLALAL === undefined){
throw "Error: process.env.BLALAL === undefined";
}
module.exports = function(req, res, next){
...
}
is it a bad practice ?
As said on the express api reference:
app.VERB(path, [callback...], callback)
The app.VERB() methods provide the routing functionality in Express,
where VERB is one of the HTTP verbs, such as app.post().
app.use([path], function)
Use the given middleware function, with optional mount path,
defaulting to "/".
The "mount" path is stripped and is not visible to the middleware
function. The main effect of this feature is that mounted middleware
may operate without code changes regardless of its "prefix" pathname.
IMO
The functionality may be nearly the same, but there is an underlying semantic meaning. The routes itself should be set through the app.VERB api, while any middleware should be set through the app.use api.
Normally middlewares modify the request or response objects, or inject functionality from other module that may answer the request, or not.
connect.static is a good example. It could be really an app or an HttpServer by itself, but is injected as middleware on other app object.
I personally don't like require inside other commands then var bla = require('bla');, it makes code much worse readable in my opinion and you did not get anything in return.
I am not sure what was your intention, but if your code depends on environment variable, it is better to throw immediately than later when your route is called. So app.use is better then app.all. But I don't understand why aren't you simply test your condition inside app.js and why you hide it in somemodule.
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.