public BindingExpression(BindingMode mode, Binding.Parsing.Expressions.BindingPathExpression path, RedwoodProperty sourceProperty = null, RedwoodBindable source = null)
{
Path = path;
Mode = mode;
SourceProperty = sourceProperty ?? Controls.RedwoodControl.DataContextProperty;
Source = source;
}
public static CommandMarkupExpression GetCommandExpressionOrNull(RedwoodProperty property, RedwoodBindable obj)
{
var value = obj.GetRawValue(property);
if (value is CommandMarkupExpression)
{
return (CommandMarkupExpression)value;
}
return null;
}
public static BindingMarkup GetBindingExpressionOrNull(RedwoodProperty property, RedwoodBindable obj)
{
var value = obj.GetRawValue(property);
if (value is BindingMarkup)
{
return (BindingMarkup)value;
}
return null;
}
/// <summary>
/// Translates to knockout property.
/// </summary>
public static string TranslateToKnockoutProperty(RedwoodBindable target, RedwoodProperty property, BindingMarkup binding)
{
var path = binding.Path;
// TODO: support for other than two-way modes
var sb = new StringBuilder();
var result = TranslateToKnockoutProperty(path, sb, allowConstants: false);
if (result != null)
{
ThrowBindingContainsUnsupportedExpression();
}
return sb.ToString();
}
/// <summary>
/// Gets the chain of data context property values.
/// </summary>
private static Stack<Tuple<RedwoodBindable, BindingMarkup>> GetDataContextBindingChain(RedwoodBindable control)
{
var parents = new Stack<Tuple<RedwoodBindable, BindingMarkup>>();
while (control != null)
{
var binding = (BindingMarkup)control.GetRawValue(RedwoodControl.DataContextProperty, true);
if (binding != null)
{
parents.Push(new Tuple<RedwoodBindable, BindingMarkup>(control, binding));
}
control = control.Parent;
}
return parents;
}
/// <summary>
/// Builds the path.
/// </summary>
public string BuildPath(RedwoodBindable control)
{
var parents = GetDataContextBindingChain(control);
var sb = new StringBuilder();
while (parents.Count > 0)
{
var item = parents.Pop();
if (sb.Length > 0)
{
sb.Append(".");
}
sb.Append(KnockoutBindingHelper.TranslateToKnockoutProperty(item.Item1, RedwoodControl.DataContextProperty, item.Item2));
}
return sb.ToString();
}
protected internal void SetParent(RedwoodBindable parent)
{
VerifyAccess();
this.parent = parent;
}
public object Evaluate(RedwoodBindable redwoodBindable)
{
// TODO: implementat
return null;
}
private object GetDataContext(RedwoodBindable target, RedwoodProperty property)
{
object result = null;
bool isDataContextBinding = (property == SourceProperty);
if (isDataContextBinding)
{
// if this is binding on "DataContext" - read value from parent
if (target.Parent != null)
result = target.Parent.GetRawValue(SourceProperty);
}
else
{
result = target.GetValue(SourceProperty);
}
return result;
}
public override object GetValue(RedwoodBindable target, RedwoodProperty property)
{
var dataContext = GetDataContext(Source ?? target, property);
var result = Path.Evaluate(dataContext);
return result;
}
public virtual object GetValue(RedwoodBindable target, RedwoodProperty property)
{
return RedwoodProperty.UnsetValue;
}