Chris Ainsley. Clean configuration - The foundation of clean code

Transcription

1 Chris Ainsley Clean configuration - The foundation of clean code

2 Best time to discover a configuration issue? Runtime Deployment App initialization Build-time Interactively

3 Agenda Current Approaches Issues with Current Approaches Rion / Myrion A super slide heavy example Questions

4 Common issues

5 1. Null / Type Checking issues Possibly null pointer exception here if connections was not provided. Type was not tested

6 1. Null / Type Checking issues NULL

7 1. Null / Type Checking issues Change of contract requires careful untangling

8 2. Whitespace Issues Trailing whitespace is significant

9 3. Weak Referential Integrity Rules need to be enforced

10 3. Referential Integrity NULL

11 4. Embedding Opaque Error prone Time consuming

12 5. Loosely Coupled Handlers

13 5. Loosely Coupled Handlers

14 5. Loosely Coupled Handlers 1 2

15 5. Loosely Coupled Handlers Now we add: Runtime exception risk Manual remedy required

16 5. Loosely Coupled Handlers (enums)

17 5. Loosely Coupled Handlers

18 5. Loosely Coupled Handlers Runtime exception risk Manual remedy required

19 6. Verbosity

20

21 Costs of getting it wrong Deployment cancellation / retry Runtime Bugs Humble Pie

22 Schemas (abbreviated)

23 Rion An Object Notation

24 Introducing Rion

25 Attribute Introducing Rion

26 Introducing Rion Attribute Collection

27 Introducing Rion Attribute Collection Object

28 Introducing Rion Attribute Collection Object Boilerplate light Strongly Typed Sandboxed Easy to visually parse. Tokenizable Advanced features

29 Sample Rion Parsed Representation

30 Introducing Rion Rion JSON

31 Rion - Object Id Type Type Id and type

32 Rion - Attribute Id Value Leading & trailing whitespace not significant Id Id Values Multi Line Attribute Value

33 Rion - Collection Collection Id Identified objects within collection Collection Id Anonymous objects within collection

34 Dictionary syntax Id Dictionary Lookup Key Regular expression syntax Id Value Backslashes interpreted literally in this syntax

35 $${ } blocks are active content. Rion Active Content

36 Rion Conditional Blocks Environment filter Model elements to be excluded unless environment filter matches Current environment passed to context of parser. Conditional blocks disabled by the sandbox by default.

37 Myrion A model-based code-generator

38 Myrion A model-based code-generator

39 Utilises Rion to create easy internal DSLs

40 So we can do this kind of thing.

41

42 The Pillars of Myrion Schema Asset Generator Tooling

43 Myrion Usage Scenarios Application Configuration Model-Based Code Generation Model Injection

44 What is in the metaschema? Class / Interface hierarchy Class Members Validation rules Scoping / referential integrity. Tooling Hints More

45 Schema Driven Development

46 Schema Driven Development

47 Schema Driven Development

48 Schema Driven Development

49 Schema Driven Development

50 Schema Driven Development

51 Let s develop a simple model for a UI Define some UI Forms Forms will have one or more widgets Nominate Form As Default Display Wire Up To Engine

52 Not much to look at

53 Creating a schema Press Ctrl + Space

54 Creating a schema Package / Domain Root class / Entry point Defined classes Entry point class Expected items within class 0100

55 Something about nothing A valid empty document 0100

56 Generated Files Builder Class Pojo Model 0100

57 model/gui.java Modified Snippet from Gui.java 0100

58 builder/guibuilder.java Modified Snippet from GuiBuilder.java 0100

59 Define a skeleton form class classes[]

60 Maps Keyed object store Ordered or unordered Can be referenced from elsewhere

61 Define Forms At Root Level classes[]/gui//content[]//forms Gui.java

62 Schema So Far

63 Valid document Invalid document

64 Define Some Enumerations Schema Will Be Bootstrap Centric We Should Generally Avoid To Model Around Implementation Now We Define 3 Enumerations

65 enumerations[] FormType.java

66 enumerations[] StatusType.java

67 enumerations[] IconType.java

68 Schema So Far.

69

70 Add some attributes to form

71 classes[]/form/content[] Form.java

72 classes[]/form/content[] Form.java

73 classes[]/form/content[] Form.java

74 classes[]/form/content[] Form.java

75 classes[]/form/content[] GuiBuilder.java

76 classes[]/form/content[] Form.java

77 Creating the formitem abstract class

78 classes[] FormItem.java

79 Creating A Regular Expression

80 / GuiBuilder.java

81 Create Text Widget Base Class

82 classes[]

83 Some Concrete Widgets

84 classes[]

85 Adding Form Items To A Form

86 Lists For items without an identifier A list of objects

87 classes[]/form/content[]

88 So, where are we?

89 Valid document Invalid document Requires 1 or more widgets

90 Multiple Choice Widgets

91 classes[] Enforced by builder

92 classes[]

93 Pairing items with descriptions

94 classes[]/multiple_choice

95 Adding a reference

96 classes[]/gui/content[] Form.java

97 Strategic Sensitivity Make The Contract Part Of The API Let the compiler flag issues

98 Dispatchers

99 Auto generated FormitemDispatcher.java

100 Client code (hand written) <<Could be anywhere>>.java

101 What happens if we introduce new widget?

102 classes[]

103 Auto-generated

104 Client code (hand written) Must implement ondropdown(dropdown) <<Could be anywhere>>.java

105 <<Could be anywhere>>.java All is well

106 Change in nullability

107 classes[]/gui/content[] Gui.java

108 classes[]/gui/content[] Gui.java

109 Null Change Scenarios

110 Compiler will flag missing method

111 Prompt to make required changes

112 Generating Assets

113

114 Model Builder Dispatchers

115 Portable Model/Dispatchers have zero dependencies Builder package has no dependencies except Rion

116 Portable Model/Dispatchers have zero dependencies Builder package has no dependencies except Rion

117 Generated Documentation

118 Output Formats HTML AsciiDoc

119

120

121 Best time to discover a configuration issue? Build-time Interactively

122 Final Words

123 Questions? Rion Myrion Contact Feedback Twitter myrion.io/rion myrion.io TBC