In this guide I want to show you how easily you can put Facebook Login module to the authentication page on your PrestaShop website. Of course - to use this guide you need my cheapest Facebook Login addon. On module configuration page please select option that says that you want to display Login button on "customer account" section. Then read the rest of the guide or alternatively watch the video.
Authentication.tpl - modifications
PrestaShop in default-bootstrap template doesnt have any hook on authentication page. This means that we can't insert some modules to the account creation box, or to customer log in form. But of course we can easily modify the authentication page - after that we will be able to put modules there. So, please open authentication.tpl file - you can find it in your theme directory. If you use default-bootstrap theme path to this file looks like: /themes/default-bootstrap/authentication.tpl.
Find there code
<button class="btn btn-default button button-medium exclusive" type="submit" id="SubmitCreate" name="SubmitCreate"> <span> <i class="icon-user left"></i> {l s='Create an account'} </span> </button>
and right below add this tiny snippet that will load the Facebook Login buttons and also other like Google login etc.
<div style="clear:both; display:block; margin-top:15px;"> {Hook::exec('displayCustomerAccountForm')} </div>
Highlighted line is the most important thing. This line means that PrestaShop will load here modules associated with displayCustomerAccountForm hook. Modules that i mentioned (Facebook login and Google login) support this position. After modifications to authentication.tpl file please save changes. In some cases please also clear shop cache and recompile the theme. Your shop will display social login buttons on your PrestaShop authentication page now, exactly the same as I show on the video based on PrestaShop 1.6 and default-bootstrap theme (it works the same in other templates too!)