Shipping and Tax [ 208 ] { if( $this->shippingCost > $rule['match_amount'] ) { $match = true; } } elseif( $match_operator == '<' ) { if( $this->shippingCost < $rule['match_amount'] ) { $match = true; } } If a rule match was found, we then take the rule into account. if( $match == true ) { // set the shipping cost based on the rule operator and // the rule amount $rule_operator = $rule['rule_operator']; if( $rule_operator == '=' ) { $this->shippingCost = $rule['rule_amount']; } elseif( $rule_operator == '+' ) { $this->shippingCost = $this->shippingCost + $rule['rule_amount']; } elseif( $rule_operator == '-' ) { $this->shippingCost = $this->shippingCost - $rule['rule_amount']; } elseif( $rule_operator == '*' ) { $this->shippingCost = $this->shippingCost * $rule['rule_amount']; } elseif( $rule_operator == '/' ) { $this->shippingCost = $this->shippingCost / $rule['rule_amount']; } } } If the product is based on the basket cost, we then do the same as before, except that the rule matching depends on the cost of the shopping basket. elseif( $rule['match_type'] == 'products' ) { // rule depends on the basket cost $match = false; $match_operator = $rule['match_operator']; // check to see our basket cost meets the rule if( $match_operator == '==' ) { if( $this->shippingCost == $rule['match_amount'] ) { $match = true; } } elseif( $match_operator == '<>' ) { if( $this->cost <> $rule['match_amount'] ) { $match = true; } } elseif( $match_operator == '>=' ) { if( $this->cost >= $rule['match_amount'] ) { $match = true; } } This material is copyright and is licensed for the sole use by jackie tracey on 23rd February 2010 953 Quincy Drive, , Brick, , 08724 Chapter 8 [ 209 ] elseif( $match_operator == '<=' ) { if( $this->cost <= $rule['match_amount'] ) { $match = true; } } elseif( $match_operator == '>' ) { if( $this->cost > $rule['match_amount'] ) { $match = true; } } elseif( $match_operator == '<' ) { if( $this->cost < $rule['match_amount'] ) { $match = true; } } if( $match == true ) { // set the shipping cost based on the rule operator // and the rule amount $rule_operator = $rule['rule_operator']; if( $rule_operator == '=' ) { $this->shippingCost = $rule['rule_amount']; } elseif( $rule_operator == '+' ) { $this->shippingCost = $this->shippingCost + $rule['rule_amount']; } elseif( $rule_operator == '-' ) { $this->shippingCost = $this->shippingCost - $rule['rule_amount']; } elseif( $rule_operator == '*' ) { $this->shippingCost = $this->shippingCost * $rule['rule_amount']; } elseif( $rule_operator == '/' ) { $this->shippingCost = $this->shippingCost / $rule['rule_amount']; } } } } } Tax There are three main ways to tackle tax costs in an e-commerce environment: We include tax in our product prices We assign tax codes to products to separately calculate and display tax costs We calculate tax based on the location of the buyer • • • This material is copyright and is licensed for the sole use by jackie tracey on 23rd February 2010 953 Quincy Drive, , Brick, , 08724 Shipping and Tax [ 210 ] The exact requirement for a particular store depends on the store itself and the laws applicable in that country or state. In some situations we can include the tax for a product in its price; it doesn't need to be displayed to the customer. In others, we may wish for tax to be shown and calculated for the customer, if they are able to reclaim this tax (for example UK/EU VAT), and in some states in the US different states have different taxes depending on the buyer or seller, where some customers may be taxed, others not, or the tax may be based on the state the seller resides in themselves. Most situations can be handled by associating products with tax calculations, so let's focus on that. However, we will also discuss how we may implement a location-based tax system, to charge tax depending on the customer's delivery or billing address. Separately calculating tax values We could either have: Tax included in a product price, and a tax rule calculating how much of the product's price should be tax Product costs stored without tax, and associated with their relevant tax calculations The main difference to the way tax calculations would need to work and the shipping costs is that tax costs actually need to be integrated before the basket; that is, the products themselves should incorporate tax costs. We will look at the second of these two options. This would require: Products to have a tax code associated with them A table of tax codes to be stored in our database, along with calculation details The tax codes (just a reference for the type of tax; for instance, at the time of writing in the UK we would have: zero-rated VAT—0%, standard rate VAT—15%, reduced rate VAT—5%, and different products may have different tax codes associated with them) would have a calculation value and operation associated with them, similar to our shipping rules, this allows the framework to easily add/subtract/divide/ multiply the product cost with the calculation value. • • • • This material is copyright and is licensed for the sole use by jackie tracey on 23rd February 2010 953 Quincy Drive, , Brick, , 08724 Chapter 8 [ 211 ] Field Type Description ID Integer, Primary Key, Auto Increment The ID for the tax code Tax_code Varchar Name of the tax code Calculation_value Double The value applied to the order cost Calculation_operation Enum The arithmetic operation applied to the order cost and the calculation value, to compute the tax. The following SQL represents this table: CREATE TABLE `tax_codes` ( `ID` INT NOT NULL AUTO_INCREMENT PRIMARY KEY, `tax_code` varchar(255) NOT NULL, `calculation_value` DOUBLE NOT NULL, `calculation_operation` ENUM( '+', '-', '*', '/', '=' ) NOT NULL, INDEX ( `tax_code` ) ) ENGINE = INNODB; Again, for example, UK standard rate VAT would have a value of 1.15, and an operation of multiply by. To create a truly exible tax system for an e-commerce system would involve a book of its own. The simplest methods that we have discussed are relatively straightforward to implement, especially because we have done some very similar work with our shipping methods. To think about: Location-based tax costs In some situations, we may have different taxes applicable depending on the locations of the buyers and sellers respective to one another. This may be something we would wish to implement. Advice from a tax professional is recommended to determine if this is required for a particular use or implementation of your framework in a particular store. A look at our basket nowat our basket now our basket now Now that we have implemented shipping costs to our store, our basket has some changes since we last looked at it: We have a row in the products table for the shipping costs The order total includes the shipping costs There is a drop-down list of shipping methods allowing customers to change the shipping method, which updates costs accordingly. • • • This material is copyright and is licensed for the sole use by jackie tracey on 23rd February 2010 953 Quincy Drive, , Brick, , 08724 Shipping and Tax [ 212 ] Here's a view of our new basket: Summary In this chapter, we discussed different ways to approach shipping costs and tax values for products within our e-commerce store. This included: Creating shipping methods Creating shipping rules to cap, reduce, wipe, or alter shipping costs based on the cost of a basket, or have the shipping cost otherwise calculated Setting shipping costs for each product based on the product and the shipping method Setting shipping costs for products based on weights and the shipping method How we would introduce tax costs to products Now that we have looked into shipping and tax in detail, we can look at discount codes, purchasable voucher codes, and referrals in the next chapter. • • • • • This material is copyright and is licensed for the sole use by jackie tracey on 23rd February 2010 953 Quincy Drive, , Brick, , 08724 . the time of writing in the UK we would have: zero-rated VAT—0%, standard rate VAT— 15% , reduced rate VAT 5% , and different products may have different tax codes associated with them) would. table: CREATE TABLE `tax_codes` ( `ID` INT NOT NULL AUTO_INCREMENT PRIMARY KEY, `tax_code` varchar( 255 ) NOT NULL, `calculation_value` DOUBLE NOT NULL, `calculation_operation` ENUM( '+',. example, UK standard rate VAT would have a value of 1. 15, and an operation of multiply by. To create a truly exible tax system for an e-commerce system would involve a book of its own. The