/// <summary>
/// Gets the view model path expression.
/// </summary>
public override string GetViewModelPathExpression(DotvvmBindableControl control, DotvvmProperty property)
{
// find the parent markup control and calculate number of DataContext changes
int numberOfDataContextChanges;
var current = control.GetClosestControlBindingTarget(out numberOfDataContextChanges) as DotvvmBindableControl;
current.EnsureControlHasId();
return string.Join(".", Enumerable.Range(0, numberOfDataContextChanges).Select(i => "_parent").Concat(new[] { "_controlState_" + current.ID, Expression }));
}
/// <summary>
/// Translates the expression to client script.
/// </summary>
public override string TranslateToClientScript(DotvvmBindableControl control, DotvvmProperty property)
{
ValidateExpression(Expression);
// find the parent markup control and calculate number of DataContext changes
int numberOfDataContextChanges;
var current = control.GetClosestControlBindingTarget(out numberOfDataContextChanges) as DotvvmBindableControl;
current.EnsureControlHasId();
return string.Join(".", Enumerable.Range(0, numberOfDataContextChanges).Select(i => "$parent").Concat(new[] { "$controlState()", current.ID + "()", Expression }));
}
/// <summary>
/// Evaluates the specified expression.
/// </summary>
public override object Evaluate(DotvvmBindableControl control, DotvvmProperty property)
{
ValidateExpression(Expression);
// find the parent markup control and calculate number of DataContext changes
int numberOfDataContextChanges;
var current = control.GetClosestControlBindingTarget(out numberOfDataContextChanges) as DotvvmBindableControl;
if (current == null || !current.RequiresControlState)
{
throw new Exception("The {controlState: ...} binding can only be used in a markup control that supports ControlState!"); // TODO: exception handling
}
else
{
object value;
return current.ControlState.TryGetValue(Expression, out value) ? value : DefaultValue;
}
}
private DotvvmControl GetRootControl(DotvvmBindableControl control)
{
return control.GetClosestControlBindingTarget();
}
