mcs/class/referencesource/System.Data/System/Data/Filter/NameNode.cs

   1 //------------------------------------------------------------------------------
   2 // <copyright file="NameNode.cs" company="Microsoft">
   3 //     Copyright (c) Microsoft Corporation.  All rights reserved.
   4 // </copyright>
   5 // <owner current="true" primary="true">Microsoft</owner>
   6 // <owner current="true" primary="false">Microsoft</owner>
   7 // <owner current="false" primary="false">Microsoft</owner>
   8 //------------------------------------------------------------------------------
   9
  10 namespace System.Data {
  11     using System;
  12     using System.ComponentModel;
  13     using System.Collections.Generic;
  14     using System.Diagnostics;
  15     using System.Globalization;
  16
  17     internal sealed class NameNode : ExpressionNode {
  18         internal char open = '\0';
  19         internal char close = '\0';
  20         internal string name;
  21         internal bool found;
  22         internal bool type = false;
  23         internal DataColumn column;
  24
  25         internal NameNode(DataTable table, char[] text, int start, int pos) : base(table) {
  26             this.name = ParseName(text, start, pos);
  27         }
  28
  29         internal NameNode(DataTable table, string name) : base(table) {
  30             this.name = name;
  31         }
  32
  33         internal override bool IsSqlColumn{
  34             get{
  35                 return column.IsSqlType;
  36             }
  37         }
  38
  39         internal override void Bind(DataTable table, List<DataColumn> list) {
  40             BindTable(table);
  41             if (table == null)
  42                 throw ExprException.UnboundName(name);
  43
  44             try {
  45                 this.column = table.Columns[name];
  46             }
  47             catch (Exception e) {
  48                 found = false;
  49                 //
  50                 if (!Common.ADP.IsCatchableExceptionType(e)) {
  51                     throw;
  52                 }
  53                 throw ExprException.UnboundName(name);
  54             }
  55
  56             if (column == null)
  57                 throw ExprException.UnboundName(name);
  58
  59             name = column.ColumnName;
  60             found = true;
  61
  62             // add column to the dependency list, do not add duplicate columns
  63             Debug.Assert(column != null, "Failed to bind column " + name);
  64
  65             int i;
  66             for (i = 0; i < list.Count; i++) {
  67                 // walk the list, check if the current column already on the list
  68                 DataColumn dataColumn = list[i];
  69                 if (column == dataColumn) {
  70                     break;
  71                 }
  72             }
  73             if (i >= list.Count) {
  74                 list.Add(column);
  75             }
  76         }
  77
  78         internal override object Eval() {
  79             // can not eval column without ROW value;
  80             throw ExprException.EvalNoContext();
  81         }
  82
  83         internal override object Eval(DataRow row, DataRowVersion version) {
  84             if (!found) {
  85                 throw ExprException.UnboundName(name);
  86             }
  87
  88             if (row == null) {
  89                 if(IsTableConstant()) // this column is TableConstant Aggregate Function
  90                     return column.DataExpression.Evaluate();
  91                 else {
  92                     throw ExprException.UnboundName(name);
  93                 }
  94             }
  95
  96             return column[row.GetRecordFromVersion(version)];
  97         }
  98
  99         internal override object Eval(int[] records) {
 100             throw ExprException.ComputeNotAggregate(this.ToString());
 101         }
 102
 103         internal override bool IsConstant() {
 104             return false;
 105         }
 106
 107         internal override bool IsTableConstant() {
 108             if (column != null && column.Computed) {
 109                 return this.column.DataExpression.IsTableAggregate();
 110             }
 111             return false;
 112         }
 113
 114         internal override bool HasLocalAggregate() {
 115             if (column != null && column.Computed) {
 116                 return this.column.DataExpression.HasLocalAggregate();
 117             }
 118             return false;
 119         }
 120
 121         internal override bool HasRemoteAggregate() {
 122             if (column != null && column.Computed) {
 123                 return this.column.DataExpression.HasRemoteAggregate();
 124             }
 125             return false;
 126         }
 127
 128         internal override bool DependsOn(DataColumn column) {
 129             if (this.column == column)
 130                 return true;
 131
 132             if (this.column.Computed) {
 133                 return this.column.DataExpression.DependsOn(column);
 134             }
 135
 136             return false;
 137         }
 138
 139         internal override ExpressionNode Optimize() {
 140             return this;
 141         }
 142
 143         /// <devdoc>
 144         ///     Parses given name and checks it validity
 145         /// </devdoc>
 146         internal static string ParseName(char[] text, int start, int pos) {
 147             char esc = '\0';
 148             string charsToEscape = "";
 149             int saveStart = start;
 150             int savePos = pos;
 151
 152             if (text[start] == '`') {
 153                 Debug.Assert(text[checked((int)pos-1)] == '`', "Invalid identifyer bracketing, pos = " + pos.ToString(CultureInfo.InvariantCulture) + ", end = " + text[checked((int)pos-1)].ToString(CultureInfo.InvariantCulture));
 154                 start = checked((int)start+1);
 155                 pos = checked((int)pos-1);
 156                 esc = '\\';
 157                 charsToEscape = "`";
 158             }
 159             else if (text[start] == '[') {
 160                 Debug.Assert(text[checked((int)pos-1)] == ']', "Invalid identifyer bracketing of name " + new string(text, start, pos-start) + " pos = " + pos.ToString(CultureInfo.InvariantCulture) + ", end = " + text[checked((int)pos-1)].ToString(CultureInfo.InvariantCulture));
 161                 start = checked((int)start+1);
 162                 pos = checked((int)pos-1);
 163                 esc = '\\';
 164                 charsToEscape = "]\\";
 165             }
 166
 167             if (esc != '\0') {
 168                 // scan the name in search for the ESC
 169                 int posEcho = start;
 170
 171                 for (int i = start; i < pos; i++) {
 172                     if (text[i] == esc) {
 173                         if (i+1 < pos && charsToEscape.IndexOf(text[i+1]) >= 0) {
 174                             i++;
 175                         }
 176                     }
 177                     text[posEcho] = text[i];
 178                     posEcho++;
 179                 }
 180                 pos = posEcho;
 181             }
 182
 183             if (pos == start)
 184                 throw ExprException.InvalidName(new string(text, saveStart, savePos - saveStart));
 185
 186             return new string(text, start, pos - start);
 187         }
 188     }
 189 }