Merge pull request #50 from NetTopologySuite/fix/issue049_handle_deci…

…mal_fields

Handle decimal fields. Fix #49.

src/NetTopologySuite.IO.Esri.Shapefile/Dbf/Fields/DbfNumericDecimalField.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Text;
+
+namespace NetTopologySuite.IO.Esri.Dbf.Fields
+{
+    /// <summary>
+    /// Int64 field definition.
+    /// </summary>
+    public class DbfNumericDecimalField : DbfNumericField<decimal>
+    {
+        /// <summary>
+        /// Intializes new instance of the numerif field class.
+        /// </summary>
+        /// <param name="name">Field name.</param>
+        /// <param name="length">The number of significant digits (including decimal separator).</param>
+        /// <param name="precision">The number of fractional digits.</param>
+        public DbfNumericDecimalField(string name, int length, int precision)
+            : base(name, DbfType.Numeric, length, precision)
+        {
+        }
+
+        /// <summary>
+        ///  Initializes a new instance of the field class.
+        /// </summary>
+        /// <param name="name">Field name.</param>
+        public DbfNumericDecimalField(string name) : this(name, MaxFieldLength, MaxFieldPrecision)
+        {
+        }
+
+        /// <inheritdoc/>
+        protected override decimal StringToNumber(string s)
+        {
+            return decimal.Parse(s, CultureInfo.InvariantCulture);
+        }
+    }
+}

src/NetTopologySuite.IO.Esri.Shapefile/Dbf/Fields/DbfNumericDoubleField.cs

@@ -10,6 +10,8 @@ namespace NetTopologySuite.IO.Esri.Dbf.Fields
     /// </summary>
     public class DbfNumericDoubleField : DbfNumericField<double>
     {
+        internal static readonly int DefaultFieldLength = 19; // 17 digits + decimal separator + sign https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/builtin-types/floating-point-numeric-types#characteristics-of-the-floating-point-types
+
         /// <summary>
         /// Intializes new instance of the numerif field class.
         /// </summary>

src/NetTopologySuite.IO.Esri.Shapefile/Dbf/Fields/DbfNumericField.cs

@@ -37,12 +37,17 @@ internal static DbfField Create(string name, int length, int precision)
                 return new DbfNumericInt32Field(name, length);
             }
 
-            if (precision <= 0)
+            if (precision <= 0 && length <= DbfNumericInt64Field.DefaultFieldLength)
             {
                 return new DbfNumericInt64Field(name, length);
             }
 
-            return new DbfNumericDoubleField(name, length, precision);
+            if (length <= DbfNumericDoubleField.DefaultFieldLength)
+            {
+                return new DbfNumericDoubleField(name, length, precision);
+            }
+
+            return new DbfNumericDecimalField(name, length, precision);
         }
 
     }

src/NetTopologySuite.IO.Esri.Shapefile/Dbf/Fields/DbfNumericInt32Field.cs

@@ -10,7 +10,7 @@ namespace NetTopologySuite.IO.Esri.Dbf.Fields
     /// </summary>
     public class DbfNumericInt32Field : DbfNumericField<int>
     {
-        internal static readonly int DefaultFieldLength = 10; //-2147483648..2147483647 => 11, but Esri uses 10
+        internal static readonly int DefaultFieldLength = 10; //-2147483648..2147483647 (11..10 digits)
 
         /// <summary>
         /// Intializes new instance of the numerif field class.

src/NetTopologySuite.IO.Esri.Shapefile/Dbf/Fields/DbfNumericInt64Field.cs

@@ -10,6 +10,8 @@ namespace NetTopologySuite.IO.Esri.Dbf.Fields
     /// </summary>
     public class DbfNumericInt64Field : DbfNumericField<long>
     {
+        internal static readonly int DefaultFieldLength = 19; // -9223372036854775808 to 9223372036854775807 (20..19 digits)
+
         /// <summary>
         /// Intializes new instance of the numerif field class.
         /// </summary>

test/NetTopologySuite.IO.Esri.Test/Issues/Issue049.cs

@@ -0,0 +1,30 @@
+using NetTopologySuite.IO.Esri.Shapefiles.Readers;
+using NUnit.Framework;
+
+namespace NetTopologySuite.IO.Esri.Test.Issues;
+
+/// <summary>
+/// https://github.com/NetTopologySuite/NetTopologySuite.IO.Esri/issues/49
+/// </summary>
+internal class Issue049
+{
+    [Test]
+    public void Decimal0_OpenShapefile()
+    {
+        var shpPath = TestShapefiles.PathTo("Issues/049/221-1_28.03.202411-16.shp");
+        var options = new ShapefileReaderOptions
+        {
+            GeometryBuilderMode = GeometryBuilderMode.FixInvalidShapes
+        };
+        using var shpReader = Shapefile.OpenRead(shpPath, options);
+
+        Assert.AreEqual(shpReader.ShapeType, ShapeType.Polygon);
+
+        while (shpReader.Read())
+        {
+            var dosis = shpReader.Fields["DOSIS"].Value.ToString();
+            Assert.IsNotEmpty(dosis);
+            Assert.IsFalse(shpReader.Geometry.IsEmpty);
+        }
+    }
+}

test/TestData/TestShapefiles/Issues/049/221-1_28.03.202411-16.prj

@@ -0,0 +1 @@
+GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137,298.257223563]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]]