Field Validation

[alsaffar]

Hi there,

I want to make some validation for the email field in my form,

I want to make sure that the "@" character is exists and the "." is exists also and the email shouldn't start with a space,

[e-mail] // start with a space
namedomain.com // doesn't have a "@"
name@domaincom // doesn't have a "."

So, I want to avoid people keep on submitting invalid addresses.

How can I achieve this?

[tomhath]

In the book "Mastering Regular Expressions" Jeff Feidl presents some thoughts on validating an email address with a regular expression. I believe the expression he came up with was something like 60 lines long. A web search might be in order, this is not something to try at home...

[edspace]

You can put 50 regular expressions there and 50 substr statements but nothing is going to stop the user from putting a false email.

[e-mail] // with no space, with both @ and .

If u really need to get the correct email address than u have to force them to go through the process of activating their account from a unique link that they get by opening an email u send to them. Or maybe u can just send them a computer generated password that they can only get if they can look at the email account they filled in.

[alsaffar]

my target is to get my customer's attention that they're sending wrong emails by mistake, I'm not talking about sik people those who are really want to play around?

At least there's a small script that helps me avoiding that!

[ken_ip]

Many useful scripts on the net. e.g. www.hotscripts.com

[NiXXeD]

This little snippet should return 1 with a correct email address...

eregi("^{[a-z0-9-]+(\.[a-z0-9-]+)@[a-z0-9-]+(\.[a-z0-9-]+)$",} $email)

where $email is your user's entered email address...

It checks to make sure not just the @ but that everything is correct. You could have 2 .'s after the @ or several .'s before the @.... Anyway, hope this helps...

[[deleted]]

I would recomend you to use something like NiXXeD's suggestion but to trim the email to avoid acciden spaces whith just one more line:
$email = trim($email);

eregi("^{[a-z0-9-]+(\.[a-z0-9-]+)@[a-z0-9-]+(\.[a-z0-9-]+)$",} $email)

NiXXeD

[alsaffar]

I'm satisfied with this script I found, cause it gives the reason of the error, but I'm really intersted in using the trim function to avoid any space, where do I have to use it???

function isEmailAddr(email)
{
  var result = false
  var theStr = new String(email)
  var index = theStr.indexOf("@");
  if (index > 0)
  {
    var pindex = theStr.indexOf(".",index);
    if ((pindex > index+1) && (theStr.length > pindex+1))
	result = true;
  }
  return result;
}

function FormValidator(theForm)
{

  if (theForm.joinEmail.value == "")
  {
    alert("You must write something in the email field!");
    theForm.joinEmail.focus();
    return (false);
  }

  if (!isEmailAddr(theForm.joinEmail.value))
  {
    alert("Your Email should looks like: [email][e-mail][/email]");
    theForm.joinEmail.focus();
    return (false);
  }

  if (theForm.joinEmail.value.length < 3)
  {
    alert("Your email should have at least 3 characters");
    theForm.joinEmail.focus();
    return (false);
  }

  return (true);
}

and my html code is:

<FORM ACTION="Join.php" METHOD="POST" name="join" onsubmit="return FormValidator(this)">
<input type="text" name="joinEmail" size="23">
<INPUT TYPE="submit" VALUE="submit"></FORM>

[NiXXeD]

You would use the $email = trim($email); before you called your function that you found. This way, you get rid of the spaces before you check if it's a valid email. That script you have doesn't really give you much more error than mine would, with a little proper code. And saying the user has to have [e-mail] may not be correct, because for me at work, its [e-mail] (I work with wells fargo). The only thing I would say is wrong with the script you found is the isEmailAddr function. Let me rewrite it for you using the reg expression that I used before. It will return more correct email addresses I would assume...

function isEmailAddr($email){
    if(eregi("^[_a-z0-9-]+(\\.[_a-z0-9-]+)*@[a-z0-9-]+(\\.[a-z0-9-]+)*$", $email)){
        return 1;
    }else{
        return 0;
    }
}
//and just make sure that you call this next line before you use the above function
$email = trim($email);

Also, I noticed the script you found is javascript... Not that I am against using that for validation or anything, but if the user turned off javascript, they could put in a bad email address... So if I were you, I'd try to validate in php, since it cannot be avoided. Anyways, hope this helps...

[NiXXeD]

Oh and also if you like those error messages for the user, you can do something like this to generate the same error (I'm not sure if there is a better way)

function doValidate(){ //whatever vars
    $email = trim(addslashes(trim_tags($_POST["email"], ''))); //just for whatever's sake
    //but I do stress using the addslashes and trim_tags because a user can 
    //really mess up your page if you let them.
    if(isEmailAddr($email)){
        //do something
    }else{
        echo "<script> alert(\"Please enter a correct email address! (EX: [email][e-mail][/email])\"); </script>";
    }
    //validate whatever else
}