DxTabs.RenderMode Property

Specifies how the DxTabs component loads tab content.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v21.1.dll

NuGet Package: DevExpress.Blazor

Declaration

[DefaultValue(TabsRenderMode.Default)]
[Parameter]
public TabsRenderMode RenderMode { get; set; }

Property Value

Type	Default	Description
TabsRenderMode	**Default**	A TabsRenderMode enumeration value.

Available values:

Name	Description
Default	The component initially loads only content of an active tab. When a user selects another tab, its content replaces the content of the previously active tab in the DOM. Note the component does not keep the tab’s state.
AllTabs	The component renders the content of all tabs in the DOM and maintains the tab’s state. This mode speeds up navigation between tabs, but can increase memory consumption.
OnDemand	The component initially loads content of an active tab, then loads the content of other tabs when a user selects them. In this case, the component maintains the tab’s state. Use this mode to improve performance of your application.

Remarks

Use the RenderMode property to specify how the DxTabs component loads tab content.

Render modes include:

• Default
• AllTabs
• OnDemand

Default Mode

The DxTabs component initially only loads content of an active tab. When a user selects another tab, its content replaces the content of the previously active tab in the DOM. Note the DxTabs component does not keep the state of tabs.

<DxTabs RenderMode="TabsRenderMode.Default">
    ...
</DxTabs>

AllTabs Mode

In this mode, DxTabs renders the content of all tabs in the DOM and maintains the tab’s state.

The AllTabs mode speeds up navigation between tabs, but can increase memory consumption.

<DxTabs RenderMode="TabsRenderMode.AllTabs">
    ...
</DxTabs>

OnDemand Mode

In this mode, the component initially loads content of an active tab, then loads the content of other tabs when a user selects them. In this case, the component maintains the state of tabs.

Use the OnDemand mode to improve performance of your application.

<DxTabs RenderMode="TabsRenderMode.OnDemand">
    ...
</DxTabs>

Example

The code below demonstrates how to activate the OnDemand mode:

Index.razor

@inject Data.EmployeeService EmployeeService
@using Tabs.Data

@if (Employees == null) {
    <p><em>Loading...</em></p>
}
else {
    <div class="card w-75 ch-220 m-5">
        <DxTabs RenderMode="TabsRenderMode.OnDemand">
            @foreach (var employee in Employees) {
                <DxTabPage Text="@(employee.FirstName + ' ' +  employee.LastName)">
                    <div class="media demo-tab-page-content">
                        <div class="media-body pl-3 pt-3">
                            <h5 class="mt-0">@employee.Title @employee.FirstName @employee.LastName</h5>
                            <p><b>Birthday:</b> @employee.BirthDate.ToShortDateString()</p>
                            <p>@employee.Notes</p>
                        </div>
                    </div>
                </DxTabPage>
            }
        </DxTabs>
    </div>
}

@code {
    IEnumerable<Employee> Employees;

    protected override async Task OnInitializedAsync() {
        Employees = (await EmployeeService.Load()).Skip(5).Take(3);
    }
}

Employee.cs

using System;

namespace Tabs.Data {
    public class Employee {
        public string Title { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string Position { get; set; }
        public DateTime BirthDate { get; set; }
        public DateTime HireDate { get; set; }
        public string Notes { get; set; }
        public string FileName { get; set; }
    }
}

Employees.cs

using System;
using System.Collections.Generic;

namespace Tabs.Data {
    public static class Employees {
        public static List<Employee> Load() {
            var dataSource = new List<Employee>() {
                new Employee() { Title="Mr.", FirstName="John", LastName="Heart", Position="CEO", BirthDate=DateTime.Parse("1964/03/16"),
                    HireDate=DateTime.Parse("1995/01/15"),
                    Notes="John has been in the Audio/Video industry since 1990. He has led DevAv as its CEO since 2003. When not working hard as the CEO, John loves to golf and bowl. He once bowled a perfect game of 300.", FileName="JohnHeart" },
                new Employee() { Title="Mrs.", FirstName="Olivia", LastName="Peyton", Position="Sales Assistant", BirthDate=DateTime.Parse("1981/06/03"),
                    HireDate=DateTime.Parse("2012/05/14"),
                    Notes="Olivia loves to sell. She has been selling DevAV products since 2012. Olivia was homecoming queen in high school. She is expecting her first child in 6 months. Good Luck Olivia.", FileName="OliviaPeyton" },
                new Employee() { Title="Mr.", FirstName="Robert", LastName="Reagan", Position="CMO", BirthDate=DateTime.Parse("1974/09/07"),
                    HireDate=DateTime.Parse("2002/11/08"),
                    Notes="Robert was recently voted the CMO of the year by CMO Magazine. He is a proud member of the DevAV Management Team. Robert is a championship BBQ chef, so when you get the chance ask him for his secret recipe.", FileName="RobertReagan" },
                new Employee() { Title="Ms.", FirstName="Greta", LastName="Sims", Position="HR Manager", BirthDate=DateTime.Parse("1977/11/22"),
                    HireDate=DateTime.Parse("1998/04/23"),
                    Notes="Greta has been DevAV's HR Manager since 2003. She joined DevAV from Sonee Corp. Greta is currently training for the NYC marathon. Her best marathon time is 4 hours. Go Greta.", FileName="GretaSims" },
                new Employee() { Title="Mr.", FirstName="Brett", LastName="Wade", Position="IT Manager", BirthDate=DateTime.Parse("1968/12/01"),
                    HireDate=DateTime.Parse("2009/03/06"),
                    Notes="Brett came to DevAv from Microsoft and has led our IT department since 2012. When he is not working hard for DevAV, he coaches Little League (he was a high school pitcher).", FileName="BrettWade" },
                new Employee() { Title="Mrs.", FirstName="Sandra", LastName="Johnson", Position="Controller", BirthDate=DateTime.Parse("1974/11/15"),
                    HireDate=DateTime.Parse("2005/05/11"),
                    Notes="Sandra is a CPA and has been our controller since 2008. She loves to interact with staff so if you've not met her, be certain to say hi. Sandra has 2 daughters both of whom are accomplished gymnasts.", FileName="SandraJohnson" },
                new Employee() { Title="Mr.", FirstName="Kevin", LastName="Carter", Position="Shipping Manager", BirthDate=DateTime.Parse("1978/01/09"),
                    HireDate=DateTime.Parse("2009/08/11"),
                    Notes="Kevin is our hard-working shipping manager and has been helping that department work like clockwork for 18 months. When not in the office, he is usually on the basketball court playing pick-up games.", FileName="KevinCarter" },
                new Employee() { Title="Ms.", FirstName="Cynthia", LastName="Stanwick", Position="HR Assistant", BirthDate=DateTime.Parse("1985/06/05"),
                    HireDate=DateTime.Parse("2008/03/24"),
                    Notes="Cindy joined us in 2008 and has been in the HR department for 2 years. She was recently awarded employee of the month. Way to go Cindy!" , FileName="CynthiaStanwick"},
                new Employee() { Title="Dr.", FirstName="Kent", LastName="Samuelson", Position="Ombudsman", BirthDate=DateTime.Parse("1972/09/11"),
                    HireDate=DateTime.Parse("2009/04/22"),
                    Notes="As our ombudsman, Kent is on the front-lines solving customer problems and helping our partners address issues out in the field. He is a classically trained musician and is a member of the Chamber Orchestra." , FileName="KentSamuelson"},
            };
            return dataSource;
        }
        public static List<Employee> DataSource { get { return Load(); } }
    }
}

EmployeeService.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Tabs.Data;

namespace Tabs.Data {
    class EmployeeService {
        readonly IList<Employee> _dataSource;

        public EmployeeService() {
            _dataSource = Employees.Load();
        }
        public void Remove(Employee dataItem) {
            _dataSource.Remove(dataItem);
        }
        public void Update(Employee product, Dictionary<string, object> newValue) {
            foreach(var field in newValue.Keys) {
                switch(field) {
                    case "BirthDate":
                        product.BirthDate = (DateTime)newValue[field];
                        break;
                    case "FirstName":
                        product.FirstName = (string)newValue[field];
                        break;
                    case "LastName":
                        product.LastName = (string)newValue[field];
                        break;
                    case "Position":
                        product.Position = (string)newValue[field];
                        break;
                    case "Title":
                        product.Title = (string)newValue[field];
                        break;
                    case "Notes":
                        product.Notes = (string)newValue[field];
                        break;
                    case "HireDate":
                        product.HireDate = (DateTime)newValue[field];
                        break;
                    case "FileName":
                        product.FileName = (string)newValue[field];
                        break;
                }
            }
        }
        public Task<IQueryable<Employee>> Load() {
            return Task.FromResult(_dataSource.AsQueryable());
        }

        public void Insert(Dictionary<string, object> newValue) {
            if(!newValue.ContainsKey(nameof(Employee.LastName)))
                newValue.Add(nameof(Employee.LastName), Guid.NewGuid().ToString());

            var dataItem = new Employee();
            dataItem.FileName = "Unavailable";
            Update(dataItem, newValue);
            _dataSource.Add(dataItem);
        }
    }
}

Startup.cs

public class Startup {
// ...
    public void ConfigureServices(IServiceCollection services) {
    // ...
        services.AddSingleton<EmployeeService>();
        // ...
    }
    // ...
}