Express.js routing: optional splat param?
node.jsExpressnode.js Problem Overview
I have a route that looks like this:
app.all('/path/:namedParam/*splat?',function(req,res,next){
if(!req.params.length){
// do something when there is no splat
} else {
// do something with splat
}
});
however, this doesn't work - if I call path/foo/bar
it hits the route, but if I call path/foo
, it doesn't.
Is it possible to have an optional splat param, or do I have to use a regex to detect this?
Edit:
to be clearer, here are the requirements I'm trying to achieve:
- the first and second params are required
- the first param is static, the second is a named param.
- any number of optional additional params can be appended and still hit the route.
node.js Solutions
Solution 1 - node.js
This works for /path and /path/foo on express 4, note the *
before ?
.
router.get('/path/:id*?', function(req, res, next) {
res.render('page', { title: req.params.id });
});
Solution 2 - node.js
I just had the same problem and solved it. This is what I used:
app.get('path/:required/:optional*?', ...)
This should work for path/meow
, path/meow/voof
, path/meow/voof/moo/etc
...
It seems by dropping the /
between ?
and *
, the last /
becomes optional too while :optional?
remains optional.
Solution 3 - node.js
Will this do what you're after?
app.all('/path/:namedParam/:optionalParam?',function(req,res,next){
if(!req.params.optionalParam){
// do something when there is no optionalParam
} else {
// do something with optionalParam
}
});
More on Express' routing here, if you haven't looked: http://expressjs.com/guide/routing.html
Solution 4 - node.js
Suppose you have this url: /api/readFile/c:/a/a.txt
If you want req.params.path
to be c:
:
'/api/readFile/:path*
If you want req.params.path
to be c:/a/a.txt
:
'/api/readFile/:path([^/]*)'
Solution 5 - node.js
Here's the current way I'm solving this problem, it doesn't appear that express supports any number of splat params with an optional named param:
app.all(/\/path\/([^\/]+)\/?(.+)?/,function(req,res,next){
// Note: this is all hacked together because express does not appear to support optional splats.
var params = req.params[1] ? [req.params[1]] : [],
name = req.params[0];
if(!params.length){
// do something when there is no splat
} else {
// do something with splat
}
});
I'd love to have this use named params for readability and consistency - if another answer surfaces that allows this I'll accept it.
Solution 6 - node.js
The above solutions using optional doesn't work in Express 4. And I tried couple of ways using search patterns, but not working either. And then I found this method and seems fired for unlimited nested path, http://expressjs.com/api.html#router
// this will only be invoked if the path starts with /bar from the mount point
router.use('/bar', function(req, res, next) {
// ... maybe some additional /bar logging ...
// to get the url after bar, you can try
var filepath = req.originalUrl.replace(req.baseUrl, "");
next();
});
It's match all /bar, /bar/z, /bar/a/b/c etc. And after that, you can read req.originalUrl, since params are not filled, ex. you can try compare baseUrl and originalUrl to get the remaining path.
Solution 7 - node.js
I got around this problem by using a combination of a middleware that add trailing slashes to url and router.get('/bar/*?', ...
, which will pick up everything after /bar/
, and return undefined
if it is just /bar/
. If the visitor asked for /bar
, the express-slash
middleware will add a slash to the request and turns the request into /bar/
.