Express param functions
Express param pre-condition functions.
Works with Express 2.5.x
$ npm install express-params
Simply invoke the
extend() method on an express
HTTPServer to add this functionality.
var express =params =app = express;params;
Regular expressions can be used to extract data from pathname
segments as shown below. When matched
the capture groups of the
Another use-case for regular expression parameters is to validate input, for example here we may want to route via numeric id, followed by a route which will accept other values.
Functions with arity < 3 (less than three parameters) are not
considered to be middleware-style, and are useful for type coercion.
For example below we pass
Number, a function which accepts a string coercing to a number, alternatively we could use
parseInt here. The result of
req.params.id will then be a number, however if we were to issue
GET /user/tj the result would be
NaN, which is considered invalid by
next('route') is called, ignoring the route.
The following default logic is applied to test if a return value is invalid:
return null == val|| false === val|| 'number' == typeof val && ;
It's safe to throw in these functions, as connect's router wraps them in a try/catch block, and they are not asynchronous.
First install dependencies:
$ npm install -g
Then run the tests:
$ make test
(The MIT License)
Copyright (c) 2011 TJ Holowaychuk <email@example.com>
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
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