add opengraph tags to HTML

tayloraswift · tayloraswift · commit e523952e387f · 2024-02-22T23:27:25.000Z
diff --git a/Sources/DOM/HTML/HTML.Attribute.Factory (mxt).swift b/Sources/DOM/HTML/HTML.Attribute.Factory (mxt).swift
@@ -1,5 +1,10 @@
 extension HTML.Attribute.Factory
 {
+    @available(*, unavailable,
+        message: "Use the typed 'property' property on 'HTML.AttributeEncoder' instead.")
+    @inlinable public
+    var property:HTML.Attribute { .property }
+
     @available(*, unavailable,
         message: "Use the typed 'rel' property on 'HTML.AttributeEncoder' instead.")
     @inlinable public
diff --git a/Sources/DOM/HTML/HTML.Attribute.swift b/Sources/DOM/HTML/HTML.Attribute.swift
@@ -2,7 +2,7 @@ import DynamicLookupMacros
 
 extension HTML
 {
-    @GenerateDynamicMemberFactory(excluding: "rel")
+    @GenerateDynamicMemberFactory(excluding: "rel", "property")
     @frozen public
     enum Attribute:String, DOM.Attribute, Equatable, Hashable, Sendable
     {
@@ -136,5 +136,9 @@ extension HTML
         case value
         case width
         case wrap
+
+        /// A non-standard HTML attribute defined in [RDFa](https://en.wikipedia.org/wiki/RDFa)
+        /// for use in the `<meta>` tag.
+        case property
     }
 }
diff --git a/Sources/HTML/Encoding/HTML.AttributeEncoder (ext).swift b/Sources/HTML/Encoding/HTML.AttributeEncoder (ext).swift
@@ -1,13 +1,20 @@
 extension HTML.AttributeEncoder
 {
     @inlinable public
-    var rel:HTML.Attribute.Rel?
+    var property:HTML.Attribute.Property?
     {
-        get
+        get { nil }
+        set (value)
         {
-            nil
+            self[name: .property] = value?.rawValue
         }
-        set(value)
+    }
+
+    @inlinable public
+    var rel:HTML.Attribute.Rel?
+    {
+        get { nil }
+        set (value)
         {
             self[name: .rel] = value?.rawValue
         }
diff --git a/Sources/HTML/Types/HTML.Attribute.Property.swift b/Sources/HTML/Types/HTML.Attribute.Property.swift
@@ -0,0 +1,30 @@
+extension HTML.Attribute
+{
+    /// See https://ogp.me/
+    @frozen public
+    enum Property:String, Equatable, Hashable, Sendable
+    {
+        case og_audio = "og:audio"
+        case og_audio_type = "og:audio:type"
+
+        case og_image = "og:image"
+        case og_image_alt = "og:image:alt"
+        case og_image_type = "og:image:type"
+        case og_image_width = "og:image:width"
+        case og_image_height = "og:image:height"
+
+        case og_video = "og:video"
+        case og_video_type = "og:video:type"
+        case og_video_width = "og:video:width"
+        case og_video_height = "og:video:height"
+
+        case og_description = "og:description"
+        case og_determiner = "og:determiner"
+        case og_locale = "og:locale"
+        case og_locale_alternate = "og:locale:alternate"
+        case og_site_name = "og:site_name"
+        case og_title = "og:title"
+        case og_type = "og:type"
+        case og_url = "og:url"
+    }
+}
diff --git a/Sources/SwiftinitRender/Pages/Swiftinit.RenderablePage.swift b/Sources/SwiftinitRender/Pages/Swiftinit.RenderablePage.swift
@@ -56,6 +56,8 @@ extension Swiftinit.RenderablePage
         {
             $0[.head]
             {
+                let favicon:String = "\(format.assets[.favicon_png])"
+
                 $0[.title] = self.title
                 $0[.meta] { $0.charset = "UTF-8" }
                 $0[.meta]
@@ -65,7 +67,7 @@ extension Swiftinit.RenderablePage
                 }
                 $0[.link]
                 {
-                    $0.href = "\(format.assets[.favicon_png])"
+                    $0.href = favicon
                     $0.type = "\(MediaType.image(.png))"
                     $0.rel = .icon
                 }
@@ -98,9 +100,24 @@ extension Swiftinit.RenderablePage
 
                 if  let description:String = self.description
                 {
+                    //  It is regrettable that we need to duplicate the description text here,
+                    //  particularly because we do not compress dynamic content. However, it is
+                    //  necessary for Onebox to render link previews correctly.
                     $0[.meta] { $0.name = "description" ; $0.content  = description }
+                    $0[.meta] { $0.property = .og_description ; $0.content = description }
+                }
+                else
+                {
+                    $0[.meta]
+                    {
+                        $0.property = .og_description
+                        $0.content = "No overview available"
+                    }
                 }
 
+                $0[.meta] { $0.property = .og_title ; $0.content = self.title }
+                $0[.meta] { $0.property = .og_image ; $0.content = favicon }
+
                 self.head(augmenting: &$0, format: format)
             }
 

Original file line number	Diff line number	Diff line change
`@@ -2,7 +2,7 @@ import DynamicLookupMacros`
`2`	`2`
`3`	`3`	`extension HTML`
`4`	`4`	`{`
`5`		`- @GenerateDynamicMemberFactory(excluding: "rel")`
	`5`	`+ @GenerateDynamicMemberFactory(excluding: "rel", "property")`
`6`	`6`	`@frozen public`
`7`	`7`	`enum Attribute:String, DOM.Attribute, Equatable, Hashable, Sendable`
`8`	`8`	`{`
`@@ -136,5 +136,9 @@ extension HTML`
`136`	`136`	`case value`
`137`	`137`	`case width`
`138`	`138`	`case wrap`
	`139`	`+`
	`140`	`+ /// A non-standard HTML attribute defined in [RDFa](https://en.wikipedia.org/wiki/RDFa)`
	`141`	+ /// for use in the `<meta>` tag.
	`142`	`+ case property`
`139`	`143`	`}`
`140`	`144`	`}`
Original file line number	Diff line number	Diff line change
`@@ -1,13 +1,20 @@`
`1`	`1`	`extension HTML.AttributeEncoder`
`2`	`2`	`{`
`3`	`3`	`@inlinable public`
`4`		`- var rel:HTML.Attribute.Rel?`
	`4`	`+ var property:HTML.Attribute.Property?`
`5`	`5`	`{`
`6`		`- get`
	`6`	`+ get { nil }`
	`7`	`+ set (value)`
`7`	`8`	`{`
`8`		`- nil`
	`9`	`+ self[name: .property] = value?.rawValue`
`9`	`10`	`}`
`10`		`- set(value)`
	`11`	`+ }`
	`12`	`+`
	`13`	`+ @inlinable public`
	`14`	`+ var rel:HTML.Attribute.Rel?`
	`15`	`+ {`
	`16`	`+ get { nil }`
	`17`	`+ set (value)`
`11`	`18`	`{`
`12`	`19`	`self[name: .rel] = value?.rawValue`
`13`	`20`	`}`
Original file line number	Diff line number	Diff line change
`@@ -56,6 +56,8 @@ extension Swiftinit.RenderablePage`
`56`	`56`	`{`
`57`	`57`	`$0[.head]`
`58`	`58`	`{`
	`59`	`+ let favicon:String = "\(format.assets[.favicon_png])"`
	`60`	`+`
`59`	`61`	`$0[.title] = self.title`
`60`	`62`	`$0[.meta] { $0.charset = "UTF-8" }`
`61`	`63`	`$0[.meta]`
`@@ -65,7 +67,7 @@ extension Swiftinit.RenderablePage`
`65`	`67`	`}`
`66`	`68`	`$0[.link]`
`67`	`69`	`{`
`68`		`- $0.href = "\(format.assets[.favicon_png])"`
	`70`	`+ $0.href = favicon`
`69`	`71`	`$0.type = "\(MediaType.image(.png))"`
`70`	`72`	`$0.rel = .icon`
`71`	`73`	`}`
`@@ -98,9 +100,24 @@ extension Swiftinit.RenderablePage`
`98`	`100`
`99`	`101`	`if let description:String = self.description`
`100`	`102`	`{`
	`103`	`+ // It is regrettable that we need to duplicate the description text here,`
	`104`	`+ // particularly because we do not compress dynamic content. However, it is`
	`105`	`+ // necessary for Onebox to render link previews correctly.`
`101`	`106`	`$0[.meta] { $0.name = "description" ; $0.content = description }`
	`107`	`+ $0[.meta] { $0.property = .og_description ; $0.content = description }`
	`108`	`+ }`
	`109`	`+ else`
	`110`	`+ {`
	`111`	`+ $0[.meta]`
	`112`	`+ {`
	`113`	`+ $0.property = .og_description`
	`114`	`+ $0.content = "No overview available"`
	`115`	`+ }`
`102`	`116`	`}`
`103`	`117`
	`118`	`+ $0[.meta] { $0.property = .og_title ; $0.content = self.title }`
	`119`	`+ $0[.meta] { $0.property = .og_image ; $0.content = favicon }`
	`120`	`+`
`104`	`121`	`self.head(augmenting: &$0, format: format)`
`105`	`122`	`}`
`106`	`123`