jQuery Validation Error Return a Link - php

Question

I am using jquery Validation Plugin. I have an email field. If the email is in use, I want the validation plugin to give an error with a link to the client's page.
IE: if I input the email john#bobo.com and he is client #312 with the name John Mark, I want my error to be:
John Mark is using that email.
Preferably I would like to have my external file just echo the entire error and have the jQuery Validation plugin to display that full error. If not, I would like to have both the client name and client id to be returned and then be able to output the error message with a link.
jQuery Code:
$().ready(function() {
// Validate the form
$('#sign-up_area').validate({
rules: {
firstName: "required",
lastName: "required",
email_address: {
email: true,
remote: {
url: "includes/databasecheck.php",
type: "post",
success: function(html){
$("#email").html(html);
}
}
}
},
messages: {
firstName: "First Name Required",
lastName: "Last Name Required",
email_address: {
email: "Email address need to be valid.",
//remote: jQuery.format("{0} is taken")
},
}
});
});
Form:
<form action="#" method="post" id="sign-up_area">
<h2 id="reference" name="reference" class="heading-reference">Client</h2>
<fieldset>
<label for="firstName">First Name:</label>
<input type="text" name="firstName" id="firstName" value="">
</fieldset>
<fieldset>
<label for="lastName">Last Name:</label>
<input type="text" name="lastName" id="lastName" value="">
</fieldset>
<fieldset>
<label for="email_address">Email:</label>
<input type="text" name="email_address" id="email_address" value="">
<div id="email" class="error"></div>
</fieldset>
<fieldset class="form-actions">
<input type="submit" value="Submit">
</fieldset></form>
databasecheck.php
<?php
include_once("config.php"); // database connection
if(isset($_POST['email_address'])) {
$stmt = $mysqli->prepare("SELECT client_id, CONCAT(firstName, ' ', lastName) AS whole_name FROM client WHERE email = ? LIMIT 1");
$stmt->bind_param('s', $_POST['email_address']);
$stmt->execute(); // Execute the prepared query.
$stmt->store_result();
$stmt->bind_result($client_id, $whole_name);
$stmt->fetch();
echo ''.$whole_name.' is using that email.';
}
?>

Answer 1

As per the documentation for the Remote Method, the error message can just be whatever you return from your server.
The response is evaluated as JSON and must be true for valid elements, and can be any false, undefined or null for invalid elements, using the default message; or a string, eg. "That name is already taken, try peter123 instead" to display as the error message.
As long as you construct the custom error message on the server as valid JSON, your code is fine with the message for remote removed...
rules: {
firstName: "required",
lastName: "required",
email_address: {
email: true,
remote: {
url: "includes/databasecheck.php",
type: "post",
success: function(html){
$("#email").html(html);
}
}
}
},
messages: {
firstName: "First Name Required",
lastName: "Last Name Required",
email_address: {
email: "Email address need to be valid."
// The remote error message is coming from the server automatically
// remote: jQuery.format("{0} is taken") // <- REMOVE
},
}
Try this PHP:
if(isset($_POST['email_address'])) {
$stmt = $mysqli->prepare("SELECT client_id, CONCAT(firstName, ' ', lastName) AS whole_name FROM client WHERE email = ? LIMIT 1");
$stmt->bind_param('s', $_POST['email_address']);
$stmt->execute(); // Execute the prepared query.
$stmt->store_result();
$stmt->bind_result($client_id, $whole_name);
$stmt->fetch();
$response = ''.$whole_name.' is using that email.';
echo json_encode($response); // failed validation- show the message
} else {
echo "true"; // passed validation- no message
}
See: http://php.net/manual/en/function.json-encode.php