WIP on page revisions (#13)

- Simplify redirectToGet usage
- Move a few functions to HttpContext extension properties
- Modify bare response to allow content not from a template
- Fix uploaded date/time handling

src/MyWebLog.Domain/DataTypes.fs

@@ -405,11 +405,6 @@ module WebLog =
         TimeZoneInfo.ConvertTimeFromUtc
             (DateTime (date.Ticks, DateTimeKind.Utc), TimeZoneInfo.FindSystemTimeZoneById webLog.timeZone) 
 
-    /// Convert a date/time in the web log's local date/time to UTC
-    let utcTime webLog (date : DateTime) =
-        TimeZoneInfo.ConvertTimeToUtc
-            (DateTime (date.Ticks, DateTimeKind.Unspecified), TimeZoneInfo.FindSystemTimeZoneById webLog.timeZone)
-
 
 /// A user of the web log
 [<CLIMutable; NoComparison; NoEquality>]

src/MyWebLog/Caches.fs

@@ -7,15 +7,28 @@ open MyWebLog.Data
 [<AutoOpen>]
 module Extensions =
     
+    open System.Security.Claims
+    open Microsoft.AspNetCore.Antiforgery
     open Microsoft.Extensions.DependencyInjection
     
     type HttpContext with
-        /// The web log for the current request
+        
-        member this.WebLog = this.Items["webLog"] :?> WebLog
+        /// The anti-CSRF service
+        member this.AntiForgery = this.RequestServices.GetRequiredService<IAntiforgery> ()
+        
+        /// The cross-site request forgery token set for this request
+        member this.CsrfTokenSet = this.AntiForgery.GetAndStoreTokens this
 
         /// The data implementation
         member this.Data = this.RequestServices.GetRequiredService<IData> ()
         
+        /// The user ID for the current request
+        member this.UserId =
+            WebLogUserId (this.User.Claims |> Seq.find (fun c -> c.Type = ClaimTypes.NameIdentifier)).Value
+
+        /// The web log for the current request
+        member this.WebLog = this.Items["webLog"] :?> WebLog
+
 
 open System.Collections.Concurrent
 

src/MyWebLog/Handlers/Admin.fs

@@ -39,10 +39,10 @@ let dashboard : HttpHandler = fun next ctx -> task {
 let listCategories : HttpHandler = fun next ctx -> task {
     let! catListTemplate = TemplateCache.get "admin" "category-list-body" ctx.Data
     let hash = Hash.FromAnonymousObject {|
+        page_title = "Categories"
+        csrf       = ctx.CsrfTokenSet
         web_log    = ctx.WebLog
         categories = CategoryCache.get ctx
-        page_title = "Categories"
-        csrf       = csrfToken ctx
     |}
     hash.Add ("category_list", catListTemplate.Render hash)
     return! viewForTheme "admin" "category-list" next ctx hash
@@ -53,7 +53,7 @@ let listCategoriesBare : HttpHandler = fun next ctx -> task {
     return!
         Hash.FromAnonymousObject {|
             categories = CategoryCache.get ctx
-            csrf       = csrfToken ctx
+            csrf       = ctx.CsrfTokenSet
         |}
         |> bareForTheme "admin" "category-list-body" next ctx
 }
@@ -73,9 +73,9 @@ let editCategory catId : HttpHandler = fun next ctx -> task {
     | Some (title, cat) ->
         return!
             Hash.FromAnonymousObject {|
-                csrf       = csrfToken ctx
-                model      = EditCategoryModel.fromCategory cat
                 page_title = title
+                csrf       = ctx.CsrfTokenSet
+                model      = EditCategoryModel.fromCategory cat
                 categories = CategoryCache.get ctx
             |}
             |> bareForTheme "admin" "category-edit" next ctx
@@ -127,9 +127,9 @@ let listPages pageNbr : HttpHandler = fun next ctx -> task {
     let! pages  = ctx.Data.Page.findPageOfPages webLog.id pageNbr
     return!
         Hash.FromAnonymousObject {|
-            csrf       = csrfToken ctx
-            pages      = pages |> List.map (DisplayPage.fromPageMinimal webLog)
             page_title = "Pages"
+            csrf       = ctx.CsrfTokenSet
+            pages      = pages |> List.map (DisplayPage.fromPageMinimal webLog)
             page_nbr   = pageNbr
             prev_page  = if pageNbr = 2 then "" else $"/page/{pageNbr - 1}"
             next_page  = $"/page/{pageNbr + 1}"
@@ -153,26 +153,37 @@ let editPage pgId : HttpHandler = fun next ctx -> task {
         let! templates = templatesForTheme ctx "page"
         return!
             Hash.FromAnonymousObject {|
-                csrf       = csrfToken ctx
+                page_title = title
+                csrf       = ctx.CsrfTokenSet
                 model      = model
                 metadata   = Array.zip model.metaNames model.metaValues
                              |> Array.mapi (fun idx (name, value) -> [| string idx; name; value |])
-                page_title = title
                 templates  = templates
             |}
             |> viewForTheme "admin" "page-edit" next ctx
     | None -> return! Error.notFound next ctx
 }
 
+// POST /admin/page/{id}/delete
+let deletePage pgId : HttpHandler = fun next ctx -> task {
+    let webLog = ctx.WebLog
+    match! ctx.Data.Page.delete (PageId pgId) webLog.id with
+    | true ->
+        do! PageListCache.update ctx
+        do! addMessage ctx { UserMessage.success with message = "Page deleted successfully" }
+    | false -> do! addMessage ctx { UserMessage.error with message = "Page not found; nothing deleted" }
+    return! redirectToGet "admin/pages" next ctx
+}
+
 // GET /admin/page/{id}/permalinks
 let editPagePermalinks pgId : HttpHandler = fun next ctx -> task {
     match! ctx.Data.Page.findFullById (PageId pgId) ctx.WebLog.id with
     | Some pg ->
         return!
             Hash.FromAnonymousObject {|
-                csrf       = csrfToken ctx
+                page_title = "Manage Prior Permalinks"
+                csrf       = ctx.CsrfTokenSet
                 model      = ManagePermalinksModel.fromPage pg
-                page_title = $"Manage Prior Permalinks"
             |}
             |> viewForTheme "admin" "permalinks" next ctx
     | None -> return! Error.notFound next ctx
@@ -186,7 +197,7 @@ let savePagePermalinks : HttpHandler = fun next ctx -> task {
     match! ctx.Data.Page.updatePriorPermalinks (PageId model.id) webLog.id links with
     | true ->
         do! addMessage ctx { UserMessage.success with message = "Page permalinks saved successfully" }
-        return! redirectToGet (WebLog.relativeUrl webLog (Permalink $"admin/page/{model.id}/permalinks")) next ctx
+        return! redirectToGet $"admin/page/{model.id}/permalinks" next ctx
     | false -> return! Error.notFound next ctx
 }
 
@@ -197,27 +208,74 @@ let editPageRevisions pgId : HttpHandler = fun next ctx -> task {
     | Some pg ->
         return!
             Hash.FromAnonymousObject {|
-                csrf       = csrfToken ctx
+                page_title = "Manage Page Revisions"
+                csrf       = ctx.CsrfTokenSet
                 model      = ManageRevisionsModel.fromPage webLog pg
-                page_title = $"Manage Page Permalinks"
             |}
             |> viewForTheme "admin" "revisions" next ctx
     | None -> return! Error.notFound next ctx
 }
 
-// POST /admin/page/{id}/delete
+// GET /admin/page/{id}/revisions/purge
-let deletePage pgId : HttpHandler = fun next ctx -> task {
+let purgePageRevisions pgId : HttpHandler = fun next ctx -> task {
     let webLog = ctx.WebLog
-    match! ctx.Data.Page.delete (PageId pgId) webLog.id with
+    let data   = ctx.Data
-    | true ->
+    match! data.Page.findFullById (PageId pgId) webLog.id with
-        do! PageListCache.update ctx
+    | Some pg ->
-        do! addMessage ctx { UserMessage.success with message = "Page deleted successfully" }
+        do! data.Page.update { pg with revisions = [ List.head pg.revisions ] }
-    | false -> do! addMessage ctx { UserMessage.error with message = "Page not found; nothing deleted" }
+        do! addMessage ctx { UserMessage.success with message = "Prior revisions purged successfully" }
-    return! redirectToGet (WebLog.relativeUrl webLog (Permalink "admin/pages")) next ctx
+        return! redirectToGet $"admin/page/{pgId}/revisions" next ctx
+    | None -> return! Error.notFound next ctx
+}
+
+open Microsoft.AspNetCore.Http
+
+/// Find the page and the requested revision
+let private findPageRevision pgId revDate (ctx : HttpContext) = task {
+    match! ctx.Data.Page.findFullById (PageId pgId) ctx.WebLog.id with
+    | Some pg ->
+        let asOf = parseToUtc revDate
+        return Some pg, pg.revisions |> List.tryFind (fun r -> r.asOf = asOf)
+    | None -> return None, None
+}
+
+// GET /admin/page/{id}/revision/{revision-date}/preview
+let previewPageRevision (pgId, revDate) : HttpHandler = fun next ctx -> task {
+    match! findPageRevision pgId revDate ctx with
+    | Some _, Some rev ->
+        return! bareForTheme "admin" "" next ctx (Hash.FromAnonymousObject {| content = MarkupText.toHtml rev.text |})
+    | None, _
+    | _, None -> return! Error.notFound next ctx
 }
 
 open System
 
+// POST /admin/page/{id}/revision/{revision-date}/restore
+let restorePageRevision (pgId, revDate) : HttpHandler = fun next ctx -> task {
+    match! findPageRevision pgId revDate ctx with
+    | Some pg, Some rev ->
+        do! ctx.Data.Page.update
+                { pg with
+                    revisions = { rev with asOf = DateTime.UtcNow }
+                                  :: (pg.revisions |> List.filter (fun r -> r.asOf <> rev.asOf))
+                }
+        do! addMessage ctx { UserMessage.success with message = "Revision restored successfully" }
+        return! redirectToGet $"admin/page/{pgId}/revisions" next ctx
+    | None, _
+    | _, None -> return! Error.notFound next ctx
+}
+
+// POST /admin/page/{id}/revision/{revision-date}/delete
+let deletePageRevision (pgId, revDate) : HttpHandler = fun next ctx -> task {
+    match! findPageRevision pgId revDate ctx with
+    | Some pg, Some rev ->
+        do! ctx.Data.Page.update { pg with revisions = pg.revisions |> List.filter (fun r -> r.asOf <> rev.asOf) }
+        do! addMessage ctx { UserMessage.success with message = "Revision deleted successfully" }
+        return! bareForTheme "admin" "" next ctx (Hash.FromAnonymousObject {| content = "" |})
+    | None, _
+    | _, None -> return! Error.notFound next ctx
+}
+
 #nowarn "3511"
 
 // POST /admin/page/save
@@ -233,7 +291,7 @@ let savePage : HttpHandler = fun next ctx -> task {
                 { Page.empty with
                     id          = PageId.create ()
                     webLogId    = webLog.id
-                    authorId    = userId ctx
+                    authorId    = ctx.UserId
                     publishedOn = now
                 }
         | pgId -> return! data.Page.findFullById (PageId pgId) webLog.id
@@ -268,21 +326,18 @@ let savePage : HttpHandler = fun next ctx -> task {
         do! (if model.pageId = "new" then data.Page.add else data.Page.update) page
         if updateList then do! PageListCache.update ctx
         do! addMessage ctx { UserMessage.success with message = "Page saved successfully" }
-        return!
+        return! redirectToGet $"admin/page/{PageId.toString page.id}/edit" next ctx
-            redirectToGet (WebLog.relativeUrl webLog (Permalink $"admin/page/{PageId.toString page.id}/edit")) next ctx
     | None -> return! Error.notFound next ctx
 }
 
 // -- TAG MAPPINGS --
 
-open Microsoft.AspNetCore.Http
-
 /// Get the hash necessary to render the tag mapping list
 let private tagMappingHash (ctx : HttpContext) = task {
     let! mappings = ctx.Data.TagMap.findByWebLog ctx.WebLog.id
     return Hash.FromAnonymousObject {|
+        csrf        = ctx.CsrfTokenSet
         web_log     = ctx.WebLog
-        csrf        = csrfToken ctx
         mappings    = mappings
         mapping_ids = mappings |> List.map (fun it -> { name = it.tag; value = TagMapId.toString it.id })
     |}
@@ -317,9 +372,9 @@ let editMapping tagMapId : HttpHandler = fun next ctx -> task {
     | Some tm ->
         return!
             Hash.FromAnonymousObject {|
-                csrf       = csrfToken ctx
-                model      = EditTagMapModel.fromMapping tm
                 page_title = if isNew then "Add Tag Mapping" else $"Mapping for {tm.tag} Tag" 
+                csrf       = ctx.CsrfTokenSet
+                model      = EditTagMapModel.fromMapping tm
             |}
             |> bareForTheme "admin" "tag-mapping-edit" next ctx
     | None -> return! Error.notFound next ctx
@@ -361,8 +416,8 @@ open MyWebLog.Data
 let themeUpdatePage : HttpHandler = fun next ctx -> task {
     return!
         Hash.FromAnonymousObject {|
-            csrf       = csrfToken ctx
             page_title = "Upload Theme"
+            csrf       = ctx.CsrfTokenSet
         |}
         |> viewForTheme "admin" "upload-theme" next ctx
 }
@@ -457,13 +512,13 @@ let updateTheme : HttpHandler = fun next ctx -> task {
             do! ThemeAssetCache.refreshTheme (ThemeId themeName) data
             TemplateCache.invalidateTheme themeName
             do! addMessage ctx { UserMessage.success with message = "Theme updated successfully" }
-            return! redirectToGet (WebLog.relativeUrl ctx.WebLog (Permalink "admin/dashboard")) next ctx
+            return! redirectToGet "admin/dashboard" next ctx
         | Ok _ ->
             do! addMessage ctx { UserMessage.error with message = "You may not replace the admin theme" }
-            return! redirectToGet (WebLog.relativeUrl ctx.WebLog (Permalink "admin/theme/update")) next ctx
+            return! redirectToGet "admin/theme/update" next ctx
         | Error message ->
             do! addMessage ctx { UserMessage.error with message = message }
-            return! redirectToGet (WebLog.relativeUrl ctx.WebLog (Permalink "admin/theme/update")) next ctx
+            return! redirectToGet "admin/theme/update" next ctx
     else
         return! RequestErrors.BAD_REQUEST "Bad request" next ctx
 }
@@ -480,11 +535,12 @@ let settings : HttpHandler = fun next ctx -> task {
     let! themes   = data.Theme.all ()
     return!
         Hash.FromAnonymousObject {|
-            csrf  = csrfToken ctx
+            page_title = "Web Log Settings"
+            csrf       = ctx.CsrfTokenSet
+            web_log    = webLog
             model      = SettingsModel.fromWebLog webLog
-            pages =
+            pages      = seq
-                seq {
+                {   KeyValuePair.Create ("posts", "- First Page of Posts -")
-                    KeyValuePair.Create ("posts", "- First Page of Posts -")
                     yield! allPages
                            |> List.sortBy (fun p -> p.title.ToLower ())
                            |> List.map (fun p -> KeyValuePair.Create (PageId.toString p.id, p.title))
@@ -495,12 +551,10 @@ let settings : HttpHandler = fun next ctx -> task {
                  |> Seq.ofList
                  |> Seq.map (fun it -> KeyValuePair.Create (ThemeId.toString it.id, $"{it.name} (v{it.version})"))
                  |> Array.ofSeq
-            upload_values =
+            upload_values = [|
-                [|  KeyValuePair.Create (UploadDestination.toString Database, "Database")
+                    KeyValuePair.Create (UploadDestination.toString Database, "Database")
                     KeyValuePair.Create (UploadDestination.toString Disk,     "Disk")
                 |]
-            web_log    = webLog
-            page_title = "Web Log Settings"
         |}
         |> viewForTheme "admin" "settings" next ctx
 }
@@ -526,6 +580,6 @@ let saveSettings : HttpHandler = fun next ctx -> task {
             if Directory.Exists oldDir then Directory.Move (oldDir, Path.Combine (uploadRoot, webLog.slug))
     
         do! addMessage ctx { UserMessage.success with message = "Web log settings saved successfully" }
-        return! redirectToGet (WebLog.relativeUrl webLog (Permalink "admin/settings")) next ctx
+        return! redirectToGet "admin/settings" next ctx
     | None -> return! Error.notFound next ctx
 }

src/MyWebLog/Handlers/Error.fs

@@ -2,21 +2,20 @@
 module MyWebLog.Handlers.Error
 
 open System.Net
-open System.Threading.Tasks
 open Giraffe
-open Microsoft.AspNetCore.Http
 open MyWebLog
 
 /// Handle unauthorized actions, redirecting to log on for GETs, otherwise returning a 401 Not Authorized response
-let notAuthorized : HttpHandler = fun next ctx -> task {
+let notAuthorized : HttpHandler =
+    handleContext (fun ctx ->
         if ctx.Request.Method = "GET" then
             let returnUrl = WebUtility.UrlEncode ctx.Request.Path
-        return!
+            redirectTo false (WebLog.relativeUrl ctx.WebLog (Permalink $"user/log-on?returnUrl={returnUrl}"))
-            redirectTo false (WebLog.relativeUrl ctx.WebLog (Permalink $"user/log-on?returnUrl={returnUrl}")) next ctx
+                earlyReturn ctx
         else
-        return! (setStatusCode 401 >=> fun _ _ -> Task.FromResult<HttpContext option> None) next ctx
+            setStatusCode 401 earlyReturn ctx)
-}
+
 
 /// Handle 404s from the API, sending known URL paths to the Vue app so that they can be handled there
-let notFound : HttpHandler =
+let notFound : HttpHandler = fun _ ->
-    setStatusCode 404 >=> text "Not found"
+    (setStatusCode 404 >=> text "Not found") earlyReturn

src/MyWebLog/Handlers/Feed.fs

@@ -423,9 +423,9 @@ let editSettings : HttpHandler = fun next ctx -> task {
         webLog.rss.customFeeds
         |> List.map (DisplayCustomFeed.fromFeed (CategoryCache.get ctx))
         |> Array.ofList
-    return! Hash.FromAnonymousObject
+    return! Hash.FromAnonymousObject {|
-        {|  csrf         = csrfToken ctx
             page_title   = "RSS Settings"
+            csrf         = ctx.CsrfTokenSet
             model        = EditRssModel.fromRssOptions webLog.rss
             custom_feeds = feeds
         |}
@@ -442,7 +442,7 @@ let saveSettings : HttpHandler = fun next ctx -> task {
         do! data.WebLog.updateRssOptions webLog
         WebLogCache.set webLog
         do! addMessage ctx { UserMessage.success with message = "RSS settings updated successfully" }
-        return! redirectToGet (WebLog.relativeUrl webLog (Permalink "admin/settings/rss")) next ctx
+        return! redirectToGet "admin/settings/rss" next ctx
     | None -> return! Error.notFound next ctx
 }
 
@@ -454,9 +454,9 @@ let editCustomFeed feedId : HttpHandler = fun next ctx -> task {
         | _     -> ctx.WebLog.rss.customFeeds |> List.tryFind (fun f -> f.id = CustomFeedId feedId)
     match customFeed with
     | Some f ->
-        return! Hash.FromAnonymousObject
+        return! Hash.FromAnonymousObject {|
-            {|  csrf          = csrfToken ctx
                 page_title    = $"""{if feedId = "new" then "Add" else "Edit"} Custom RSS Feed"""
+                csrf          = ctx.CsrfTokenSet
                 model         = EditCustomFeedModel.fromFeed f
                 categories    = CategoryCache.get ctx
                 medium_values = [|
@@ -494,8 +494,7 @@ let saveCustomFeed : HttpHandler = fun next ctx -> task {
                 UserMessage.success with
                   message = $"""Successfully {if model.id = "new" then "add" else "sav"}ed custom feed"""
             }
-            let nextUrl = $"admin/settings/rss/{CustomFeedId.toString feed.id}/edit" 
+            return! redirectToGet $"admin/settings/rss/{CustomFeedId.toString feed.id}/edit" next ctx
-            return! redirectToGet (WebLog.relativeUrl webLog (Permalink nextUrl)) next ctx
         | None -> return! Error.notFound next ctx
     | None -> return! Error.notFound next ctx
 }
@@ -519,6 +518,6 @@ let deleteCustomFeed feedId : HttpHandler = fun next ctx -> task {
             do! addMessage ctx { UserMessage.success with message = "Custom feed deleted successfully" }
         else
             do! addMessage ctx { UserMessage.warning with message = "Custom feed not found; no action taken" }
-        return! redirectToGet (WebLog.relativeUrl webLog (Permalink "admin/settings/rss")) next ctx
+        return! redirectToGet "admin/settings/rss" next ctx
     | None -> return! Error.notFound next ctx
 }

src/MyWebLog/Handlers/Helpers.fs

@@ -101,7 +101,7 @@ let private populateHash hash ctx = task {
 }
 
 /// Render a view for the specified theme, using the specified template, layout, and hash
-let viewForTheme theme template next ctx = fun (hash : Hash) -> task {
+let viewForTheme theme template next ctx (hash : Hash) = task {
     do! populateHash hash ctx
     
     // NOTE: DotLiquid does not support {% render %} or {% include %} in its templates, so we will do a 2-pass render;
@@ -119,13 +119,14 @@ let viewForTheme theme template next ctx = fun (hash : Hash) -> task {
 }
 
 /// Render a bare view for the specified theme, using the specified template and hash
-let bareForTheme theme template next ctx = fun (hash : Hash) -> task {
+let bareForTheme theme template next ctx (hash : Hash) = task {
     do! populateHash hash ctx
     
-    // Bare templates are rendered with layout-bare
+    if not (hash.ContainsKey "content") then
         let! contentTemplate = TemplateCache.get theme template ctx.Data
         hash.Add ("content", contentTemplate.Render hash)
     
+    // Bare templates are rendered with layout-bare
     let! layoutTemplate = TemplateCache.get theme "layout-bare" ctx.Data
     
     // add messages as HTTP headers
@@ -146,36 +147,21 @@ let bareForTheme theme template next ctx = fun (hash : Hash) -> task {
 }
 
 /// Return a view for the web log's default theme
-let themedView template next ctx = fun (hash : Hash) -> task {
+let themedView template next ctx hash =
-    return! viewForTheme (deriveWebLogFromHash hash ctx).themePath template next ctx hash
+    viewForTheme (deriveWebLogFromHash hash ctx).themePath template next ctx hash
-}
+
 
 /// Redirect after doing some action; commits session and issues a temporary redirect
-let redirectToGet url : HttpHandler = fun next ctx -> task {
+let redirectToGet url : HttpHandler = fun _ ctx -> task {
     do! commitSession ctx
-    return! redirectTo false url next ctx
+    return! redirectTo false (WebLog.relativeUrl ctx.WebLog (Permalink url)) earlyReturn ctx
 }
 
-open System.Security.Claims
-
-/// Get the user ID for the current request
-let userId (ctx : HttpContext) =
-    WebLogUserId (ctx.User.Claims |> Seq.find (fun c -> c.Type = ClaimTypes.NameIdentifier)).Value
-
-open Microsoft.AspNetCore.Antiforgery
-
-/// Get the Anti-CSRF service
-let private antiForgery (ctx : HttpContext) = ctx.RequestServices.GetRequiredService<IAntiforgery> ()
-
-/// Get the cross-site request forgery token set
-let csrfToken (ctx : HttpContext) =
-    (antiForgery ctx).GetAndStoreTokens ctx
-
 /// Validate the cross-site request forgery token in the current request
 let validateCsrf : HttpHandler = fun next ctx -> task {
-    match! (antiForgery ctx).IsRequestValidAsync ctx with
+    match! ctx.AntiForgery.IsRequestValidAsync ctx with
     | true -> return! next ctx
-    | false -> return! RequestErrors.BAD_REQUEST "CSRF token invalid" next ctx
+    | false -> return! RequestErrors.BAD_REQUEST "CSRF token invalid" earlyReturn ctx
 }
 
 /// Require a user to be logged on
@@ -226,6 +212,13 @@ let getCategoryIds slug ctx =
     |> Seq.map (fun c -> CategoryId c.id)
     |> List.ofSeq
 
+open System
+open System.Globalization
+
+/// Parse a date/time to UTC 
+let parseToUtc (date : string) =
+    DateTime.Parse (date, null, DateTimeStyles.AdjustToUniversal)
+
 open Microsoft.Extensions.Logging
 
 /// Log level for debugging

src/MyWebLog/Handlers/Post.fs

@@ -198,9 +198,9 @@ let home : HttpHandler = fun next ctx -> task {
         | Some page ->
             return!
                 Hash.FromAnonymousObject {|
+                    page_title = page.title
                     page       = DisplayPage.fromPage webLog page
                     categories = CategoryCache.get ctx
-                    page_title = page.title
                     is_home    = true
                 |}
                 |> themedView (defaultArg page.template "single-page") next ctx
@@ -215,7 +215,7 @@ let all pageNbr : HttpHandler = fun next ctx -> task {
     let! posts  = data.Post.findPageOfPosts webLog.id pageNbr 25
     let! hash   = preparePostList webLog posts AdminList "" pageNbr 25 ctx data
     hash.Add ("page_title", "Posts")
-    hash.Add ("csrf", csrfToken ctx)
+    hash.Add ("csrf", ctx.CsrfTokenSet)
     return! viewForTheme "admin" "post-list" next ctx hash
 }
 
@@ -238,11 +238,11 @@ let edit postId : HttpHandler = fun next ctx -> task {
         let  model     = EditPostModel.fromPost webLog post
         return!
             Hash.FromAnonymousObject {|
-                csrf            = csrfToken ctx
+                page_title      = title
+                csrf            = ctx.CsrfTokenSet
                 model           = model
                 metadata        = Array.zip model.metaNames model.metaValues
                                   |> Array.mapi (fun idx (name, value) -> [| string idx; name; value |])
-                page_title      = title
                 templates       = templates
                 categories      = cats
                 explicit_values = [|
@@ -262,9 +262,9 @@ let editPermalinks postId : HttpHandler = fun next ctx -> task {
     | Some post ->
         return!
             Hash.FromAnonymousObject {|
-                csrf       = csrfToken ctx
+                page_title = "Manage Prior Permalinks"
+                csrf       = ctx.CsrfTokenSet
                 model      = ManagePermalinksModel.fromPost post
-                page_title = $"Manage Prior Permalinks"
             |}
             |> viewForTheme "admin" "permalinks" next ctx
     | None -> return! Error.notFound next ctx
@@ -278,7 +278,7 @@ let savePermalinks : HttpHandler = fun next ctx -> task {
     match! ctx.Data.Post.updatePriorPermalinks (PostId model.id) webLog.id links with
     | true ->
         do! addMessage ctx { UserMessage.success with message = "Post permalinks saved successfully" }
-        return! redirectToGet (WebLog.relativeUrl webLog (Permalink $"admin/post/{model.id}/permalinks")) next ctx
+        return! redirectToGet $"admin/post/{model.id}/permalinks" next ctx
     | false -> return! Error.notFound next ctx
 }
 
@@ -288,7 +288,7 @@ let delete postId : HttpHandler = fun next ctx -> task {
     match! ctx.Data.Post.delete (PostId postId) webLog.id with
     | true  -> do! addMessage ctx { UserMessage.success with message = "Post deleted successfully" }
     | false -> do! addMessage ctx { UserMessage.error with message = "Post not found; nothing deleted" }
-    return! redirectToGet (WebLog.relativeUrl webLog (Permalink "admin/posts")) next ctx
+    return! redirectToGet "admin/posts" next ctx
 }
 
 #nowarn "3511"
@@ -306,7 +306,7 @@ let save : HttpHandler = fun next ctx -> task {
                 { Post.empty with
                     id        = PostId.create ()
                     webLogId  = webLog.id
-                    authorId  = userId ctx
+                    authorId  = ctx.UserId
                 }
         | postId -> return! data.Post.findFullById (PostId postId) webLog.id
     }
@@ -323,7 +323,7 @@ let save : HttpHandler = fun next ctx -> task {
         let post =
             match model.setPublished with
             | true ->
-                let dt = WebLog.utcTime webLog model.pubOverride.Value
+                let dt = parseToUtc (model.pubOverride.Value.ToString "o")
                 match model.setUpdated with
                 | true ->
                     { post with
@@ -342,7 +342,6 @@ let save : HttpHandler = fun next ctx -> task {
                    |> List.length = List.length pst.Value.categoryIds) then
             do! CategoryCache.update ctx
         do! addMessage ctx { UserMessage.success with message = "Post saved successfully" }
-        return!
+        return! redirectToGet $"admin/post/{PostId.toString post.id}/edit" next ctx
-            redirectToGet (WebLog.relativeUrl webLog (Permalink $"admin/post/{PostId.toString post.id}/edit")) next ctx
     | None -> return! Error.notFound next ctx
 }

src/MyWebLog/Handlers/Routes.fs

@@ -40,9 +40,9 @@ module CatchAll =
                 debug (fun () -> $"Found page by permalink")
                 yield fun next ctx ->
                     Hash.FromAnonymousObject {|
+                        page_title = page.title
                         page       = DisplayPage.fromPage webLog page
                         categories = CategoryCache.get ctx
-                        page_title = page.title
                         is_page    = true
                     |}
                     |> themedView (defaultArg page.template "single-page") next ctx
@@ -123,6 +123,8 @@ let router : HttpHandler = choose [
                 routef "s/page/%i"                   Admin.listPages
                 routef "/%s/edit"                    Admin.editPage
                 routef "/%s/permalinks"              Admin.editPagePermalinks
+                routef "/%s/revision/%s/preview"     Admin.previewPageRevision
+                routef "/%s/revisions"               Admin.editPageRevisions
             ])
             subRoute "/post" (choose [
                 route  "s"              >=> Post.all 1
@@ -158,6 +160,9 @@ let router : HttpHandler = choose [
                 route  "/save"                   >=> Admin.savePage
                 route  "/permalinks"             >=> Admin.savePagePermalinks
                 routef "/%s/delete"                  Admin.deletePage
+                routef "/%s/revision/%s/delete"      Admin.deletePageRevision
+                routef "/%s/revision/%s/restore"     Admin.restorePageRevision
+                routef "/%s/revisions/purge"         Admin.purgePageRevisions
             ])
             subRoute "/post" (choose [
                 route  "/save"       >=> Post.save

src/MyWebLog/Handlers/Upload.fs

@@ -118,8 +118,8 @@ let list : HttpHandler = fun next ctx -> task {
 
     return!
         Hash.FromAnonymousObject {|
-            csrf       = csrfToken ctx
             page_title = "Uploaded Files"
+            csrf       = ctx.CsrfTokenSet
             files      = allFiles
         |}
         |> viewForTheme "admin" "upload-list" next ctx
@@ -129,17 +129,16 @@ let list : HttpHandler = fun next ctx -> task {
 let showNew : HttpHandler = fun next ctx -> task {
     return!
         Hash.FromAnonymousObject {|
-            csrf        = csrfToken ctx
-            destination = UploadDestination.toString ctx.WebLog.uploads
             page_title  = "Upload a File"
+            csrf        = ctx.CsrfTokenSet
+            destination = UploadDestination.toString ctx.WebLog.uploads
         |}
         |> viewForTheme "admin" "upload-new" next ctx
 }
 
 /// Redirect to the upload list
-let showUploads : HttpHandler = fun next ctx -> task {
+let showUploads : HttpHandler =
-    return! redirectToGet (WebLog.relativeUrl ctx.WebLog (Permalink "admin/uploads")) next ctx
+    redirectToGet "admin/uploads"
-}
 
 // POST /admin/upload/save
 let save : HttpHandler = fun next ctx -> task {

src/MyWebLog/Handlers/User.fs

@@ -13,6 +13,7 @@ let hashedPassword (plainText : string) (email : string) (salt : Guid) =
 
 open DotLiquid
 open Giraffe
+open MyWebLog
 open MyWebLog.ViewModels
 
 // GET /user/log-on
@@ -26,9 +27,9 @@ let logOn returnUrl : HttpHandler = fun next ctx -> task {
             | false -> None
     return!
         Hash.FromAnonymousObject {|
-            model      = { LogOnModel.empty with returnTo = returnTo }
             page_title = "Log On"
-            csrf       = csrfToken ctx
+            csrf       = ctx.CsrfTokenSet
+            model      = { LogOnModel.empty with returnTo = returnTo }
         |}
         |> viewForTheme "admin" "log-on" next ctx
 }
@@ -36,7 +37,6 @@ let logOn returnUrl : HttpHandler = fun next ctx -> task {
 open System.Security.Claims
 open Microsoft.AspNetCore.Authentication
 open Microsoft.AspNetCore.Authentication.Cookies
-open MyWebLog
 
 // POST /user/log-on
 let doLogOn : HttpHandler = fun next ctx -> task {
@@ -56,8 +56,7 @@ let doLogOn : HttpHandler = fun next ctx -> task {
             AuthenticationProperties (IssuedUtc = DateTimeOffset.UtcNow))
         do! addMessage ctx
                 { UserMessage.success with message = $"Logged on successfully | Welcome to {webLog.name}!" }
-        return! redirectToGet (defaultArg model.returnTo (WebLog.relativeUrl webLog (Permalink "admin/dashboard")))
+        return! redirectToGet (defaultArg model.returnTo "admin/dashboard") next ctx
-                    next ctx
     | _ ->
         do! addMessage ctx { UserMessage.error with message = "Log on attempt unsuccessful" }
         return! logOn model.returnTo next ctx
@@ -67,19 +66,19 @@ let doLogOn : HttpHandler = fun next ctx -> task {
 let logOff : HttpHandler = fun next ctx -> task {
     do! ctx.SignOutAsync CookieAuthenticationDefaults.AuthenticationScheme
     do! addMessage ctx { UserMessage.info with message = "Log off successful" }
-    return! redirectToGet (WebLog.relativeUrl ctx.WebLog Permalink.empty) next ctx
+    return! redirectToGet "" next ctx
 }
 
 /// Display the user edit page, with information possibly filled in
 let private showEdit (hash : Hash) : HttpHandler = fun next ctx -> task {
     hash.Add ("page_title", "Edit Your Information")
-    hash.Add ("csrf", csrfToken ctx)
+    hash.Add ("csrf", ctx.CsrfTokenSet)
     return! viewForTheme "admin" "user-edit" next ctx hash
 }
 
 // GET /admin/user/edit
 let edit : HttpHandler = fun next ctx -> task {
-    match! ctx.Data.WebLogUser.findById (userId ctx) ctx.WebLog.id with
+    match! ctx.Data.WebLogUser.findById ctx.UserId ctx.WebLog.id with
     | Some user -> return! showEdit (Hash.FromAnonymousObject {| model = EditUserModel.fromUser user |}) next ctx
     | None -> return! Error.notFound next ctx
 }
@@ -89,7 +88,7 @@ let save : HttpHandler = requireUser >=> validateCsrf >=> fun next ctx -> task {
     let! model = ctx.BindFormAsync<EditUserModel> ()
     if model.newPassword = model.newPasswordConfirm then
         let data = ctx.Data
-        match! data.WebLogUser.findById (userId ctx) ctx.WebLog.id with
+        match! data.WebLogUser.findById ctx.UserId ctx.WebLog.id with
         | Some user ->
             let pw, salt =
                 if model.newPassword = "" then
@@ -108,7 +107,7 @@ let save : HttpHandler = requireUser >=> validateCsrf >=> fun next ctx -> task {
             do! data.WebLogUser.update user
             let pwMsg = if model.newPassword = "" then "" else " and updated your password"
             do! addMessage ctx { UserMessage.success with message = $"Saved your information{pwMsg} successfully" }
-            return! redirectToGet (WebLog.relativeUrl ctx.WebLog (Permalink "admin/user/edit")) next ctx
+            return! redirectToGet "admin/user/edit" next ctx
         | None -> return! Error.notFound next ctx
     else
         do! addMessage ctx { UserMessage.error with message = "Passwords did not match; no updates made" }

src/admin-theme/page-edit.liquid

@@ -16,8 +16,15 @@
                    value="{{ model.permalink }}">
             <label for="permalink">Permalink</label>
             {%- if model.page_id != "new" %}
-              {%- capture perm_edit %}admin/page/{{ model.page_id }}/permalinks{% endcapture -%}
+              <span class="form-text">
-              <span class="form-text"><a href="{{ perm_edit | relative_link }}">Manage Permalinks</a></span>
+                <a href="{{ "admin/page/" | append: model.page_id | append: "/permalinks" | relative_link }}">
+                  Manage Permalinks
+                </a>
+                <span class="text-muted"> &bull; </span>
+                <a href="{{ "admin/page/" | append: model.page_id | append: "/revisions" | relative_link }}">
+                  Manage Revisions
+                </a>
+              </span>
             {% endif -%}
           </div>
           <div class="mb-2">

src/admin-theme/revisions.liquid

@@ -1,6 +1,6 @@
 <h2 class="my-3">{{ page_title }}</h2>
 <article>
-  <form method="post">
+  <form method="post" hx-target="body">
     <input type="hidden" name="{{ csrf.form_field_name }}" value="{{ csrf.request_token }}">
     <input type="hidden" name="id" value="{{ model.id }}">
     <div class="container">
@@ -9,19 +9,20 @@
           <p style="line-height:1.2rem;">
             <strong>{{ model.current_title }}</strong><br>
             <small class="text-muted">
-              {%- capture back_link %}admin/{{ model.entity }}/{{ model.id }}/edit{% endcapture -%}
+              <a href="{{ "admin/" | append: model.entity | append: "/" | append: model.id | append: "/edit" | relative_link }}">
-              <a href="{{ back_link | relative_link }}">&laquo; Back to Edit {{ model.entity | capitalize }}</a>
+                &laquo; Back to Edit {{ model.entity | capitalize }}
+              </a>
             </small>
           </p>
         </div>
       </div>
       {%- assign revision_count = model.revisions | size -%}
-      {%- capture rev_url_base %}admin/{{ model.entity }}/{{ model.id }}/revision{% endcapture -%}
+      {%- assign rev_url_base = "admin/" | append: model.entity | append: "/" | append: model.id | append: "/revision" -%}
       {%- if revision_count > 1 %}
-        {% capture delete_all %}{{ rev_url_base }}s/purge{% endcapture %}
         <div class="row mb-3">
           <div class="col">
-            <button type="button" class="btn btn-sm btn-danger" hx-post="{{ delete_all | relative_link }}"
+            <button type="button" class="btn btn-sm btn-danger"
+                    hx-post="{{ rev_url_base | append: "s/purge" | relative_link }}"
                     hx-confirm="This will remove all revisions but the current one; are you sure this is what you wish to do?">
               Delete All Prior Revisions
             </button>
@@ -29,28 +30,40 @@
         </div>
       {%- endif %}
       {% for rev in model.revisions %}
-        <div class="row mb-3">
+        {%- assign as_of_string = rev.as_of | date: "o" -%}
-          <div class="col">
+        {%- assign as_of_id = "rev_" | append: as_of_string | replace: "\.", "_" | replace: ":", "-" -%}
-            {{ rev.as_of_local | date: "MMMM d, yyyy" }} at {{ rev.as_of_local | date: "h:mmaa" | downcase }}
+        <div id="{{ as_of_id }}" class="row mb-3">
-            <span class="badge bg-secondary text-uppercase">{{ ref.format }}</span>
+          <div class="col-12 mb-3">
+            {{ rev.as_of_local | date: "MMMM d, yyyy" }} at {{ rev.as_of_local | date: "h:mmtt" | downcase }}
+            <span class="badge bg-secondary text-uppercase ms-2">{{ rev.format }}</span>
             {%- if forloop.first %}
               <span class="badge bg-primary text-uppercase ms-2">Current Revision</span>
             {%- endif %}<br>
             {% unless forloop.first %}
-              {%- capture rev_url_prefix %}{{ rev_url_base }}/{{ rev.as_of | date: "o" }}{% endcapture -%}
+              {%- assign rev_url_prefix = rev_url_base | append: "/" | append: as_of_string -%}
+              {%- assign rev_restore = rev_url_prefix | append: "/restore" | relative_link -%}
+              {%- assign rev_delete  = rev_url_prefix | append: "/delete"  | relative_link -%}
               <small>
-                <a href="TODO">Preview</a>
+                <a href="{{ rev_url_prefix | append: "/preview" | relative_link }}" hx-target="#{{ as_of_id }}_preview">
+                  Preview
+                </a>
                 <span class="text-muted"> &bull; </span>
-                {%- capture rev_restore %}{{ rev_url_prefix }}/restore{% endcapture -%}
+                <a href="{{ rev_restore }}" hx-post="{{ rev_restore }}">Restore as Current</a>
-                {%- capture rev_restore_link %}{{ rev_restore | relative_link }}{% endcapture -%}
-                <a href="{{ rev_restore_link }}" hx-post="{{ rev_restore_link }}">Restore as Current</a>
                 <span class="text-muted"> &bull; </span>
-                {%- capture rev_del %}{{ rev_url_prefix }}/delete{% endcapture -%}
+                <a href="{{ rev_delete }}" hx-post="{{ rev_delete }}" hx-target="#{{ as_of_id }}" hx-swap="outerHtml"
-                {%- capture rev_del_link %}{{ rev_del | relative_link }}{% endcapture -%}
+                   class="text-danger">
-                <a href="{{ rev_del_link }}" hx-post="{{ rev_del_link }}" class="text-danger">Delete</a>
+                  Delete
+                </a>
               </small>
             {% endunless %}
           </div>
+          {% unless forloop.first %}
+            <div class="col-12 mb-3">
+              <div id="{{ as_of_id }}_preview" class="mwl-revision-preview">
+                <span class="text-muted fst-italic">preview not loaded</span>
+              </div>
+            </div>
+          {% endunless %}
         </div>
       {% endfor %}
     </div>

src/admin-theme/wwwroot/admin.css

@@ -85,3 +85,6 @@ a.text-danger:link:hover, a.text-danger:visited:hover {
   background-color: var(--light-accent);
   color: var(--dark-gray);
 }
+.mwl-revision-preview {
+  max-height: 90vh;
+}