Fehlende Datei ergänzt ... sorry, jetzt haut es aber wieder hin :D

Controllers/LendController.cs

@@ -0,0 +1,84 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using AutoMapper;
+using BuecherwurmAPI.Data;
+using BuecherwurmAPI.DTOs;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.JsonPatch;
+using Microsoft.Extensions.Logging;
+using BuecherwurmAPI.Models;
+
+namespace BuecherwurmAPI.Controllers
+{
+    [Route("api/leihvorgang")]
+    [ApiController]
+    public class LendController : ControllerBase
+    {
+        private readonly ILendRepo _repository;
+        private readonly IMapper _mapper;
+        
+        public LendController(ILendRepo repository, IMapper mapper)
+        {
+            _repository = repository;
+            _mapper = mapper;
+        }
+        
+        //GET api/leihvorgang
+        [HttpGet]
+        public ActionResult<IEnumerable<Lend>> LendsGet()
+        {
+            return Ok(_repository.GetAllLends());
+        }
+        
+        //POST api/leihvorgang
+        [HttpPost]
+        public ActionResult<LendReadDTO> LendsPost(Lend lend)
+        {
+            /*
+                Internally a lend is stored with an id
+                but the client shouldn't be allowed to set or change it
+                therefore the package 'AutoMapper' is used to prevent errors
+                that could happen when doing this task manually.
+                It takes the information from the client and maps it to the
+                corresponding internal object which then will be returned.
+                Furthermore it could be used to keep some attributes secret.
+                Another nice effect of this is that the implementation could be changed 
+                while the interface could be retained by some minor changes in the code.
+                
+                DTO stands for Data Transfer Object
+            */
+            var item = new Lend
+            {
+                Id = 256,
+                Customer = lend.Customer,
+                Returned = lend.Returned,
+                ItemId = lend.ItemId,
+                ReturnDate = lend.ReturnDate
+            };
+            return Ok(item);
+            //return Ok(_mapper.Map<LendReadDTO>(item));
+        }
+
+        //GET api/leihvorgang/{id}
+        [HttpGet("{id}")]
+        public ActionResult<Lend> LendById(int id)
+        {
+            var lend = _repository.GetLendById(id);
+            return Ok(lend);
+        }
+
+        //PATCH api/leihvorgang/{id}
+        [HttpPatch("{id}")]
+        public ActionResult LendPatchById(int id, JsonPatchDocument<Lend> patchDocument)
+        {
+            var lend = _repository.GetLendById(id);
+            if (lend == null)
+            {
+                return NotFound();
+            }
+            return Ok();
+        }
+    }
+}