private object PerformDataBinding(string expression, BindingContext context, bool ignoreErrors)
{
object value;
int index = expression.IndexOf('.');
if (index > 0)
{
string symbolName = expression.Substring(0, index).Trim();
value = context.ResolveSymbol(symbolName, !ignoreErrors);
if (value != null)
{
expression = expression.Substring(index + 1).Trim();
try
{
value = PerformDataBinding(value, expression, context);
}
catch
{
if (!ignoreErrors) throw;
value = null;
}
}
}
else
{
value = context.ResolveSymbol(expression, !ignoreErrors);
}
return value;
}
/// <summary>
/// Evaluates the specified expression.
/// </summary>
/// <param name="expression">The expression.</param>
/// <param name="context">The context.</param>
/// <returns></returns>
public object Evaluate(string expression, BindingContext context)
{
bool ignoreErrors;
if (IsDataBindingExpression(ref expression, out ignoreErrors))
{
return PerformDataBinding(expression, context, ignoreErrors);
}
return expression;
}
public Delegate CreateActionDelegate(Type genericEventHandlerType, EventDescriptor eventDescriptor,
BindingContext context)
{
Type eventArgsType = EventUtil.GetEventArgsType(eventDescriptor);
EventHandlerInfo eventHandlerInfo =
GetEventHandlerInfo(genericEventHandlerType, eventArgsType);
if (eventHandlerInfo != null)
{
object eventHandler = Activator.CreateInstance(
eventHandlerInfo.EventHandlerType, new object[] {context});
return Delegate.CreateDelegate(eventDescriptor.EventType, eventHandler,
eventHandlerInfo.EventMethod);
}
return null;
}
private object PerformIndexDataBinding(object target, string expression,
BindingContext context, int start)
{
int end;
string indexProperty = expression.Substring(0, start).Trim();
if (!string.IsNullOrEmpty(indexProperty))
{
target = DataBinder.Eval(target, indexProperty);
}
string indexExpression = ExtractIndexerExpression(expression, start, out end);
object indexer = Evaluate(indexExpression, context);
indexExpression = string.Format("{0}{1}{2}", indexExprStartChars[0],
indexer, indexExprEndChars[0]);
target = DataBinder.Eval(target, indexExpression);
expression = expression.Substring(end + 1).TrimStart('.');
return PerformDataBinding(target, expression, context);
}
private object PerformDataBinding(object target, string expression, BindingContext context)
{
if (string.IsNullOrEmpty(expression)) return target;
int indexStart = expression.IndexOfAny(indexExprStartChars);
if (indexStart < 0)
{
int formatIndex = expression.LastIndexOf(':');
if (formatIndex < 0)
{
return DataBinder.Eval(target, expression);
}
else
{
string format = expression.Substring(formatIndex + 1);
expression = expression.Substring(0, formatIndex);
return DataBinder.Eval(target, expression, format);
}
}
else
{
return PerformIndexDataBinding(target, expression, context, indexStart);
}
}
/// <summary>
/// Initializes a new instance of the <see cref="AbstractEventScope"/> class.
/// </summary>
/// <param name="context">The context.</param>
protected AbstractEventScope(BindingContext context)
{
this.context = context;
}
/// <summary>
/// Adds the action arguments.
/// </summary>
/// <param name="context">The context.</param>
/// <param name="resolvedActionArgs">The resolved action args.</param>
protected virtual void AddActionArguments(BindingContext context,
IDictionary resolvedActionArgs)
{
}
/// <summary>
/// Adds the action arguments.
/// </summary>
/// <param name="context">The context.</param>
/// <param name="resolvedActionArgs">The resolved action args.</param>
void IBindingScope.AddActionArguments(BindingContext context,
IDictionary resolvedActionArgs)
{
AddActionArguments(context, resolvedActionArgs);
}
/// <summary>
/// Adds the action arguments.
/// </summary>
/// <param name="context">The context.</param>
/// <param name="resolvedActionArgs">The resolved action args.</param>
protected override void AddActionArguments(BindingContext context,
IDictionary resolvedActionArgs)
{
context.ResolveActionArguments(action.ActionArguments, resolvedActionArgs);
}
