URI validation functions

Synopsis

Common url validation methods

    var validUrl = require('valid-url');

    if (validUrl.isUri(suspect)){
        console.log('Looks like an URI');
    } else {
        console.log('Not a URI');
    }

Replicates the functionality of Richard Sonnen sonnen@richardsonnen.com perl module : http://search.cpan.org/~sonnen/Data-Validate-URI-0.01/lib/Data/Validate/URI.pm full code here into a nodejs module. Translated practically line by line from perl. It passes all the original tests.

Description

(copied from original perl module)

This module collects common URI validation routines to make input validation, and untainting easier and more readable. All functions return an untainted value if the test passes, and undef if it fails. This means that you should always check for a defined status explicitly. Don't assume the return will be true. The value to test is always the first (and often only) argument. There are a number of other URI validation modules out there as well (see below.) This one focuses on being fast, lightweight, and relatively 'real-world'. i.e. it's good if you want to check user input, and don't need to parse out the URI/URL into chunks. Right now the module focuses on HTTP URIs, since they're arguably the most common. If you have a specialized scheme you'd like to have supported, let me know.

Installation

    npm install valid-url

Methods

/*
 * @Function isUri(value)
 *
 * @Synopsis  is the value a well-formed uri?
 * @Description  
        Returns the untainted URI if the test value appears to be well-formed.  Note that
        you may really want one of the more practical methods like is_http_uri or is_https_uri,
        since the URI standard (RFC 3986) allows a lot of things you probably don't want.
 * @Arguments 
 *   value  The potential URI to test.
 *
 * @Returns The untainted RFC 3986 URI on success, undefined on failure.
 * @Notes 
        This function does not make any attempt to check whether the URI is accessible
        or 'makes sense' in any meaningful way.  It just checks that it is formatted
        correctly.
 *
 */


/*
 * @Function isHttpUri(value)
 * @Synopsis   is the value a well-formed HTTP uri?
 * @Description  
        Specialized version of isUri() that only likes http:// urls.  As a result, it can
        also do a much more thorough job validating.  Also, unlike isUri() it is more
        concerned with only allowing real-world URIs through.  Things like relative
        hostnames are allowed by the standards, but probably aren't wise.  Conversely,
        null paths aren't allowed per RFC 2616 (should be '/' instead), but are allowed
        by this function.

        This function only works for fully-qualified URIs.  /bob.html won't work.  
        See RFC 3986 for the appropriate method to turn a relative URI into an absolute 
        one given its context.

        Returns the untainted URI if the test value appears to be well-formed.

        Note that you probably want to either call this in combo with is_https_uri(). i.e.

        if(isHttpUri(uri) || isHttpsUri(uri)) console.log('Good');

        or use the convenience method isWebUri which is equivalent.

 * @Arguments 
 *   value  The potential URI to test.
 *
 * @Returns The untainted RFC 3986 URI on success, undefined on failure.
 * @Notes 
        This function does not make any attempt to check whether the URI is accessible
        or 'makes sense' in any meaningful way.  It just checks that it is formatted
        correctly.
 */



/*
 * @Function isHttpsUri(value)
 * @Synopsis   is the value a well-formed HTTPS uri?
 * @Description  
        See is_http_uri() for details.  This version only likes the https URI scheme.
        Otherwise it's identical to is_http_uri()
 * @Arguments 
 *   value  The potential URI to test.
 *
 * @Returns The untainted RFC 3986 URI on success, undefined on failure.
 * @Notes 
        This function does not make any attempt to check whether the URI is accessible
        or 'makes sense' in any meaningful way.  It just checks that it is formatted
        correctly.
 */


 /*
 * @Function isWebUri(value)
 * @Synopsis   is the value a well-formed HTTP or HTTPS uri?
 * @Description  
        This is just a convenience method that combines isHttpUri and isHttpsUri
        to accept most common real-world URLs.
 * @Arguments 
 *   value  The potential URI to test.
 *
 * @Returns The untainted RFC 3986 URI on success, undefined on failure.
 * @Notes 
        This function does not make any attempt to check whether the URI is accessible
        or 'makes sense' in any meaningful way.  It just checks that it is formatted
        correctly.
 */

See also

RFC 3986, RFC 3966, RFC 4694, RFC 4759, RFC 4904