In this guide i want to show you the way of how to add "you bought this product before" notification to product pages if logged customer that currently browse website bought it. This modification will appear only for users that are logged - because only for that kind of users it is possible to check orders history. Whole modification will be based on template modifications only, features available by default in PrestaShop  classess allows to achieve that.

What we need to do?

Process requires several steps, each of them is very important to build such feature. Let's say that this is an algorithm to solve the problem:

1. Check if customer is logged in
2. If not - do nothing
3. If so - get all customer orders from database
4. for each of customer's order check if there is a product for which we want to dispaly such notification
5. if not - do nothing
6. f so - display notification "you bought this product before"

We want to put this notificaiton to product page above the add to cart button. Exactly as I show on image above. This requires modification of product.tpl file located in your theme directory only. We've got an algorithm to make it work properly. So, we can start the modification process.

Modification of product.pl file

Open product.tpl file that is located in your theme directory. Usually path to the file looks like themes/your-theme/product.tpl (where 'your-theme' is the directory of template that you currently use). Guide is based on default-bootstrap template but it will work in each available template.

Near the line 387 (or somewhere else if you use modified version of product.tpl) you should have a code like:

<div class="box-cart-bottom">
    <div{if (!$allow_oosp && $product->quantity <= 0) || !$product->available_for_order || (isset($restricted_country_mode) && $restricted_country_mode) || $PS_CATALOG_MODE} class="unvisible"{/if}>
        <p id="add_to_cart" class="buttons_bottom_block no-print">
            <button type="submit" name="Submit" class="exclusive">
                <span>{if $content_only && (isset($product->customization_required) && $product->customization_required)}{l s='Customize'}{else}{l s='Add to cart'}{/if}</span>
            </button>
        </p>
    </div>
    {if isset($HOOK_PRODUCT_ACTIONS) && $HOOK_PRODUCT_ACTIONS}{$HOOK_PRODUCT_ACTIONS}{/if}
</div>

Inside the main div: <div class="box-cart-bottom"> paste code below. Code is an algorithm that i mentioned before. It checks if customer is logged, if so - it gets all orders of currently logged customer and then - checks each order for product. If there is a product - modification will display information about that.

{assign var='context' value=Context::getContext()}
{assign var='product_bought' value='0'}
{if $context->customer->isLogged()==true}
        {foreach Order::getIdOrderProduct($context->customer->id, Tools::getValue('id_product')) AS $orders}
            {if isset($orders)}
                {if $orders !=0}
                    {assign var='product_bought' value='1'}
                {/if}
            {/if}
        {/foreach}
{/if}
{if $product_bought == 1}
    <div class="alert alert-info">{l s='You bought this product before'}
    </div>
{/if}

Full modified code of this product page section should look like:

<div class="box-cart-bottom">
    {assign var='context' value=Context::getContext()}
    {assign var='product_bought' value='0'}
    {if $context->customer->isLogged()==true}
            {foreach Order::getIdOrderProduct($context->customer->id, Tools::getValue('id_product')) AS $orders}
                {if isset($orders)}
                    {if $orders !=0}
                        {assign var='product_bought' value='1'}
                    {/if}
                {/if}
            {/foreach}
    {/if}
    {if $product_bought == 1}
        <div class="alert alert-info">{l s='You bought this product before'}
        </div>
    {/if}

    <div{if (!$allow_oosp && $product->quantity <= 0) || !$product->available_for_order || (isset($restricted_country_mode) && $restricted_country_mode) || $PS_CATALOG_MODE} class="unvisible"{/if}>
        <p id="add_to_cart" class="buttons_bottom_block no-print">
            <button type="submit" name="Submit" class="exclusive">
                <span>{if $content_only && (isset($product->customization_required) && $product->customization_required)}{l s='Customize'}{else}{l s='Add to cart'}{/if}</span>
            </button>
        </p>
    </div>
    {if isset($HOOK_PRODUCT_ACTIONS) && $HOOK_PRODUCT_ACTIONS}{$HOOK_PRODUCT_ACTIONS}{/if}
</div>

Of course you can put code to display notification anywhere on product page you want. Just move it to other section and save the changes.