// when you adding a product on order, you can set a specific price

classes/Product.php

@@ -2191,12 +2191,13 @@ class ProductCore extends ObjectModel
 	* @param variable_reference $specificPriceOutput.
 	* 	If a specific price applies regarding the previous parameters, this variable is filled with the corresponding SpecificPrice object
 	* @param boolean $with_ecotax insert ecotax in price output.
+	* @param bool $flush_cache set to true in order to flush getPriceStatic cache for these parameters
 	* @return float Product price
 	*/
 	public static function getPriceStatic($id_product, $usetax = true, $id_product_attribute = null, $decimals = 6, $divisor = null,
 		$only_reduc = false, $usereduc = true, $quantity = 1, $force_associated_tax = false, $id_customer = null, $id_cart = null,
 		$id_address = null, &$specific_price_output = null, $with_ecotax = true, $use_group_reduction = true, Context $context = null,
-		$use_customer_price = true)
+		$use_customer_price = true, $flush_cache = false)
 	{
 		if (!$context)
 			$context = Context::getContext();
@@ -2234,6 +2235,10 @@ class ProductCore extends ObjectModel
 				$condition = ' AND `id_product_attribute` = '.(int)$id_product_attribute;
 			}
 
+			// Flush cache
+			if (isset(self::$_cart_quantity[$cache_name]) && $flush_cache)
+				unset(self::$_cart_quantity[$cache_name]);
+
 			if (!isset(self::$_cart_quantity[$cache_name]) || self::$_cart_quantity[$cache_name] != (int)$quantity)
 			{
 				self::$_cart_quantity[$cache_name] = Db::getInstance(_PS_USE_SQL_SLAVE_)->getValue('
@@ -2305,7 +2310,8 @@ class ProductCore extends ObjectModel
 			$specific_price_output,
 			$use_group_reduction,
 			$id_customer,
-			$use_customer_price
+			$use_customer_price,
+			$flush_cache
 		);
 	}
 
@@ -2327,12 +2333,12 @@ class ProductCore extends ObjectModel
 	* @param boolean $with_ecotax insert ecotax in price output.
 	* @param variable_reference $specific_price_output
 	* 	If a specific price applies regarding the previous parameters, this variable is filled with the corresponding SpecificPrice object
-	*
+	* @param bool $flush_cache set to true in order to flush getPriceStatic cache for these parameters
 	* @return float Product price
 	**/
 	public static function priceCalculation($id_shop, $id_product, $id_product_attribute, $id_country, $id_state, $zipcode, $id_currency,
 		$id_group, $quantity, $use_tax, $decimals, $only_reduc, $use_reduc, $with_ecotax, &$specific_price, $use_group_reduction,
-		$id_customer = 0, $use_customer_price = true)
+		$id_customer = 0, $use_customer_price = true, $flush_cache = false)
 	{
 		if (!$use_customer_price)
 			$id_customer = 0;
@@ -2358,11 +2364,17 @@ class ProductCore extends ObjectModel
 			$id_customer
 		);
 
+		// Flush cache
+		if (isset(self::$_prices[$cache_id]) && $flush_cache)
+			unset(self::$_prices[$cache_id]);
+
 		if (isset(self::$_prices[$cache_id]))
 			return self::$_prices[$cache_id];
 
 		// fetch price & attribute price
 		$cache_id_2 = $id_product.'-'.$id_product_attribute;
+		if (isset(self::$_pricesLevel2[$cache_id_2]) && $flush_cache)
+			unset(self::$_pricesLevel2[$cache_id_2]);
 		if (!isset(self::$_pricesLevel2[$cache_id_2]))
 		{
 			$sql = new DbQuery();

classes/SpecificPrice.php

@@ -75,6 +75,8 @@ class SpecificPriceCore extends ObjectModel
 	{
 		if (parent::add($autodate, $nullValues))
 		{
+			// Flush cache when we adding a new specific price
+			self::$_specificPriceCache = array();
 			// Set cache of feature detachable to true
 			Configuration::updateGlobalValue('PS_SPECIFIC_PRICE_FEATURE_ACTIVE', '1');
 			return true;
@@ -82,10 +84,21 @@ class SpecificPriceCore extends ObjectModel
 		return false;
 	}
 
+	public function update($null_values = false)
+	{
+		if (parent::update($null_values))
+		{
+			// Flush cache when we updating a new specific price
+			self::$_specificPriceCache = array();
+		}
+	}
+
 	public function delete()
 	{
 		if (parent::delete())
 		{
+			// Flush cache when we deletind a new specific price
+			self::$_specificPriceCache = array();
 			// Refresh cache of feature detachable
 			Configuration::updateGlobalValue('PS_SPECIFIC_PRICE_FEATURE_ACTIVE', self::isCurrentlyUsed($this->def['table']));
 			return true;
@@ -223,7 +236,7 @@ class SpecificPriceCore extends ObjectModel
 			SELECT *,
 					'.self::_getScoreQuery($id_product, $id_shop, $id_currency, $id_country, $id_group, $id_customer).'
 			FROM `'._DB_PREFIX_.'specific_price`
-			WHERE   
+			WHERE
 					`id_product` IN(0, '.(int)$id_product.') AND
 					'.(!$all_combinations ? '`id_product_attribute` IN(0, '.(int)$id_product_attribute.') AND ' : '').'
 					`id_shop` IN(0, '.(int)$id_shop.') AND
@@ -268,7 +281,7 @@ class SpecificPriceCore extends ObjectModel
 			SELECT *,
 					'.self::_getScoreQuery($id_product, $id_shop, $id_currency, $id_country, $id_group, $id_customer).'
 			FROM `'._DB_PREFIX_.'specific_price`
-			WHERE	
+			WHERE
 					`id_product` IN(0, '.(int)$id_product.') AND
 					`id_product_attribute` IN(0, '.(int)$id_product_attribute.') AND
 					`id_shop` IN(0, '.(int)$id_shop.') AND

controllers/admin/AdminOrdersController.php

@@ -1219,21 +1219,45 @@ class AdminOrdersControllerCore extends AdminController
 		$this->context->cart = $cart;
 		$this->context->customer = new Customer($order->id_customer);
 
-		// Add product to cart
-		$cart->updateQty($product_informations['product_quantity'], $product->id, isset($combination) ? $combination->id : null, false, 'up', new Shop($cart->id_shop));
-
 		$use_taxes = ($order->getTaxCalculationMethod() == PS_TAX_INC);
 
 		$initial_prodcut_price_tax_incl = Product::getPriceStatic($product->id, $use_taxes, isset($combination) ? $combination->id : null, 2, null, false, true, 1,
 			false, $order->id_customer, $cart->id, $order->{Configuration::get('PS_TAX_ADDRESS_TYPE')});
 
-		if ($product_informations['product_price_tax_incl'] < $initial_prodcut_price_tax_incl)
+		// Creating specific price if needed
+		if ($product_informations['product_price_tax_incl'] != $initial_prodcut_price_tax_incl)
 		{
-			$reduction_tax_incl = $initial_prodcut_price_tax_incl - $product_informations['product_price_tax_incl'];
+			$specific_price = new SpecificPrice();
-
+			$specific_price->id_shop = 0;
-			// TODO Use Specific price !!!
+			$specific_price->id_group_shop = 0;
+			$specific_price->id_currency = 0;
+			$specific_price->id_country = 0;
+			$specific_price->id_group = 0;
+			$specific_price->id_customer = $order->id_customer;
+			$specific_price->id_product = $product->id;
+			if (isset($combination))
+				$specific_price->id_product_attribute = $combination->id;
+			else
+				$specific_price->id_product_attribute = 0;
+			$specific_price->price = $product_informations['product_price_tax_excl'];
+			$specific_price->from_quantity = 1;
+			$specific_price->reduction = 0;
+			$specific_price->reduction_type = 'amount';
+			$specific_price->from = '0000-00-00 00:00:00';
+			$specific_price->to = '0000-00-00 00:00:00';
+			$specific_price->add();
 		}
 
+		// Flush cache
+		// @TODO clean the following line used only in order to clean cache of getPriceStatic method
+		$specific_price_output = null;
+		Product::getPriceStatic($product->id, $use_taxes, isset($combination) ? $combination->id : null, 2, null, false, true, 1,
+			false, $order->id_customer, $cart->id, $order->{Configuration::get('PS_TAX_ADDRESS_TYPE')}, $specific_price_output, true, true, null,
+			true, true);
+
+		// Add product to cart
+		$cart->updateQty($product_informations['product_quantity'], $product->id, isset($combination) ? $combination->id : null, false, 'up', new Shop($cart->id_shop));
+
 		// If order is valid, we can create a new invoice or edit an existing invoice
 		if ($order->hasInvoice())
 		{
@@ -1340,6 +1364,10 @@ class AdminOrdersControllerCore extends AdminController
 		// Save changes of order
 		$order->update();
 
+		// Delete specific price if exists
+		if (isset($specific_price))
+			$specific_price->delete();
+
 		$products = $this->getProducts($order);
 		// Get the last product
 		$product = $products[max(array_keys($products))];

js/admin_order.js

@@ -370,7 +370,8 @@ function init()
 			$('#add_product_product_stock').css('font-weight', 'normal').css('color', 'black').css('font-size', '1em');;
 	});
 
-	$('#submitAddProduct').click(function() {
+	$('#submitAddProduct').click(function(e) {
+		e.preventDefault();
 		var go = true;
 
 		if ($('input#add_product_product_id').val() == 0)