Extending a Base Product for Multiple Customers

Details how MediaGeniX builds customised, made-to-measure software for its customers.

Transcript

1. ESUG 2012 Extending a Base Product for Multiple Customers Denis Defreyne MediaGeniX NG 1
3. “ Your product is cool, but it’s missing feature X! 3 — CUSTOMER
4. “ Yes, feature X would be nice… for you, but nobody else! 4 — YOU
5. “Why did you not implement feature X? :( 5 — CUSTOMER
6. “Ugh, this product is getting bloated! :( 6 — OTHER CUSTOMER
7. Contents 1. Customisations 2. Techniques 3. Modules 7
8. 1. Customisations 8
9. Customisation = extra bits of code for a single customer 9
10. Customisations 10 ‣ New functionality e.g. new issue checks (no porn at noon) ‣ Extended functionality e.g. extra metadata on films, contracts, … ‣ Changed functionality e.g. parental rating management in UK, Finland
11. Integrations 11 ‣ Playout server ‣ Commercial scheduling system ‣ Music scheduling system ‣ … unique for every customer!
12. Customisations are only possible if you have FEW customers 12
13. Requirements ‣ Be customer-specific ‣ Be fine-grained ‣ Allow merging bugfixes ‣ Be decoupled 13
14. Why? 14 ‣ Talk to other devices You’ll have static on your TV otherwise ‣ Cater to a diverse market No two broadcasters have the same workflow ‣ Resolve conflicting requirements Don’t compromise, let them both have it their way ‣ Make customers happy! But don’t over-do it :)
16. 2. Techniques 16
17. Techniques 17 1. Site classes 2. Behaviors 3. Convenience methods
18. Techniques 18 1. Site classes 2. Behaviors 3. Convenience methods
19. Site classes – example 19
20. Site classes – example 20
21. Site class = subclass for one specific customer 21
22. Site = customer 22
23. Site classes 23 Film
24. Site classes 24 Film FilmMTV
25. MTV Site classes 25 Film  class  >>  siteClassForMTV ^FilmMTV
26. BASE Site classes 26 newAustinPowersFilm ^Film  siteClass  new title:  'Adventures  at  ESUG'; duration:  (Duration  fromMinutes:  93); yourself
27. WHATS’On code for MTV only Packages 27 MTV BASE FRAMEWORK WHATS’On code shared between customers MediaGeniX framework code
28. Packages 28 MTV VTM VRT TV2 NRK SBS FI NPO VPRO PRO7 FOX FTO …
29. Extensions in packages 29 PACKAGE A MusicClip MusicClip>>title MusicClip>>videoFile MusicClip>>audioFile MusicClip>>is16Plus PACKAGE B MusicClip>>contract MusicClip>>agency Contract Agreement
30. MTV Site classes 30 Film  class  >>  siteClassForMTV ^FilmMTV
31. Site classes 31 BASE Film MusicClip Commercial MTV FilmMTV Film>>siteClassForMTV
32. Film  >>  siteClassForMTV Film  siteClass  new 32
33. FRAMEWORK Site classes 33 Class  >>  siteClass ^Site  current  siteClassOf:  self  
34. MTV Site classes 34 SiteMTV  >>  siteClassOf:  aClass ^aClass  siteClassForMTV    
35. BASE Site classes 35 Site  >>  siteClassOf:  aClass ^aClass
36. BASE Site classes – example 36 Film  class  >>  buildSuperModelWith:  aBuilder super  buildSuperModelWith:  aBuilder. aBuilder addString:  #title  name:  'Title'; addDuration:  #duration  name:  'Duration'
38. BASE Site classes – example 38 Film  class  >>  buildSuperModelWith:  aBuilder super  buildSuperModelWith:  aBuilder. aBuilder addString:  #title  name:  'Title'; addDuration:  #duration  name:  'Duration'
39. MTV Site classes – example 39 FilmMTV  class  >>  buildSuperModelWith:  aBuilder super  buildSuperModelWith:  aBuilder. aBuilder addString:  #idForMTV  name:  'ID  for  MTV'
40. Site classes – example 40
41. Site classes – example 41
42. BASE Site classes – example 42 FilmEditor  class  >>  form ^self  newForm addFormField:  #title; addFormField:  #duration; yourself
43. MTV Site classes – example 43 FilmEditor  >>  siteClassForMTV ^FilmEditorMTV FilmEditorMTV  class  >>  form ^super  form addFormField:  #idForMTV; yourself
44. Site classes – example 44
45. Site classes – example 45
46. BASE Site classes – example 46 FilmEditor  class  >>  form ^self  newForm addFormField:  #title; addFormField:  #duration; addFormField:  #imdbRating; yourself
47. Site classes – example 47
48. Site classes – example 48
49. BASE Site classes – example 49 Film  >>  openInEditor ^FilmEditor  siteClass openWithEditee:  self
50. Call #siteClass everywhere? 50 YES! It’s not as bad as you may think…
51. PRO TIP Avoid long methods 51
52. Techniques 52 1. Site classes 2. Behaviors 3. Convenience methods
53. Behaviors 53 Product Film Commercial MusicClip
54. Product ProductMTV Behaviors 54
55. Behaviors 55 Product Film Commercial MusicClip
56. Behaviors 56 Product Film Commercial MusicClip ProductBehavior ProductBehaviorMTV
57. Behavior class = siteclassable class with behavior from original class 57
58. FRAMEWORK Behaviors 58 BehaviorObject  class  >>  newOn:  anObject ^self  new orig:  anObject; yourself
59. BASE Behaviors – example 59 Product  >>  hasValidCertForTx:  aTx ^self  certification  isOkayForTx:  aTx
60. BASE Behaviors – example 60 ProductBehavior  >>  hasValidCertForTx:  aTx ^self  orig  certification  isOkayForTx:  aTx
61. MTV Behaviors – example 61 ProductBehaviorMTV  >>  hasValidCertForTx:  aTx ^self  orig  videoFiles  allSatisfy: [:f  |  f  certification  isOkayForTx:  aTx]
62. BASE Behaviors – example 62 Product  >>  hasValidCertForTx:  aTx ^self  behavior  hasValidCertForTx:  aTx
63. BASE Behaviors – example 63 Product  >>  behavior behavior  ifNil:    [behavior  :=  ProductBehavior  siteClass        newOn:  self]. ^behavior
64. PRO TIP 64 Prefer composition over inheritance
65. Techniques 65 1. Site classes 2. Behaviors 3. Convenience methods
66. Convenience method = commonly implemented or overridden method 66
67. Convenience methods 67 buildSuperModelWith:  aBuilder addToolsMenuItemsTo:  aMenu addCommandsToToolBar:  aToolBar
68. Convenience methods 68 buildSuperModelWith:  aBuilder buildSuperModelForMTVWith:  aBuilder addToolsMenuItemsTo:  aMenu addToolsMenuItemsForMTVTo:  aMenu addCommandsToToolBar:  aToolBar addCommandsToToolBarForMTV:  aToolBar
69. MTV Convenience methods 69 FilmMTV  class  >>  buildSuperModelWith:  aBuilder super  buildSuperModelWith:  aBuilder. aBuilder addString:  #idForMTV  name:  'ID  for  MTV'
70. MTV Convenience methods 70 Film  class  >>  buildSuperModelForMTVWith:  aBuilder super  buildSuperModelForMTVWith:  aBuilder. aBuilder addString:  #idForMTV  name:  'ID  for  MTV'
71. FRAMEWORK Convenience methods 71 Site  >>  buildSuperModelWith:  aBuilder                for:  aClass aClass  buildSuperModelWith:  aBuilder
72. MTV Convenience methods 72 SiteMTV  >>  buildSuperModelWith:  aBuilder                      for:  aClass super  buildSuperModelWith:  aBuilder  for:  aClass. aClass  buildSuperModelForMTVWith:  aBuilder.
73. PRO TIP 73 Use convenience methods for common methods only
74. Techniques to avoid ‣ Branches Use them, but not for customer-specific code ‣ VisualWorks “overrides” They prevent access to original code 74
75. Techniques 75 1. Site classes 2. Behaviors 3. Convenience methods
76. 3. Modules 76
77. Module = pluggable component that provides a set of related functionalities 77
78. Example modules ‣ Contract management ‣ Secondary events (logos) ‣ Video on demand 78
79. BASE Super models in modules 79 Film  class  >>  buildSuperModelWith:  aBuilder super buildSuperModelWith:  aBuilder. aBuilder "  …  other  attributes  here  …  " addReference:  #contract to:  Contract  name:  'Contract' W R O N G
80. MTV Activating modules SiteMTV  >>  moduleClasses ^OrderedCollection  new add:  ContractModule; add:  SecondaryEventsModule; yourself 80
81. Super models in modules 81
82. BASE Super models in modules 82 Film  class  >> buildSuperModelForContractModuleWith:  aBuilder super buildSuperModelForContractModuleWith:  aBuilder. aBuilder addReference:  #contract to:  Contract  name:  'Contract'
83. FRAMEWORK Super models in modules 83 Site  >>  buildSuperModelWith:  aBuilder                for:  aClass aClass  buildSuperModelWith:  aBuilder.
84. FRAMEWORK Super models in modules 84 Site  >>  buildSuperModelWith:  aBuilder                for:  aClass aClass  buildSuperModelWith:  aBuilder. self  modules  do: [:m  | m  buildSuperModelWith:  aBuilder  for:  aClass].
85. FRAMEWORK Super models in modules 85 Module  >>  buildSuperModelWith:  aBuilder                    for:  aClass "nothing  by  default"
86. BASE Super models in modules 86 ContractPresentModule  >>  buildSuperModelWith:  aBuilder                                                  for:  aClass aClass  buildSuperModelForContractModuleWith: aBuilder.
87. Extensions in modules 87
88. BASE Extensions in modules 88 FilmEditor  class  >>  form form  :=  self  newForm. form  addFormField:  #title. form  addFormField:  #duration. ^form
89. BASE Extensions in modules 89 FilmEditor  class  >>  form form  :=  self  newForm. form  addFormField:  #title. form  addFormField:  #duration. form  addFormField:  #contract. ^form W R O N G
90. BASE Extensions in modules 90 FilmEditor  class  >>  form form  :=  self  newForm. form  addFormField:  #title. form  addFormField:  #duration. ContractModule  current addFieldsTo:  form  for:  self. ^form
91. BASE Extensions in modules 91 ContractPresentModule  >>    addFieldsTo:  aForm    for:  anEditor anEditor  addContractFieldsTo:  aForm
92. BASE Extensions in modules 92 FilmEditor  >>    addContractFieldsTo:  aForm    aForm  addFormField:  #contract.
93. BASE Extensions in modules 93 ContractAbsentModule  >>    addFieldsTo:  aForm    for:  aSender    "nothing  by  default"
94. Extensions in modules 94 CONTRACT
95. Extensions in modules 95 CONTRACT
96. Site classes vs. modules 96 ‣ Modules can be shared across sites ‣ Modules require hooks
97. Recap 97
98. Techniques 98 ‣ Use site classes whenever possible ‣ Use behaviors when site classes fail (inheritance trees) ‣ Use modules when you need more separation
99. Requirements ‣ Be customer-specific (with packages) ‣ Be fine-grained (with site classes) ‣ Allow merging bugfixes (with packages) ‣ Be decoupled (with site classes and modules) 99
100. 100 “ Your product is cool, but it’s missing feature X! — CUSTOMER Do not worry. We’ll implement it for you! — YOU
101. 101 ? MAIL denis.defreyne@mediagenix.tv TWITTER @ddfreyne GITHUB github.com/ddfreyne
102. Extra Slides 102
103. FRAMEWORK Site classing modules 103 Site  >>  modules ^self  moduleClasses  collect: [:c  |  c  siteClass  new]
104. FRAMEWORK Site classing modules 104 SuperModellary  >>  buildSuperModelFor:  aClass    builder  :=  SuperModelBuilder  new.    Site  current  buildSuperModelWith:  builder        for:  aClass.    supermodels  at:  aClass  put:  builder  superModel.
105. BASE Extensions in modules 105 FilmEditor  class  >>  form form  :=  self  newForm. form  addFormField:  #title. form  addFormField:  #duration. ContractModule  current addFieldsTo:  form  for:  self. ^form
106. BASE Extensions in modules 106 FilmEditor  class  >>  form form  :=  self  newForm. form  addFormField:  #title. form  addFormField:  #duration. ContractModule  current  isAvailable  ifTrue: [form  addFormField:  #contract]. ^form
107. BASE Extensions in modules 107 Film  >>  isLegallyBroadcastable ^ContractModule  current  isAvailable ifFalse:  [true] ifTrue:  [self  contract  isSigned].
108. BASE Extensions in modules 108 Film  >>  isLegallyBroadcastable ^ContractModule  current  isAvailable ifFalse:  [true] ifTrue:  [self  contract  isSigned].
109. BASE Extensions in modules 109 Film  >>  isLegallyBroadcastable ^ContractModule  current isFilmLegallyBroadcastable:  self
110. BASE Extensions in modules 110 ContractPresentModule  >>    isFilmLegallyBroadcastable:  aFilm ^aFilm  contract  isSigned
111. BASE Extensions in modules 111 ContractAbsentModule  >>    isFilmLegallyBroadcastable:  aFilm ^true