/// <summary>
/// Evaluates the specified expression in the context of specified control.
/// </summary>
public object Evaluate(ValueBindingExpression expression, DotvvmProperty property, DotvvmBindableControl contextControl)
{
var visitor = EvaluateDataContextPath(contextControl);
// evaluate the final expression
EvaluateBinding(visitor, expression.Expression, expression.GetViewModelPathExpression(contextControl, property));
return visitor.Result;
}
/// <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>
/// 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>
/// 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 }));
}
public void Add(string name, DotvvmBindableControl control, DotvvmProperty property, Action nullBindingAction)
{
var binding = control.GetValueBinding(property);
if (binding == null)
{
nullBindingAction();
}
else
{
info.Add(new KnockoutBindingInfo() { Name = name, Expression = control.GetValueBinding(property).GetKnockoutBindingExpression() });
}
}
protected object ExecDelegate(DotvvmBindableControl contextControl, bool seeThis, bool setRootControl = false)
{
var dataContexts = GetDataContexts(contextControl, seeThis);
var control = setRootControl ? GetRootControl(contextControl) : null;
try
{
return Delegate(dataContexts, control);
}
catch (NullReferenceException)
{
return null;
}
}
/// <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;
}
}
public override object Evaluate(DotvvmBindableControl control, DotvvmProperty property)
{
// I can execute the delegate, or find the property and get its value
// TODO: whats better ??
return ExecDelegate(control, property != DotvvmBindableControl.DataContextProperty, setRootControl: true);
//// find the parent markup control and calculate number of DataContext changes
//int numberOfDataContextChanges;
//var current = control.GetClosestControlBindingTarget(out numberOfDataContextChanges);
//// get the property
//var sourceProperty = DotvvmProperty.ResolveProperty(current.GetType(), OriginalString);
//if (sourceProperty == null)
//{
// throw new Exception(string.Format("The markup control of type '{0}' does not have a property '{1}'!", current.GetType(), ExpressionTree)); // TODO: exception handling
//}
//// check whether the property contains binding
//if (current is DotvvmBindableControl)
//{
// var originalBinding = ((DotvvmBindableControl)current).GetBinding(sourceProperty);
// if (originalBinding != null && originalBinding.GetType() == typeof(ValueBindingExpression))
// {
// // ValueBindingExpression must be modified to be evaluated against the original DataContext
// return new ValueBindingExpression(string.Join(".",
// Enumerable.Repeat("$parent", numberOfDataContextChanges)
// .Concat(new[] { originalBinding.OriginalString })));
// }
// else if (originalBinding != null)
// {
// return originalBinding;
// }
//}
//// otherwise evaluate on server
//return current.GetValue(sourceProperty);
}
/// <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;
}
private DotvvmControl GetRootControl(DotvvmBindableControl control)
{
return control.GetClosestControlBindingTarget();
}
protected void ExecUpdateDelegate(DotvvmBindableControl contextControl, object value, bool seeThis, bool setRootControl = false)
{
var dataContexts = GetDataContexts(contextControl, seeThis);
var control = setRootControl ? GetRootControl(contextControl) : null;
UpdateDelegate(dataContexts, control, value);
}
public override object Evaluate(DotvvmBindableControl control, DotvvmProperty property)
{
throw new NotImplementedException();
}
/// <summary>
/// Updates the viewModel with the new value.
/// </summary>
public virtual void UpdateSource(object value, DotvvmBindableControl control, DotvvmProperty property)
{
ExecUpdateDelegate(control, value, property != DotvvmBindableControl.DataContextProperty);
}
/// <summary>
/// Evaluates the binding.
/// </summary>
public virtual object Evaluate(DotvvmBindableControl control, DotvvmProperty property)
{
return ExecDelegate(control, property != DotvvmBindableControl.DataContextProperty);
}
/// <summary>
/// Updates the value.
/// </summary>
public override void UpdateSource(object value, DotvvmBindableControl control, DotvvmProperty property)
{
control.ControlState[property.Name] = value;
}
/// <summary>
/// Evaluates the PropertyInfo for the expression.
/// </summary>
public PropertyInfo EvaluateProperty(ValueBindingExpression expression, DotvvmProperty property, DotvvmBindableControl control, out object target)
{
var visitor = EvaluateDataContextPath(control);
target = visitor.Result;
// evaluate the final expression
var node = ParseBinding(expression.Expression);
string propertyName = null;
if (node is IdentifierNameSyntax)
{
propertyName = ((IdentifierNameSyntax)node).ToString();
}
else if (node is MemberAccessExpressionSyntax)
{
target = visitor.Visit(((MemberAccessExpressionSyntax)node).Expression);
propertyName = ((MemberAccessExpressionSyntax)node).Name.ToString();
}
if (propertyName != null && !visitor.IsSpecialPropertyName(propertyName))
{
var propertyInfo = target.GetType().GetProperty(propertyName);
if (propertyInfo != null)
{
return propertyInfo;
}
}
throw new NotSupportedException(string.Format("Cannot update the source of the binding '{0}'!", expression.Expression));
}
public override object Evaluate(DotvvmBindableControl control, DotvvmProperty property)
{
return ExecDelegate(control, true, true);
}
/// <summary>
/// Finds the binding of the specified type on the specified viewmodel path.
/// </summary>
private FindBindingResult FindControlCommandBinding(string[] path, string commandId, DotvvmControl viewRootControl, DotvvmBindableControl targetControl, string validationTargetPath)
{
// walk the control tree and find the path
ControlCommandBindingExpression resultBinding = null;
DotvvmProperty resultProperty = null;
DotvvmBindableControl resultControl = null;
var walker = new ControlTreeWalker(viewRootControl);
walker.ProcessControlTree((control) =>
{
// compare path
if (control is DotvvmBindableControl && ViewModelPathComparer.AreEqual(path, walker.CurrentPathArray))
{
// find bindings of current control
var bindableControl = (DotvvmBindableControl)control;
var binding = bindableControl.GetAllBindings().Where(p => p.Value is ControlCommandBindingExpression)
.FirstOrDefault(b => b.Value.BindingId == commandId);
if (binding.Key != null)
{
// verify that the target control is the control command target
if (bindableControl.GetClosestControlBindingTarget() == targetControl)
{
// we have found the binding, now get the validation path
var currentValidationTargetPath = KnockoutHelper.GetValidationTargetExpression(bindableControl);
if (currentValidationTargetPath == validationTargetPath)
{
// the validation path is equal, we have found the binding
resultBinding = (ControlCommandBindingExpression)binding.Value;
resultProperty = binding.Key;
resultControl = bindableControl;
}
}
}
}
});
return new FindBindingResult
{
Property = resultProperty,
Binding = resultBinding,
Control = resultControl
};
}
