Update documentation with Version Conflict handeling + new screenshot…

…s + allow using local package icons

README.md

@@ -177,6 +177,8 @@ Press the **Push** button to push your package up to the server. Be sure to set
 
 You can use [NuGet.Server](http://nugetserver.net/), [NuGet Gallery](https://github.com/NuGet/NuGetGallery), [ProGet](http://inedo.com/proget), etc to create your own NuGet server.
 
+> **Note:** NuGetForUnity currently only supports NuGet Api version v1
+
 Alternatively, you can use a "local feed" which is just a folder on your hard-drive or a network share.
 
 Be sure to set the proper URL/path in the _NuGet.config_ file and you should be good to go!
@@ -197,3 +199,24 @@ For more information see [.Net Tool Documentaion](https://learn.microsoft.com/en
 ## Usage
 
 Restore nuget packages of a single Unity Project: `dotnet nugetforunity restore <PROJECT_PATH>`. If installed as a global tool it can be called without the `dotnet` prefix: `nugetforunity restore <PROJECT_PATH>`.
+
+# Common issues when installing NuGet packages
+
+Unity is relatively special as it uses a different runtime, a fork of the [Mono](https://docs.unity3d.com/Manual/Mono.html) runtime, than the standerd .Net from Microsoft uses. For some platforms Unity even uses [IL2CPP](https://docs.unity3d.com/Manual/IL2CPP.html) that compiles all C# code to C++ code. So Unity also uses a different build-system. This can lead to some issues with NuGet packages that heavily depend on the standard .Net build-system. NuGetForUnity tries to handle most of the changes needed for NuGet packages to work inside Unity but it is not able to resolve all issues.
+
+## Version Conflicts
+
+If two NuGet packages depend on the same package but reference different versions of it, Unity shows a error like:
+
+```
+Assembly 'Assets/Packages/System.Diagnostics.EventLog.4.7.0/lib/netstandard2.0/System.Diagnostics.EventLog.dll' will not be loaded due to errors:
+System.Diagnostics.EventLog references strong named System.Security.Principal.Windows Assembly references: 4.1.1.0 Found in project: 4.1.3.0.
+Assembly Version Validation can be disabled in Player Settings "Assembly Version Validation"
+```
+
+As mentioned in the message this error can be suppresed by changing a setting. Just go to Edit -> Project Settings -> Player -> Scroll down and expand "Other Settings" than uncheck "Assembly Version Validation" unther the "Configuration" section.
+
+<details>
+<summary>Screenshot of Player Settings</summary>
+<img src="docs/screenshots/assembly-version-validation-setting.png" />
+</details>

src/NuGetForUnity/Editor/NuGetPackageTextureHelper.cs

@@ -23,7 +23,12 @@ internal static Task<Texture2D> DownloadImage(string url)
             try
             {
                 var fromCache = false;
-                if (ExistsInDiskCache(url))
+                if (url.StartsWith("file://"))
+                {
+                    // we only cache images coming from a remote server.
+                    fromCache = true;
+                }
+                else if (ExistsInDiskCache(url))
                 {
                     url = "file:///" + GetFilePath(url);
                     fromCache = true;
@@ -35,7 +40,7 @@ internal static Task<Texture2D> DownloadImage(string url)
                     var downloadHandler = new DownloadHandlerTexture(false);
 
                     request.downloadHandler = downloadHandler;
-                    request.timeout = 1;
+                    request.timeout = 1; // 1 second
                     var operation = request.SendWebRequest();
                     operation.completed += asyncOperation =>
                     {

src/NuGetForUnity/Editor/NugetPackage.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Threading.Tasks;
 using UnityEngine;
 
@@ -39,8 +40,11 @@ public class NugetPackage : NugetPackageIdentifier, IEquatable<NugetPackage>, IE
         [SerializeField]
         private Texture2D icon;
 
-        public Task<Texture2D> iconTask;
+        private Task<Texture2D> iconTask;
 
+        /// <summary>
+        ///     Gets or sets the URL for the location of the icon of the NuGet package.
+        /// </summary>
         public string IconUrl;
 
         /// <summary>
@@ -194,6 +198,12 @@ public static NugetPackage FromNuspec(NuspecFile nuspec)
 
             package.Dependencies = nuspec.Dependencies;
 
+            // handle local icon files, preferred if the file exists.
+            if (!string.IsNullOrEmpty(nuspec.IconFilePath) && (string.IsNullOrEmpty(nuspec.IconUrl) || File.Exists(nuspec.IconFilePath)))
+            {
+                package.IconUrl = $"file:///{nuspec.IconFilePath}";
+            }
+
             return package;
         }
 

src/NuGetForUnity/Editor/NugetWindow.cs

@@ -817,6 +817,12 @@ private void DrawPackage(NugetPackage package, GUIStyle packageStyle, GUIStyle c
                         // as this is called every frame we don't need to wait for the task we can just use the image if it is available
                         icon = package.IconTask.Result;
                     }
+                    else if (installed != null && installed.IconTask != null && installed.IconTask.IsCompleted && installed.IconTask.Result != null)
+                    {
+                        // fallback to the icon of the already installed package (somehow there are cases where the update package has no icon URL)
+                        // as this is called every frame we don't need to wait for the task we can just use the image if it is available
+                        icon = installed.IconTask.Result;
+                    }
 
                     if (icon != null)
                     {

src/NuGetForUnity/Editor/NuspecFile.cs

@@ -68,6 +68,18 @@ public NuspecFile()
         /// </summary>
         public string IconUrl { get; set; }
 
+        /// <summary>
+        ///     Gets the path to a icon file. The path is relative to the root folder of the package. This is a alternative to using a URL <see cref="IconUrl" />
+        ///     .
+        /// </summary>
+        public string Icon { get; private set; }
+
+        /// <summary>
+        ///     Gets the full path to a icon file. This is only set if the .nuspec file contains a <see cref="Icon" />. This is a alternative to using a URL
+        ///     <see cref="IconUrl" />.
+        /// </summary>
+        public string IconFilePath { get; private set; }
+
         /// <summary>
         ///     Gets or sets a value indicating whether the license of the NuGet package needs to be accepted in order to use it.
         /// </summary>
@@ -124,9 +136,9 @@ public NuspecFile()
         public string Authors { get; set; }
 
         /// <summary>
-        ///     Loads the .nuspec file inside the .nupkg file at the given filepath.
+        ///     Loads the .nuspec file inside the .nupkg file at the given file path.
         /// </summary>
-        /// <param name="nupkgFilepath">The filepath to the .nupkg file to load.</param>
+        /// <param name="nupkgFilepath">The file path to the .nupkg file to load.</param>
         /// <returns>The .nuspec file loaded from inside the .nupkg file.</returns>
         public static NuspecFile FromNupkgFile(string nupkgFilepath)
         {
@@ -142,30 +154,27 @@ public static NuspecFile FromNupkgFile(string nupkgFilepath)
 
                     using (var stream = entry.Open())
                     {
-                        nuspec = Load(stream);
+                        nuspec = Load(stream).SetIconFilePath(nupkgFilepath);
                     }
                 }
             }
             else
             {
                 Debug.LogErrorFormat("Package could not be read: {0}", nupkgFilepath);
-
-                //nuspec.Id = packageId;
-                //nuspec.Version = packageVersion;
                 nuspec.Description = string.Format("COULD NOT LOAD {0}", nupkgFilepath);
             }
 
             return nuspec;
         }
 
         /// <summary>
-        ///     Loads a .nuspec file at the given filepath.
+        ///     Loads a .nuspec file at the given file path.
         /// </summary>
-        /// <param name="filePath">The full filepath to the .nuspec file to load.</param>
+        /// <param name="filePath">The full file path to the .nuspec file to load.</param>
         /// <returns>The newly loaded <see cref="NuspecFile" />.</returns>
         public static NuspecFile Load(string filePath)
         {
-            return Load(XDocument.Load(filePath));
+            return Load(XDocument.Load(filePath)).SetIconFilePath(filePath);
         }
 
         /// <summary>
@@ -202,6 +211,7 @@ public static NuspecFile Load(XDocument nuspecDocument)
             nuspec.LicenseUrl = (string)metadata.Element(XName.Get("licenseUrl", nuspecNamespace)) ?? string.Empty;
             nuspec.ProjectUrl = (string)metadata.Element(XName.Get("projectUrl", nuspecNamespace)) ?? string.Empty;
             nuspec.IconUrl = (string)metadata.Element(XName.Get("iconUrl", nuspecNamespace)) ?? string.Empty;
+            nuspec.Icon = (string)metadata.Element(XName.Get("icon", nuspecNamespace)) ?? string.Empty;
             nuspec.RequireLicenseAcceptance = bool.Parse((string)metadata.Element(XName.Get("requireLicenseAcceptance", nuspecNamespace)) ?? "False");
             nuspec.Description = (string)metadata.Element(XName.Get("description", nuspecNamespace)) ?? string.Empty;
             nuspec.Summary = (string)metadata.Element(XName.Get("summary", nuspecNamespace)) ?? string.Empty;
@@ -259,7 +269,6 @@ public static NuspecFile Load(XDocument nuspecDocument)
             var filesElement = package.Element(XName.Get("files", nuspecNamespace));
             if (filesElement != null)
             {
-                //UnityEngine.Debug.Log("Loading files!");
                 foreach (var fileElement in filesElement.Elements(XName.Get("file", nuspecNamespace)))
                 {
                     var file = new NuspecContentFile();
@@ -402,5 +411,15 @@ private static string ConvertFromNupkgTargetFrameworkName(string targetFramework
 
             return convertedTargetFramework;
         }
+
+        private NuspecFile SetIconFilePath(string containingFilePath)
+        {
+            if (!string.IsNullOrEmpty(Icon))
+            {
+                IconFilePath = Path.Combine(Path.GetDirectoryName(Path.GetFullPath(containingFilePath)), Icon);
+            }
+
+            return this;
+        }
     }
 }