If you have built a custom item renderer for a DataGroup or List you may have come across warnings in your Flash Builder console output similar to this:
warning: unable to bind to property 'firstName' on class 'Object' (class is not an IEventDispatcher)
Continue reading Binding warnings when using Object in a List dataProvider
This post looks at a couple ways of defining a custom item renderer on a DataGroup, but it also applies the same way to a SkinnableDataContainer, spark List, and any other spark components that support item rendering.
Continue reading Different ways of assigning an item renderer in Flex 4
The default spark List skin wraps the the underlying DataGroup with a Scroller component to easily provide scrolling functionality. Custom skinning the Scroller component isn’t very flexible; you can custom skin each scrollbar to change the visuals on them, but you can’t easily reposition them. In these cases it usually makes more sense to get rid of the Scroller and hook up the scrollbars directly.
Continue reading Changing the position of the scroll bars in a spark List
It’s easy to delete an item in a spark List from within an item renderer. This is handy if you have a List with a custom renderer that provides a button to delete the item that is associated with that renderer.
Continue reading Deleting items in a List from an item renderer
The spark DataGroup component is designed to take data items and pass them through an item renderer to create a visual representation of that data. In Flex 4 it is very easy to build custom item renderers.
This sample application demonstrates how you can create an item renderer that only shows some information by default and allows the user to drill down to see more information by clicking on an item or it’s associated “twisty” icon.
Continue reading Expanding item renderers in a DataGroup or List
The spark List component in Flex 4 has virtualization enabled by default. Virtualization is an optimization that only renders items that are currently in view which allows the List to support very large data sets. You can learn more about how virtualization works in Flex 4 by reading the Spark Virtualization Spec.
Continue reading Performance implications of the List itemRenderer vs. itemRendererFunction properties
This sample demonstrates one way of modifying the postLayoutTransformOffsets property of an ItemRenderer in a List in order to have the items appear to zoom in when hovered or selected.
Continue reading Zoom in on items in a List with a TileLayout
I built a small sample application that demonstrates one way of building a navigation bar in Flex 4 that makes it really easy to toggle between different views in an application. This approach uses spark RadioButtons with a very simple custom skin.
Continue reading Creating a navigation bar using RadioButtons in Flex 4
DataGroup is a new component introduced in Flex 4 that is responsible for turning data items like Strings and Objects into visual elements. The process of turning boring old data items into a visual representation is called item rendering. DataGroup is the lightest weight component that deals with item rendering. It has no skin and no concept of selection. A SkinnableDataContainer is exactly the same as a DataGroup except it has a skin and a List provides selection functionality.
Continue reading Introduction to the DataGroup Component in Flex 4