/// <summary>
/// QueryableResourceExpression visit method.
/// </summary>
/// <param name="rse">QueryableResourceExpression expression to visit</param>
/// <returns>Visited QueryableResourceExpression expression</returns>
internal override Expression VisitQueryableResourceExpression(QueryableResourceExpression rse)
{
if ((ResourceExpressionType)rse.NodeType == ResourceExpressionType.ResourceNavigationProperty)
{
if (rse.IsOperationInvocation && !(rse.Source is QueryableResourceExpression))
{
var normalizerRewrites = new Dictionary <Expression, Expression>(ReferenceEqualityComparer <Expression> .Instance);
var e = Evaluator.PartialEval(rse.Source);
e = ExpressionNormalizer.Normalize(e, normalizerRewrites);
e = ResourceBinder.Bind(e, this.context);
this.Visit(e);
}
else
{
this.Visit(rse.Source);
}
this.uriBuilder.Append(UriHelper.FORWARDSLASH).Append(this.ExpressionToString(rse.MemberExpression, /*inPath*/ true));
}
else if (rse.MemberExpression != null)
{
// this is a resource set expression
// we should be at the very beginning of
// the URI
Debug.Assert(this.uriBuilder.Length == 0, "The builder is not empty while we are adding a resourceset");
string entitySetName = (String)((ConstantExpression)rse.MemberExpression).Value;
this.uriBuilder.Append(this.context.BaseUriResolver.GetEntitySetUri(entitySetName));
}
else
{
this.uriBuilder.Append(this.context.BaseUriResolver.BaseUriOrNull);
}
WebUtil.RaiseVersion(ref this.uriVersion, rse.UriVersion);
if (rse.ResourceTypeAs != null)
{
this.uriBuilder.Append(UriHelper.FORWARDSLASH);
UriHelper.AppendTypeSegment(this.uriBuilder, rse.ResourceTypeAs, this.context, /*inPath*/ true, ref this.uriVersion);
}
if (rse.KeyPredicateConjuncts.Count > 0)
{
this.context.UrlKeyDelimiter.AppendKeyExpression(rse.GetKeyProperties(), kvp => ClientTypeUtil.GetServerDefinedName(kvp.Key), kvp => kvp.Value.Value, this.uriBuilder);
}
if (rse.IsOperationInvocation)
{
this.VisitOperationInvocation(rse);
}
if (rse.CountOption == CountOption.CountSegment)
{
// append $count segment: /$count
this.uriBuilder.Append(UriHelper.FORWARDSLASH).Append(UriHelper.DOLLARSIGN).Append(UriHelper.COUNT);
}
this.VisitQueryOptions(rse);
return(rse);
}
/// <summary>
/// Converts expression to Uri
/// </summary>
/// <param name="e">The expression</param>
/// <returns>Converted uri</returns>
public virtual Uri Convert(Expression e)
{
Uri uri;
Dictionary <Expression, Expression> rewrites = null;
if (!(e is ResourceSetExpression))
{
rewrites = new Dictionary <Expression, Expression>(ReferenceEqualityComparer <Expression> .Instance);
e = Evaluator.PartialEval(e);
e = ExpressionNormalizer.Normalize(e, rewrites);
e = ResourceBinder.Bind(e);
}
UriWriter.Translate(false, e, out uri);
return(uri);
}
internal string Bind(Expression expression)
{
Argument.AssertNotNull(expression, nameof(expression));
Dictionary <Expression, Expression> normalizerRewrites = new Dictionary <Expression, Expression>(ReferenceEqualityComparer <Expression> .Instance);
// Evaluate any local evaluatable expressions ( lambdas etc)
Expression partialEvaluatedExpression = Evaluator.PartialEval(expression);
// Normalize expression, replace String Comparisons etc.
Expression normalizedExpression = ExpressionNormalizer.Normalize(partialEvaluatedExpression, normalizerRewrites);
// Parse the Bound expression into sub components, i.e. take count, filter, select columns, request options, opcontext, etc.
ExpressionParser parser = GetExpressionParser();
parser.Translate(normalizedExpression);
// Return the FilterString.
return(parser.FilterString == "true" ? null : parser.FilterString);
}
internal ExecutionInfo Bind()
{
ExecutionInfo retVal = new ExecutionInfo();
// IQueryable impl
if (this.Expression != null)
{
Dictionary <Expression, Expression> normalizerRewrites = new Dictionary <Expression, Expression>(ReferenceEqualityComparer <Expression> .Instance);
// Step 1. Evaluate any local evaluatable expressions ( lambdas etc)
Expression partialEvaluatedExpression = Evaluator.PartialEval(this.Expression);
// Step 2. Normalize expression, replace String Comparisons etc.
Expression normalizedExpression = ExpressionNormalizer.Normalize(partialEvaluatedExpression, normalizerRewrites);
// Step 3. Bind Expression, Analyze predicates and create query option expressions. End result is a single ResourceSetExpression
Expression boundExpression = ResourceBinder.Bind(normalizedExpression);
// Step 4. Parse the Bound expression into sub components, i.e. take count, filter, select columns, request options, opcontext, etc.
ExpressionParser parser = new ExpressionParser();
parser.Translate(boundExpression);
// Step 5. Store query components & params
this.TakeCount = parser.TakeCount;
this.FilterString = parser.FilterString;
this.SelectColumns = parser.SelectColumns;
retVal.RequestOptions = parser.RequestOptions;
retVal.OperationContext = parser.OperationContext;
// Step 6. If projection & no resolver then generate a resolver to perform the projection
if (parser.Resolver == null)
{
if (parser.Projection != null && parser.Projection.Selector != ProjectionQueryOptionExpression.DefaultLambda)
{
Type intermediateType = parser.Projection.Selector.Parameters[0].Type;
// Convert Expression to take type object as input to allow for direct invocation.
ParameterExpression paramExpr = Expression.Parameter(typeof(object));
Func <object, TElement> projectorFunc = Expression.Lambda <Func <object, TElement> >(
Expression.Invoke(parser.Projection.Selector, Expression.Convert(paramExpr, intermediateType)), paramExpr).Compile();
// Generate a resolver to do the projection.
retVal.Resolver = (pk, rk, ts, props, etag) =>
{
// Parse to intermediate type
ITableEntity intermediateObject = (ITableEntity)EntityUtilities.InstantiateEntityFromType(intermediateType);
intermediateObject.PartitionKey = pk;
intermediateObject.RowKey = rk;
intermediateObject.Timestamp = ts;
intermediateObject.ReadEntity(props, parser.OperationContext);
intermediateObject.ETag = etag;
// Invoke lambda expression
return(projectorFunc(intermediateObject));
};
}
else
{
// No op - No resolver or projection specified.
}
}
else
{
retVal.Resolver = (EntityResolver <TElement>)parser.Resolver.Value;
}
}
retVal.RequestOptions = TableRequestOptions.ApplyDefaults(retVal.RequestOptions, this.queryProvider.Table.ServiceClient);
retVal.OperationContext = retVal.OperationContext ?? new OperationContext();
return(retVal);
}
