Add pagination to resources API

src/Moryx.AbstractionLayer.Resources.Endpoints/InvalidQueryParameterAttribute.cs

@@ -0,0 +1,19 @@
+// Copyright (c) 2025, Phoenix Contact GmbH & Co. KG
+// Licensed under the Apache License, Version 2.0
+
+using Microsoft.AspNetCore.Mvc.Abstractions;
+using Microsoft.AspNetCore.Mvc.ActionConstraints;
+using Microsoft.AspNetCore.Routing;
+
+namespace Moryx.AbstractionLayer.Resources.Endpoints;
+
+/// <summary>
+/// The attribute controls the selection of an action method based on the existance of a query parameter <paramref name="paramName"/>.
+/// </summary>
+/// <param name="paramName">The query parameter to mark this method as invalid for selection</param>
+public class InvalidQueryParameterAttribute(string paramName) : ActionMethodSelectorAttribute
+{
+    /// <inheritdoc />
+    public override bool IsValidForRequest(RouteContext routeContext, ActionDescriptor action) =>
+        !routeContext.HttpContext.Request.Query.ContainsKey(paramName);
+}

src/Moryx.AbstractionLayer.Resources.Endpoints/PagedResult.cs

@@ -0,0 +1,32 @@
+// Copyright (c) 2025, Phoenix Contact GmbH & Co. KG
+// Licensed under the Apache License, Version 2.0
+
+namespace Moryx.AbstractionLayer.Resources.Endpoints;
+
+/// <summary>
+/// Generic paged result returned from endpoints providing the <see cref="Items"/>
+/// with corresponding metadata from the request.
+/// </summary>
+/// <typeparam name="ItemType">Type of the items to be returned</typeparam>
+public sealed class PagedResult<ItemType>
+{
+    /// <summary>
+    /// The requested page from the total set of items
+    /// </summary>
+    public int PageNumber { get; set; }
+
+    /// <summary>
+    /// The maximum page size provided for the request
+    /// </summary>
+    public int PageSize { get; set; }
+
+    /// <summary>
+    /// The total number of items available
+    /// </summary>
+    public long TotalCount { get; set; }
+
+    /// <summary>
+    /// The items returned for the request
+    /// </summary>
+    public ItemType[] Items { get; set; }
+}

src/Moryx.AbstractionLayer.Resources.Endpoints/PagedResultExtensions.cs

@@ -0,0 +1,40 @@
+// Copyright (c) 2025, Phoenix Contact GmbH & Co. KG
+// Licensed under the Apache License, Version 2.0
+
+namespace Moryx.AbstractionLayer.Resources.Endpoints;
+
+/// <summary>
+/// Extension methods on the <see cref="PagedResult{ItemType}"/> for fluent instance creation
+/// </summary>
+public static class PagedResultExtensions
+{
+    extension<ItemType>(PagedResult<ItemType> pagedResult)
+    {
+        /// <summary>
+        /// Adds the <paramref name="pagination"/> meta informtaion to this <paramref name="pagedResult"/>
+        /// </summary>
+        /// <returns></returns>
+        public PagedResult<ItemType> With(PaginationParameters pagination)
+        {
+            pagedResult.PageNumber = pagination.PageNumber;
+            pagedResult.PageSize = pagination.PageSize;
+            // ToDo: Verify that already added results match the metadata
+            return pagedResult;
+        }
+
+        /// <summary>
+        /// Populates this <paramref name="pagedResult"/> with the <paramref name="fullSet"/>
+        /// of items taking already configured <see cref="PagedResult{ItemType}.PageNumber"/>
+        /// and <see cref="PagedResult{ItemType}.PageSize"/> into account
+        /// </summary>
+        /// <returns></returns>
+        public PagedResult<ItemType> Of(IEnumerable<ItemType> fullSet)
+        {
+            // ToDo: Account for unset metadata
+            pagedResult.TotalCount = fullSet.Count();
+            var skip = (pagedResult.PageNumber - 1) * pagedResult.PageSize;
+            pagedResult.Items = [.. fullSet.Skip(skip).Take(pagedResult.PageSize)];
+            return pagedResult;
+        }
+    }
+}

src/Moryx.AbstractionLayer.Resources.Endpoints/PaginationParameters.cs

@@ -0,0 +1,20 @@
+// Copyright (c) 2025, Phoenix Contact GmbH & Co. KG
+// Licensed under the Apache License, Version 2.0
+
+namespace Moryx.AbstractionLayer.Resources.Endpoints;
+
+/// <summary>
+/// Parameters used for paging requests.
+/// </summary>
+public sealed class PaginationParameters
+{
+    /// <summary>
+    /// The page number for a query returning a list of items; default to 1
+    /// </summary>
+    public int PageNumber { get; set => field = Math.Max(value, 1); } = 1;
+
+    /// <summary>
+    /// The number of items provided on the page; defaults to 20 with a minimum of 0 and a maximum of 100
+    /// </summary>
+    public int PageSize { get; set => field = Math.Min(Math.Max(value, 0), 100); } = 20;
+}

src/Moryx.AbstractionLayer.Resources.Endpoints/PaginationParametersExtensions.cs

@@ -0,0 +1,18 @@
+// Copyright (c) 2025, Phoenix Contact GmbH & Co. KG
+// Licensed under the Apache License, Version 2.0
+
+namespace Moryx.AbstractionLayer.Resources.Endpoints;
+
+/// <summary>
+/// Extension methods for handling pagination
+/// </summary>
+public static class PaginationParametersExtensions
+{
+    extension(PaginationParameters pagination)
+    {
+        /// <summary>
+        /// Calculates the number of items to be skipped with the request
+        /// </summary>
+        public int Skip() => (pagination.PageNumber - 1) * pagination.PageSize;
+    }
+}

src/Moryx.AbstractionLayer.Resources.Endpoints/RequiresQueryParameterAttribute.cs

@@ -0,0 +1,19 @@
+// Copyright (c) 2025, Phoenix Contact GmbH & Co. KG
+// Licensed under the Apache License, Version 2.0
+
+using Microsoft.AspNetCore.Mvc.Abstractions;
+using Microsoft.AspNetCore.Mvc.ActionConstraints;
+using Microsoft.AspNetCore.Routing;
+
+namespace Moryx.AbstractionLayer.Resources.Endpoints;
+
+/// <summary>
+/// The attribute controls the selection of an action method based on the existance of a query parameter <paramref name="paramName"/>.
+/// </summary>
+/// <param name="paramName">The required query parameter to mark this method as valid for selection</param>
+public class RequiresQueryParameterAttribute(string paramName) : ActionMethodSelectorAttribute
+{
+    /// <inheritdoc />
+    public override bool IsValidForRequest(RouteContext routeContext, ActionDescriptor action) =>
+        routeContext.HttpContext.Request.Query.ContainsKey(paramName);
+}

src/Moryx.AbstractionLayer.Resources.Endpoints/ResourceManagementController.cs

@@ -1,20 +1,21 @@
 // Copyright (c) 2025, Phoenix Contact GmbH & Co. KG
 // Licensed under the Apache License, Version 2.0
 
+using System.ComponentModel.DataAnnotations;
 using System.Net;
 using System.Reflection;
+using System.Runtime.Serialization;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Mvc.ModelBinding;
+using Moryx.AbstractionLayer.Activities;
+using Moryx.AbstractionLayer.Resources.Endpoints.Properties;
 using Moryx.Asp.Extensions;
+using Moryx.Configuration;
+using Moryx.Runtime.Modules;
 using Moryx.Serialization;
 using Moryx.Tools;
-using Moryx.Runtime.Modules;
-using Moryx.Configuration;
-using System.Runtime.Serialization;
-using System.ComponentModel.DataAnnotations;
-using Moryx.AbstractionLayer.Resources.Endpoints.Properties;
 
 namespace Moryx.AbstractionLayer.Resources.Endpoints
 {
@@ -68,11 +69,14 @@ public ActionResult<ResourceModel[]> GetDetailsBatch([FromQuery] long[] ids)
         }
 
         [HttpPost]
+        [InvalidQueryParameter(nameof(PaginationParameters.PageNumber))]
         [ProducesResponseType(StatusCodes.Status200OK)]
         [ProducesResponseType(StatusCodes.Status417ExpectationFailed)]
         [Route("query")]
         [Authorize(Policy = ResourcePermissions.CanViewTree)]
-        public ActionResult<ResourceModel[]> GetResources(ResourceQuery query)
+        public ActionResult<ResourceModel[]> GetResources(ResourceQuery query) => QueryResourceModels(query);
+
+        private ResourceModel[] QueryResourceModels(ResourceQuery query)
         {
             var filter = new ResourceQueryFilter(query, _resourceTypeTree);
             var resourceProxies = _resourceManagement.GetAllResources<IResource>(r => filter.Match(r as Resource)).ToArray();
@@ -82,6 +86,17 @@ public ActionResult<ResourceModel[]> GetResources(ResourceQuery query)
             return values;
         }
 
+        [HttpPost("query")]
+        [RequiresQueryParameter(nameof(PaginationParameters.PageNumber))]
+        [ProducesResponseType(StatusCodes.Status200OK)]
+        [ProducesResponseType(StatusCodes.Status400BadRequest)]
+        [Authorize(Policy = ResourcePermissions.CanViewTree)]
+        public ActionResult<PagedResult<ResourceModel>> GetResources([FromBody] ResourceQuery query, [FromQuery] PaginationParameters parameters)
+        {
+            var resourceModels = QueryResourceModels(query);
+            return new PagedResult<ResourceModel>().With(parameters).Of(resourceModels);
+        }
+
         [HttpGet]
         [ProducesResponseType(StatusCodes.Status200OK)]
         [ProducesResponseType(StatusCodes.Status404NotFound)]

src/Moryx.Resources.Web/src/app/api/fn/resource-modification/construct-with-parameters.ts

@@ -8,7 +8,7 @@ import { filter, map } from 'rxjs/operators';
 import { StrictHttpResponse } from '../../strict-http-response';
 import { RequestBuilder } from '../../request-builder';
 
-import { ResourceModel as MoryxAbstractionLayerResourcesEndpointsResourceModel } from '../../models/Moryx/AbstractionLayer/Resources/Endpoints/resource-model';
+import { ResourceModel } from '../../models/resource-model';
 import { Entry } from '@moryx/ngx-web-framework/entry-editor/src/models/entry';
 
 
@@ -18,7 +18,7 @@ export interface ConstructWithParameters$Params {
       body?: Entry
 }
 
-export function constructWithParameters(http: HttpClient, rootUrl: string, params: ConstructWithParameters$Params, context?: HttpContext): Observable<StrictHttpResponse<MoryxAbstractionLayerResourcesEndpointsResourceModel>> {
+export function constructWithParameters(http: HttpClient, rootUrl: string, params: ConstructWithParameters$Params, context?: HttpContext): Observable<StrictHttpResponse<ResourceModel>> {
   const rb = new RequestBuilder(rootUrl, constructWithParameters.PATH, 'post');
   if (params) {
     rb.path('type', params.type, {});
@@ -31,7 +31,7 @@ export function constructWithParameters(http: HttpClient, rootUrl: string, param
   ).pipe(
     filter((r: any): r is HttpResponse<any> => r instanceof HttpResponse),
     map((r: HttpResponse<any>) => {
-      return r as StrictHttpResponse<MoryxAbstractionLayerResourcesEndpointsResourceModel>;
+      return r as StrictHttpResponse<ResourceModel>;
     })
   );
 }