/// <summary>
/// Gets all data context on the path to root
/// </summary>
public static object[] GetDataContexts(DotvvmBindableControl contextControl, bool seeThis)
{
var context = seeThis ? contextControl.GetValue(DotvvmBindableControl.DataContextProperty, false) : null;
return
(context == null ? new object[0] : new[] { context })
.Concat(contextControl.GetAllAncestors().OfType<DotvvmBindableControl>()
.Where(c => c.properties.ContainsKey(DotvvmBindableControl.DataContextProperty))
.Select(c => c.GetValue(DotvvmBindableControl.DataContextProperty, false)))
.ToArray();
}
/// <summary>
/// Evaluates the data context path and returns the visitor with hierarchy.
/// </summary>
private ExpressionEvaluationVisitor EvaluateDataContextPath(DotvvmBindableControl contextControl)
{
// get the hierarchy of DataContext the control is in
var dataContexts = contextControl.GetAllAncestors().OfType<DotvvmBindableControl>()
.Select(c => new { Binding = c.GetBinding(DotvvmBindableControl.DataContextProperty, false), Control = c })
.Where(b => b.Binding != null)
.ToList();
// evaluate the DataContext path
var viewRoot = contextControl.GetRoot();
var visitor = new ExpressionEvaluationVisitor(GetRootDataContext(viewRoot), viewRoot) { AllowMethods = AllowMethods };
for (var i = dataContexts.Count - 1; i >= 0; i--)
{
var binding = dataContexts[i].Binding;
if (!(binding is ValueBindingExpression))
{
throw new Exception("The DataContext property can only contain value bindings!"); // TODO: exception handling
}
var pathExpression = ((ValueBindingExpression)binding).GetViewModelPathExpression(dataContexts[i].Control, DotvvmBindableControl.DataContextProperty);
EvaluateBinding(visitor, binding.Expression, pathExpression);
}
return visitor;
}
