Expose and manage system media types (#16343)

* Expose and manage system media types

* Removed license :D

src/Umbraco.Cms.Api.Management/Controllers/MediaType/Tree/MediaTypeTreeControllerBase.cs

@@ -8,6 +8,7 @@ using Umbraco.Cms.Core.Models;
 using Umbraco.Cms.Core.Models.Entities;
 using Umbraco.Cms.Core.Services;
 using Umbraco.Cms.Web.Common.Authorization;
+using Umbraco.Extensions;
 
 namespace Umbraco.Cms.Api.Management.Controllers.MediaType.Tree;
 
@@ -38,6 +39,7 @@ public class MediaTypeTreeControllerBase : FolderTreeControllerBase<MediaTypeTre
             if (mediaTypes.TryGetValue(entity.Id, out IMediaType? mediaType))
             {
                 responseModel.Icon = mediaType.Icon ?? responseModel.Icon;
+                responseModel.IsDeletable = mediaType.IsSystemMediaType() is false;
             }
 
             return responseModel;

src/Umbraco.Cms.Api.Management/Mapping/MediaType/MediaTypeMapDefinition.cs

@@ -48,6 +48,8 @@ public class MediaTypeMapDefinition : ContentTypeMapDefinition<IMediaType, Media
                 MediaType = referenceByIdModel,
                 CompositionType = compositionType,
             });
+        target.IsDeletable = source.IsSystemMediaType() is false;
+        target.AliasCanBeChanged = source.IsSystemMediaType() is false;
     }
 
     // Umbraco.Code.MapAll

src/Umbraco.Cms.Api.Management/OpenApi.json

@@ -38642,12 +38642,14 @@
       "MediaTypeResponseModel": {
         "required": [
           "alias",
+          "aliasCanBeChanged",
           "allowedAsRoot",
           "allowedMediaTypes",
           "compositions",
           "containers",
           "icon",
           "id",
+          "isDeletable",
           "isElement",
           "name",
           "properties",
@@ -38735,6 +38737,12 @@
                 }
               ]
             }
+          },
+          "isDeletable": {
+            "type": "boolean"
+          },
+          "aliasCanBeChanged": {
+            "type": "boolean"
           }
         },
         "additionalProperties": false
@@ -38765,6 +38773,7 @@
           "hasChildren",
           "icon",
           "id",
+          "isDeletable",
           "isFolder",
           "name"
         ],
@@ -38793,6 +38802,9 @@
           },
           "icon": {
             "type": "string"
+          },
+          "isDeletable": {
+            "type": "boolean"
           }
         },
         "additionalProperties": false

src/Umbraco.Cms.Api.Management/ViewModels/MediaType/MediaTypeResponseModel.cs

@@ -7,4 +7,8 @@ public class MediaTypeResponseModel : ContentTypeResponseModelBase<MediaTypeProp
     public IEnumerable<MediaTypeSort> AllowedMediaTypes { get; set; } = Enumerable.Empty<MediaTypeSort>();
 
     public IEnumerable<MediaTypeComposition> Compositions { get; set; } = Enumerable.Empty<MediaTypeComposition>();
+
+    public bool IsDeletable { get; set; }
+
+    public bool AliasCanBeChanged { get; set; }
 }

src/Umbraco.Cms.Api.Management/ViewModels/Tree/MediaTypeTreeItemResponseModel.cs

@@ -3,4 +3,6 @@
 public class MediaTypeTreeItemResponseModel : FolderTreeItemResponseModel
 {
     public string Icon { get; set; } = string.Empty;
+
+    public bool IsDeletable { get; set; }
 }

src/Umbraco.Core/Models/MediaType.cs

@@ -1,5 +1,6 @@
 using System.Runtime.Serialization;
 using Umbraco.Cms.Core.Strings;
+using Umbraco.Extensions;
 
 namespace Umbraco.Cms.Core.Models;
 
@@ -45,6 +46,21 @@ public class MediaType : ContentTypeCompositionBase, IMediaType
     /// <inheritdoc />
     public override ISimpleContentType ToSimple() => new SimpleContentType(this);
 
+    /// <inheritdoc />
+    public override string Alias
+    {
+        get => base.Alias;
+        set
+        {
+            if (this.IsSystemMediaType() && value != Alias)
+            {
+                throw new InvalidOperationException("Cannot change the alias of a system media type");
+            }
+
+            base.Alias = value;
+        }
+    }
+
     /// <inheritdoc />
     IMediaType IMediaType.DeepCloneWithResetIdentities(string newAlias) =>
         (IMediaType)DeepCloneWithResetIdentities(newAlias);

src/Umbraco.Core/Services/ContentTypeEditing/MediaTypeEditingService.cs

@@ -42,6 +42,11 @@ internal sealed class MediaTypeEditingService : ContentTypeEditingServiceBase<IM
 
     public async Task<Attempt<IMediaType?, ContentTypeOperationStatus>> UpdateAsync(IMediaType mediaType, MediaTypeUpdateModel model, Guid userKey)
     {
+        if (mediaType.IsSystemMediaType() && mediaType.Alias != model.Alias)
+        {
+            return Attempt.FailWithStatus<IMediaType?, ContentTypeOperationStatus>(ContentTypeOperationStatus.NotAllowed, null);
+        }
+
         Attempt<IMediaType?, ContentTypeOperationStatus> result = await ValidateAndMapForUpdateAsync(mediaType, model);
         if (result.Success)
         {

src/Umbraco.Core/Services/ContentTypeServiceBaseOfTRepositoryTItemTService.cs

@@ -620,6 +620,11 @@ public abstract class ContentTypeServiceBase<TRepository, TItem> : ContentTypeSe
             return ContentTypeOperationStatus.NotFound;
         }
 
+        if (CanDelete(item) is false)
+        {
+            return ContentTypeOperationStatus.NotAllowed;
+        }
+
         Delete(item, performingUserId);
 
         scope.Complete();
@@ -628,6 +633,11 @@ public abstract class ContentTypeServiceBase<TRepository, TItem> : ContentTypeSe
 
     public void Delete(TItem item, int userId = Constants.Security.SuperUserId)
     {
+        if (CanDelete(item) is false)
+        {
+            throw new InvalidOperationException("The item was not allowed to be deleted");
+        }
+
         using (ICoreScope scope = ScopeProvider.CreateCoreScope())
         {
             EventMessages eventMessages = EventMessagesFactory.Get();
@@ -695,6 +705,10 @@ public abstract class ContentTypeServiceBase<TRepository, TItem> : ContentTypeSe
     public void Delete(IEnumerable<TItem> items, int userId = Constants.Security.SuperUserId)
     {
         TItem[] itemsA = items.ToArray();
+        if (itemsA.All(CanDelete) is false)
+        {
+            throw new InvalidOperationException("One or more items were not allowed to be deleted");
+        }
 
         using (ICoreScope scope = ScopeProvider.CreateCoreScope())
         {
@@ -750,6 +764,8 @@ public abstract class ContentTypeServiceBase<TRepository, TItem> : ContentTypeSe
 
     protected abstract void DeleteItemsOfTypes(IEnumerable<int> typeIds);
 
+    protected virtual bool CanDelete(TItem item) => true;
+
     #endregion
 
     #region Copy

src/Umbraco.Core/Services/MediaTypeService.cs

@@ -8,6 +8,7 @@ using Umbraco.Cms.Core.Persistence.Repositories;
 using Umbraco.Cms.Core.Scoping;
 using Umbraco.Cms.Core.Services.Changes;
 using Umbraco.Cms.Core.Services.Locking;
+using Umbraco.Extensions;
 
 namespace Umbraco.Cms.Core.Services;
 
@@ -77,6 +78,9 @@ public class MediaTypeService : ContentTypeServiceBase<IMediaTypeRepository, IMe
         }
     }
 
+    protected override bool CanDelete(IMediaType item)
+        => item.IsSystemMediaType() is false;
+
     #region Notifications
 
     protected override SavingNotification<IMediaType> GetSavingNotification(