src/MyWebLog/DotLiquidBespoke.fs

@@ -3,6 +3,7 @@ module MyWebLog.DotLiquidBespoke
 
 open System
 open System.IO
+open System.Web
 open DotLiquid
 open MyWebLog.ViewModels
 
@@ -22,11 +23,13 @@ let permalink (ctx : Context) (item : obj) (linkFunc : WebLog -> Permalink -> st
     | Some link -> linkFunc (webLog ctx) (Permalink link)
     | None      -> $"alert('unknown item type {item.GetType().Name}')"
 
+
 /// A filter to generate an absolute link
 type AbsoluteLinkFilter () =
     static member AbsoluteLink (ctx : Context, item : obj) =
         permalink ctx item WebLog.absoluteUrl
 
+
 /// A filter to generate a link with posts categorized under the given category
 type CategoryLinkFilter () =
     static member CategoryLink (ctx : Context, catObj : obj) =
@@ -50,6 +53,7 @@ type EditPageLinkFilter () =
         |> function
         | Some pageId -> WebLog.relativeUrl (webLog ctx) (Permalink $"admin/page/{pageId}/edit")
         | None        -> $"alert('unknown page object type {pageObj.GetType().Name}')"
+ 
     
 /// A filter to generate a link that will edit a post
 type EditPostLinkFilter () =
@@ -62,6 +66,7 @@ type EditPostLinkFilter () =
         |> function
         | Some postId -> WebLog.relativeUrl (webLog ctx) (Permalink $"admin/post/{postId}/edit")
         | None        -> $"alert('unknown post object type {postObj.GetType().Name}')"
+ 
     
 /// A filter to generate nav links, highlighting the active link (exact match)
 type NavLinkFilter () =
@@ -78,11 +83,62 @@ type NavLinkFilter () =
         }
         |> Seq.fold (+) ""
 
+
+/// Create various items in the page header based on the state of the page being generated
+type PageHeadTag () =
+    inherit Tag ()
+    
+    override this.Render (context : Context, result : TextWriter) =
+        let webLog = webLog context
+        // spacer
+        let s      = "    "
+        let getBool name =
+            context.Environments[0].[name] |> Option.ofObj |> Option.map Convert.ToBoolean |> Option.defaultValue false
+        
+        result.WriteLine $"""<meta name="generator" content="{context.Environments[0].["generator"]}">"""
+        
+        // Theme assets
+        let has fileName = File.Exists (Path.Combine ("wwwroot", "themes", webLog.themePath, fileName))
+        if has "style.css" then
+            result.WriteLine $"""{s}<link rel="stylesheet" href="/themes/{webLog.themePath}/style.css">"""
+        if has "favicon.ico" then
+            result.WriteLine $"""{s}<link rel="icon" href="/themes/{webLog.themePath}/favicon.ico">"""
+        
+        // RSS feeds and canonical URLs
+        let feedLink title url =
+            let escTitle = HttpUtility.HtmlAttributeEncode title
+            let relUrl   = WebLog.relativeUrl webLog (Permalink url)
+            $"""{s}<link rel="alternate" type="application/rss+xml" title="{escTitle}" href="{relUrl}">"""
+        
+        if webLog.rss.feedEnabled && getBool "is_home" then
+            result.WriteLine (feedLink webLog.name webLog.rss.feedName)
+            result.WriteLine $"""{s}<link rel="canonical" href="{WebLog.absoluteUrl webLog Permalink.empty}">"""
+        
+        if webLog.rss.categoryEnabled && getBool "is_category_home" then
+            let slug = context.Environments[0].["slug"] :?> string
+            result.WriteLine (feedLink webLog.name $"category/{slug}/{webLog.rss.feedName}")
+            
+        if webLog.rss.tagEnabled && getBool "is_tag_home" then
+            let slug = context.Environments[0].["slug"] :?> string
+            result.WriteLine (feedLink webLog.name $"tag/{slug}/{webLog.rss.feedName}")
+            
+        if getBool "is_post" then
+            let post = context.Environments[0].["model"] :?> PostDisplay
+            let url  = WebLog.absoluteUrl webLog (Permalink post.posts[0].permalink)
+            result.WriteLine $"""{s}<link rel="canonical" href="{url}">"""
+        
+        if getBool "is_page" then
+            let page = context.Environments[0].["page"] :?> DisplayPage
+            let url  = WebLog.absoluteUrl webLog (Permalink page.permalink)
+            result.WriteLine $"""{s}<link rel="canonical" href="{url}">"""
+
+        
 /// A filter to generate a relative link
 type RelativeLinkFilter () =
     static member RelativeLink (ctx : Context, item : obj) =
         permalink ctx item WebLog.relativeUrl
 
+
 /// A filter to generate a link with posts tagged with the given tag
 type TagLinkFilter () =
     static member TagLink (ctx : Context, tag : string) =
@@ -92,6 +148,7 @@ type TagLinkFilter () =
         | Some tagMap -> tagMap.urlValue
         | None        -> tag.Replace (" ", "+")
         |> function tagUrl -> WebLog.relativeUrl (webLog ctx) (Permalink $"tag/{tagUrl}/")
+
             
 /// Create links for a user to log on or off, and a dashboard link if they are logged off
 type UserLinksTag () =

src/MyWebLog/Handlers/Feed.fs

@@ -33,28 +33,16 @@ let deriveFeedType (ctx : HttpContext) feedPath : (FeedType * int) option =
         debug (fun () -> "Found standard feed")
         Some (StandardFeed feedPath, postCount)
     | false ->
-        // Category feed
-        match CategoryCache.get ctx |> Array.tryFind (fun cat -> cat.slug = feedPath.Replace (name, "")) with
-        | Some cat ->
-            debug (fun () -> "Found category feed")
-            Some (CategoryFeed (CategoryId cat.id, feedPath), postCount)
+        // Category and tag feeds are handled by defined routes; check for custom feed
+        match webLog.rss.customFeeds
+              |> List.tryFind (fun it -> feedPath.EndsWith (Permalink.toString it.path)) with
+        | Some feed ->
+            debug (fun () -> "Found custom feed")
+            Some (Custom (feed, feedPath),
+                  feed.podcast |> Option.map (fun p -> p.itemsInFeed) |> Option.defaultValue postCount)
         | None ->
-            // Tag feed
-            match feedPath.StartsWith "/tag/" with
-            | true  ->
-                debug (fun () -> "Found tag feed")
-                Some (TagFeed (feedPath.Replace("/tag/", "").Replace(name, ""), feedPath), postCount)
-            | false ->
-                // Custom feed
-                match webLog.rss.customFeeds
-                      |> List.tryFind (fun it -> feedPath.EndsWith (Permalink.toString it.path)) with
-                | Some feed ->
-                    debug (fun () -> "Found custom feed")
-                    Some (Custom (feed, feedPath),
-                          feed.podcast |> Option.map (fun p -> p.itemsInFeed) |> Option.defaultValue postCount)
-                | None ->
-                    debug (fun () -> $"No matching feed found")
-                    None
+            debug (fun () -> $"No matching feed found")
+            None
 
 /// Determine the function to retrieve posts for the given feed
 let private getFeedPosts (webLog : WebLog) feedType =
@@ -252,12 +240,41 @@ let private selfAndLink webLog feedType =
     |> function
     | path -> Permalink path, Permalink (path.Replace ($"/{webLog.rss.feedName}", ""))
 
+/// Set the title and description of the feed based on its source
+let private setTitleAndDescription feedType (webLog : WebLog) (cats : DisplayCategory[]) (feed : SyndicationFeed) =
+    let cleanText opt def = TextSyndicationContent (stripHtml (defaultArg opt def))
+    match feedType with
+    | StandardFeed _ ->
+        feed.Title       <- cleanText None webLog.name
+        feed.Description <- cleanText webLog.subtitle webLog.name
+    | CategoryFeed (CategoryId catId, _) ->
+        let cat = cats |> Array.find (fun it -> it.id = catId)
+        feed.Title       <- cleanText None $"""{webLog.name} - "{stripHtml cat.name}" Category"""
+        feed.Description <- cleanText cat.description $"""Posts categorized under "{cat.name}" """
+    | TagFeed (tag, _) ->
+        feed.Title       <- cleanText None $"""{webLog.name} - "{tag}" Tag"""
+        feed.Description <- cleanText None $"""Posts with the "{tag}" tag"""
+    | Custom (custom, _) ->
+        match custom.podcast with
+        | Some podcast ->
+            feed.Title       <- cleanText None podcast.title
+            feed.Description <- cleanText podcast.subtitle podcast.title
+        | None ->
+            match custom.source with
+            | Category (CategoryId catId) ->
+                let cat = cats |> Array.find (fun it -> it.id = catId)
+                feed.Title       <- cleanText None $"""{webLog.name} - "{stripHtml cat.name}" Category"""
+                feed.Description <- cleanText cat.description $"""Posts categorized under "{cat.name}" """
+            | Tag tag ->
+                feed.Title       <- cleanText None $"""{webLog.name} - "{tag}" Tag"""
+                feed.Description <- cleanText None $"""Posts with the "{tag}" tag"""
+    
 /// Create a feed with a known non-zero-length list of posts    
 let createFeed (feedType : FeedType) posts : HttpHandler = fun next ctx -> backgroundTask {
     let  webLog     = ctx.WebLog
     let  conn       = ctx.Conn
-    let! authors    = Post.getAuthors     webLog posts conn
-    let! tagMaps    = Post.getTagMappings webLog posts conn
+    let! authors    = getAuthors     webLog posts conn
+    let! tagMaps    = getTagMappings webLog posts conn
     let  cats       = CategoryCache.get ctx
     let  podcast    = match feedType with Custom (feed, _) when Option.isSome feed.podcast -> Some feed | _ -> None
     let  self, link = selfAndLink webLog feedType
@@ -274,14 +291,13 @@ let createFeed (feedType : FeedType) posts : HttpHandler = fun next ctx -> backg
         
     let feed = SyndicationFeed ()
     addNamespace feed "content" Namespace.content
+    setTitleAndDescription feedType webLog cats feed
     
-    feed.Title           <- TextSyndicationContent webLog.name
-    feed.Description     <- TextSyndicationContent <| defaultArg webLog.subtitle webLog.name
     feed.LastUpdatedTime <- DateTimeOffset <| (List.head posts).updatedOn
     feed.Generator       <- generator ctx
     feed.Items           <- posts |> Seq.ofList |> Seq.map toItem
     feed.Language        <- "en"
-    feed.Id              <- webLog.urlBase
+    feed.Id              <- WebLog.absoluteUrl webLog link
     webLog.rss.copyright |> Option.iter (fun copy -> feed.Copyright <- TextSyndicationContent copy)
     
     feed.Links.Add (SyndicationLink (Uri (WebLog.absoluteUrl webLog self), "self", "", "application/rss+xml", 0L))

src/MyWebLog/Handlers/Helpers.fs

@@ -160,6 +160,32 @@ let templatesForTheme (ctx : HttpContext) (typ : string) =
     }
     |> Array.ofSeq
 
+/// Get all authors for a list of posts as metadata items
+let getAuthors (webLog : WebLog) (posts : Post list) conn =
+    posts
+    |> List.map (fun p -> p.authorId)
+    |> List.distinct
+    |> Data.WebLogUser.findNames webLog.id conn
+
+/// Get all tag mappings for a list of posts as metadata items
+let getTagMappings (webLog : WebLog) (posts : Post list) =
+    posts
+    |> List.map (fun p -> p.tags)
+    |> List.concat
+    |> List.distinct
+    |> fun tags -> Data.TagMap.findMappingForTags tags webLog.id
+
+/// Get all category IDs for the given slug (includes owned subcategories)   
+let getCategoryIds slug ctx =
+    let allCats = CategoryCache.get ctx
+    let cat     = allCats |> Array.find (fun cat -> cat.slug = slug)
+    // Category pages include posts in subcategories
+    allCats
+    |> Seq.ofArray
+    |> Seq.filter (fun c -> c.id = cat.id || Array.contains cat.name c.parentNames)
+    |> Seq.map (fun c -> CategoryId c.id)
+    |> List.ofSeq
+
 open Microsoft.Extensions.Logging
 
 /// Log level for debugging

src/MyWebLog/Handlers/Post.fs

@@ -2,10 +2,21 @@
 module MyWebLog.Handlers.Post
 
 open System
+open MyWebLog
 
 /// Parse a slug and page number from an "everything else" URL
-let private parseSlugAndPage (slugAndPage : string seq) =
-    let slugs   = (slugAndPage |> Seq.skip 1 |> Seq.head).Split "/" |> Array.filter (fun it -> it <> "")
+let private parseSlugAndPage webLog (slugAndPage : string seq) =
+    let fullPath = slugAndPage |> Seq.head
+    let slugPath = slugAndPage |> Seq.skip 1 |> Seq.head
+    let slugs, isFeed =
+        let feedName = $"/{webLog.rss.feedName}"
+        let notBlank = Array.filter (fun it -> it <> "")
+        if (   (webLog.rss.categoryEnabled && fullPath.StartsWith "/category/")
+            || (webLog.rss.tagEnabled      && fullPath.StartsWith "/tag/"     ))
+           && slugPath.EndsWith feedName then
+            notBlank (slugPath.Replace(feedName, "").Split "/"), true
+        else
+            notBlank (slugPath.Split "/"), false
     let pageIdx = Array.IndexOf (slugs, "page")
     let pageNbr =
         match pageIdx with
@@ -13,7 +24,7 @@ let private parseSlugAndPage (slugAndPage : string seq) =
         | idx when idx + 2 = slugs.Length -> Some (int slugs[pageIdx + 1])
         | _ -> None
     let slugParts = if pageIdx > 0 then Array.truncate pageIdx slugs else slugs
-    pageNbr, String.Join ("/", slugParts)
+    pageNbr, String.Join ("/", slugParts), isFeed
 
 /// The type of post list being prepared
 type ListType =
@@ -23,23 +34,6 @@ type ListType =
     | SinglePost
     | TagList
 
-open MyWebLog
-
-/// Get all authors for a list of posts as metadata items
-let getAuthors (webLog : WebLog) (posts : Post list) conn =
-    posts
-    |> List.map (fun p -> p.authorId)
-    |> List.distinct
-    |> Data.WebLogUser.findNames webLog.id conn
-
-/// Get all tag mappings for a list of posts as metadata items
-let getTagMappings (webLog : WebLog) (posts : Post list) =
-    posts
-    |> List.map (fun p -> p.tags)
-    |> List.concat
-    |> List.distinct
-    |> fun tags -> Data.TagMap.findMappingForTags tags webLog.id
-    
 open System.Threading.Tasks
 open DotLiquid
 open MyWebLog.ViewModels
@@ -91,7 +85,12 @@ let preparePostList webLog posts listType (url : string) pageNbr perPage ctx con
           olderLink  = olderLink
           olderName  = olderPost |> Option.map (fun p -> p.title)
         }
-    return Hash.FromAnonymousObject {| model = model; categories = CategoryCache.get ctx; tag_mappings = tagMappings |}
+    return Hash.FromAnonymousObject {|
+        model        = model
+        categories   = CategoryCache.get ctx
+        tag_mappings = tagMappings
+        is_post      = match listType with SinglePost -> true | _ -> false
+    |}
 }
 
 open Giraffe
@@ -117,27 +116,30 @@ let pageOfPosts pageNbr : HttpHandler = fun next ctx -> task {
 let pageOfCategorizedPosts slugAndPage : HttpHandler = fun next ctx -> task {
     let webLog = ctx.WebLog
     let conn   = ctx.Conn
-    match parseSlugAndPage slugAndPage with
-    | Some pageNbr, slug -> 
+    match parseSlugAndPage webLog slugAndPage with
+    | Some pageNbr, slug, isFeed ->
         let allCats = CategoryCache.get ctx
         let cat     = allCats |> Array.find (fun cat -> cat.slug = slug)
-        // Category pages include posts in subcategories
-        let catIds  =
-            allCats
-            |> Seq.ofArray
-            |> Seq.filter (fun c -> c.id = cat.id || Array.contains cat.name c.parentNames)
-            |> Seq.map (fun c -> CategoryId c.id)
-            |> List.ofSeq
-        match! Data.Post.findPageOfCategorizedPosts webLog.id catIds pageNbr webLog.postsPerPage conn with
-        | posts when List.length posts > 0 ->
-            let! hash    = preparePostList webLog posts CategoryList cat.slug pageNbr webLog.postsPerPage ctx conn
-            let  pgTitle = if pageNbr = 1 then "" else $""" <small class="archive-pg-nbr">(Page {pageNbr})</small>"""
-            hash.Add ("page_title", $"{cat.name}: Category Archive{pgTitle}")
-            hash.Add ("subtitle", cat.description.Value)
-            hash.Add ("is_category", true)
-            return! themedView "index" next ctx hash
-        | _ -> return! Error.notFound next ctx
-    | None, _ -> return! Error.notFound next ctx
+        if isFeed then
+            return! Feed.generate (Feed.CategoryFeed ((CategoryId cat.id), $"category/{slug}/{webLog.rss.feedName}"))
+                        (defaultArg webLog.rss.itemsInFeed webLog.postsPerPage) next ctx
+        else
+            let allCats = CategoryCache.get ctx
+            let cat     = allCats |> Array.find (fun cat -> cat.slug = slug)
+            // Category pages include posts in subcategories
+            match! Data.Post.findPageOfCategorizedPosts webLog.id (getCategoryIds slug ctx) pageNbr webLog.postsPerPage
+                       conn with
+            | posts when List.length posts > 0 ->
+                let! hash    = preparePostList webLog posts CategoryList cat.slug pageNbr webLog.postsPerPage ctx conn
+                let  pgTitle = if pageNbr = 1 then "" else $""" <small class="archive-pg-nbr">(Page {pageNbr})</small>"""
+                hash.Add ("page_title", $"{cat.name}: Category Archive{pgTitle}")
+                hash.Add ("subtitle", defaultArg cat.description "")
+                hash.Add ("is_category", true)
+                hash.Add ("is_category_home", (pageNbr = 1))
+                hash.Add ("slug", slug)
+                return! themedView "index" next ctx hash
+            | _ -> return! Error.notFound next ctx
+    | None, _, _ -> return! Error.notFound next ctx
 }
 
 open System.Web
@@ -147,33 +149,39 @@ open System.Web
 let pageOfTaggedPosts slugAndPage : HttpHandler = fun next ctx -> task {
     let webLog = ctx.WebLog
     let conn   = ctx.Conn
-    match parseSlugAndPage slugAndPage with
-    | Some pageNbr, rawTag -> 
+    match parseSlugAndPage webLog slugAndPage with
+    | Some pageNbr, rawTag, isFeed -> 
         let  urlTag = HttpUtility.UrlDecode rawTag
         let! tag    = backgroundTask {
             match! Data.TagMap.findByUrlValue urlTag webLog.id conn with
             | Some m -> return m.tag
             | None   -> return urlTag
         }
-        match! Data.Post.findPageOfTaggedPosts webLog.id tag pageNbr webLog.postsPerPage conn with
-        | posts when List.length posts > 0 ->
-            let! hash    = preparePostList webLog posts TagList rawTag pageNbr webLog.postsPerPage ctx conn
-            let  pgTitle = if pageNbr = 1 then "" else $""" <small class="archive-pg-nbr">(Page {pageNbr})</small>"""
-            hash.Add ("page_title", $"Posts Tagged &ldquo;{tag}&rdquo;{pgTitle}")
-            hash.Add ("is_tag", true)
-            return! themedView "index" next ctx hash
-        // Other systems use hyphens for spaces; redirect if this is an old tag link
-        | _ ->
-            let spacedTag = tag.Replace ("-", " ")
-            match! Data.Post.findPageOfTaggedPosts webLog.id spacedTag pageNbr 1 conn with
+        if isFeed then
+            return! Feed.generate (Feed.TagFeed (tag, $"tag/{rawTag}/{webLog.rss.feedName}"))
+                        (defaultArg webLog.rss.itemsInFeed webLog.postsPerPage) next ctx
+        else
+            match! Data.Post.findPageOfTaggedPosts webLog.id tag pageNbr webLog.postsPerPage conn with
             | posts when List.length posts > 0 ->
-                let endUrl = if pageNbr = 1 then "" else $"page/{pageNbr}"
-                return!
-                    redirectTo true
-                        (WebLog.relativeUrl webLog (Permalink $"""tag/{spacedTag.Replace (" ", "+")}/{endUrl}"""))
-                        next ctx
-            | _ -> return! Error.notFound next ctx
-    | None, _ -> return! Error.notFound next ctx
+                let! hash    = preparePostList webLog posts TagList rawTag pageNbr webLog.postsPerPage ctx conn
+                let  pgTitle = if pageNbr = 1 then "" else $""" <small class="archive-pg-nbr">(Page {pageNbr})</small>"""
+                hash.Add ("page_title", $"Posts Tagged &ldquo;{tag}&rdquo;{pgTitle}")
+                hash.Add ("is_tag", true)
+                hash.Add ("is_tag_home", (pageNbr = 1))
+                hash.Add ("slug", rawTag)
+                return! themedView "index" next ctx hash
+            // Other systems use hyphens for spaces; redirect if this is an old tag link
+            | _ ->
+                let spacedTag = tag.Replace ("-", " ")
+                match! Data.Post.findPageOfTaggedPosts webLog.id spacedTag pageNbr 1 conn with
+                | posts when List.length posts > 0 ->
+                    let endUrl = if pageNbr = 1 then "" else $"page/{pageNbr}"
+                    return!
+                        redirectTo true
+                            (WebLog.relativeUrl webLog (Permalink $"""tag/{spacedTag.Replace (" ", "+")}/{endUrl}"""))
+                            next ctx
+                | _ -> return! Error.notFound next ctx
+    | None, _, _ -> return! Error.notFound next ctx
 }
 
 // GET /

src/MyWebLog/Handlers/Routes.fs

@@ -39,7 +39,11 @@ module CatchAll =
             | Some page ->
                 debug (fun () -> $"Found page by permalink")
                 yield fun next ctx ->
-                    Hash.FromAnonymousObject {| page = DisplayPage.fromPage webLog page; page_title = page.title |}
+                    Hash.FromAnonymousObject {|
+                        page       = DisplayPage.fromPage webLog page
+                        page_title = page.title
+                        is_page    = true
+                    |}
                     |> themedView (defaultArg page.template "single-page") next ctx
             | None -> ()
             // RSS feed

src/MyWebLog/MyWebLog.fsproj

@@ -12,8 +12,8 @@
     <Compile Include="Handlers\Error.fs" />
     <Compile Include="Handlers\Helpers.fs" />
     <Compile Include="Handlers\Admin.fs" />
-    <Compile Include="Handlers\Post.fs" />
     <Compile Include="Handlers\Feed.fs" />
+    <Compile Include="Handlers\Post.fs" />
     <Compile Include="Handlers\User.fs" />
     <Compile Include="Handlers\Routes.fs" />
     <Compile Include="DotLiquidBespoke.fs" />

src/MyWebLog/Program.fs

@@ -215,6 +215,7 @@ let main args =
     ]
     |> List.iter Template.RegisterFilter
     
+    Template.RegisterTag<PageHeadTag>  "page_head"
     Template.RegisterTag<UserLinksTag> "user_links"
     
     [   // Domain types

src/MyWebLog/themes/bit-badger/layout.liquid

@@ -3,11 +3,9 @@
   <head>
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width">
-    <meta name="generator" content="{{ generator }}">
     <title>{{ page_title }} &raquo; Bit Badger Solutions</title>
     <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Oswald|Raleway">
-    <link rel="stylesheet" href="/themes/{{ web_log.theme_path }}/style.css">
-    <link rel="icon" href="/themes/{{ web_log.theme_path }}/favicon.ico">
+    {% page_head -%}
   </head>
   <body>
     <header class="site-header">

src/MyWebLog/themes/daniel-j-summers/layout.liquid

@@ -4,25 +4,19 @@
     <meta charset="utf-8">
     <meta http-equiv="X-UA-Compatible" content="IE=edge">
     <meta name="viewport" content="width=device-width, initial-scale=1">
-    <meta name="generator" content="{{ generator }}">
     <title>
-      {%- if is_home %}
+      {%- if is_home -%}
         {{ web_log.name }}{% if web_log.subtitle %} | {{ web_log.subtitle.value }}{% endif %}
-      {%- else %}
+      {%- else -%}
         {{ page_title | strip_html }}{% if page_title and page_title != "" %} &raquo; {% endif %}{{ web_log.name }}
-      {%- endif %}
+      {%- endif -%}
     </title>
     <link rel="preload" href="https://fonts.googleapis.com/css?family=Quicksand|Oswald" as="style">
     <link rel="preload" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.3.0/css/font-awesome.min.css" as="style">
     <link rel="preload" href="/themes/{{ web_log.theme_path }}/style.css" as="style">
     <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.3.0/css/font-awesome.min.css">
-    <link rel="stylesheet" href="/themes/{{ web_log.theme_path }}/style.css">
-    {%- if is_home %}
-      <link rel="alternate" type="application/rss+xml" title="{{ web_log.name | escape }}"
-            href="{{ "feed.xml" | relative_link }}">
-      <link rel="canonical" href="{{ "" | absolute_url }}">
-    {%- endif %}
     <script src="/themes/{{ web_log.theme_path }}/djs.js"></script>
+    {% page_head -%}
   </head>
   <body>
     <nav class="site-header" role="navigation">

src/MyWebLog/themes/default/layout.liquid

@@ -3,11 +3,10 @@
   <head>
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width">
-    <meta name="generator" content="{{ generator }}">
     <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/css/bootstrap.min.css"
           integrity="sha384-EVSTQN3/azprG1Anm3QDgpJLIm9Nao0Yz1ztcQTwFspd3yD65VohhpuuCOmLASjC" crossorigin="anonymous">
-    <link rel="stylesheet" href="/themes/{{ web_log.theme_path }}/style.css">
     <title>{{ page_title | escape }}{% if page_title %} &laquo; {% endif %}{{ web_log.name | escape }}</title>
+    {% page_head -%}
   </head>
   <body>
     <header>

src/MyWebLog/themes/tech-blog/layout.liquid

@@ -4,21 +4,14 @@
     <meta charset="utf-8">
     <meta http-equiv="X-UA-Compatible" content="IE=edge">
     <meta name="viewport" content="width=device-width, initial-scale=1">
-    <meta name="generator" content="{{ generator }}">
     <title>
-      {%- if is_home %}
+      {%- if is_home -%}
         {{ web_log.name }}{% if web_log.subtitle %} | {{ web_log.subtitle.value }}{% endif %}
-      {%- else %}
+      {%- else -%}
         {{ page_title | strip_html }}{% if page_title and page_title != "" %} &raquo; {% endif %}{{ web_log.name }}
-      {%- endif %}
+      {%- endif -%}
     </title>
-    <link rel="stylesheet" href="/themes/{{ web_log.theme_path }}/style.css">
-    {%- if is_home %}
-      <link rel="alternate" type="application/rss+xml" title="{{ web_log.name }}"
-            href="{{ "feed.xml" | absolute_link }}">
-      <link rel="canonical" href="{{ "" | absolute_link }}">
-    {%- endif %}
-    <link rel="icon" href="/themes/bit-badger/favicon.ico">
+    {% page_head -%}
   </head>
   <body>
     <header class="site-header">