/// <summary>
/// Called by QueryProvider to execute queries
/// </summary>
/// <param name="expression">ExpressionTree to parse</param>
/// <returns>list of objects with query results</returns>
internal object Execute(Expression expression, bool isEnumerable)
{
Dictionary <string, string> parameters = null;
// request processor is specific to request type (i.e. Status, User, etc.)
var reqProc = CreateRequestProcessor(expression, isEnumerable);
// we need the where expression because it contains the criteria for the request
var whereFinder = new FirstWhereClauseFinder();
var whereExpression = whereFinder.GetFirstWhere(expression);
if (whereExpression != null)
{
var lambdaExpression = (LambdaExpression)
((UnaryExpression)(whereExpression.Arguments[1])).Operand;
// translate variable references in expression into constants
lambdaExpression = (LambdaExpression)Evaluator.PartialEval(lambdaExpression);
parameters = reqProc.GetParameters(lambdaExpression);
}
// construct REST endpoint, based on input parameters
var url = reqProc.BuildURL(parameters);
// execute the query and return results
var queryableList = TwitterExecute.QueryTwitter(url, reqProc);
if (isEnumerable)
{
return(queryableList);
}
else
{
return(queryableList[0]);
}
}
public void GetParametersTest()
{
var dmProc = new DirectMessageRequestProcessor<DirectMessage>();
var ctx = new TwitterContext();
var directMessages =
from tweet in ctx.DirectMessage
where tweet.Type == DirectMessageType.SentTo
select tweet;
var whereFinder = new FirstWhereClauseFinder();
var whereExpression = whereFinder.GetFirstWhere(directMessages.Expression);
var lambdaExpression = (LambdaExpression)((UnaryExpression)(whereExpression.Arguments[1])).Operand;
lambdaExpression = (LambdaExpression)Evaluator.PartialEval(lambdaExpression);
var queryParams = dmProc.GetParameters(lambdaExpression);
Assert.IsTrue(
queryParams.Contains(
new KeyValuePair<string, string>("Type", ((int)DirectMessageType.SentTo).ToString())));
}
public void GetParametersTest()
{
var reqProc = new StatusRequestProcessor<Status>();
var ctx = new TwitterContext();
var publicQuery =
from tweet in ctx.Status
where tweet.Type == StatusType.Public
select tweet;
var whereFinder = new FirstWhereClauseFinder();
var whereExpression = whereFinder.GetFirstWhere(publicQuery.Expression);
var lambdaExpression = (LambdaExpression)((UnaryExpression)(whereExpression.Arguments[1])).Operand;
lambdaExpression = (LambdaExpression)Evaluator.PartialEval(lambdaExpression);
var queryParams = reqProc.GetParameters(lambdaExpression);
Assert.IsTrue(
queryParams.Contains(
new KeyValuePair<string, string>("Type", ((int)StatusType.Public).ToString())));
}
