Does anyone have a code sample of how I can supply a different
itemRenderer to a List based on the data Type of the item in any given
row?
I have a heterogeneous collection of Types in an ArrayCollection
(Property Sheet or User Preferences list) and want to render each row
differently based on the data Type of the row item.
For those of you familiar with MS WPF, it includes the notion of
something called a "DataTemplate" which is essentially an Item Renderer
that is used by the framework to render a particular data Type in a
heterogeneous collection or on a form. I'd like to do the same thing in
Flex within a List.
Is there such a notion in Flex? Can it be done simply?
I've tried implementing a Factory pattern where I supply a single
itemRenderer (VBox) class to the List component which is an ActionScript
class that simply overrides the "data" setter, and tests the Type of the
"data" property (the row item type) and if it's a certain Type it
instantiates or replaces a child container that properly renders the
data based on its Type. This is not a simple pattern to follow or
communicate. I'd like to find a simpler way.
I've also tried using a single renderer with multiple top level
components that use data binding to dynamically set "includeInLayout"
and "visible" so only one of the top level components will render. This
works, but the performance on a large list is abysmal in our ad hoc
tests. Simple renderers not using "includeInLayout" were much faster.
I've also tried using States to determine which part of the mxml to
render based on the Type, but the pattern is just too complicated and
too verbose.
I'm in search of the cleanest possible pattern to recreate what you get
out of the box with WPF, as I am sure someone at Adobe thought of this
(it's an amazingly common use case), but it's just a matter of my
learning how to do this.
Thanks for your suggestions!
Erik
Erik Thomas | Small Business Group, Intuit | Staff Engineer |
650-944-2602
