> Markdown version of [Login](https://vaadin.com/docs/v14/ds/components/login). Section index: [llms.txt](https://vaadin.com/docs/v14/ds/llms.txt)

# Login

Login is a component that contains a login form. You can use it for authenticating the user with a username and password. It is compatible with password managers, supports internationalization and works on all device sizes.

`LoginBasic.java`

```java
LoginForm loginForm = new LoginForm();
add(loginForm);
```

## <a id="basic-login-componentform"></a>Basic Login Component/Form

The basic Login component consists of a title (**Log in**), two input fields (**Username** and **Password**), and two buttons (**Log in** and **Forgot password**).

You can customize the form’s title and labels using internationalization.

`LoginInternationalization.java`

```java
LoginI18n i18n = LoginI18n.createDefault();

LoginI18n.Form i18nForm = i18n.getForm();
i18nForm.setTitle("Kirjaudu sisään");
i18nForm.setUsername("Käyttäjänimi");
i18nForm.setPassword("Salasana");
i18nForm.setSubmit("Kirjaudu sisään");
i18nForm.setForgotPassword("Unohtuiko salasana?");
i18n.setForm(i18nForm);

LoginI18n.ErrorMessage i18nErrorMessage = i18n.getErrorMessage();
i18nErrorMessage.setTitle("Väärä käyttäjätunnus tai salasana");
i18nErrorMessage.setMessage("Tarkista että käyttäjätunnus ja salasana ovat oikein ja yritä uudestaan.");
i18n.setErrorMessage(i18nErrorMessage);

LoginForm loginForm = new LoginForm();
loginForm.setI18n(i18n);
```

The basic Login component can be used to create login pages featuring rich content.

`LoginRichContent.java`

```java
// See login-rich-content.css
addClassName("login-rich-content");

LoginForm loginForm = new LoginForm();
loginForm.getElement().getThemeList().add("dark");
```

`login-rich-content.css`

```css
.login-rich-content {
  background-image: url("../../../src/main/resources/images/earth.jpg");
  background-position: center;
  background-size: cover;
  display: flex;
  height: 500px;
}
.login-rich-content vaadin-login-form {
  align-items: center;
  display: flex;
  max-width: 300px;
}
.login-rich-content vaadin-login-form-wrapper {
  background-image: none;
}
```

> **Note: Password managers**
>
> Login is incompatible with password managers if placed inside another component’s \[[1](#_footnotedef_1)] shadow root. This is not an issue when using Login’s modal overlay.

## <a id="modal-overlay"></a>Modal Overlay

Login features its own modal overlay. Use it to create simple login pages (that are full screen on mobile devices) or to handle authentication without a dedicated login page. You can also use it to handle re-authentication when the user’s session has expired.

The overlay can be opened programmatically or through user interaction, for example, by using a login button.

`LoginOverlayBasic.java`

```java
LoginOverlay loginOverlay = new LoginOverlay();
add(loginOverlay);

Button login = new Button("Log in");
login.addClickListener(event -> loginOverlay.setOpened(true));
```

### <a id="header"></a>Header

The overlay has a header and the login form. By default, the header contains placeholders for the application’s title and description. Both properties are configurable.

`login-overlay-header-preview.ts`

```typescript
import { html, LitElement, customElement } from 'lit-element';
import { applyTheme } from 'Frontend/generated/theme';
import './login-overlay-mockup';

@customElement('login-overlay-header')
export class Example extends LitElement {
    protected createRenderRoot() {
        const root = super.createRenderRoot();
        // Apply custom theme (only supported if your app uses one)
        applyTheme(root);
        return root;
    }

    render() {
        return html`
      <login-overlay-mockup
        headerTitle="TaskMob"
        description="Built with ♥ by Vaadin"
      ></login-overlay-mockup>
    `;
    }
}
```

`LoginOverlayHeader.java`

```java
LoginOverlay loginOverlay = new LoginOverlay();
loginOverlay.setTitle("TaskMob");
loginOverlay.setDescription("Built with ♥ by Vaadin");
```

## <a id="validation"></a>Validation

Login shows an error message when authentication fails. The error message consists of a title and a message. It is displayed directly underneath the form’s title.

`login-validation-preview.ts`

```typescript
import { html, LitElement, customElement } from 'lit-element';
import { applyTheme } from 'Frontend/generated/theme';
import './login-overlay-mockup';

@customElement('login-validation')
export class Example extends LitElement {
    protected createRenderRoot() {
        const root = super.createRenderRoot();
        // Apply custom theme (only supported if your app uses one)
        applyTheme(root);
        return root;
    }

    render() {
        return html`<login-overlay-mockup error></login-overlay-mockup>`;
    }
}
```

`LoginValidation.java`

```java
loginOverlay.setError(true);
```

The error message is customizable using internationalization. It should contain instructions on how to resolve the problem.

More information can also be provided to the user, for example, by linking to a page with helpful material or by displaying contact information.

`login-additional-information-preview.ts`

```typescript
import { customElement, html, LitElement, query } from 'lit-element';
import { applyTheme } from 'Frontend/generated/theme';
import './login-overlay-mockup';
import { LoginOverlayMockupElement } from './login-overlay-mockup';

@customElement('login-additional-information')
export class Example extends LitElement {
    protected createRenderRoot() {
        const root = super.createRenderRoot();
        // Apply custom theme (only supported if your app uses one)
        applyTheme(root);
        return root;
    }

    @query('login-overlay-mockup')
    private login?: LoginOverlayMockupElement;
    firstUpdated() {
        if (this.login && this.login.i18n) {
            this.login.i18n = {
                ...this.login.i18n,
                additionalInformation: `Please, contact admin@company.com if you're experiecing issues logging into your account`,
            };
        }
    }

    render() {
        return html`<login-overlay-mockup></login-overlay-mockup>`;
    }
}
```

`LoginAdditionalInformation.java`

```java
LoginI18n i18n = LoginI18n.createDefault();
i18n.setAdditionalInformation("Please, contact admin@company.com if you're experiencing issues logging into your account");

LoginOverlay loginOverlay = new LoginOverlay();
loginOverlay.setI18n(i18n);
```

## <a id="internationalization-i18n"></a>Internationalization (i18n)

Login’s titles, descriptions, labels, and messages are all customizable using internationalization.

`login-overlay-internationalization-preview.ts`

```typescript
import { html, LitElement, customElement } from 'lit-element';
import { LoginI18n } from '@vaadin/vaadin-login/vaadin-login-overlay';
import { applyTheme } from 'Frontend/generated/theme';
import './login-overlay-mockup';

@customElement('login-overlay-internationalization-preview')
export class Example extends LitElement {
    protected createRenderRoot() {
        const root = super.createRenderRoot();
        // Apply custom theme (only supported if your app uses one)
        applyTheme(root);
        return root;
    }

    private i18n: LoginI18n = {
        header: {
            title: 'Sovelluksen nimi',
            description: 'Sovelluksen kuvaus',
        },
        form: {
            title: 'Kirjaudu sisään',
            username: 'Käyttäjänimi',
            password: 'Salasana',
            submit: 'Kirjaudu sisään',
            forgotPassword: 'Unohtuiko salasana?',
        },
        errorMessage: {
            title: 'Väärä käyttäjätunnus tai salasana',
            message: 'Tarkista että käyttäjätunnus ja salasana ovat oikein ja yritä uudestaan.',
        },
        additionalInformation: 'Jos tarvitset lisätietoja käyttäjälle.',
    };

    render() {
        return html`
      <login-overlay-mockup
        .i18n="${this.i18n}"
        .headerTitle="${this.i18n.header?.title}"
        .description="${this.i18n.header?.description}"
      ></login-overlay-mockup>
    `;
    }
}
```

`LoginOverlayInternationalization.java`

```java
LoginI18n i18n = LoginI18n.createDefault();

LoginI18n.Header i18nHeader = i18n.getHeader();
i18nHeader.setTitle("Sovelluksen nimi");
i18nHeader.setDescription("Sovelluksen kuvaus");

LoginI18n.Form i18nForm = i18n.getForm();
i18nForm.setTitle("Kirjaudu sisään");
i18nForm.setUsername("Käyttäjänimi");
i18nForm.setPassword("Salasana");
i18nForm.setSubmit("Kirjaudu sisään");
i18nForm.setForgotPassword("Unohtuiko salasana?");
i18n.setForm(i18nForm);

LoginI18n.ErrorMessage i18nErrorMessage = i18n.getErrorMessage();
i18nErrorMessage.setTitle("Väärä käyttäjätunnus tai salasana");
i18nErrorMessage.setMessage("Tarkista että käyttäjätunnus ja salasana ovat oikein ja yritä uudestaan.");
i18n.setErrorMessage(i18nErrorMessage);

i18n.setAdditionalInformation("Jos tarvitset lisätietoja käyttäjälle.");

LoginOverlay loginOverlay = new LoginOverlay();
loginOverlay.setI18n(i18n);
```

<!-- vale Vale.Terms = NO -->

### <a id="header-2"></a>Header

The header is only shown for modal login forms.

| Property    | Default value               |
| ----------- | --------------------------- |
| Title       | *"App name"*                |
| Description | *"Application description"* |

<!-- vale Vale.Terms = YES -->

### <a id="form"></a>Form

Customize the form’s title, input field and button labels.

| Property        | Default value       |
| --------------- | ------------------- |
| Title           | *"Log in"*          |
| Username        | *"Username"*        |
| Password        | *"Password"*        |
| Submit          | *"Log in"*          |
| Forgot password | *"Forgot password"* |

### <a id="error-message"></a>Error Message

Login’s error message is shown when authentication fails. It consists of a title and message.

| Property | Default value                                                                    |
| -------- | -------------------------------------------------------------------------------- |
| Title    | *"Incorrect username or password"*                                               |
| Message  | *"Check that you have entered the correct username and password and try again."* |

<!-- vale Vaadin.TooWordy = NO -->

### <a id="additional-information"></a>Additional Information

This property is hidden unless its value is explicitly set.

| Property               | Default value |
| ---------------------- | ------------- |
| Additional information | -             |

<!-- vale Vaadin.TooWordy = YES -->

## <a id="technical"></a>Technical

### <a id="handling-events"></a>Handling Events

#### <a id="login-event"></a>Login Event

You can add a listener to login events and/or define an action for which a POST request is fired. From the event, you can prevent the POST request.

The login button is disabled when clicked to prevent multiple submissions. To restore it, call `component.setEnabled(true)`.

#### <a id="forgot-password"></a>Forgot Password

You can add an event listener so you can provide instructions for password recovery for your users.

#### <a id="cross-site-request-forgery-csrf-tokens"></a>Cross-Site Request Forgery (CSRF) Tokens

If the page contains the following meta tags with a CSRF token, the token is automatically included in a form POST request:

```html
<meta name="_csrf_parameter" content="_csrf">
<meta name="_csrf" content="71dac59f-34ee-4b31-b478-2891cbd0c55d">
```

This token is submitted as `_csrf=71dac59f-34ee-4b31-b478-2891cbd0c55d`, that is, using the `_csrf_parameter` content as the variable name and the `_csrf` content as the value.

`9CA8E14E-A01E-4C48-8D08-D4B1E6A3D287`

---

[1](#_footnoteref_1). When added to a web component that uses shadow root, password managers are unable to find the input fields and thus not work.