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comparison Source/Data/Linq/Builder/CastBuilder.cs @ 0:f990fcb411a9

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Копия текущей версии из github
author cin
date Thu, 27 Mar 2014 21:46:09 +0400
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-1:000000000000 0:f990fcb411a9
1 using System;
2 using System.Data;
3 using System.Linq.Expressions;
4
5 namespace BLToolkit.Data.Linq.Builder
6 {
7 using BLToolkit.Linq;
8
9 class CastBuilder : MethodCallBuilder
10 {
11 protected override bool CanBuildMethodCall(ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo)
12 {
13 return methodCall.IsQueryable("Cast");
14 }
15
16 protected override IBuildContext BuildMethodCall(ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo)
17 {
18 var sequence = builder.BuildSequence(new BuildInfo(buildInfo, methodCall.Arguments[0]));
19
20 return new CastContext(sequence, methodCall);
21 }
22
23 protected override SequenceConvertInfo Convert(
24 ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo, ParameterExpression param)
25 {
26 return null;
27 }
28
29 class CastContext : PassThroughContext
30 {
31 public CastContext(IBuildContext context, MethodCallExpression methodCall)
32 : base(context)
33 {
34 _methodCall = methodCall;
35 }
36
37 private readonly MethodCallExpression _methodCall;
38
39 public override void BuildQuery<T>(Query<T> query, ParameterExpression queryParameter)
40 {
41 var expr = BuildExpression(null, 0);
42 var mapper = Builder.BuildMapper<T>(expr);
43
44 query.SetQuery(mapper.Compile());
45 }
46
47 public override Expression BuildExpression(Expression expression, int level)
48 {
49 var expr = base.BuildExpression(expression, level);
50 var type = _methodCall.Method.GetGenericArguments()[0];
51
52 if (expr.Type != type)
53 expr = Expression.Convert(expr, type);
54
55 return expr;
56 }
57 }
58 }
59 }