/// <summary>
/// 从远程获取对象实例。
/// </summary>
/// <param name="parameter">获取前检索用的参数信息。</param>
/// <param name="targetType">需要获取的最终类型。</param>
/// <returns>符合条件的实例对象。</returns>
public object GetObject(RemoteDataParameter parameter, Type targetType)
{
var uri = parameter.BuildUri();
var method = "GetByOData";
if (parameter.Executor == "Count" || parameter.Executor == "LongCount")
{
method = "CountByOData";
}
else if (parameter.Executor == "Any")
{
method = "AnyByOData";
}
var absoluteUrl = string.Format("{0}#{1}", Client.BaseAddress, method);
if (parameter.Executor == "First" || parameter.Executor == "FirstOrDefault")
{
targetType = typeof(IQueryable <>).MakeGenericType(targetType);
}
var result = Client.GetAsync(method).FetchValue(targetType, "GET", absoluteUrl);
if (parameter.Executor == "First" || parameter.Executor == "FirstOrDefault")
{
return((result as IEnumerable).OfType <object>().FirstOrDefault());
}
return(result);
}
/// <summary>
/// Creates an array of Database compatible parameters from the provided array of parameters
/// </summary>
/// <param name="inputParams">the parameters that were provided by the client</param>
/// <param name="connection">the connection that can be used to re-create parameters that were lost</param>
/// <returns>an array of parameters that is compatible to the underlaying database connection</returns>
private IDbDataParameter[] BuildParameters(IDbDataParameter[] inputParams, IDbWrapper connection)
{
IDbDataParameter[] retVal = null;
if (parameters != null)
{
retVal = new IDbDataParameter[inputParams.Length];
for (int i = 0; i < inputParams.Length; i++)
{
RemoteDataParameter param = inputParams[i] as RemoteDataParameter;
if (param == null)
{
throw new InvalidOperationException(
"Need to provide Parameters that were created by the connection!");
}
lock (this.parameters)
{
IDbDataParameter dbParam;
if (this.parameters.ContainsKey(param.ObjectId))
{
dbParam = this.parameters[param.ObjectId];
}
else
{
dbParam = connection.GetParameter(param.ParameterName, param.Value);
}
param.ApplyTo(dbParam);
retVal[i] = dbParam;
}
}
}
return(retVal);
}
public object Execute(Expression expression)
{
var dataParameter = new RemoteDataParameter();
var methodCallExpression = expression as MethodCallExpression;
dataParameter.Executor = methodCallExpression.Method.Name;
var processor = RemoteObjectContext.DefaultObjectResolver.GetInstance <IExpressionProcessor>();
processor.DataParameter = dataParameter;
processor.Writer = RemoteObjectContext.DefaultObjectResolver.GetInstance <IExpressionWriter>();
processor.Build(methodCallExpression);
return(DataFetcher.GetObject(dataParameter, methodCallExpression.Method.ReturnType));
}
private string ReplenishURL(IMethodCallMessage methodCall)
{
var data = new List <string>();
var parameters = methodCall.MethodBase.GetParameters();
for (int i = 0; i < methodCall.ArgCount; i++)
{
var argName = methodCall.GetInArgName(i);
var arg = methodCall.GetInArg(i);
var parameter = parameters.First(p => p.Name == argName);
var binding = parameter.GetCustomAttribute <ParameterBindingAttribute>();
if (binding == null)
{
continue;
}
if (binding.BindingType == "Uri")
{
data.Add(string.Format("{0}={1}", argName, Uri.EscapeUriString(ReferenceEquals(arg, null) ? "null" : arg.ToString())));
}
else if (binding.BindingType == "ODataParameter" && !ReferenceEquals(arg, null))
{
var dataParameter = new RemoteDataParameter();
var processor = RemoteObjectContext.DefaultObjectResolver.GetInstance <IExpressionProcessor>();
processor.Writer = RemoteObjectContext.DefaultObjectResolver.GetInstance <IExpressionWriter>();
processor.DataParameter = dataParameter;
processor.Build((arg as LambdaExpression).Body as MethodCallExpression);
data.Add(dataParameter.BuildUri());
}
}
return(string.Join("&", data));
}
