Please note: This hack has been updated for simpleContact Pro 2.01. You can download the latest version from the support page, or if you prefer to stick with 2.0 for the time being, just substitute $err for $errors in the code below. If you have any questions you are welcome to contact me.
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A small but vocal amount of users have asked for CAPTCHA support in simpleContact Pro.
I must say, I am not a fan of CAPTCHAs. I consider them to be inadequate from a usability and accessibility point of view and decent server-side validation can stop most spam. I use my own applications on my websites and receive practically no spam. I'm not too inflexible though to deny user's requests if they can be catered for by a straightforward hack, so here is my solution to CAPTCHA support.
Please note: As I indicated in my definition of a hack, this post doesn't indicate my intention to build a CAPTCHA into a general release.
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reCAPTCHA is one of the better CAPTCHAs out there. It provides an audio alternative and also provides a useful service by helping to digitise books. I will use reCAPTCHA for this hack.
First, you must visit http://recaptcha.net and sign up for a free account. You can choose your own username and password and enter the domain (or domains) that you want to use reCAPTCHA on. You will be provided with a private key and a public key. You will need both of these to implement this hack.
1) Download reCAPTCHA PHP library
Download the reCAPTCHA PHP library and upload it to your sc_admin/include folder.
2) Modify contact form validation
Open sc_admin/include/contact.php
Add the following code from line 9:
include_once($include_directory."/recaptchalib.php");
$publickey = "YOUR-PUBLIC-KEY-HERE";
$privatekey = "YOUR-PRIVATE-KEY-HERE";
Add the following code from line 143 (on one line):
$resp = recaptcha_check_answer($privatekey,$_SERVER["REMOTE_ADDR"],
$_POST["recaptcha_challenge_field"],$_POST["recaptcha_response_field"]);
Add this code onto the next line:
if (!$resp->is_valid) { $err["recaptcha"] = "reCAPTCHA entered incorrectly"; }
3) Modify contact form
Open contact.php
Find the line that says:
<?php showForm(); ?>
Add this code from the next line:
<?php
print recaptcha_get_html($publickey);
if (array_key_exists("recaptcha",$err)) {
printf("<p class=\"err\"><em>%s</em></p>",$err["recaptcha"]);
}
?>
If you view your contact form you should now have a working reCAPTCHA before the submit button.
