Add exit this page component generation

src/GovUk.Frontend.AspNetCore/ComponentGeneration/DefaultComponentGenerator.ExitThisPage.cs

@@ -0,0 +1,43 @@
+using System;
+using System.Collections.Immutable;
+using HtmlTags;
+
+namespace GovUk.Frontend.AspNetCore.ComponentGeneration;
+
+public partial class DefaultComponentGenerator
+{
+    internal const string ExitThisPageElement = "div";
+
+    /// <inheritdoc/>
+    public HtmlTag GenerateExitThisPage(ExitThisPageOptions options)
+    {
+        ArgumentNullException.ThrowIfNull(options);
+        options.Validate();
+
+        return new HtmlTag(ExitThisPageElement)
+            .AddEncodedAttributeIfNotNull("id", options.Id)
+            .AddClass("govuk-exit-this-page")
+            .AddClasses(ExplodeClasses(options.Classes))
+            .UnencodedAttr("data-module", "govuk-exit-this-page")
+            .MergeEncodedAttributes(options.Attributes)
+            .AddEncodedAttributeIf(options.ActivatedText.NormalizeEmptyString() is not null, "data-i18n.activated", HtmlEncode(options.ActivatedText))
+            .AddEncodedAttributeIf(options.TimedOutText.NormalizeEmptyString() is not null, "data-i18n.timed-out", HtmlEncode(options.TimedOutText))
+            .AddEncodedAttributeIf(options.PressTwoMoreTimesText.NormalizeEmptyString() is not null, "data-i18n.press-two-more-times", HtmlEncode(options.PressTwoMoreTimesText))
+            .AddEncodedAttributeIf(options.PressOneMoreTimeText.NormalizeEmptyString() is not null, "data-i18n.press-one-more-time", HtmlEncode(options.PressOneMoreTimeText))
+            .Append(GenerateButton(new ButtonOptions()
+            {
+                Html = (options.Html.NormalizeEmptyString() ?? options.Text.NormalizeEmptyString()) is not null ?
+                    options.Html :
+                    new HtmlTag("span")
+                        .AddClass("govuk-visually-hidden")
+                        .Text("Emergency")
+                        .After(new HtmlTag(null).Text("Exit this page"))
+                        .ToHtmlString(),
+                Text = options.Text.NormalizeEmptyString(),
+                Classes = "govuk-button--warning govuk-exit-this-page__button govuk-js-exit-this-page-button",
+                Href = options.RedirectUrl.NormalizeEmptyString() ?? "https://www.bbc.co.uk/weather",
+                Attributes = ImmutableDictionary<string, string?>.Empty
+                    .Add("rel", "nofollow noreferrer")
+            }));
+    }
+}

src/GovUk.Frontend.AspNetCore/ComponentGeneration/ExitThisPageOptions.cs

@@ -0,0 +1,24 @@
+using System.Collections.Generic;
+
+namespace GovUk.Frontend.AspNetCore.ComponentGeneration;
+
+#pragma warning disable CS1591 // Missing XML comment for publicly visible type or member
+
+public record ExitThisPageOptions
+{
+    public string? Text { get; set; }
+    public string? Html { get; set; }
+    public string? RedirectUrl { get; set; }
+    public string? Id { get; set; }
+    public string? Classes { get; set; }
+    public IReadOnlyDictionary<string, string?>? Attributes { get; set; }
+    public string? ActivatedText { get; set; }
+    public string? TimedOutText { get; set; }
+    public string? PressTwoMoreTimesText { get; set; }
+    public string? PressOneMoreTimeText { get; set; }
+
+    internal void Validate()
+    {
+
+    }
+}

src/GovUk.Frontend.AspNetCore/ComponentGeneration/IComponentGenerator.cs

@@ -43,6 +43,12 @@ public interface IComponentGenerator
     /// <returns>An <see cref="HtmlTag"/> with the component's HTML.</returns>
     HtmlTag GenerateErrorSummary(ErrorSummaryOptions options);
 
+    /// <summary>
+    /// Generates an exit this pagecomponent.
+    /// </summary>
+    /// <returns>An <see cref="HtmlTag"/> with the component's HTML.</returns>
+    HtmlTag GenerateExitThisPage(ExitThisPageOptions options);
+
     /// <summary>
     /// Generates a fieldset component.
     /// </summary>

tests/GovUk.Frontend.AspNetCore.Tests/ComponentGeneration/ComponentTests.cs

@@ -57,6 +57,13 @@ public void ErrorSummary(ComponentTestCaseData<ErrorSummaryOptions> data) =>
             data,
             (generator, options) => generator.GenerateErrorSummary(options).ToHtmlString());
 
+    [Theory]
+    [ComponentFixtureData("exit-this-page", typeof(ExitThisPageOptions), exclude: "testing")]
+    public void ExitThisPage(ComponentTestCaseData<ExitThisPageOptions> data) =>
+        CheckComponentHtmlMatchesExpectedHtml(
+            data,
+            (generator, options) => generator.GenerateExitThisPage(options).ToHtmlString());
+
     [Theory]
     [ComponentFixtureData("fieldset", typeof(FieldsetOptions))]
     public void Fieldset(ComponentTestCaseData<FieldsetOptions> data) =>