public override Type GetChildDataContextType(Type dataContext, Type parentDataContext, RedwoodControl control)
{
var type = control.GetType();
var property = type.GetProperty(PropertyName);
if (property == null) throw new Exception($"property { PropertyName } does not exists on { type.FullName }.");
return property.GetValue(control).GetType();
}
public static Type GetDataContextType(Type parentDataContext, RedwoodControl control)
{
var dataContext = (control as RedwoodBindableControl)?.DataContext?.GetType() ?? parentDataContext;
var attributes = control.GetType().GetCustomAttributes<DataContextChangeAttribute>();
foreach (var attribute in attributes)
{
dataContext = attribute.GetChildDataContextType(dataContext, parentDataContext, control);
}
return dataContext;
}
/// <summary>
/// Validates the control command.
/// </summary>
public void ValidateControlCommand(string[] path, string command, RedwoodControl viewRootControl, RedwoodControl targetControl, ref string validationTargetPath)
{
// find the binding
RedwoodProperty targetProperty;
var binding = FindControlCommandBinding(path, command, viewRootControl, (RedwoodBindableControl)targetControl, ref validationTargetPath, out targetProperty);
if (binding == null)
{
ThrowEventValidationException();
return;
}
}
public override Type GetChildDataContextType(Type dataContext, Type parentDataContext, RedwoodControl control)
{
if(dataContext.IsArray)
{
return dataContext.GetElementType();
}
var ienumerable = dataContext.GetInterfaces()
.FirstOrDefault(i => i.IsGenericType && i.GetGenericTypeDefinition() == typeof(IEnumerable<>));
if (ienumerable != null)
{
return ienumerable.GetGenericArguments()[0];
}
else throw new NotSupportedException();
}
/// <summary>
/// Validates the command.
/// </summary>
public void ValidateCommand(string[] path, string command, RedwoodControl viewRootControl, ref string validationTargetPath)
{
// find the binding
RedwoodProperty targetProperty;
RedwoodBindableControl targetControl;
var binding = FindCommandBinding(path, command, viewRootControl, ref validationTargetPath, out targetControl, out targetProperty);
if (binding == null)
{
ThrowEventValidationException();
return;
}
// validate the command against the control
if (targetControl is IEventValidationHandler)
{
if (!((IEventValidationHandler)targetControl).ValidateCommand(targetProperty))
{
ThrowEventValidationException();
return;
}
}
}
/// <summary>
/// Finds the binding of the specified type on the specified viewmodel path.
/// </summary>
private CommandBindingExpression FindCommandBinding(string[] path, string command, RedwoodControl viewRootControl, ref string validationTargetPath, out RedwoodBindableControl targetControl, out RedwoodProperty targetProperty)
{
// walk the control tree and find the path
CommandBindingExpression result = null;
RedwoodBindableControl resultControl = null;
RedwoodProperty resultProperty = null;
string resultValidationTargetPath = validationTargetPath;
var walker = new NonEvaluatingControlTreeWalker(viewRootControl);
walker.ProcessControlTree((ViewModel, control) =>
{
// compare path
if (result == null && control is RedwoodBindableControl && ViewModelPathComparer.AreEqual(path, walker.CurrentPathArray))
{
// find bindings of current control
var bindableControl = (RedwoodBindableControl)control;
var binding = bindableControl.GetAllBindings().Where(p => p.Value is CommandBindingExpression)
.FirstOrDefault(b => b.Value.Expression == command);
if (binding.Key != null)
{
// we have found the binding, now get the validation path
var currentValidationTargetPath = KnockoutHelper.GetValidationTargetExpression(bindableControl, true);
if (currentValidationTargetPath == resultValidationTargetPath)
{
// the validation path is equal, we have found the binding
result = (CommandBindingExpression)binding.Value;
resultControl = bindableControl;
resultProperty = binding.Key;
resultValidationTargetPath = KnockoutHelper.GetValidationTargetExpression(bindableControl, false);
}
}
}
});
validationTargetPath = resultValidationTargetPath;
targetControl = resultControl;
targetProperty = resultProperty;
return result;
}
public abstract void CreateControls(RedwoodRequestContext context, RedwoodControl container);
/// <summary>
/// Evaluates the command arguments.
/// </summary>
private static object[] EvaluateCommandArguments(object viewModel, RedwoodControl viewRootControl, List<object> hierarchy, InvocationExpressionSyntax node)
{
var arguments = node.ArgumentList.Arguments.Select(a =>
{
var evaluator = new ExpressionEvaluationVisitor(viewModel, viewRootControl, hierarchy);
return evaluator.Visit(a);
}).ToArray();
return arguments;
}
/// <summary>
/// Finds the method on control.
/// </summary>
private static MethodInfo FindMethodOnControl(RedwoodControl targetControl, InvocationExpressionSyntax node)
{
MethodInfo method;
var methods = targetControl.GetType().GetMethods().Where(m => m.Name == node.Expression.ToString()).ToList();
if (methods.Count == 0)
{
throw new Exception(string.Format("The control '{0}' does not have a function '{1}'!", targetControl.GetType().FullName, node.Expression));
}
else if (methods.Count > 1)
{
throw new Exception(string.Format("The control '{0}' has more than one function called '{1}'! Overloading in {{controlCommand: ...}} binding is not yet supported!", targetControl.GetType().FullName, node.Expression));
}
method = methods[0];
return method;
}
public void BuildContent(RedwoodRequestContext context, RedwoodControl container)
{
var controlBuilderFactory = context.Configuration.ServiceLocator.GetService<IControlBuilderFactory>();
var control = BuildContentBody(controlBuilderFactory);
container.Children.Add(control);
}
public abstract Type GetChildDataContextType(Type dataContext, Type parentDataContext, RedwoodControl control);
public void OnAddedToParent(RedwoodControl parent)
{
SetParent(parent);
}
public override void CreateControls(RedwoodRequestContext context, RedwoodControl container)
{
ContentTemplate.BuildContent(context, container);
}
/// <summary>
/// Invokes the specified method on all controls in the page control tree.
/// </summary>
private void InvokePageLifeCycleEventRecursive(RedwoodControl control, Action<RedwoodControl> action)
{
foreach (var child in control.GetThisAndAllDescendants())
{
action(child);
}
}
/// <summary>
/// Resolves the command called on the ViewModel.
/// </summary>
public ActionInfo GetFunction(RedwoodControl viewRootControl, RedwoodRequestContext context, string[] path, string command)
{
return GetFunction(null, viewRootControl, context, path, command);
}
/// <summary>
/// Translates the binding expression to the knockout command name.
/// </summary>
public static string TranslateToKnockoutCommand(RedwoodControl target, RedwoodProperty property, CommandMarkupExpression binding)
{
return DataContextPathBuilder.Default.BuildPath(target);
}
/// <summary>
/// Resolves the command called on the RedwoodControl.
/// </summary>
public ActionInfo GetFunction(RedwoodControl targetControl, RedwoodControl viewRootControl, RedwoodRequestContext context, string[] path, string command)
{
// event validation
var validationTargetPath = context.ModelState.ValidationTargetPath;
if (targetControl == null)
{
eventValidator.ValidateCommand(path, command, viewRootControl, ref validationTargetPath);
}
else
{
eventValidator.ValidateControlCommand(path, command, viewRootControl, targetControl, ref validationTargetPath);
}
// resolve the path in the view model
var viewModel = context.ViewModel;
List<object> hierarchy = ResolveViewModelPath(viewModel, viewRootControl, path);
// resolve validation target
if (!string.IsNullOrEmpty(validationTargetPath))
{
var hierarchyCopy = new List<object>(hierarchy);
context.ModelState.ValidationTarget = EvaluateOnViewModel(viewModel, viewRootControl, hierarchyCopy, validationTargetPath);
}
// find the function
var tree = CSharpSyntaxTree.ParseText(command, new CSharpParseOptions(LanguageVersion.CSharp5, DocumentationMode.Parse, SourceCodeKind.Interactive));
var expr = tree.EnsureSingleExpression();
var node = expr.ChildNodes().First() as InvocationExpressionSyntax;
if (node == null)
{
throw new ParserException("The expression in {command: ...} binding must be a method call!");
}
MethodInfo method;
object target;
if (targetControl != null)
{
// the function is invoked on the control object
method = FindMethodOnControl(targetControl, node);
target = targetControl;
}
else
{
// the function is invoked on the viewmodel
method = FindMethodOnViewModel(viewModel, viewRootControl, hierarchy, node, out target);
}
// validate that we can safely call the method
ValidateMethod(method);
// parse arguments
var arguments = EvaluateCommandArguments(viewModel, viewRootControl, hierarchy, node);
// return the delegate for further invoke
return new ActionInfo()
{
IsControlCommand = target != null,
Target = target,
MethodInfo = method,
Arguments = method.GetParameters().Select((param, index) => new ActionParameterInfo()
{
ParameterInfo = param,
Value = arguments[index]
}).ToArray()
};
}
/// <summary>
/// Resolves the path in the view model and returns the target object.
/// </summary>
private List<object> ResolveViewModelPath(object viewModel, RedwoodControl viewRootControl, string[] path)
{
var visitor = new ExpressionEvaluationVisitor(viewModel, viewRootControl);
var outputHierarchy = new List<object>();
outputHierarchy.Add(viewModel);
foreach (var expression in path)
{
// evaluate path fragment
var pathTree = CSharpSyntaxTree.ParseText(expression, new CSharpParseOptions(LanguageVersion.CSharp5, DocumentationMode.Parse, SourceCodeKind.Interactive));
var pathExpr = pathTree.EnsureSingleExpression();
var result = visitor.Visit(pathExpr);
visitor.BackupCurrentPosition(result, expression);
outputHierarchy.Add(result);
}
return outputHierarchy;
}
/// <summary>
/// Evaluates the expression the on view model with specified hierarchy.
/// </summary>
private object EvaluateOnViewModel(object viewModel, RedwoodControl viewRootControl, List<object> hierarchy, string expression)
{
var pathTree = CSharpSyntaxTree.ParseText(expression, new CSharpParseOptions(LanguageVersion.CSharp5, DocumentationMode.Parse, SourceCodeKind.Interactive));
var pathExpr = pathTree.EnsureSingleExpression();
var visitor = new ExpressionEvaluationVisitor(viewModel, viewRootControl, hierarchy);
return visitor.Visit(pathExpr);
}
/// <summary>
/// Finds the method on view model.
/// </summary>
private static MethodInfo FindMethodOnViewModel(object viewModel, RedwoodControl viewRootControl, List<object> hierarchy, InvocationExpressionSyntax node, out object target)
{
MethodInfo method;
var methodEvaluator = new ExpressionEvaluationVisitor(viewModel, viewRootControl, hierarchy)
{
AllowMethods = true
};
method = methodEvaluator.Visit(node.Expression) as MethodInfo;
if (method == null)
{
throw new Exception("The command path was not found!");
}
target = methodEvaluator.MethodInvocationTarget;
return method;
}