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clsDataListBinder

This binder binds a collection into a WebForms DataList and uses a naming convention for child controls to write edited row values back into the corresponding business objects. It combines base reflection services with row scanning, key-based object matching, and IDataErrorInfo harvesting so repeated item templates can participate in the same page-level validation flow as single-control binders.

Purpose

  • Populate a DataList from a collection and trigger the control's standard databinding pipeline.
  • Match templated row controls back to source objects by key so user edits can be persisted.
  • Aggregate collection and row-level validation messages from IDataErrorInfo implementations.

Context

  • Namespace: SAIF.Presentation.Web.Binding
  • Assembly/package: SAIF.Presentation.Web.Binding.Infragistics103 (embedded/bundled as source, not independently packaged)

Public members

Member Signature Purpose
KeyProperty Property KeyProperty As String Names the source property used to align DataList rows with collection objects during write-back and validation.
BoundControlPrefix Property BoundControlPrefix As String Defines the control-ID prefix used to discover editable template controls that participate in binding.
BindProperty Property BindProperty As String Stores the primary bind-property name associated with this binder instance.
BindSource Property BindSource As IEnumerable Holds the collection bound into the DataList and reused for validation and row write-back.
DataList Property DataList As DataList Attaches the concrete DataList control and registers it with the base binder pipeline.
Init() Overrides Sub Init() Hooks UpdateCommand when event-driven write-back is enabled for the current bind direction.
ObjectToControl() Overrides Function ObjectToControl() As Boolean Assigns the collection as the control's DataSource and calls DataBind().
New() Sub New() Creates a binder preconfigured to use the default value-oriented control bind property.
## Inherited public members
Member Signature Purpose
--- --- ---
ContainsError ReadOnly Property ContainsError As Boolean Set by GetErrors()/validation processing; when true, Validate()/RefreshValidation() counts this binder toward the overall invalid result and its control receives error-state CSS via SetControlFormat().
IsDualBinding ReadOnly Property IsDualBinding As Boolean When true, ObjectToControl()/ControlToObject() read and write the display object/property while GetErrors() checks a separate validation object/property, as configured by AddDualBinder().
ControlPadding Property ControlPadding As PadArgs When UsePadding is enabled, pads or trims the value written to the control during ObjectToControl(), so fixed-width display formatting is applied without changing the underlying object value.
ObjectPadding Property ObjectPadding As PadArgs When UsePadding is enabled, pads or strips padding from the value written back to the bound property during ControlToObject(), so stored data is not polluted with display-only padding characters.
UsePadding Property UsePadding As Boolean Enables the ControlPadding/ObjectPadding transforms during ObjectToControl()/ControlToObject(); when false, values pass through unpadded regardless of the padding arguments configured.
UseEvents Property UseEvents As Boolean When true, Init() wires the control's native change event so a user edit immediately calls ControlToObject() instead of waiting for an explicit BindToObject()/Validate() call.
ControlErrors ReadOnly Property ControlErrors As ArrayList Holds the error text GetErrors() collects from the bound object's IDataErrorInfo implementation; Validate() aggregates these strings into the consolidated ErrorLabel/SAIFMessage output.
BindType Property BindType As BindTypes Determines which of ObjectToControl()/ControlToObject() actually run during DataBind()/BindToObject(), controlling whether this binder is push-only, pull-only, both, or validation-only.
FormControl Overridable Property FormControl As WebControl Setting this property runs ProcessControl, which applies binder-specific control setup (event wiring readiness, CSS baseline) before the control participates in binding and validation passes.
FormControlID Overridable ReadOnly Property FormControlID As String Supplied to Update() and error-focus logic to locate this binder's control instance on the page without holding a direct control reference.
Init() MustOverride Sub Init() Called once during AddBinder() registration; each concrete binder overrides this to hook the native control event needed for event-driven ControlToObject() and to perform any control-specific setup.
ObjectToControl() MustOverride Function ObjectToControl() As Boolean Invoked by DataBind() for binders configured as ObjectToControl/TwoWay; each concrete binder overrides this to translate the bound property's value into the control-specific display state.
ControlToObject() Protected Friend MustOverride Sub ControlToObject() Invoked by BindToObject() for binders configured as ControlToObject/TwoWay; each concrete binder overrides this to convert the control's current value back into the bound property's type.
SetControlFormat(inValid As Boolean) Protected Friend Overridable Sub SetControlFormat(inValid As Boolean) Called by Validate()/RefreshValidation() after error collection; sets the control's CssClass to the valid/error color per BR-BIND-001, BR-BIND-002, and BR-BIND-003, giving the reader a visual cue of validation state.
GetErrors() Protected Friend Overridable Sub GetErrors() Reads the bound object's IDataErrorInfo.Item(property) during Validate()/RefreshValidation() and appends any non-empty message to ControlErrors, driving both ContainsError and the consolidated error display.
GetObjectValueAsString(inBizObject, inPropertyName) Function GetObjectValueAsString(inBizObject As Object, inPropertyName As String) As String Used by ObjectToControl() to fetch the bound property's current value as display-ready text, applying ObjectPadding/ControlPadding first when UsePadding is enabled.
GetObjectValue(inBizObject, inPropertyName) Function GetObjectValue(inBizObject As Object, inPropertyName As String) As Object Used by ObjectToControl() and type-sensitive binders to fetch the bound property's value in its native CLR type, before any control-specific conversion or formatting.
SetObjectValueAsString(inBizObject, inPropertyName, inValue) Protected Function SetObjectValueAsString(inBizObject As Object, inPropertyName As String, inValue As String) As Boolean Used by ControlToObject() to write a control-derived string back onto the bound property, applying padding/trim rules first when UsePadding is enabled, so the object receives a correctly formatted value.
SetObjectValue(inBizObject, inPropertyName, inValue) Protected Function SetObjectValue(inBizObject As Object, inPropertyName As String, inValue As Object) As Boolean Used by ControlToObject() to write a converted, strongly typed value back onto the bound property, bypassing string formatting for binders that perform their own type conversion.
ValidationKey Friend Overridable ReadOnly Property ValidationKey As String Computed by AddBinder() to key the bound object into m_ValidationObjects per BR-BIND-006, ensuring repeated Validate() passes re-check the correct distinct object.
IsSAIFFrameWorkObject Friend Overridable ReadOnly Property IsSAIFFrameWorkObject(Optional inObj As Object) As Boolean Detects SAIF framework objects by walking the CLR base-type chain for clsBusinessBase/clsBusinessCollectionBase.
## Behavioral notes
- ControlToObject() iterates every rendered DataListItem and delegates row synchronization to BindItem().
- BindItem() uses KeyProperty and DataList.DataKeys(item.ItemIndex) to locate the target object, then updates matching child CheckBox controls whose IDs follow BoundControlPrefix + PropertyName.
- GetErrors() first captures collection-level IDataErrorInfo.Error text, then validates each object against each rendered row and adds per-property messages to ControlErrors.
- When a row-level invalid property maps to a child CheckBox, the binder applies an inline red BackColor style to that control.

Constraints and usage notes

  • Write-back depends on DataList.DataKeys being populated with values compatible with KeyProperty.
  • Only child controls whose IDs start with BoundControlPrefix are considered during validation and update processing.
  • The current BindItem() implementation writes back CheckBox values; other child control types in the item template are ignored.

Sources

  • SAIF.Presentation.Web.Binding.Infragistics103\ASPControls\clsDataListBinder.vb
  • SAIF.Presentation.Web.Binding.Infragistics103\clsObjectBinderbase.vb