Presentation at Flash Camp Chicago regarding Flex 4 component changes

1. Component Development in the Flex 4 Model Michael Labriola Digital Primates Twitter: mlabriola

2. Who are you? Michael Labriola Senior Consultant at Digital Primates Flex Geek Team Mentor Project Lead for FlexUnit 4

3. What is this session about? Component Development Components are the root of everything in Flex. Know how to make them work and know Flex

4. What are we doing? Implement and create a layout class Implement and create a skin Create a custom component using the Flex 4 component framework

5. What are Flex Components?

6. Why do you care? Flex is a component framework Everything is a component in Flex Understand components and understand Flex When you want something new, that does something different, you want to create a component

7. Important things to understand In Flex 4 components are composed of two pieces The form The function

8. The Function What the component does How it does it When it does it Defines what the component is Buttons are about being clicked List is about selection and virtualization

9. The Form A list doesn’t have to be horizontal or vertical to be a list Buttons don’t need to be rectangles What makes a list a list? What makes a button a button?

10. Separation Separating these pieces favors composition over inheritance By separating form and function we gain and we lose.

11. We Gain The capability of having one set of functionality look many different ways Back to the list example, a list can be horizontal, vertical, circular, etc. but we only have to maintain the code in one list class

12. We Lose We lose a lot of dead weight We lose a lot of extra classes Example of layout objects embedded in a class

13. There are two types of UI Components in Flex Controls Interact with a user Present data Accept gestures Containers Hold other containers and controls Control positioning of children

14. On the topic of losing weight There are two types of things in the Flex world, those that can be skinned and those that cannot Roughly corresponding to those that have their own visual appearance and those that simply influence the visualization of others Why? Because we don’t want to burden everything in the world with functionality it doesn’t need

15. Groups are the Base Type of Container Groups don’t have a visual identity of their own Groups can accept a layout object to handle the layout of children

16. Layout Types Layout types built into flex BasicLayout HorizontalLayout VerticalLayout The important part about this is creating your own layouts Circle Layout Advanced Circle Layout

17. Create a Circle Layout

18. Controls and Some Containers can be Skinned Controls can also have their visual appearance modified and quite easily by skinning

19. Skins Skins are classes defined in MXML They are based on the Skin class They are applied to components using The skinClass Or by CSS

20. Definitions Think about the list class No visual elements can exist inside the list or it reduces skin-ability All visuals exist in the skin That means the component provides the functionality and controls aspects of the skin That could get ugly

21. Contracts That means we must have some sort of contract between a skin and a component. This contract defines the minimum things that must be present inside of the skin to be considered valid This contract is fulfilled in two ways

22. Components Declare skin parts (required or not) Declare skin states HELP!

23. Skins Specify a HostComponent <fx:Metadata> [HostComponent("spark.components.Button")] </fx:Metadata> Declare states <s:states> <s:State name="up" /> <s:State name="over" /> </s:states> Establish visuals

24. Visuals What type of visuals?

25. CODE

26. Q & A Seriously? You must have some questions by now?

27. Play and Vote Take a look at the latest beta bits: http://labs.adobe.com/technologies/flashbuilder4/

28. Resources Labriola’sBlog http://blogs.digitalprimates.net/codeSlinger/ Tapper’s Blog http://blogs.digitalprimates.net/jefftapper/ Follow us on twitter mlabriola and jefftapper