Trying to Validate URL Using JavaScript

I want to validate a URL and display message. Below is my code:

$("#pageUrl").keydown(function(){
        $(".status").show();
        var url = $("#pageUrl").val();

        if(isValidURL(url)){

        $.ajax({
            type: "POST",
            url: "demo.php",
            data: "pageUrl="+ url,
            success: function(msg){
                if(msg == 1 ){
                    $(".status").html('<img src="images/success.gif"/><span><strong>SiteID:</strong>12345678901234456</span>');
                }else{
                    $(".status").html('<img src="images/failure.gif"/>');
                }
            }
            });

            }else{

                    $(".status").html('<img src="images/failure.gif"/>');
            }

    });


function isValidURL(url){
    var RegExp = /(ftp|http|https):\/\/(\w+:{0,1}\w*@)?(\S+)(:[0-9]+)?(\/|\/([\w#!:.?+=&%@!\-\/]))?/;

    if(RegExp.test(url)){
        return true;
    }else{
        return false;
    }
}

My problem is now it will show an error message even when entering a proper URL until it matches regular expression, and it return true even if the URL is something like "http://wwww".

I appreciate your suggestions.

Solution 1:

Someone mentioned the Jquery Validation plugin, seems overkill if you just want to validate the url, here is the line of regex from the plugin:

return this.optional(element) || /^(https?|ftp):\/\/(((([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(%[\da-f]{2})|[!\$&'\(\)\*\+,;=]|:)*@)?(((\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])\.(\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])\.(\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])\.(\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5]))|((([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])))\.)+(([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])))\.?)(:\d*)?)(\/((([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(%[\da-f]{2})|[!\$&'\(\)\*\+,;=]|:|@)+(\/(([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(%[\da-f]{2})|[!\$&'\(\)\*\+,;=]|:|@)*)*)?)?(\?((([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(%[\da-f]{2})|[!\$&'\(\)\*\+,;=]|:|@)|[\uE000-\uF8FF]|\/|\?)*)?(\#((([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(%[\da-f]{2})|[!\$&'\(\)\*\+,;=]|:|@)|\/|\?)*)?$/i.test(value);

Here is where they got it from: http://projects.scottsplayground.com/iri/

Pointed out by @nhahtdh This has been updated to:

        // Copyright (c) 2010-2013 Diego Perini, MIT licensed
        // https://gist.github.com/dperini/729294
        // see also https://mathiasbynens.be/demo/url-regex
        // modified to allow protocol-relative URLs
        return this.optional( element ) || /^(?:(?:(?:https?|ftp):)?\/\/)(?:\S+(?::\S*)?@)?(?:(?!(?:10|127)(?:\.\d{1,3}){3})(?!(?:169\.254|192\.168)(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))|(?:(?:[a-z\u00a1-\uffff0-9]-*)*[a-z\u00a1-\uffff0-9]+)(?:\.(?:[a-z\u00a1-\uffff0-9]-*)*[a-z\u00a1-\uffff0-9]+)*(?:\.(?:[a-z\u00a1-\uffff]{2,})).?)(?::\d{2,5})?(?:[/?#]\S*)?$/i.test( value );

source: https://github.com/jzaefferer/jquery-validation/blob/c1db10a34c0847c28a5bd30e3ee1117e137ca834/src/core.js#L1349

Solution 2:

It's not practical to parse URLs using regex. A full implementation of the RFC1738 rules would result in an enormously long regex (assuming it's even possible). Certainly your current expression fails many valid URLs, and passes invalid ones.

Instead:

a. use a proper URL parser that actually follows the real rules. (I don't know of one for JavaScript; it would probably be overkill. You could do it on the server side though). Or,

b. just trim away any leading or trailing spaces, then check it has one of your preferred schemes on the front (typically ‘http://’ or ‘https://’), and leave it at that. Or,

c. attempt to use the URL and see what lies at the end, for example by sending it am HTTP HEAD request from the server-side. If you get a 404 or connection error, it's probably wrong.

it return true even if url is something like "http://wwww".

Well, that is indeed a perfectly valid URL.

If you want to check whether a hostname such as ‘wwww’ actually exists, you have no choice but to look it up in the DNS. Again, this would be server-side code.

Solution 3:

function validateURL(textval) {
    var urlregex = /^(https?|ftp):\/\/([a-zA-Z0-9.-]+(:[a-zA-Z0-9.&%$-]+)*@)*((25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]?)(\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9]?[0-9])){3}|([a-zA-Z0-9-]+\.)*[a-zA-Z0-9-]+\.(com|edu|gov|int|mil|net|org|biz|arpa|info|name|pro|aero|coop|museum|[a-zA-Z]{2}))(:[0-9]+)*(\/($|[a-zA-Z0-9.,?'\\+&%$#=~_-]+))*$/;
    return urlregex.test(textval);
}

This can return true for URLs like:

http://stackoverflow.com/questions/1303872/url-validation-using-javascript

or:

http://regexlib.com/DisplayPatterns.aspx?cattabindex=1&categoryId=2

Solution 4:

I written also a URL validation function base on rfc1738 and rfc3986 to check http and https urls. I try to hold this modular, so it can be better maintained and adapted to own requirements.

The RegExp in one line is show at end of this post.

The RegExp accept HTTP and HTTPS URLs with some international domain or IPv4 number. IPv6 is not supported yet.

window.isValidURL = (function() {// wrapped in self calling function to prevent global pollution

     //URL pattern based on rfc1738 and rfc3986
    var rg_pctEncoded = "%[0-9a-fA-F]{2}";
    var rg_protocol = "(http|https):\\/\\/";

    var rg_userinfo = "([a-zA-Z0-9$\\-_.+!*'(),;:&=]|" + rg_pctEncoded + ")+" + "@";

    var rg_decOctet = "(25[0-5]|2[0-4][0-9]|[0-1][0-9][0-9]|[1-9][0-9]|[0-9])"; // 0-255
    var rg_ipv4address = "(" + rg_decOctet + "(\\." + rg_decOctet + "){3}" + ")";
    var rg_hostname = "([a-zA-Z0-9\\-\\u00C0-\\u017F]+\\.)+([a-zA-Z]{2,})";
    var rg_port = "[0-9]+";

    var rg_hostport = "(" + rg_ipv4address + "|localhost|" + rg_hostname + ")(:" + rg_port + ")?";

    // chars sets
    // safe           = "$" | "-" | "_" | "." | "+"
    // extra          = "!" | "*" | "'" | "(" | ")" | ","
    // hsegment       = *[ alpha | digit | safe | extra | ";" | ":" | "@" | "&" | "=" | escape ]
    var rg_pchar = "a-zA-Z0-9$\\-_.+!*'(),;:@&=";
    var rg_segment = "([" + rg_pchar + "]|" + rg_pctEncoded + ")*";

    var rg_path = rg_segment + "(\\/" + rg_segment + ")*";
    var rg_query = "\\?" + "([" + rg_pchar + "/?]|" + rg_pctEncoded + ")*";
    var rg_fragment = "\\#" + "([" + rg_pchar + "/?]|" + rg_pctEncoded + ")*";

    var rgHttpUrl = new RegExp( 
        "^"
        + rg_protocol
        + "(" + rg_userinfo + ")?"
        + rg_hostport
        + "(\\/"
        + "(" + rg_path + ")?"
        + "(" + rg_query + ")?"
        + "(" + rg_fragment + ")?"
        + ")?"
        + "$"
    );

    // export public function
    return function (url) {
        if (rgHttpUrl.test(url)) {
            return true;
        } else {
            return false;
        }
    };
})();

RegExp in one line:

var rg = /^(http|https):\/\/(([a-zA-Z0-9$\-_.+!*'(),;:&=]|%[0-9a-fA-F]{2})+@)?(((25[0-5]|2[0-4][0-9]|[0-1][0-9][0-9]|[1-9][0-9]|[0-9])(\.(25[0-5]|2[0-4][0-9]|[0-1][0-9][0-9]|[1-9][0-9]|[0-9])){3})|localhost|([a-zA-Z0-9\-\u00C0-\u017F]+\.)+([a-zA-Z]{2,}))(:[0-9]+)?(\/(([a-zA-Z0-9$\-_.+!*'(),;:@&=]|%[0-9a-fA-F]{2})*(\/([a-zA-Z0-9$\-_.+!*'(),;:@&=]|%[0-9a-fA-F]{2})*)*)?(\?([a-zA-Z0-9$\-_.+!*'(),;:@&=\/?]|%[0-9a-fA-F]{2})*)?(\#([a-zA-Z0-9$\-_.+!*'(),;:@&=\/?]|%[0-9a-fA-F]{2})*)?)?$/;

Trying to Validate URL Using JavaScript

Solution 1:

Solution 2:

Solution 3:

Solution 4:

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