#11: add implementation for reading iEnumerables

GBase/DataHandling/XmlDataReader.cs

@@ -10,6 +10,7 @@ using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using System.Xml.Linq;
+using GBase.Helpers;
 using GBase.Interfaces.DataHandling;
 using GBase.Interfaces.DataHandling.Xml;
 
@@ -90,10 +91,8 @@ namespace GBase.DataHandling
 
                 IEnumerable<string> values = valueElements.Select(v => v.Value);
 
-                if (typeof(TProperty) != typeof(string) && typeof(TProperty).GetInterfaces().Contains(typeof(IEnumerable)))
-                {
-                    return null; //FixMe: Implement handling for IEnumerables
-                }
+                if (typeof(TProperty) != typeof(string) && typeof(TProperty).GetInterfaces().Contains(typeof(IEnumerable))) //read property is an IEnumerable
+                    return values.Select(Enumerables.ConvertToGBaseEnumerable<TProperty>).ToList();
 
                 return values.Select(value => (TProperty)Convert.ChangeType(value, typeof(TProperty))).ToList();
             }, _cancellationToken);

GBase/Exceptions/InterfaceEnumerablePassedException.cs

@@ -0,0 +1,27 @@
+// Author: Gockner, Simon
+// Created: 2020-02-14
+// Copyright(c) 2020 SimonG. All Rights Reserved.
+
+using System;
+using System.Collections.Generic;
+
+namespace GBase.Exceptions
+{
+    /// <summary>
+    /// <see cref="Exception"/> that an interface was passed as the generic type of an <see cref="IEnumerable{T}"/>
+    /// </summary>
+    public class InterfaceEnumerablePassedException : Exception
+    {
+        /// <summary>
+        /// <see cref="Exception"/> that an interface was passed as the generic type of an <see cref="IEnumerable{T}"/>
+        /// </summary>
+        /// <param name="interfaceType"></param>
+        public InterfaceEnumerablePassedException(Type interfaceType)
+            : base($"Interface {interfaceType.FullName} was passed to an IEnumerable<T>. This is not allowed.")
+        {
+            InterfaceType = interfaceType;
+        }
+
+        public Type InterfaceType { get; }
+    }
+}

GBase/GBase.csproj

@@ -25,4 +25,8 @@
     <PackageReference Include="LightweightIocContainer" Version="2.1.0" />
   </ItemGroup>
 
+  <ItemGroup>
+    <ProjectReference Include="..\GBase.Api\GBase.Api.csproj" />
+  </ItemGroup>
+
 </Project>

GBase/GBase.xml

@@ -344,6 +344,17 @@
             </summary>
             <returns>A <see cref="T:System.Threading.Tasks.ValueTask"/> to await</returns>
         </member>
+        <member name="T:GBase.Exceptions.InterfaceEnumerablePassedException">
+            <summary>
+            <see cref="T:System.Exception"/> that an interface was passed as the generic type of an <see cref="T:System.Collections.Generic.IEnumerable`1"/>
+            </summary>
+        </member>
+        <member name="M:GBase.Exceptions.InterfaceEnumerablePassedException.#ctor(System.Type)">
+            <summary>
+            <see cref="T:System.Exception"/> that an interface was passed as the generic type of an <see cref="T:System.Collections.Generic.IEnumerable`1"/>
+            </summary>
+            <param name="interfaceType"></param>
+        </member>
         <member name="T:GBase.Factories.IGBaseEntryFactory">
             <summary>
             Factory for the <see cref="T:GBase.Interfaces.IGBaseEntry"/>
@@ -539,6 +550,14 @@
             <param name="enumerable">The <see cref="T:System.Collections.IEnumerable"/></param>
             <returns></returns>
         </member>
+        <member name="M:GBase.Helpers.Enumerables.ConvertToGBaseEnumerable``1(System.String)">
+            <summary>
+            Convert a given <see cref="T:System.String"/> to an <see cref="T:System.Collections.Generic.IEnumerable`1"/> of <see cref="T:System.Type"/> <typeparamref name="TEnumerable"/>
+            </summary>
+            <typeparam name="TEnumerable">The <see cref="T:System.Collections.Generic.IEnumerable`1"/> <see cref="T:System.Type"/></typeparam>
+            <param name="string">The given <see cref="T:System.String"/></param>
+            <returns>An <see cref="T:System.Collections.Generic.IEnumerable`1"/> of <see cref="T:System.Type"/> <typeparamref name="TEnumerable"/></returns>
+        </member>
         <member name="T:GBase.Installers.DataHandlingInstaller">
             <summary>
             <see cref="T:LightweightIocContainer.Interfaces.Installers.IIocInstaller"/> for the data handling

GBase/Helpers/Enumerables.cs

@@ -2,13 +2,20 @@
 // Created: 2020-02-13
 // Copyright(c) 2020 SimonG. All Rights Reserved.
 
+using System;
 using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
 using System.Text;
+using GBase.Api;
+using GBase.Exceptions;
 
 namespace GBase.Helpers
 {
     internal static class Enumerables
     {
+        private const char ENUMERABLE_STRING_DIVIDER = ',';
+
         /// <summary>
         /// Convert an <see cref="IEnumerable"/> to a GBase <see cref="string"/>
         /// </summary>
@@ -19,14 +26,51 @@ namespace GBase.Helpers
             StringBuilder @string = new StringBuilder();
             foreach (var item in enumerable)
             {
-                @string.Append($"{item},");
+                @string.Append($"{item}{ENUMERABLE_STRING_DIVIDER}");
             }
 
             char lastChar = @string[^1];
-            if (lastChar == ',')
+            if (lastChar == ENUMERABLE_STRING_DIVIDER)
                 @string.Remove(@string.Length - 1, 1);
 
             return @string.ToString();
         }
+
+        /// <summary>
+        /// Convert a given <see cref="string"/> to an <see cref="IEnumerable{T}"/> of <see cref="Type"/> <typeparamref name="TEnumerable"/>
+        /// </summary>
+        /// <typeparam name="TEnumerable">The <see cref="IEnumerable{T}"/> <see cref="Type"/></typeparam>
+        /// <param name="string">The given <see cref="string"/></param>
+        /// <returns>An <see cref="IEnumerable{T}"/> of <see cref="Type"/> <typeparamref name="TEnumerable"/></returns>
+        public static TEnumerable ConvertToGBaseEnumerable<TEnumerable>(string @string)
+        {
+            //get generic type parameter of TEnumerable
+            Type genericType = typeof(TEnumerable).GetGenericArguments()[0];
+
+            Type listType = typeof(List<>);
+            Type genericList = listType.MakeGenericType(genericType);
+            IList enumerable = (IList) Activator.CreateInstance(genericList);
+
+            foreach (var value in @string.Split(ENUMERABLE_STRING_DIVIDER))
+            {
+                object item;
+
+                if (genericType.GetInterfaces().Contains(typeof(IGBaseObject)))
+                {
+                    if (genericType.IsInterface)
+                        throw new InterfaceEnumerablePassedException(genericType);
+
+                    IGBaseObject gBaseObject = (IGBaseObject) Activator.CreateInstance(genericType);
+                    gBaseObject.InitializeFromString(value);
+                    item = gBaseObject;
+                }
+                else 
+                    item = Convert.ChangeType(value, genericType);
+
+                enumerable.Add(item);
+            }
+            
+            return (TEnumerable) enumerable;
+        }
     }
 }

GBase/Properties/AssemblyInfo.cs

@@ -0,0 +1,7 @@
+// Author: Gockner, Simon
+// Created: 2020-02-14
+// Copyright(c) 2020 SimonG. All Rights Reserved.
+
+using System.Runtime.CompilerServices;
+
+[assembly:InternalsVisibleTo("Test.GBase")]