Checking end of email address

Hi,

I have a register form why i take an email address. I have validation running to check it is a valid email and there is something in the field but i only want a user to enter an email address which ends in .co.uk i have searched around but cannot find anything. Does anyone know how i would check to make sure the user has entered a .co.uk email address.

Cheers,
Adam

 

http://www.jsfiddle.net/dimitar/JGrBM/ - this is a proper, RFC compliant valid email test which will ALLOW all the example emails i have included.

i have also added a check to see if it's a .co.uk specifically.

(function() {
    // define string prototypes for later testing.
    var validEmailRegex = /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
  
    String.prototype.isEmail = function() {
        // returns true if a string is a valid email
        return this.match(validEmailRegex);
    };
    
    String.prototype.isUKEmail = function() {
        // returns true if a string contains .co.uk
        return this.toLowerCase().indexOf(".co.uk") === -1 ? false : true;
    }
        
    String.prototype.isValidUKEmail = function() {
        // returns true if a mail is valid and uk.
        return this.isEmail() && this.isUKEmail();
    }
})();
 
// example use

// data set
var data = [
    '"Abc\@def"@example.com',
    '"Fred Bloggs"@example.com',
    '"Joe\\Blow"@example.com',
    '"Abc@def"@example.com',
    'customer/department=shipping@example.com',
    '$A12345@example.com',
    'foo@copmpany.co.uk',
    '!def!xyz%abc@example.com',
    '_somename@example.com'
 ];


// analyze them all
var count = data.length, isUK;
while (count--) {
    if (!data[count].isEmail())
        document.write("INVALID: the email <strong>" + data[count] + "</strong> incorrectly reported as non-valid<br />");
    else {
        isUK = (data[count].isUKEmail()) ? 'UK' : 'foreign';
        document.write("OK: the email <strong>" + data[count] + "</strong> recognised correctly, " + isUK + "<br />");
    }
 };
 
// exmaple where it only checks for a valid uk email.
document.write("<br/><br/>");

count = data.length;
while (count--) {
    if (data[count].isValidUKEmail())
        document.write("UK email: <strong>" + data[count] + "</strong><br/>");
}
 

Code (javascript):

the reason for this is simple: read http://haacked.com/archive/2007/08/21/i-knew-how-to-validate-an-email-address-until-i.aspx

 

Will have to bookmark that one for future reference...

 

Thanks for that As my JS is very limited, i am just wondering how i would call this? Or better yet just call the check if it is .co.uk feature as i have all the other validation in place.

 

sure. basically, it's called prototyping. each js entity (element, number, array, string etc) has a prototype chain which defines methods available any member object with the same constructor will inherit. For example, Array may have .forEach, String may have .toLowerCase() etc - all stored in the prototype. hence you can do "THIS IS CAPS".toLowerCase() which will return the string in lowercase or [1,2,4].forEach(function(nn, nnn) { ... }); will loop through all array elements and pass them to the callback function.

we are adding a new method here to the string prototype. this means ANY string created can have this method applied to it (exactly like the .toLowerCase())

eg:

"foo@bar.co.uk".isValidUKEmail(); // returns true.

// practical example
var email = document.getElementById("email").value;

if (email.isValidUKEmail()) {
.... do something
}
else {
    alert("get a .co.uk email first!");
}

Code (javascript):

of course, you can also use a normal function:

var isUK_TLD = function(email) {
    return email.toLowerCase().indexOf(".co.uk") === -1 ? false : true;
};

alert(isUK_TLD("dimitar@foobar.co.uk")); // true

Code (javascript):