LoadFromCollection - support for Dictionary properties (#1176)

* #969, #1058 - implemented EPPlusDictionaryColumnAttribute for LoadFromCollection with attributes

* #969, #1058 - added support for Dictionary property in LoadFromCollection

* #1058, #969 - LoadFromCollection, support for Dictionary property

* #1058, #969 - added testclass

* #1058, #969 - added unit test for reading column headers/keys from attribute

Author: swmal

src/EPPlus/Attributes/EPPlusDictionaryColumnAttribute.cs

@@ -0,0 +1,47 @@
+/*************************************************************************************************
+  Required Notice: Copyright (C) EPPlus Software AB. 
+  This software is licensed under PolyForm Noncommercial License 1.0.0 
+  and may only be used for noncommercial purposes 
+  https://polyformproject.org/licenses/noncommercial/1.0.0/
+
+  A commercial license to use this software can be purchased at https://epplussoftware.com
+ *************************************************************************************************
+  Date               Author                       Change
+ *************************************************************************************************
+  7/11/2023         EPPlus Software AB       EPPlus 7
+ *************************************************************************************************/
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace OfficeOpenXml.Attributes
+{
+    /// <summary>
+    /// This attributes can only be used on properties that are of the type IDictionary&lt;string, string&gt;.
+    /// Columns will be added based on the items in <see cref="EPPlusDictionaryColumnAttribute.ColumnHeaders"/>
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Method | AttributeTargets.Property | AttributeTargets.Field)]
+    internal class EPPlusDictionaryColumnAttribute : Attribute
+    {
+        /// <summary>
+        /// Order of the columns value, default value is 0
+        /// </summary>
+        public int Order
+        {
+            get;
+            set;
+        }
+
+        /// <summary>
+        /// The values of this array will be used to generate columns (one column for each item).
+        /// </summary>
+        public string[] ColumnHeaders { get; set; }
+
+        /// <summary>
+        /// Should be unique within all attributes. Will be used to retrieve the keys of the Dictionary
+        /// that also will be used to create the columns for this property.
+        /// </summary>
+        public string KeyId { get; set; }
+    }
+}

src/EPPlus/FormulaParsing/Excel/Functions/Engineering/ConvertFunction.cs

@@ -21,7 +21,7 @@ namespace OfficeOpenXml.FormulaParsing.Excel.Functions.Engineering
     [FunctionMetadata(
             Category = ExcelFunctionCategory.Engineering,
             EPPlusVersion = "5.1",
-            Description = "Calculates the modified Bessel function Yn(x)")]
+            Description = "Converts a number from one measurement system to another")]
     public class ConvertFunction : ExcelFunction
     {
         public override int ArgumentMinLength => 3;

src/EPPlus/LoadFunctions/ColumnInfo.cs

@@ -30,6 +30,10 @@ public ColumnInfo()
 
         public int SortOrder { get; set; }
 
+        public bool IsDictionaryProperty { get; set; }
+
+        public string DictinaryKey { get; set; }
+
         public List<int> SortOrderLevels { get; set; }
         public int Index { get; set; }
 

src/EPPlus/LoadFunctions/LoadFromCollection.cs

@@ -55,7 +55,7 @@ public LoadFromCollection(ExcelRangeBase range, IEnumerable<T> items, LoadFromCo
             LoadFromCollectionColumns<T> cols;
             if (parameters.Members == null)
             {
-                cols = new LoadFromCollectionColumns<T>(parameters.BindingFlags, SortOrderProperties);
+                cols = new LoadFromCollectionColumns<T>(parameters, SortOrderProperties);
                 var columns = cols.Setup();
                 _columns = columns.ToArray();
                 SetHiddenColumns();
@@ -66,7 +66,7 @@ public LoadFromCollection(ExcelRangeBase range, IEnumerable<T> items, LoadFromCo
                 {
                     throw (new ArgumentException("Parameter Members must have at least one property. Length is zero"));
                 }
-                cols = new LoadFromCollectionColumns<T>(parameters.BindingFlags, SortOrderProperties, parameters.Members);
+                cols = new LoadFromCollectionColumns<T>(parameters, SortOrderProperties);
                 var columns = cols.Setup();
                 _columns = columns.ToArray();
                 // the ValidateType method will throw an InvalidCastException
@@ -228,6 +228,18 @@ private void SetValuesAndFormulas(object[,] values, Dictionary<int, FormulaCell>
                                 {
                                     v = ((MethodInfo)member).Invoke(obj, null);
                                 }
+                                if (colInfo.IsDictionaryProperty)
+                                {
+                                    var dict = v as Dictionary<string, object>;
+                                    if(dict != null && dict.ContainsKey(colInfo.DictinaryKey))
+                                    {
+                                        v = dict[colInfo.DictinaryKey];
+                                    }
+                                    else
+                                    {
+                                        v = null;
+                                    }
+                                }
 
 #if (!NET35)
                                 if (v != null)
@@ -273,8 +285,9 @@ private object GetValueByPath(object obj, string path)
         {
             var members = path.Split('.');
             object o = obj;
-            foreach(var member in members)
+            for(var ix = 0; ix < members.Length; ix++)
             {
+                var member = members[ix];
                 if (o == null) return null;
                 var memberInfos = o.GetType().GetMember(member);
                 if(memberInfos == null || memberInfos.Length == 0)
@@ -298,6 +311,19 @@ private object GetValueByPath(object obj, string path)
                 {
                     throw new NotSupportedException("Invalid member: '" + memberInfo.Name + "', not supported member type '" + memberInfo.GetType().FullName + "'");
                 }
+                if(o is Dictionary<string, object> dict && ix < members.Length + 1)
+                {
+                    var key = members[ix + 1];
+                    if(dict.ContainsKey(key))
+                    {
+                        o = dict[key];
+                    }
+                    else
+                    {
+                        o = null;
+                    }
+                    break;
+                }
             }
             return o;
         }