51 lines
2.1 KiB
C#
51 lines
2.1 KiB
C#
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using PoweredSoft.DynamicLinq.Helpers;
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using PoweredSoft.DynamicLinq.Test;
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using System;
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using System.Collections.Generic;
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using System.Linq;
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using System.Linq.Expressions;
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using System.Text;
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using System.Threading.Tasks;
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namespace PoweredSoft.DynamicLinq.ConsoleApp
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{
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public class Program
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{
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static void Main(string[] args)
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{
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var type = typeof(Dal.Pocos.Author);
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var param = Expression.Parameter(type);
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var path = "Posts.Comments.Id";
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var expr = ResolveSelectExpression(param, path, SelectCollectionHandling.Flatten);
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var expr2 = ResolveSelectExpression(param, path, SelectCollectionHandling.Flatten, true);
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}
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public static Expression ResolveSelectExpression(ParameterExpression param, string path, SelectCollectionHandling selectCollectionHandling = SelectCollectionHandling.LeaveAsIs, bool nullChecking = false)
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{
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var notCheckNullExpression = QueryablePathHelpers.NavigatePath(param, path,
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(before, member, isFirst, isLast) => member,
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(before, member, isFirst, isLast) => member,
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(parent, innerExpression, innerExpressionLambda) =>
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{
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var listGenericArgumentType = parent.Type.GetGenericArguments().First();
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Expression ret = null;
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if (selectCollectionHandling == SelectCollectionHandling.LeaveAsIs || !QueryableHelpers.IsGenericEnumerable(innerExpression))
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ret = Expression.Call(typeof(Enumerable), "Select", new Type[] { listGenericArgumentType, innerExpression.Type }, parent, innerExpressionLambda);
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else
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ret = Expression.Call(typeof(Enumerable), "SelectMany", new Type[] { listGenericArgumentType, innerExpression.Type.GenericTypeArguments.First() }, parent, innerExpressionLambda);
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return ret;
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}
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);
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if (!nullChecking)
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return notCheckNullExpression;
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var type = notCheckNullExpression.Type;
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throw new NotSupportedException();
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}
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}
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}
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