How to hide an email addres with Captcha in Joomla 3.3.x?

Question

Is there a way to hide an email address included in an article with Captcha? I want something like a link saying "Show Email Address" and make the user solve a Captcha and if solved correctly show the email.

For example in Google Projects you can see the people involved and when you click on an email address you need to solve a Captcha before displaying it: https://code.google.com/u/112265612467218200107/

Answer 1

They're using Google reCAPTCHA Mailhide. If you want to use it once, you can simply get the HTML code from their generator. Just input your email address (e.g. [email protected]), and you'll get a code like this to paste wherever you want:

<a href="http://www.google.com/recaptcha/mailhide/d?k=01kg8W1efAQFDkyYznE3EjIA==&amp;c=VfE7N2ER5ulELye31Q05M7izax7SCQfEOEhIvght0TQ="
onclick="window.open('http://www.google.com/recaptcha/mailhide/d?k\07501kg8W1efAQFDkyYznE3EjIA\75\75\46c\75VfE7N2ER5ulELye31Q05M7izax7SCQfEOEhIvght0TQ\075',
'', 'toolbar=0,scrollbars=0,location=0,statusbar=0,menubar=0,resizable=0,
width=500,height=300'); return false;" title="Reveal this e-mail address">
i...</a>@example.com

If you need the replace all emails, you have to create a plugin, using the Google API available for reCAPTCHA. The existing plugin "plg_emailcloak" (plugins\content\emailcloak) is a good start, just create a new plugin based on this.

Answer 2

I have a simple suggestion, which applies mainly in the case you want to do this for a single article and a single email address. It won't handle any email address appearances in articles.

You can create a simple form, containing a captcha and submit button (e.g. rsforms). Setup the thank you message to display the email address, and then in your article create a modal link for the form. When clicked it will popup the form with the captcha, which after successful submission will reveal the email.