/// <summary>
/// Translate an expression tree into a compiled OData query.
/// </summary>
/// <param name="expression">The expression tree to translate</param>
/// <param name="contractResolver">The contract resolvers to use to determine property names from members used with expressions.</param>
/// <returns>An OData <see cref="QueryNode"/></returns>
internal static QueryNode Compile(Expression expression, DatasyncContractResolver contractResolver)
{
var visitor = new FilterBuildingExpressionVisitor(contractResolver);
visitor.Visit(expression);
return(visitor.FilterExpression.FirstOrDefault());
}
/// <summary>
/// Add an ordering expression to the query
/// </summary>
/// <param name="expression">An ordering method call expression</param>
/// <param name="ascending">True if the ordering is ascending, false otherwise</param>
/// <param name="prepend">True to prepend the ordering to the list</param>
internal protected void AddOrdering(MethodCallExpression expression, bool ascending, bool prepend)
{
// We only allow keySelectors that are x => x.member expressions (i.e. MemberAccessNode).
// Anything else will result in a NotSupportedException
if (expression.IsValidLambdaExpression(out LambdaExpression lambda) && lambda !.Body is MemberExpression memberExpression)
{
string memberName = FilterBuildingExpressionVisitor.GetTableMemberName(memberExpression, ContractResolver);
if (memberName != null)
{
var node = new OrderByNode(new MemberAccessNode(null, memberName), ascending);
if (prepend)
{
QueryDescription.Ordering.Insert(0, node);
}
else
{
QueryDescription.Ordering.Add(node);
}
}
}
