How to add "Show Less" option to category description pages

[PTID]

Currently, we are running an instance of Prestashop v1.6. Once the category description gets longer than 350 characters you have a "More" option popup which reveals the full category description, but then you have no option to collapse this back to the short description unless you refresh the page.  We would ideally love to see a "Less" or "Show Less" appear when it is being viewed as the full description.

 

How could we modify the category.tpl file or implement something to achieve this option?

 

Currently, the code in the category.tpl shows the following for the "More" option:

 

 {if Tools::strlen($category->description) > 350}


                                <div id="category_description_short">{$description_short}</div>


                                <div id="category_description_full" class="unvisible">{$category->description}</div>


                                <a href="{$link->getCategoryLink($category->id_category, $category->link_rewrite)|escape:'html':'UTF-8'}" class="lnk_more">{l s='More'}</a>

Edited October 27, 2015 by PTID (see edit history)