WIP on OpenGraph types (#52)

src/MyWebLog.Domain/SupportTypes.fs

@@ -382,6 +382,171 @@ type Revision = {
         { AsOf = Noda.epoch; Text = Html "" }
 
 
+/// <summary>Properties for an OpenGraph audio file</summary>
+[<CLIMutable>]
+type OpenGraphAudio = {
+    /// <summary>The URL for this audio file</summary>
+    Url: string
+    
+    /// <summary>The URL for this audio file for sites that require https</summary>
+    SecureUrl: string option
+    
+    /// <summary>The MIME type of the audio file</summary>
+    Type: string option
+} with
+    
+    /// <summary>An empty audio file</summary>
+    static member Empty =
+        { Url       = ""
+          SecureUrl = None
+          Type      = None }
+
+
+/// <summary>Properties for an OpenGraph image</summary>
+[<CLIMutable>]
+type OpenGraphImage = {
+    /// <summary>The URL for this image</summary>
+    Url: string
+    
+    /// <summary>The URL for this image for sites that require https</summary>
+    SecureUrl: string option
+    
+    /// <summary>The MIME type of the image</summary>
+    Type: string option
+    
+    /// <summary>The image width (in pixels)</summary>
+    Width: int option
+    
+    /// <summary>The image height (in pixels)</summary>
+    Height: int option
+    
+    /// <summary>Alternative text for the image</summary>
+    Alt: string option
+} with
+    
+    /// <summary>An empty image file</summary>
+    static member Empty =
+        { Url       = ""
+          SecureUrl = None
+          Type      = None
+          Width     = None
+          Height    = None
+          Alt       = None }
+
+
+/// <summary>Properties for an OpenGraph video</summary>
+[<CLIMutable>]
+type OpenGraphVideo = {
+    /// <summary>The URL for this video</summary>
+    Url: string
+    
+    /// <summary>The URL for this video for sites that require https</summary>
+    SecureUrl: string option
+    
+    /// <summary>The MIME type of the video</summary>
+    Type: string option
+    
+    /// <summary>The video width (in pixels)</summary>
+    Width: int option
+    
+    /// <summary>The video height (in pixels)</summary>
+    Height: int option
+} with
+    
+    /// <summary>An empty video file</summary>
+    static member Empty =
+        { Url       = ""
+          SecureUrl = None
+          Type      = None
+          Width     = None
+          Height    = None }
+
+
+/// <summary>Valid <c>og:type</c> values</summary>
+[<Struct>]
+type OpenGraphType =
+    | Article
+    | Book
+    | MusicAlbum
+    | MusicPlaylist
+    | MusicRadioStation
+    | MusicSong
+    | PaymentLink
+    | Profile
+    | VideoEpisode
+    | VideoMovie
+    | VideoOther
+    | VideoTvShow
+    | Website
+    
+    /// <summary>Parse a string into an OpenGraph type</summary>
+    /// <param name="typ">The string to be parsed</param>
+    /// <returns>The <c>OpenGraphType</c> parsed from the string</returns>
+    /// <exception cref="InvalidArgumentException">If the string is not valid</exception>
+    static member Parse typ =
+        match typ with
+        | "article" -> Article
+        | "book" -> Book
+        | "music.album" -> MusicAlbum
+        | "music.playlist" -> MusicPlaylist
+        | "music.radio_station" -> MusicRadioStation
+        | "music.song" -> MusicSong
+        | "payment.link" -> PaymentLink
+        | "profile" -> Profile
+        | "video.episode" -> VideoEpisode
+        | "video.movie" -> VideoMovie
+        | "video.other" -> VideoOther
+        | "video.tv_show" -> VideoTvShow
+        | "website" -> Website
+        | _ -> invalidArg (nameof typ) $"{typ} is not a valid OpenGraph type"
+    
+    override this.ToString() =
+        match this with
+        | Article -> "article"
+        | Book -> "book"
+        | MusicAlbum -> "music.album"
+        | MusicPlaylist -> "music.playlist"
+        | MusicRadioStation -> "music.radio_station"
+        | MusicSong -> "music.song"
+        | PaymentLink -> "payment.link"
+        | Profile -> "profile"
+        | VideoEpisode -> "video.episode"
+        | VideoMovie -> "video.movie"
+        | VideoOther -> "video.other"
+        | VideoTvShow -> "video.tv_show"
+        | Website -> "website"
+
+
+/// <summary>Top-level properties for OpenGraph</summary>
+[<CLIMutable>]
+type OpenGraphTopLevel = {
+    
+    /// <summary>The type of object represented</summary>
+    Type: OpenGraphType
+    
+    /// <summary>An image representing the object</summary>
+    Image: OpenGraphImage
+    
+    /// <summary>An audio file associated with the object</summary>
+    Audio: OpenGraphAudio option
+    
+    /// <summary>A short description of the object</summary>
+    Description: string option
+    
+    /// <summary>The article (a, an, the, etc.) which should be used to refer to this object</summary>
+    Determiner: string option
+    
+    /// <summary>The primary locale of the content of the object</summary>
+    Locale: string option
+    
+    /// <summary>Other locales in which the content of the object is available</summary>
+    LocaleAlternate: string list option
+    
+    /// <summary>A video file assigned with the object</summary>
+    Video: OpenGraphVideo option
+}
+
+    
 /// <summary>A permanent link</summary>
 [<Struct>]
 type Permalink =