Archive | November 2008

Flex AutoComplete Component: a new take on an old standard…

While there are a couple of other AutoComplete components out there (most notably the ones from the Flex Team and kuwamoto.org), neither of them had the features we were looking for. I struggled for a while trying to extend them but it just wasn’t working.

One of the main features we needed was for the component to show the part of the string which matches the search term. We also needed it to support selecting multiple items as well as creating an ordered list.

Latest version

As you can see in the demo, there are four main boolean properties which control how the chooser works:

  • isBrowseable: This will display a ‘Browse’ button to the right of the TextInput. If the user clicks it they will be presented with either a searchable DataGrid or a list builder (see below).
  • isMultiSelect: This enables selecting multiple values.
  • isOrderable: This makes the items in the list orderable. It provides buttons to reorder them as well as enabling drag-and-drop.
  • useListBuilder: If this is set to true, when clicking the browse button the user gets a List Builder rather than the DataGrid (note: this requires isBrowseable and isMultiSelect to be true).

Here are the other main properties:

  • labelField: Which property of the data objects to use when displayed in the TextInput and the Lists.
  • labelFunction: In place of the labelField you can specify a function for determining the string to display.
  • dropDownLabelFunction: A reference to the function used to display the matched items in the dropdown. It supports using HTML (which can be used to highlight the part of the string which matches the search pattern).
  • prompt: The message which is initially displayed in the TextInput.
  • filterFunciton: A reference to the function used to search when entering text into the TextInput. The function is passed the object being checked along with the search string
  • isEqualFunction: A reference to a function which can be used to determine if the search string should be considered equal to the object (if it returns true it will automatically select the item).

The bare minimum required to use the component is to set the dataProvider property to an ArrayCollection of objects and specify a value for labelField.

The code for the demo is pretty straight forward.

<?xml version="1.0" encoding="utf-8"?>
<mx:Application
	xmlns:mx="http://www.adobe.com/2006/mxml"
	xmlns:hc="com.hillelcoren.components.*"
	width="550" height="400"
	initialize="init()">

	<mx:Script>
		<!&#91;CDATA&#91;
			import mx.collections.ArrayCollection;

			&#91;Bindable&#93;
			public var colors:ArrayCollection;

			private function init():void
			{
				colors = new ArrayCollection(
				&#91;
					{ "name":"Almond", "hex":"#C5E17A" },

					...

					{ "name":"Yellow Orange", "hex":"#FFAE42" }
				&#93; );
			}			

			private function handleChange():void
			{
				var color:Object = chooser.chosenItem;

				if (color != null)
				{
					setStyle( "backgroundColor", color.hex );
				}
			}
		&#93;&#93;>
	</mx:Script>

	<mx:Panel width="100%" height="100%" title="Chooser Demo"
			paddingBottom="20" paddingTop="20" paddingLeft="20" paddingRight="20">
		<mx:HBox>		

			<mx:VBox horizontalAlign="left">
				<mx:CheckBox id="browesable" label="Browesable"/>
				<mx:CheckBox id="multiselect" label="Multiselect"/>
				<mx:CheckBox id="orderable" label="Orderable" enabled="{ multiselect.selected }"/>
				<mx:CheckBox id="listBuilder" label="List Builder" enabled="{ multiselect.selected }"/>
			</mx:VBox>		

			<hc:Chooser id="chooser" dataProvider="{ colors }" labelField="name"
				prompt="Choose your favorite Crayola crayon" width="300" change="handleChange()"
				isBrowseable="{ browesable.selected }" isMultiSelect="{ multiselect.selected }"
				isOrderable="{ orderable.selected }" useListBuilder="{ listBuilder.selected }"/>					

		</mx:HBox>
	</mx:Panel>
</mx:Application>

I consider this to be a version 0.9. It seems to work pretty well but I’m sure there’s a bug or two hiding in there. There are also a couple of more features I’d like to implement.

There’s no copyright… please use the code freely. I just ask that if you come up with any improvements you email them back to me.

Hope you find this component useful,
Hillel

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