private static async Task <Category> GetCategoryAsync(IPersistenceService persistence, int userId, string name)
{
var category = await
persistence.GetEntitySet <Category>()
.SingleOrDefaultAsync(c => c.UserId == userId && c.Name == name);
if (category == null)
{
throw new ValidationErrorException("Category with '{0}' name does not exist.", name);
}
return(category);
}
private async static Task <Transaction> GetTransactionAsync(IPersistenceService persistence, string id, int categoryId)
{
Guid guid;
if (!Guid.TryParseExact(id, "N", out guid))
{
throw new ValidationErrorException("Transaction ID has invalid format.");
}
var transaction = await
persistence.GetEntitySet <Transaction>()
.SingleOrDefaultAsync(t => t.Id == guid && t.CategoryId == categoryId);
if (transaction == null)
{
throw new ValidationErrorException("Transaction with '{0}' ID does not exist.", id);
}
return(transaction);
}