Design Patterns
Introduction to Design Patterns given in 2012 for AC Partners and in 2019 for itenium.
Some material:
- JavaScript exercise info
- Design Pattern definitions for this technical session
- All design patterns with UML diagrams
JavaScript
Creating a framework for generating user forms:
npm install
# React
cd JavaScript/impl-react
npm start
# Angular
cd JavaScript/impl-angular
npm start
JavaScript
See Handout.md
Exercise SOLID
Angular - Bootstrap - FormWrapperDirective:
This high level component wraps a form control for use in a Bootstrap form
There are several problems:
- It has intimate knowledge of the low level controls (setting a specific extra class 'form-check' for 'toggle')
- Another big switch statement is waiting to happen here: A control can also appear in a navbar, ... with different classes
DotNet
1 OpenClosedPrinciple
Example 1-3: Calculating shape area
Adhering to the OpenClosedPrinciple by introducing a PureFabrication (IAreaCalculator) and using Polymorphism instead of type checking.
- Example 1: Calculate area of Circles
- Example 2: A naive implementation when Rectangles are added
- Example 3: Introducing the IAreaCalculator abstraction
Example 4-7: Saving files
Keeping the code DRY:
- Example 4: Code duplication for the different "file saving mechanisms"
- Example 5: A solution with TemplateMethod
- Example 7: A solution with Strategy
- Example 6: Use FactoryMethod on Example 5 to allow each "file saving mechanism" to return custom metadata
2 Patterns
- 1-2.Observer: Examples of Observer: builtin support with
event EventHandler<EventArgs> - 3.Decorator: Example with Streams
TODO: De CheatSheet zouden moeten genummerd zijn