Adjustments Refactoring

A talk that goes into the reasons why we refactored Spree's adjustments system.

Transcript

1. View Slide

2. View Slide

3. View Slide

4. View Slide

5. View Slide

6. View Slide

7. Adjusting
   Adjustments
   Ryan Bigg
   

   View Slide

8. Orders
   

   View Slide

9. View Slide

10. 1. Retain order-wide
    adjustments
    "We screwed up. Have $20 off
    your whole order."
    

    View Slide

11. 2. Discounts + Credits
    "Use 10off to get 10%
    off this weekend!"
    "We screwed up. Have $20 off
    your whole order."
    

    View Slide

12. 3. Discounts for specific customers
    15% off for .edu customers!
    5% off for members!
    

    View Slide

13. 4. Shipping taxation
    Shipping as a service.
    

    View Slide

14. 5. Refund specific items
    $3.63 GST included
    10% GST
    "How much tax did this item incur?"
    

    View Slide

15. 6. Freeze order adjustments
    

    View Slide

16. 7. Refund VAT outside of EU
    

    View Slide

17. 8. Allow multiple discounts
    per order
    "Can I combine a free shipping promotion and
    
    a 10% off promotion?"
    "You can't!"
    

    View Slide

18. 9. Robust test suite
    ...........................................
    ...........................................
    ...........................................
    ...........................................
    ...........................................
    ...........................................
    ...........................................
    

    View Slide

19. Events
    and
    Notifications
    

    View Slide

20. fire_event('spree.cart.add')
    

    View Slide

21. 1.Find all Spree::Activator instances
    with that event name

    2. Activate them
    

    View Slide

22. #4270
    

    View Slide

23. Events
    and
    Notifications
    

    View Slide

24. A. Avoid excessive calculations
    B. Avoid multiple adjustments per line item
    C. Not overly complicate things
    Ground Rules
    

    View Slide

25. A. Avoid excessive calculations
    B. Avoid multiple adjustments per line item
    C. Not overly complicate things
    Ground Rules
    

    View Slide

26. 86,082
    lines
    

    View Slide

27. A. Avoid excessive calculations
    B. Avoid multiple adjustments per line item
    C. Not overly complicate things
    Ground Rules
    

    View Slide

28. A. Avoid excessive calculations
    B. Avoid multiple adjustments per line item
    Ground Rules
    

    View Slide

29. http://www.ohloh.net/p/magento
    

    View Slide

30. View Slide

31. View Slide

32. Sales Tax
    (it's complicated)
    

    View Slide

33. Sales Tax
    (it's super complicated)
    

    View Slide

34. New York Sales Tax = ?????
    

    View Slide

35. "Clothing and footwear
    under $110 are exempt
    from New York City and
    NY State Sales Tax.
    !
    Purchases above $110
    are subject to a 4.5% NYC
    Sales Tax and a 4% NY
    State Sales Tax."
    http://www.nyc.gov/html/dof/html/business/nys_sales_tax.shtml
    

    View Slide

36. New York Sales Tax = 0%
    

    View Slide

37. http://www.irishtimes.com/blogs/generationemigration/files/2011/11/australian_flag_3.jpg
    10% Goods and Services Tax
    

    View Slide

38. $3.63 GST included
    10% GST
    

    View Slide

39. vatlive.com
    

    View Slide

40. $6.66 VAT included
    20% VAT
    

    View Slide

41. $6.38 VAT included
    19% VAT
    

    View Slide

42. View Slide

43. http://en.wikipedia.org/wiki/Sales_taxes_in_the_United_States
    

    View Slide

44. taxcloud.net
    

    View Slide

45. View Slide

46. $0 - $4.68 extra
    0 - 11.725% Sales Tax
    

    View Slide

47. "united" states
    

    View Slide

48. OR
    

    View Slide

49. Tax Categories
    Zones
    Rates
    

    View Slide

50. Clothing
    Australia
    10%
    

    View Slide

51. Food
    NY
    8.875%
    

    View Slide

52. Old
    Adjustments
    

    View Slide

53. Old Adjustments
    * Source - Thing doing the adjustment
    * Originator - Maybe same as source, maybe not
    * Adjustable - Thing being adjusted
    * Amount - Self-explanatory
    

    View Slide

54. Tax Adjustment
    * Source = Order
    * Originator = TaxRate
    * Adjustable = Order
    

    View Slide

55. Order Tax Rate
    create_tax_charge
    

    View Slide

56. 1. tax included in price (i.e. GST)
    2. default tax zone is the same as the order's zone
    IF
    THEN
    Purchases in same country as store (price inc.)
    Adjustment
    Line Item
    Line Item
    Line Item
    Adjustment
    Adjustment
    1. Apply adjustments to every single line item
    

    View Slide

57. Spree < 2.2 - 10% GST
    $1.82 tax incl.
    

    View Slide

58. $1.82 tax incl.
    $1.82 tax incl.
    Spree < 2.2 - 10% GST
    

    View Slide

59. 1. tax included in price (i.e. VAT)
    2. default tax zone is NOT the order's zone
    IF
    THEN
    1. apply one big negative adjustment to the entire order (a refund)
    Purchases outside of the country (price inc.)
    Adjustment
    Order
    

    View Slide

60. Spree < 2.2 - 10% VAT
    $1.82 tax refund
    

    View Slide

61. Spree < 2.2 - 10% VAT
    $1.82 tax refund
    $1.82 tax refund
    1 whole-order adjustment for $3.64
    

    View Slide

62. 1. tax is NOT included in price (i.e. sales tax)
    THEN
    1. apply one big adjustment to the whole order
    Purchases in country (price excl.)
    Order Adjustment
    

    View Slide

63. Spree < 2.2 - 7% Sales Tax (NY)
    + $1.39 tax
    

    View Slide

64. Spree < 2.2 - 7% Sales Tax (NY)
    + $1.39 tax
    + $1.39 tax
    

    View Slide

65. Spree < 2.2 - 7% Sales Tax (NY)
    1 whole-order adjustment for $2.78
    + $1.39 tax
    + $1.39 tax
    

    View Slide

66. Adjustment
    Line Item
    Line Item
    Line Item
    Adjustment
    Adjustment
    Adjustment
    Order
    Order Adjustment
    Spree < 2.2
    

    View Slide

67. Adjustment
    Line Item
    Line Item
    Line Item
    Adjustment
    Adjustment
    Adjustment
    Order
    Order Adjustment
    Spree < 2.2
    

    View Slide

68. New
    Adjustments
    

    View Slide

69. Adjustment
    Line Item
    Line Item
    Line Item
    Adjustment
    Adjustment
    Adjustment
    Adjustment
    Adjustment
    Line Item
    Line Item
    Line Item
    Spree 2.2+
    +
    

    View Slide

70. 5. Refund specific items
    $3.63 GST included
    10% GST
    "How much tax did this item incur?"
    

    View Slide

71. line_item.tax_total
    shipment.tax_total
    order.tax_total
    

    View Slide

72. Included

    vs.
    Additional
    

    View Slide

73. line_item.included_tax_total
    shipment.included_tax_total
    order.included_tax_total
    line_item.additional_tax_total
    shipment.additional_tax_total
    order.additional_tax_total
    

    View Slide

74. Spree 2.2+ - 10% GST
    $3.63 tax incl.
    $1.82 tax incl.
    2 $39.98
    $59.97
    $59.97
    1 adjustment for $3.63,
    1 adjustment for $1.82
    

    View Slide

75. Spree 2.2+ - 7% Sales Tax
    1 adjustment per line item for $1.39
    + $1.39 tax
    + $1.39 tax
    

    View Slide

76. Spree 2.1+ Adjustments
    * Source
    * Originator
    * Adjustable
    * Amount
    * Included? - Counts towards final
    total
    

    View Slide

77. * Source
    * Originator
    * Adjustable
    * Amount
    * Included? - Counts towards final
    total
    Spree 2.2+ Adjustments
    

    View Slide

78. Shipment
    Adjustments
    

    View Slide

79. Shipment Adjustment
    * Source = Shipment
    * Originator = ShippingMethod
    * Adjustable = Order
    Spree 2.1
    

    View Slide

80. "Why does the cost
    of a shipment
    need to be
    an adjustment?"
    

    View Slide

81. shipment.cost = 10
    

    View Slide

82. Shipment
    Taxation
    

    View Slide

83. Shipping methods now
    have a tax category
    tax category + zone =
    rate(?)
    

    View Slide

84. Order
    create_tax_charge
    Tax Rate
    Line items
    Order
    create_tax_charge
    Tax Rate
    Shipments
    Spree 2.2. Taxation
    

    View Slide

85. Shipment Adjustment
    * Source = Shipment
    * Originator = ShippingMethod
    * Adjustable = Order
    Spree 2.1
    Shipment Adjustment
    * Source = TaxRate
    * Adjustable = Shipment
    Spree 2.2
    

    View Slide

86. Tax Adjustment
    * Source = TaxRate
    * Adjustable = LineItem
    OR
    * Adjustable = Shipment
    

    View Slide

87. Promotion
    Adjustments
    

    View Slide

88. Order Promotions
    * Source = Order
    * Originator = PromotionAction
    * Adjustable = Order
    

    View Slide

89. Spree < 2.2 - 10% off promotion
    $2 off
    

    View Slide

90. $2 off
    $2 off
    Spree < 2.2 - 10% off promotion
    1 Order Adjustment for -$4
    

    View Slide

91. $2 off
    $2 off
    Spree 2.2+ - 10% off promotion
    1 adjustment per line item for -$2
    

    View Slide

92. Promotion
    Handlers
    

    View Slide

93. Promotion Handlers
    Order Promotion
    Cart, Coupon, Free Shipping, or Page
    Promotion::Handler
    New in Spree 2.2!
    

    View Slide

94. Promotion Handlers
    Cart
    1. Find all non-code or path promotions
    2. Check if they're eligible for that line item or order
    3. Activate
    

    View Slide

95. Promotion Handlers
    Coupon
    1. Find promotion matching coupon code
    2. Validate promotion usage limit & eligiblity
    3. Attempt application of promotion to order
    4. Report on success of application
    

    View Slide

96. Promotion Handlers
    Free Shipping
    1. Find all 'Free Shipping' promotion actions
    2. Check eligibility for order
    3. Activate
    

    View Slide

97. Promotion Handlers
    Page
    1. Find promotion for specified path
    2. Check eligibility for order
    3. Activate
    

    View Slide

98. Picking
    a winner
    

    View Slide

99. 10% off!
    adjustment
    LineItem
    $10 off!
    adjustment
    

    View Slide

100. $1
     LineItem!
     @ $10
     $10
     

     View Slide

101. $15
     LineItem!
     @ $150
     $10
     

     View Slide

102. #4270
     Complex promotion rules
     

     View Slide

103. In summary…
     

     View Slide

104. "Can I combine
     a free shipping promotion
     and
     a 10% off promotion? "
     "You can!"
     ORDER SUMMARY
     Item Total: $1,599.00
     Sales Tax $80.45
     -
     Free Shipping
     Promotion (10% off)
     Order Total: $1,511.51
     -$167.95
     

     View Slide

105. PromotionAction::CreateAdjustment
     Commandment #1:
     Order Wide Adjustments
     

     View Slide

106. Commandment #2: Discounts + Credits
     Yes Not yet
     

     View Slide

107. Commandment #3: Group discounts
     Soon.
     

     View Slide

108. Commandment #4: Shipping taxation
     Yes.
     

     View Slide

109. Commandment #5: Refunding of items
     Soon.
     

     View Slide

110. Commandment #6: Adjustment freezing
     It's always been that way.
     

     View Slide

111. Commandment #7: VAT Refunding
     Of course!
     Adjustment
     Adjustment
     Adjustment
     Line Item
     Line Item
     Line Item
     

     View Slide

112. Commandment #8: Multiple discounts per order
     One promotion adjustment.
     One credit adjustment.
     One taxation adjustment.
     

     View Slide

113. Commandment #9: Robust test suite.
     Definitely.
     

     View Slide

114. Commandment A: Avoid excessive calculations.
     Calculations at an all time low.
     

     View Slide

115. Commandment B: Avoid multiple adjustments per item.
     Oops.
     One promotion adjustment.
     One credit adjustment.
     One taxation adjustment.
     

     View Slide

116. Commandment i: Line item adjustments.
     One promotion adjustment.
     One credit adjustment.
     One taxation adjustment.
     

     View Slide

117. Commandment ii: Some form of inheritance.
     Inheritance free zone.
     

     View Slide

118. Commandment iii: Take advantage of
     calculators and rules
     Done.
     

     View Slide

119. Commandment iv: Events should be scrapped.
     Gone.
     

     View Slide

120. Commandment v: Notifications should be scrapped.
     Gone.
     Replaced with Handlers.
     Gone.
     

     View Slide

121. We now have an adjustments system which is:
     SIMPLE
     

     View Slide

122. We now have an adjustments system which is:
     CONSISTENT
     Adjustment
     LineItem
     Shipment Adjustment
     

     View Slide

123. We now have an adjustments system which is:
     FLEXIBLE
     

     View Slide

124. View Slide