public AssignPropertyBuilder(DependencyEngine engine, Expression <Func <T> > targetMemberExpression, string nodeId)
{
var memberExpression = targetMemberExpression.Body as MemberExpression;
if (memberExpression == null)
{
throw new ArgumentException("Expression must be a member (field/property) accessor, for example foo.Bar", "targetMemberExpression");
}
var propertyInfo = memberExpression.Member as PropertyInfo;
var fieldInfo = memberExpression.Member as FieldInfo;
if (propertyInfo == null && fieldInfo == null)
{
throw new ArgumentException("Only fields and properties are supported", "targetMemberExpression");
}
if (propertyInfo != null && !propertyInfo.CanWrite)
{
throw new ArgumentException("Property must be writable", "targetMemberExpression");
}
if (fieldInfo != null && fieldInfo.IsInitOnly)
{
throw new ArgumentException("Field cannot be read-only", "targetMemberExpression");
}
this.engine = engine;
targetMemberDefinition = CreateMemberDefinition(targetMemberExpression, nodeId, true, true);
}
// TODO this needs to go somewhere else, some factory
public static MemberDefinition <T> CreateMemberDefinition <T>(Expression <Func <T> > expression, string nodeId, bool calculateChildren, bool isWritable, string pathOverride = null)
{
var parameterExpression = Expression.Parameter(typeof(T));
var targetAssignmentLambda = isWritable ? Expression.Lambda <Action <T> >(Expression.Assign(expression.Body, parameterExpression), parameterExpression) : null;
var memberDefinition = new MemberDefinition <T>(expression, targetAssignmentLambda, nodeId, isWritable, pathOverride);
if (calculateChildren)
{
var sourceDefinitions = ExpressionParser.GetChildSources(expression);
// Property expressions always return themselves as a child, so skip
memberDefinition.SourcePaths.AddRange(sourceDefinitions.Single().SourcePaths);
}
return(memberDefinition);
}
static bool IsRoot <T>(MemberDefinition <T> memberDefinition)
{
return(!memberDefinition.SourcePaths.Any(s => s.FullPath != "this"));
}