React Diagram - Web API Service

This example demonstrates the Diagram component communicating with a Web API service. All data editing and processing operations are delegated to the server. The DevExtreme.AspNet.Data extension's createStore method configures access to the server from the client. The server implementation is available under the DiagramEmployeesController.cs tab in the ASP.NET MVC version of this demo.

TS JS

Backend API

import React from 'react'; import Diagram, { Nodes, AutoLayout, ContextToolbox, Toolbox, Group, IContextToolboxProps, } from 'devextreme-react/diagram'; import { createStore } from 'devextreme-aspnet-data-nojquery'; const url = 'https://js.devexpress.com/Demos/NetCore/api/DiagramEmployees'; const dataSource = createStore({ key: 'ID', loadUrl: `${url}/Employees`, insertUrl: `${url}/InsertEmployee`, updateUrl: `${url}/UpdateEmployee`, deleteUrl: `${url}/DeleteEmployee`, onBeforeSend(method, ajaxOptions) { ajaxOptions.xhrFields = { withCredentials: true }; }, onInserting(values) { values.ID = 0; values.Title = values.Title || 'New Position'; values.Prefix = 'Mr'; values.FullName = 'New Employee'; values.City = 'LA'; values.State = 'CA'; values.HireDate = new Date(); }, }); const shapes: IContextToolboxProps['shapes'] = ['rectangle']; export default function App() { return ( <Diagram id="diagram"> <Nodes dataSource={dataSource} keyExpr="ID" textExpr="Title" parentKeyExpr="HeadID"> <AutoLayout type="tree" /> </Nodes> <ContextToolbox shapeIconsPerRow={2} width={100} shapes={shapes}> </ContextToolbox> <Toolbox showSearch={false} shapeIconsPerRow={2}> <Group title="Items" shapes={shapes} /> </Toolbox> </Diagram> ); }

import React from 'react'; import Diagram, { Nodes, AutoLayout, ContextToolbox, Toolbox, Group, } from 'devextreme-react/diagram'; import { createStore } from 'devextreme-aspnet-data-nojquery'; const url = 'https://js.devexpress.com/Demos/NetCore/api/DiagramEmployees'; const dataSource = createStore({ key: 'ID', loadUrl: `${url}/Employees`, insertUrl: `${url}/InsertEmployee`, updateUrl: `${url}/UpdateEmployee`, deleteUrl: `${url}/DeleteEmployee`, onBeforeSend(method, ajaxOptions) { ajaxOptions.xhrFields = { withCredentials: true }; }, onInserting(values) { values.ID = 0; values.Title = values.Title || 'New Position'; values.Prefix = 'Mr'; values.FullName = 'New Employee'; values.City = 'LA'; values.State = 'CA'; values.HireDate = new Date(); }, }); const shapes = ['rectangle']; export default function App() { return ( <Diagram id="diagram"> <Nodes dataSource={dataSource} keyExpr="ID" textExpr="Title" parentKeyExpr="HeadID" > <AutoLayout type="tree" /> </Nodes> <ContextToolbox shapeIconsPerRow={2} width={100} shapes={shapes} ></ContextToolbox> <Toolbox showSearch={false} shapeIconsPerRow={2} > <Group title="Items" shapes={shapes} /> </Toolbox> </Diagram> ); }

import React from 'react'; import ReactDOM from 'react-dom'; import App from './App.tsx'; ReactDOM.render( <App />, document.getElementById('app'), );

import React from 'react'; import ReactDOM from 'react-dom'; import App from './App.js'; ReactDOM.render(<App />, document.getElementById('app'));

<!DOCTYPE html> <html lang="en"> <head> <title>DevExtreme Demo</title> <meta http-equiv="X-UA-Compatible" content="IE=edge" /> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=5.0" /> <link rel="stylesheet" type="text/css" href="https://cdn3.devexpress.com/jslib/25.1.6/css/dx-diagram.min.css" /> <link rel="stylesheet" type="text/css" href="https://cdn3.devexpress.com/jslib/25.1.6/css/dx.light.css" /> <link rel="stylesheet" type="text/css" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.6.3/css/font-awesome.min.css" /> <link rel="stylesheet" type="text/css" href="styles.css" /> <script src="https://cdn.jsdelivr.net/npm/core-js@2.6.12/client/shim.min.js"></script> <script src="https://cdn.jsdelivr.net/npm/systemjs@0.21.3/dist/system.js"></script> <script type="text/javascript" src="config.js"></script> <script type="text/javascript"> System.import("./index.tsx"); </script> </head> <body class="dx-viewport"> <div class="demo-container"> <div id="app"></div> </div> </body> </html>

#diagram { height: 725px; }

using System; using System.Collections.Generic; namespace DevExtreme.MVC.Demos.Models.Diagram { public class InMemoryEmployeesDataContext : InMemoryDataContext<Employee> { public ICollection<Employee> Employees => ItemsInternal; protected override IEnumerable<Employee> Source => SampleData.SampleData.DiagramEmployees; protected override int GetKey(Employee item) => item.ID; protected override void SetKey(Employee item, int key) => item.ID = key; } }

using DevExtreme.AspNet.Data; using DevExtreme.AspNet.Mvc; using DevExtreme.MVC.Demos.Models.Diagram; using Newtonsoft.Json; using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Net.Http; using System.Net.Http.Formatting; using System.Web.Http; namespace DevExtreme.MVC.Demos.Controllers.ApiControllers { [Route("api/DiagramEmployees/{action}", Name = "DiagramEmployees")] public class DiagramEmployeesController : ApiController { InMemoryEmployeesDataContext db = new InMemoryEmployeesDataContext(); [HttpGet] public HttpResponseMessage Employees(DataSourceLoadOptions loadOptions) { return Request.CreateResponse(DataSourceLoader.Load(db.Employees, loadOptions)); } [HttpPost] public HttpResponseMessage InsertEmployee(FormDataCollection form) { var values = form.Get("values"); var newEmployee = new Employee(); JsonConvert.PopulateObject(values, newEmployee); Validate(newEmployee); if(!ModelState.IsValid) return Request.CreateErrorResponse(HttpStatusCode.BadRequest, ModelState.GetFullErrorMessage()); db.Employees.Add(newEmployee); db.SaveChanges(); return Request.CreateResponse(HttpStatusCode.Created, newEmployee); } [HttpPut] public HttpResponseMessage UpdateEmployee(FormDataCollection form) { var key = Convert.ToInt32(form.Get("key")); var values = form.Get("values"); var employee = db.Employees.First(e => e.ID == key); JsonConvert.PopulateObject(values, employee); Validate(employee); if(!ModelState.IsValid) return Request.CreateErrorResponse(HttpStatusCode.BadRequest, ModelState.GetFullErrorMessage()); db.SaveChanges(); return Request.CreateResponse(HttpStatusCode.OK, employee); } [HttpDelete] public void DeleteEmployee(FormDataCollection form) { var key = Convert.ToInt32(form.Get("key")); var employee = db.Employees.First(e => e.ID == key); db.Employees.Remove(employee); db.SaveChanges(); } } }

A 1-Click Solution for CRUD Web API Services with Role-based Access Control via EF Core

If you target .NET for your backend API, be sure to check out Web API Service and register your free copy today. The Solution Wizard scaffolds an OData v4 Web API Service (.NET 6+) with integrated authorization & CRUD operations powered by EF Core ORM. You can use OAuth2, JWT or custom authentication strategies alongside tools like Postman or Swagger (OpenAPI) for API testing. The built-in Web API Service also filters out secured server data based on permissions granted to users. Advanced/enterprise functions include audit trail, endpoints to download reports, file attachments, check validation, obtain localized captions, etc.

To use the free Solution Wizard (which creates the Web API Service), run the Universal Component Installer from the DevExpress Download Manager and use our predefined template in Visual Studio 2022+.

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