// Executes the expression tree that is passed to it.
internal static object Execute(Expression expression, bool isEnumerable)
{
// The expression must represent a query over the data source.
if (!IsQueryOverDataSource(expression))
{
throw new InvalidProgramException("No query over the data source was specified.");
}
// Find the call to Where() and get the lambda expression predicate.
InnermostWhereFinder whereFinder = new InnermostWhereFinder();
MethodCallExpression whereExpression = whereFinder.GetInnermostWhere(expression);
LambdaExpression lambdaExpression = (LambdaExpression)((UnaryExpression)(whereExpression.Arguments[1])).Operand;
// Send the lambda expression through the partial evaluator.
lambdaExpression = (LambdaExpression)Evaluator.PartialEval(lambdaExpression);
UserFinder uf = new UserFinder(lambdaExpression.Body);
List <string> names = uf.Usernames;
if (names.Count == 0)
{
throw new InvalidQueryException("You must specify atleast one name for this query.");
}
IQueryable <UserSession> queryableSessions = sessions.AsQueryable <UserSession>();
// Copy the expression tree that was passed in, changing only the first
// argument of the innermost MethodCallExpression.
ExpressionTreeModifier treeCopier = new ExpressionTreeModifier(queryableSessions);
Expression newExpressionTree = treeCopier.Visit(expression);
// This step creates an IQueryable that executes by replacing Queryable methods with Enumerable methods.
return(isEnumerable ? queryableSessions.Provider.CreateQuery(newExpressionTree) : queryableSessions.Provider.Execute(newExpressionTree));
}
// Executes the expression tree that is passed to it.
internal static object Execute(Expression expression, bool IsEnumerable, VismaNetAuthorization auth)
{
// The expression must represent a query over the data source.
if (!IsQueryOverDataSource(expression))
{
throw new InvalidProgramException("No query over the data source was specified.");
}
// Find the call to Where() and get the lambda expression predicate.
InnermostWhereFinder whereFinder = new InnermostWhereFinder();
MethodCallExpression whereExpression = whereFinder.GetInnermostWhere(expression);
var orderBy = GetOrderByExpression(expression);
var numberToRead = GetTakeExpression(expression);
LambdaExpression lambdaExpression;
IEnumerable <Customer> customers;
if (whereExpression != null && whereExpression.Arguments.Count > 1)
{
lambdaExpression = (LambdaExpression)((UnaryExpression)(whereExpression.Arguments[1])).Operand;
// Send the lambda expression through the partial evaluator.
lambdaExpression = (LambdaExpression)Evaluator.PartialEval(lambdaExpression);
// Get the place name(s) to query the Web service with.
var cf = new CustomerFinder(lambdaExpression.Body);
if (whereExpression.Method.Name.StartsWith("First"))
{
numberToRead = 1;
}
// Call the Web service and get the results.
customers = VismaNetApiHelper.FindCustomers(cf.UrlParams, auth, orderBy: orderBy, numberToRead: numberToRead);
}
else
{
customers = VismaNetApiHelper.FindCustomers(null, auth, orderBy: orderBy, numberToRead: numberToRead); // Return all customers
}
// Copy the IEnumerable places to an IQueryable.
IQueryable <Customer> queryableCustomers = customers.AsQueryable <Customer>();
// Copy the expression tree that was passed in, changing only the first
// argument of the innermost MethodCallExpression.
var treeCopier = new ExpressionTreeModifier <Customer>(queryableCustomers);
Expression newExpressionTree = treeCopier.Visit(expression);
// // This step creates an IQueryable that executes by replacing Queryable methods with Enumerable methods.
// if (IsEnumerable)
return(queryableCustomers.Provider.CreateQuery(newExpressionTree));
// else
// return queryableCustomers.Provider.Execute(newExpressionTree);
}
public static object ModifyExpression(Expression expression, IQueryable <Issue> issues, bool isEnumerable)
{
if (isEnumerable)
{
return(issues);
}
else
{
var treeCopier = new ExpressionTreeModifier(issues);
Expression newExpressionTree = treeCopier.Visit(expression);
return(issues.Provider.Execute(newExpressionTree));
}
}
/// <summary>
/// Executes the expression tree that is passed to it.
/// </summary>
/// <param name="expression">Expression Tree</param>
/// <param name="isEnumerable"></param>
/// <returns></returns>
internal static object Execute(Expression expression, bool isEnumerable)
{
// The expression must represent a query over the data source.
if (!IsQueryOverDataSource(expression))
{
throw new InvalidProgramException("No query over the data source was specified.");
}
// Find the call to Where() and get the lambda expression predicate.
var whereFinder = new InnermostWhereFinder();
var whereExpression = whereFinder.GetInnermostWhere(expression);
var lambdaExpression = (LambdaExpression)((UnaryExpression)(whereExpression.Arguments[1])).Operand;
// Send the lambda expression through the partial evaluator.
lambdaExpression = (LambdaExpression)Evaluator.PartialEval(lambdaExpression);
// Get the place name(s) to query the Web service with.
var lf = new TrackFinder(lambdaExpression.Body);
var locations = lf.TrackNames;
if (locations.Count == 0)
{
throw new InvalidQueryException("You must specify at least one place name in your query.");
}
// Call the Web service and get the results.
Track[] places = WebServiceHelper.GetTracks(locations);
// Copy the IEnumerable places to an IQueryable.
IQueryable <Track> queryablePlaces = places.AsQueryable();
// Copy the expression tree that was passed in, changing only the first
// argument of the innermost MethodCallExpression.
var treeCopier = new ExpressionTreeModifier(queryablePlaces);
var newExpressionTree = treeCopier.Visit(expression);
// This step creates an IQueryable that executes by replacing Queryable methods with Enumerable methods.
if (isEnumerable)
{
return(queryablePlaces.Provider.CreateQuery(newExpressionTree));
}
return(queryablePlaces.Provider.Execute(newExpressionTree));
}
