Validators and itemrenderers

Question

Hi,
I have a problem using ItemRenderer.
I have a table implemented as DataGrid in which some cells are shown by a self written itemRenderer. Depending on the type of the cells data the cell will be also used by a validator. Executing the program everything looks fine, as long as the programs window is not too small. If you scroll in the table then really ugly things happen. The wrong cells get validated by wrong validators and I have even seen that a single cell is validated by several validators.
I know that the ItemRenderer are recycled and I am pretty sure that this has dealing with the problem. But the validators should be activated and deactivated by databinding which should occure on every databinding. So I should work well? But why it doesn't?
If I use a List, and set useVirtualLayout="false"then the problem occues no more (but it looks verry different).
Thank you
Andreas Ruloffs
The main Application with the datagrid:
?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx"
initialize="application1_initializeHandler(event)">
<fx:Script>
<![CDATA[
import mx.collections.ArrayCollection;
import mx.events.FlexEvent;
private var data:ArrayCollection = new ArrayCollection();
protected function application1_initializeHandler(event:FlexEvent):void
data.addItem(new MonoAttributeData("Text1", "Halloo", "String", true, true, 5 ));
data.addItem(new MonoAttributeData("Dbl1", "1", "Double", false, true));
data.addItem(new MonoAttributeData("Int1", "2", "Integer", false, true));
data.addItem(new MonoAttributeData("Text2", "Welt", "String", true, true, 5 ));
data.addItem(new MonoAttributeData("Dbl2", "", "Double", false, true));
data.addItem(new MonoAttributeData("Int2", "54", "Integer", true, true));
data.addItem(new MonoAttributeData("Text3", "Fix", "String", true, true, 5 ));
data.addItem(new MonoAttributeData("Dbl3", "", "Double", false, true));
data.addItem(new MonoAttributeData("Int3", "54", "Integer", true, true));
dataGrid.dataProvider = data;
]]>
</fx:Script>
<mx:AdvancedDataGrid id="dataGrid"
verticalScrollPolicy="on"
horizontalScrollPolicy="off"
alternatingItemColors="[#969696,#787878]"
headerColors="[#969696,#787878]"
width="100%"
height="100%"
sortableColumns="false"
sortItemRenderer="{null}">
<mx:columns>
<mx:AdvancedDataGridColumn dataField="fieldname" headerText="Name" />
<mx:AdvancedDataGridColumn dataField="value"    headerText="Value"/>
</mx:columns>
<mx:rendererProviders>
<mx:AdvancedDataGridRendererProvider
dataField="value"
renderer="MonoLangValueItemRenderer"
columnIndex="1"/>
</mx:rendererProviders>
</mx:AdvancedDataGrid>
</s:Application>
The data model for the ItemRenderer:
package
import mx.collections.ArrayCollection;
import mx.collections.ArrayList;
public class MonoAttributeData
private var _value:String;
private var _changeable:Boolean;
private var _changed:Boolean;
private var _valid: Boolean = true;
private var _validationMessage: String;
private var _fieldType:String;                    //Double, Integer oder String
private var _fieldLength:int;
private var _fieldAllowNull:Boolean
private var _fieldname:String;
public function MonoAttributeData(fieldname:String, value:String, fieldType:String, fieldAllowNull:Boolean, changeable:Boolean, fieldLength:int = 0)
_value = value;
_changeable = changeable;
_changed = false;
_valid = true;
_validationMessage = "";
_fieldType = fieldType;
_fieldLength = fieldLength;
_fieldAllowNull = fieldAllowNull;
_fieldname = fieldname;
public function get fieldname():String
return _fieldname;
public function set fieldname(value:String):void
_fieldname = value;
public function get validationMessage():String
return _validationMessage;
public function set validationMessage(value:String):void
_validationMessage = value;
public function get valid():Boolean
return _valid;
public function set valid(value:Boolean):void
_valid = value;
[Bindable]
public function get changeable():Boolean
return _changeable;
public function set changeable(value:Boolean):void
_changeable = value;
[Bindable]
public function get changed():Boolean
return _changed;
public function set changed(value:Boolean):void
_changed = value;
[Bindable]
public function get value():String
return _value;
public function set value(value:String):void
_value = value;
[Bindable]
public function get fieldType():String
return _fieldType;
public function set fieldType(value:String):void
_fieldType = value;
[Bindable]
public function get fieldLength():int
return _fieldLength;
public function set fieldLength(value:int):void
_fieldLength = value;
[Bindable]
public function get fieldAllowNull():Boolean
return _fieldAllowNull;
public function set fieldAllowNull(value:Boolean):void
_fieldAllowNull = value;
and the ItemRenderer:
<?xml version="1.0" encoding="utf-8"?>
<s:MXAdvancedDataGridItemRenderer xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx"
width="100%" height="100%" >
<fx:Declarations>
<!-- value Commit keine Auswirkung
dataChange von Anfang an
Platzieren Sie nichtvisuelle Elemente (z.*B. Dienste, Wertobjekte) hier -->
<mx:NumberValidator id="validatorDouble"  source="{textInput}"
property="text"
valid="validatorDouble_validHandler(event)"
invalid="validatorDouble_invalidHandler(event)"
required="{!MonoAttributeData(data).fieldAllowNull}"
domain="real"
enabled="{ MonoAttributeData(data).fieldType == 'Double'}"/>
<mx:NumberValidator id="validatorInt" source="{textInput}"
property="text"
required="{!MonoAttributeData(data).fieldAllowNull}"
valid="numbervalidatorInt_validHandler(event)"
invalid="numbervalidatorInt_invalidHandler(event)"
domain="int"
enabled="{ ( MonoAttributeData(data).fieldType == 'Integer')}"/>
<mx:StringValidator id="validatorStr" source="{textInput}"
property="text"
valid="validatorStr_validHandler(event)"
invalid="validatorStr_invalidHandler(event)"
required="{!MonoAttributeData(data).fieldAllowNull}"
minLength="NaN"
maxLength="{MonoAttributeData(data).fieldLength}"
enabled="{MonoAttributeData(data).fieldType == 'String'}"/>
</fx:Declarations>
<fx:Script>
<![CDATA[
import mx.collections.ArrayList;
import mx.core.UIComponent;
import mx.events.ValidationResultEvent;
private function dataChanged():void
if(data.value != textInput.text)
var newValue:String = textInput.text;
MonoAttributeData(data).changed = true;
MonoAttributeData(data).value = newValue;
protected function validatorDouble_validHandler(event:ValidationResultEvent):void
data.valid = true;
MonoAttributeData(data).validationMessage = "";
protected function validatorDouble_invalidHandler(event:ValidationResultEvent):void
data.valid = false;
MonoAttributeData(data).validationMessage =  MonoAttributeData(data).fieldname + ": " + event.message + "\n";
protected function numbervalidatorInt_validHandler(event:ValidationResultEvent):void
data.valid = true;
MonoAttributeData(data).validationMessage = "";
protected function numbervalidatorInt_invalidHandler(event:ValidationResultEvent):void
data.valid = false;
MonoAttributeData(data).validationMessage =  MonoAttributeData(data).fieldname + ": " + event.message + "\n";
protected function validatorStr_validHandler(event:ValidationResultEvent):void
data.valid = true;
MonoAttributeData(data).validationMessage = "";
protected function validatorStr_invalidHandler(event:ValidationResultEvent):void
data.valid = false;
MonoAttributeData(data).validationMessage =  MonoAttributeData(data).fieldname + ": " + event.message + "\n";
]]>
</fx:Script>
<s:Group width="100%" height="100%">
<s:TextInput  id="textInput"
change="dataChanged()"
color="{data.changed?0x666666:0x000000}"
enabled="{data.changeable}"
text="{data.value}"
textAlign="center"
width="100%" height="100%"/>
</s:Group>
</s:MXAdvancedDataGridItemRenderer>

Answer 1

Hello,
I have solved the problem myself.
The problem was not the validators. As I proposed were they activated and deactivated correctly by databinding on each recycling.
But the textfield in the itemrenderer got a property called ‘errorText’ which was not reseted on recycling. This caused my problem. This little enhancement finally solved my problem:
private function resetValidation():void
     textInput.errorString = "";
     textInput.toolTip = "";
     validatorDouble.validate();
     validatorInt.validate();
     validatorStr.validate();
override public function set data(value:Object):void
     super.data = value;
     resetValidation();
Best regards,
Andreas Ruloffs