/// <summary>
/// Map a external field (name) to a property (expression)
/// </summary>
/// <param name="fieldKey">The field id sent by the api client (e.g. CityName)</param>
/// <param name="fieldExpression">The sort delegate (Lambda expression)</param>
protected void MapSort(string fieldKey, Expression <Func <T, object> > fieldExpression)
{
// Hack EF object expressions
LambdaExpression lambda = fieldExpression.Normalize();
if (!SortMappings.ContainsKey(fieldKey))
{
SortMappings.Add(fieldKey, lambda);
}
}
/// <summary>
/// Mapeia um identificador de campo (nome) à uma propriedade (expressão)
/// </summary>
/// <param name="fieldKey">Identificador do campo</param>
/// <param name="fieldExpression">Expressão da propriedade (LAMBDA)</param>
public void MapSort(string fieldKey, Expression <Func <EntityType, object> > fieldExpression)
{
LambdaExpression lambda = fieldExpression;
// Expressoes lambda com tipos diferente de string sao construidos com o Metodo "Convert"
// Esse algoritmo remove essa chamada da expressao, deixando a chamada pura à propriedade
// Exemplo: DE: i => Convert(i.Active) | PARA: i => i.Active
var unary = fieldExpression.Body as UnaryExpression;
if (unary != null)
{
lambda = Expression.Lambda(unary.Operand, fieldExpression.Parameters);
}
if (!SortMappings.ContainsKey(fieldKey))
{
SortMappings.Add(fieldKey, lambda);
}
}