Feature/tag helpers

src/Blend.Optimizely/TagHelpers/AnchorTagHelper.cs

@@ -0,0 +1,89 @@
+using Blend.Optimizely;
+using EPiServer.ServiceLocation;
+using Microsoft.AspNetCore.Razor.TagHelpers;
+
+namespace Blend.Optimizely.TagHelpers
+{
+    [HtmlTargetElement("a", Attributes = "content-link")]
+    public class AnchorTagHelper : TagHelper
+    {
+        private Injected<LinkResolverService> LinkResolver { get; }
+
+        /// <summary>
+        /// Some kind of link that can be resolved via Optimizely. This includes:
+        /// IResolvable for special cases
+        /// IContent objects
+        /// Url objects
+        /// LinkItem objects
+        /// ContentReference objects
+        /// </summary>
+        [HtmlAttributeName("content-link")]
+        public object ContentLink { get; set; }
+
+        /// <summary>
+        /// How should the anchor tag be handle when there is no valid href or the condition is false. 
+        /// Options are:
+        /// None, ConvertLinkToSpan, SuppressOutput, KeepInnerContent
+        /// </summary>
+        [HtmlAttributeName("link-options")]
+        public LinkOptions LinkOptions { get; set; }
+
+        [HtmlAttributeName("fallback-option")]
+        public AnchorFallbackOptions FallbackOption { get; set; }
+
+        /// <summary>
+        /// Only output an anchor tag with href when condition is true and a valid link exists. Default is true
+        /// </summary>
+        [HtmlAttributeName("condition")]
+        public bool Condition { get; set; } = true;
+
+        public override void Process(TagHelperContext context, TagHelperOutput output)
+        {
+            if (context is null || output is null)
+                return;
+
+            var resolvedLink = LinkResolver.Service.TryResolveLink(ContentLink, LinkOptions);
+            if (resolvedLink is not null && resolvedLink.Href.HasValue() && Condition)
+            {
+                output.Attributes.SetAttribute("href", resolvedLink.Href);
+
+                if (resolvedLink.Target.HasValue() && !context.AllAttributes.TryGetAttribute("target", out _))
+                    output.Attributes.SetAttribute("target", resolvedLink.Target);
+            }
+            else if (FallbackOption is AnchorFallbackOptions.ConvertLinkToSpan)
+            {
+                output.TagName = "span";
+            }
+            else if (FallbackOption is AnchorFallbackOptions.SuppressOutput)
+            {
+                output.SuppressOutput();
+                return;
+            }
+            else if (FallbackOption is AnchorFallbackOptions.KeepInnerContent)
+            {
+                output.TagName = string.Empty;
+                return;
+            }
+        }
+    }
+
+    public enum AnchorFallbackOptions
+    {
+        None = 0,
+
+        /// <summary>
+        /// If url is blank, convert the wrapping a tag to a span
+        /// </summary>
+        ConvertLinkToSpan = 1,
+
+        /// <summary>
+        /// If url is blank, suppress output
+        /// </summary>
+        SuppressOutput = 2,
+
+        /// <summary>
+        /// If url is blank, remove wrapping tag
+        /// </summary>
+        KeepInnerContent = 3
+    }
+}

src/Blend.Optimizely/TagHelpers/ConditionalWrapperHelper.cs

@@ -0,0 +1,36 @@
+using Microsoft.AspNetCore.Razor.TagHelpers;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Blend.Optimizely.TagHelpers
+{
+    [HtmlTargetElement("*", Attributes = "wrap-if")]
+    [HtmlTargetElement("*", Attributes = "suppress-if")]
+    public class ConditionalWrapperHelper : TagHelper
+    {
+        [HtmlAttributeName("wrap-if")]
+        public bool WrapIfCondition { get; set; }
+
+        [HtmlAttributeName("suppress-if")]
+        public bool SuppressIfCondition { get; set; }
+
+
+        [HtmlAttributeName("link-options")]
+        public LinkOptions LinkOptions { get; set; }
+
+        public override void Process(TagHelperContext context, TagHelperOutput output)
+        {
+            if (SuppressIfCondition)
+            {
+                output.SuppressOutput();
+            }
+            if (!WrapIfCondition)
+            {
+                output.TagName = null;
+            }
+        }
+    }
+}

src/Blend.Optimizely/TagHelpers/IImageFile.cs

@@ -0,0 +1,16 @@
+using EPiServer.Core;
+using System.Collections.Generic;
+
+namespace Blend.Optimizely.TagHelpers
+{
+    internal interface IImageFile :IContent
+    {
+        public int Width { get; set; }
+        public int Height { get; set; }
+
+        public string GetAltText();
+
+        public IEnumerable<int> ImageOptions();
+
+    }
+}

src/Blend.Optimizely/TagHelpers/ImageHelper.cs

@@ -0,0 +1,68 @@
+using EPiServer;
+using EPiServer.Core;
+using EPiServer.ServiceLocation;
+using Microsoft.AspNetCore.Razor.TagHelpers;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Blend.Optimizely.TagHelpers
+{
+    [HtmlTargetElement("Image", Attributes = "src", TagStructure = TagStructure.WithoutEndTag)]
+    public class ImageHelper : TagHelper
+    {
+        public ContentReference? src { get; set; }
+
+        [HtmlAttributeName("eager-loading")]
+        public bool EagerLoading { get; set; }
+        public override void Process(TagHelperContext context, TagHelperOutput output)
+        {
+            if (!src.HasValue() && output != null)
+            {
+                output.SuppressOutput();
+                return;
+            }
+
+            var imgUrl = src.ResolveUrl();
+            if (!imgUrl.HasValue())
+            {
+                output.SuppressOutput();
+                return;
+            }
+
+            var imageVariations = new List<string>();
+
+            var loader = ServiceLocator.Current.GetInstance<IContentLoader>();
+            if (loader.TryGet<IImageFile>(src, out var image))
+            {
+                output.Attributes.SetAttribute("alt", image.GetAltText());
+
+                if (image.Width > 0)
+                    output.Attributes.SetAttribute("width", image.Width);
+
+                if (image.Height > 0)
+                    output.Attributes.SetAttribute("height", image.Height);
+
+                imageVariations = image.ImageOptions().Where(x => x != image.Width).Select(x =>
+                {
+                    var url = new UrlBuilder(imgUrl);
+                    url.QueryCollection.Add("width", x.ToString());
+                    return (string)url + $" {x}w";
+                }).ToList();
+
+                if (imageVariations.HasValue())
+                {
+                    imageVariations.Add($"{imgUrl} {image.Width}w");
+                    output.Attributes.SetAttribute("srcset", string.Join($", ", imageVariations));
+                    output.Attributes.SetAttribute("sizes", "100vw");
+                }
+            }
+
+            output.TagName = "img";
+            output.TagMode = TagMode.SelfClosing;
+            output.Attributes.SetAttribute("src", imgUrl);
+
+            if (!EagerLoading)
+                output.Attributes.SetAttribute("loading", "lazy");
+        }
+    }
+}

src/Blend.Optimizely/TagHelpers/SourceHelper.cs

@@ -0,0 +1,61 @@
+using EPiServer;
+using EPiServer.Core;
+using Microsoft.AspNetCore.Razor.TagHelpers;
+using System.Linq;
+
+namespace Blend.Optimizely.TagHelpers
+{
+
+    [HtmlTargetElement("Source", Attributes = "srcset")]
+    public class SourceHelper : TagHelper
+    {
+        public ContentReference? src { get; set; }
+
+        public bool EagerLoading { get; set; }
+        public override void Process(TagHelperContext context, TagHelperOutput output)
+        {
+            if (!src.HasValue() && output != null)
+            {
+                output.SuppressOutput();
+                return;
+            }
+
+            var image = src.Get<IImageFile>(); // NOTE: This is likely to be a breaking change - Switching from `ImageFile` to `IImageFile`
+            var imgUrl = src.ResolveUrl();
+
+            if (image == null || !imgUrl.HasValue())
+            {
+                output.SuppressOutput();
+                return;
+            }
+
+            output.TagName = "img";
+            output.TagMode = TagMode.SelfClosing;
+            output.Attributes.SetAttribute("src", imgUrl);
+            output.Attributes.SetAttribute("alt", image.GetAltText()); // NOTE: This is likely to be a breaking change - Switching from `ContentReference` to `IImageFile`
+
+            if (image.Width > 0)
+                output.Attributes.SetAttribute("width", image.Width);
+
+            if (image.Height > 0)
+                output.Attributes.SetAttribute("height", image.Height);
+
+            var imageVariations = image.ImageOptions().Where(x => x != image.Width).Select(x =>
+            {
+                var url = new UrlBuilder(imgUrl);
+                url.QueryCollection.Add("width", x.ToString());
+                return (string)url + $" {x}w";
+            }).ToList();
+
+            if (imageVariations.HasValue())
+            {
+                imageVariations.Add($"{imgUrl} {image.Width}w");
+                output.Attributes.SetAttribute("srcset", string.Join($", ", imageVariations));
+                output.Attributes.SetAttribute("sizes", "100vw");
+            }
+
+            if (!EagerLoading)
+                output.Attributes.SetAttribute("loading", "lazy");
+        }
+    }
+}