Port Breadcrumbs to IComponentGenerator

gunndabad · Dec 25, 2024 · a9c4a60 · a9c4a60
1 parent b827f4b
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Showing 15 changed files with 183 additions and 212 deletions.
diff --git a/docs/components/breadcrumbs.md b/docs/components/breadcrumbs.md
@@ -6,9 +6,9 @@
 
 ```razor
 <govuk-breadcrumbs collapse-on-mobile="true">
-    <govuk-breadcrumbs-item asp-controller="Home" asp-action="Index">Home</govuk-breadcrumbs-item>
-    <govuk-breadcrumbs-item href="#" link-target="_blank">Passports, travel and living abroad</govuk-breadcrumbs-item>
-    <govuk-breadcrumbs-item>Travel abroad</govuk-breadcrumbs-item>
+    <item asp-controller="Home" asp-action="Index">Home</item>
+    <item href="#" link-target="_blank">Passports, travel and living abroad</item>
+    <item>Travel abroad</item>
 </govuk-breadcrumbs>
 ```
 
@@ -18,11 +18,11 @@
 
 ### `<govuk-breadcrumbs>`
 
-| Attribute | Type | Description |
-| --- | --- | --- |
-| `collapse-on-mobile` | `bool` | When true, the breadcrumbs will collapse to the first and last item only on tablet breakpoint and below. Default is `false`. |
+| Attribute | Type    | Description                                                                                                                                      |
+| --- |---------|--------------------------------------------------------------------------------------------------------------------------------------------------|
+| `collapse-on-mobile` | `bool?` | When true, the breadcrumbs will collapse to the first and last item only on tablet breakpoint and below. If not specified, `false` will be used. |
 
-### `<govuk-breadcrumbs-item>`
+### `<item>`
 
 Content is the HTML to use within the breadcrumbs item.\
 Must be inside a `<govuk-breadcrumbs>` element.

diff --git a/src/GovUk.Frontend.AspNetCore.DocSamples/Pages/Breadcrumbs/Breadcrumbs.cshtml b/src/GovUk.Frontend.AspNetCore.DocSamples/Pages/Breadcrumbs/Breadcrumbs.cshtml
@@ -1,7 +1,7 @@
 @page
 
 <govuk-breadcrumbs collapse-on-mobile="true">
-    <govuk-breadcrumbs-item asp-controller="Home" asp-action="Index">Home</govuk-breadcrumbs-item>
-    <govuk-breadcrumbs-item href="#" link-target="_blank">Passports, travel and living abroad</govuk-breadcrumbs-item>
-    <govuk-breadcrumbs-item>Travel abroad</govuk-breadcrumbs-item>
+    <item asp-controller="Home" asp-action="Index">Home</item>
+    <item href="#" link-target="_blank">Passports, travel and living abroad</item>
+    <item>Travel abroad</item>
 </govuk-breadcrumbs>
diff --git a/src/GovUk.Frontend.AspNetCore/ComponentGeneration/BreadcrumbsOptions.cs b/src/GovUk.Frontend.AspNetCore/ComponentGeneration/BreadcrumbsOptions.cs
@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Generic;
 using Microsoft.AspNetCore.Html;
 
@@ -8,9 +9,23 @@ namespace GovUk.Frontend.AspNetCore.ComponentGeneration;
 public class BreadcrumbsOptions
 {
     public bool? CollapseOnMobile { get; set; }
-    public string? Classes { get; set; }
+    public IHtmlContent? Classes { get; set; }
     public EncodedAttributesDictionary? Attributes { get; set; }
     public IReadOnlyCollection<BreadcrumbsOptionsItem>? Items { get; set; }
+
+    internal void Validate()
+    {
+        if (Items is null)
+        {
+            throw new InvalidOptionsException(GetType(), $"{nameof(Items)} must be specified.");
+        }
+
+        int i = 0;
+        foreach (var item in Items)
+        {
+            item.Validate(i++);
+        }
+    }
 }
 
 public class BreadcrumbsOptionsItem
@@ -19,4 +34,15 @@ public class BreadcrumbsOptionsItem
     public string? Text { get; set; }
     public IHtmlContent? Href { get; set; }
     public EncodedAttributesDictionary? Attributes { get; set; }
+
+    [NonStandardParameter]
+    internal EncodedAttributesDictionary? ItemAttributes { get; set; }
+
+    internal void Validate(int itemIndex)
+    {
+        if (Html.NormalizeEmptyString() is null && Text.NormalizeEmptyString() is null)
+        {
+            throw new InvalidOptionsException(GetType(), $"{nameof(Html)} or {nameof(Text)} must be specified on item {itemIndex}.");
+        }
+    }
 }
diff --git a/src/GovUk.Frontend.AspNetCore/ComponentGeneration/DefaultComponentGenerator.Breadcrumbs.cs b/src/GovUk.Frontend.AspNetCore/ComponentGeneration/DefaultComponentGenerator.Breadcrumbs.cs
@@ -0,0 +1,48 @@
+using System;
+using System.Linq;
+
+namespace GovUk.Frontend.AspNetCore.ComponentGeneration;
+
+public partial class DefaultComponentGenerator
+{
+    internal const string BreadcrumbsElement = "div";
+    internal const bool BreadcrumbsDefaultCollapseOnMobile = false;
+    internal const string BreadcrumbsItemElement = "li";
+
+    /// <inheritdoc/>
+    public virtual HtmlTagBuilder GenerateBreadcrumbs(BreadcrumbsOptions options)
+    {
+        ArgumentNullException.ThrowIfNull(options);
+        options.Validate();
+
+        return new HtmlTagBuilder(BreadcrumbsElement)
+            .WithCssClass("govuk-breadcrumbs")
+            .WithCssClasses(ExplodeClasses(options.Classes?.ToHtmlString()))
+            .When(options.CollapseOnMobile == true, b => b.WithCssClass("govuk-breadcrumbs--collapse-on-mobile"))
+            .WithAttributes(options.Attributes)
+            .WithAppendedHtml(new HtmlTagBuilder("ol")
+                .WithCssClass("govuk-breadcrumbs__list")
+                .WithAppendedHtml(options.Items!.Select(item =>
+                {
+                    var content = GetEncodedTextOrHtml(item.Text, item.Html)!;
+                    var gotLink = item.Href.NormalizeEmptyString() is not null;
+
+                    return new HtmlTagBuilder(BreadcrumbsItemElement)
+                        .WithCssClass("govuk-breadcrumbs__list-item")
+                        .WithAttributes(item.ItemAttributes)
+                        .When(
+                            !gotLink,
+                            b => b
+                                .WithAttribute("aria-current", "page", encodeValue: false)
+                                .WithAppendedHtml(content))
+                        .When(
+                            gotLink,
+                            b => b
+                                .WithAppendedHtml(new HtmlTagBuilder("a")
+                                    .WithCssClass("govuk-breadcrumbs__link")
+                                    .WithAttribute("href", item.Href!)
+                                    .WithAttributes(item.Attributes)
+                                    .WithAppendedHtml(content)));
+                })));
+    }
+}
diff --git a/src/GovUk.Frontend.AspNetCore/ComponentGeneration/IComponentGenerator.cs b/src/GovUk.Frontend.AspNetCore/ComponentGeneration/IComponentGenerator.cs
@@ -17,6 +17,12 @@ public interface IComponentGenerator
     /// <returns>An <see cref="HtmlTagBuilder"/> with the component's HTML.</returns>
     HtmlTagBuilder GenerateBackLink(BackLinkOptions options);
 
+    /// <summary>
+    /// Generates a breadcrumbs component.
+    /// </summary>
+    /// <returns>An <see cref="HtmlTagBuilder"/> with the component's HTML.</returns>
+    HtmlTagBuilder GenerateBreadcrumbs(BreadcrumbsOptions options);
+
     /// <summary>
     /// Generates a button component.
     /// </summary>

diff --git a/src/GovUk.Frontend.AspNetCore/HtmlGeneration/BreadcrumbsItem.cs b/src/GovUk.Frontend.AspNetCore/HtmlGeneration/BreadcrumbsItem.cs
diff --git a/src/GovUk.Frontend.AspNetCore/HtmlGeneration/ComponentGenerator.Breadcrumbs.cs b/src/GovUk.Frontend.AspNetCore/HtmlGeneration/ComponentGenerator.Breadcrumbs.cs
diff --git a/src/GovUk.Frontend.AspNetCore/IGovUkHtmlGenerator.cs b/src/GovUk.Frontend.AspNetCore/IGovUkHtmlGenerator.cs
@@ -22,11 +22,6 @@ TagBuilder GenerateAccordion(
         string showSectionAriaLabelText,
         IEnumerable<AccordionItem> items);
 
-    TagBuilder GenerateBreadcrumbs(
-        bool collapseOnMobile,
-        AttributeDictionary attributes,
-        IEnumerable<BreadcrumbsItem> items);
-
     TagBuilder GenerateCharacterCount(
         string textAreaId,
         int? maxLength,

diff --git a/src/GovUk.Frontend.AspNetCore/TagHelpers/BreadcrumbsContext.cs b/src/GovUk.Frontend.AspNetCore/TagHelpers/BreadcrumbsContext.cs
@@ -1,22 +1,23 @@
+using System;
 using System.Collections.Generic;
-using GovUk.Frontend.AspNetCore.HtmlGeneration;
+using GovUk.Frontend.AspNetCore.ComponentGeneration;
 
 namespace GovUk.Frontend.AspNetCore.TagHelpers;
 
 internal class BreadcrumbsContext
 {
-    private readonly List<BreadcrumbsItem> _items;
+    private readonly List<BreadcrumbsOptionsItem> _items;
 
     public BreadcrumbsContext()
     {
-        _items = new List<BreadcrumbsItem>();
+        _items = new List<BreadcrumbsOptionsItem>();
     }
 
-    public IReadOnlyCollection<BreadcrumbsItem> Items => _items;
+    public IReadOnlyCollection<BreadcrumbsOptionsItem> Items => _items;
 
-    public void AddItem(BreadcrumbsItem item)
+    public void AddItem(BreadcrumbsOptionsItem item)
     {
-        Guard.ArgumentNotNull(nameof(item), item);
+        ArgumentNullException.ThrowIfNull(item);
 
         _items.Add(item);
     }

diff --git a/src/GovUk.Frontend.AspNetCore/TagHelpers/BreadcrumbsItemTagHelper.cs b/src/GovUk.Frontend.AspNetCore/TagHelpers/BreadcrumbsItemTagHelper.cs
@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.Threading.Tasks;
+using GovUk.Frontend.AspNetCore.ComponentGeneration;
 using GovUk.Frontend.AspNetCore.HtmlGeneration;
 using Microsoft.AspNetCore.Razor.TagHelpers;
 
@@ -9,10 +10,12 @@ namespace GovUk.Frontend.AspNetCore.TagHelpers;
 /// Represents an item in a GDS breadcrumbs component.
 /// </summary>
 [HtmlTargetElement(TagName, ParentTag = BreadcrumbsTagHelper.TagName)]
+[HtmlTargetElement(ShortTagName, ParentTag = BreadcrumbsTagHelper.TagName)]
 //[OutputElementHint(ComponentGenerator.BreadcrumbsItemElement)]  // Omitted since it produces intellisense warnings
 public class BreadcrumbsItemTagHelper : TagHelper
 {
     internal const string TagName = "govuk-breadcrumbs-item";
+    internal const string ShortTagName = ShortTagNames.Item;
 
     private const string LinkAttributesPrefix = "link-";
 
@@ -27,27 +30,22 @@ public override async Task ProcessAsync(TagHelperContext context, TagHelperOutpu
     {
         var breadcrumbsContext = context.GetContextItem<BreadcrumbsContext>();
 
-        var childContent = await output.GetChildContentAsync();
+        var childContent = (await output.GetChildContentAsync()).Snapshot();
 
         if (output.Content.IsModified)
         {
             childContent = output.Content;
         }
 
-        string? href = null;
+        var attributes = new EncodedAttributesDictionary(output.Attributes);
+        attributes.Remove("href", out var href);
 
-        if (output.Attributes.TryGetAttribute("href", out var hrefAttribute))
+        breadcrumbsContext.AddItem(new BreadcrumbsOptionsItem()
         {
-            href = hrefAttribute.Value.ToString();
-            output.Attributes.Remove(hrefAttribute);
-        }
-
-        breadcrumbsContext.AddItem(new BreadcrumbsItem()
-        {
-            Attributes = output.Attributes.ToAttributeDictionary(),
+            ItemAttributes = attributes,
             Href = href,
-            LinkAttributes = LinkAttributes.ToAttributeDictionary(),
-            Content = childContent.Snapshot()
+            Attributes = EncodedAttributesDictionary.FromDictionaryWithEncodedValues(LinkAttributes),
+            Html = childContent
         });
 
         output.SuppressOutput();