[FEATURE] Make Shipping methods be available based on cart conditions (…

…extcode#545)

Implemented the ability to configure conditions in typoscript setup to switch shipping methods
based on products in the cart. This allows e.g. for dynamic application of shipping methods,
ensuring that shipping method A (free) is used by default, and shipping method B (with actual
costs) is applied when physical products are detected in the cart.

Fixes: extcode#545

Classes/Domain/Model/Cart/Service.php

@@ -203,18 +203,33 @@ public function getFallBackId(): ?int
 
     public function isAvailable(): bool
     {
+        $return = true;
+        // keep available.from and available.until even though this is redundant to ...
         if (isset($this->config['available'])) {
-            $availableFrom = $this->config['available']['from'];
-            if (isset($availableFrom) && $this->cart->getGross() < (float)$availableFrom) {
+            $availableFrom = $this->config['available']['from'] ?? false;
+            if ($availableFrom && $this->cart->getGross() < (float)$availableFrom) {
                 return false;
             }
-            $availableUntil = $this->config['available']['until'];
-            if (isset($availableUntil) && $this->cart->getGross() > (float)$availableUntil) {
+            $availableUntil = $this->config['available']['until'] ?? false;
+            if ($availableUntil && $this->cart->getGross() > (float)$availableUntil) {
                 return false;
             }
         }
 
-        return true;
+        if (isset($this->config['available']) && is_array($this->config['available']) && isset($this->config['available']['_typoScriptNodeValue'])) {
+            $availableType = $this->config['available']['_typoScriptNodeValue'];
+
+            $conditionValue = $this->getConditionValueFromCart($availableType);
+
+            $return = false;
+            foreach ($this->config['available'] as $availableKey => $availableValue) {
+                if (is_array($availableValue) && ((float)$availableValue['value']  <= (float)$conditionValue)) {
+                    $return = (bool) ($availableValue['available'] ?? false);
+                }
+            }
+        }
+
+        return $return;
     }
 
     public function isFree(): bool

Documentation/Administrator/Configuration/ShippingMethods/FlexibleAvailabilityForShipping/Index.rst

@@ -0,0 +1,104 @@
+.. include:: ../../../../Includes.txt
+
+..  _shipping_method_flex_availablility:
+
+============================
+Flexible availability for shipping
+============================
+
+It can be a requirement that the shipping method availability should depend on
+the products in the shopping cart. For these cases the extension provides a default
+implementation (see `cart/Classes/Domain/Model/Cart/Service.php`) with
+configuration options very similar to
+ :ref:`Flexible prices for shipping <shipping_method_flex_price>`.
+The implementation can be adapted to own needs by using the `ServiceInterface`
+also described in :ref:`Flexible prices for shipping <shipping_method_flex_price>`.
+
+.. code-block:: typoscript
+   :caption: Can be set in e.g. EXT:sitepackage/Configuration/TypoScript/setup.typoscript
+
+   plugin.tx_cart {
+    shippings {
+        countries {
+            de {
+                preset = 1
+                options {
+                    1 {
+                        title = PDF/Email
+                        taxClassId = 1
+                        fallBackId = 2
+                        status = open
+                        free {
+                            from = 0
+                        }
+                        available = by_number_of_physical_products
+                        available {
+                            0 {
+                                value = 0
+                                available = 1
+                            }
+                            2 {
+                                value = 1
+                                available = 0
+                            }
+                        }
+                    }
+
+                    2 {
+                        title = Standard Delivery
+                        taxClassId = 1
+                        fallBackId = 1
+                        status = open
+                        extra = 99.00
+                        available = by_number_of_physical_products
+                        available {
+                            0 {
+                                value = 0
+                                available = 0
+                            }
+                            2 {
+                                value = 1
+                                available = 1
+                            }
+                        }
+                    }
+                }
+            }
+        }
+   }
+
+plugin.tx_cart.shipping.countries.de
+====================================
+.. confval:: options.<n>.available
+
+   :Type: string
+
+   ============================== ===========================================
+   Setting                        Explanation what is used for the comparison
+   ============================== ===========================================
+   by_price                       The total price of the shopping cart.
+   by_price_of_physical_products  The total price of physical products in the shopping cart (EXT:cart_products allows to define products as "virtual producs").
+   by_quantity                    The amount of physical(!) products. (This is a synonym for `by_number_of_physical_products`)
+   by_number_of_physical_products The amount of physical products
+   by_number_of_virtual_products  The amount of virtual products
+   by_number_of_all_products      The amount of all products
+   by_service_attribute_1_sum     The sum of the values of `Service Attribute 1` of all products in the cart.
+   by_service_attribute_1_max     The highest value of `Service Attribute 1` of all product in the cart.
+   by_service_attribute_2_sum     The sum of the values of `Service Attribute 2` of all products in the cart.
+   by_service_attribute_2_max     The highest value of `Service Attribute 2` of all product in the cart.
+   by_service_attribute_3_sum     The sum of the values of `Service Attribute 3` of all products in the cart.
+   by_service_attribute_3_max     The highest value of `Service Attribute 3` of all product in the cart.
+   ============================== ===========================================
+
+
+.. confval:: options.<n>.available.<m>.value
+
+   :Type: int
+
+   Defines the matching condition.
+
+.. confval:: options.<n>.available.<m>.available
+
+   :Type: float
+
+   Boolean value to define whether the shipping method is available.

Documentation/Administrator/Configuration/ShippingMethods/Index.rst

@@ -289,3 +289,4 @@ See :ref:`plugin.tx_cart.settings.showCartAction.showPartials.shippingMethodForm
    :titlesonly:
 
    FlexiblePricesForShipping/Index
+   FlexibleAvailabilityForShipping/Index