add service using AsyncLocal for instance context across request

Author: Jondyr

src/Altinn.App.Api/Controllers/ResourceController.cs

@@ -11,14 +11,16 @@ namespace Altinn.App.Api.Controllers;
 public class ResourceController : ControllerBase
 {
     private readonly IAppResources _appResourceService;
+    private readonly IInstanceContext _instanceContext;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="ResourceController"/> class
     /// </summary>
     /// <param name="appResourcesService">The execution service</param>
-    public ResourceController(IAppResources appResourcesService)
+    public ResourceController(IAppResources appResourcesService, IInstanceContext instanceContext)
     {
         _appResourceService = appResourcesService;
+        _instanceContext = instanceContext;
     }
 
     /// <summary>
@@ -71,6 +73,32 @@ public ActionResult GetLayouts(string org, string app, string id)
         return Ok(layouts);
     }
 
+    /// <summary>
+    /// Endpoint for layouts with instance context
+    /// </summary>
+    /// <param name="org"></param>
+    /// <param name="app"></param>
+    /// <param name="instanceOwnerPartyId"></param>
+    /// <param name="instanceId"></param>
+    /// <param name="layoutSetId"></param>
+    /// <returns></returns>
+    [ProducesResponseType(typeof(string), StatusCodes.Status200OK, "text/plain")]
+    [HttpGet]
+    [Route("{org}/{app}/instance/{instanceOwnerPartyId:int}/{instanceId}/layouts/{layoutSetId}")]
+    public ActionResult GetInstanceLayouts(
+        string org,
+        string app,
+        int instanceOwnerPartyId,
+        string instanceId,
+        string layoutSetId
+    )
+    {
+        _instanceContext.InstanceId = instanceId;
+        _instanceContext.InstanceOwnerPartyId = instanceOwnerPartyId;
+        string layouts = _appResourceService.GetLayoutsForSet(layoutSetId);
+        return Ok(layouts);
+    }
+
     /// <summary>
     /// Get the layout settings.
     /// </summary>

src/Altinn.App.Core/Extensions/ServiceCollectionExtensions.cs

@@ -168,6 +168,7 @@ IWebHostEnvironment env
         services.TryAddTransient<IPDP, PDPAppSI>();
         services.TryAddTransient<IPrefill, PrefillSI>();
         services.TryAddTransient<ISigningCredentialsResolver, SigningCredentialsResolver>();
+        services.TryAddSingleton<IInstanceContext, InstanceContext>();
         services.TryAddSingleton<IAppResources, AppResourcesSI>();
         services.TryAddSingleton<IAppMetadata, AppMetadata>();
         services.TryAddSingleton<IFrontendFeatures, FrontendFeatures>();

src/Altinn.App.Core/Implementation/InstanceContext.cs

@@ -0,0 +1,19 @@
+using Altinn.App.Core.Internal.App;
+
+public class InstanceContext : IInstanceContext
+{
+    private static readonly AsyncLocal<int?> _instanceOwnerPartyId = new();
+    private static readonly AsyncLocal<string?> _instanceId = new();
+
+    public string? InstanceId
+    {
+        get => _instanceId.Value;
+        set => _instanceId.Value = value;
+    }
+
+    public int? InstanceOwnerPartyId
+    {
+        get => _instanceOwnerPartyId.Value;
+        set => _instanceOwnerPartyId.Value = value;
+    }
+}

src/Altinn.App.Core/Internal/App/IInstanceContext.cs

@@ -0,0 +1,17 @@
+namespace Altinn.App.Core.Internal.App;
+
+/// <summary>
+/// Interface for accessing instance context information
+/// </summary>
+public interface IInstanceContext
+{
+    /// <summary>
+    /// Instance Id
+    /// </summary>
+    string? InstanceId { get; set; }
+
+    /// <summary>
+    /// Party Id
+    /// </summary>
+    int? InstanceOwnerPartyId { get; set; }
+}