WIP on Fluid model/filters

src/MyWebLog/Handlers/Helpers.fs

@@ -23,7 +23,6 @@ type ISession with
 [<Literal>]
 let MESSAGES = "messages"
 
-
 /// The HTTP item key for loading the session
 let private sessionLoadedKey = "session-loaded"
 
@@ -132,6 +131,7 @@ let redirectToGet url : HttpHandler = fun _ ctx -> task {
 }
 
 /// The MIME type for podcast episode JSON chapters
+[<Literal>]
 let JSON_CHAPTERS = "application/json+chapters"
 
 
@@ -185,10 +185,10 @@ let viewForTheme themeId template next ctx (viewCtx: AppViewContext) = task {
     // Render view content...
     match! Template.Cache.get themeId template ctx.Data with
     | Ok contentTemplate ->
-        let forLayout = { updated with Content = Template.render contentTemplate updated }
+        let forLayout = { updated with Content = Template.render contentTemplate updated ctx.Data }
         // ...then render that content with its layout
         match! Template.Cache.get themeId (if isHtmx ctx then "layout-partial" else "layout") ctx.Data with
-        | Ok layoutTemplate ->  return! htmlString (Template.render layoutTemplate forLayout) next ctx
+        | Ok layoutTemplate ->  return! htmlString (Template.render layoutTemplate forLayout ctx.Data) next ctx
         | Error message -> return! Error.server message next ctx
     | Error message -> return! Error.server message next ctx
 }
@@ -199,7 +199,7 @@ let bareForTheme themeId template next ctx viewCtx = task {
     let  withContent = task {
         if updated.Content = "" then 
             match! Template.Cache.get themeId template ctx.Data with
-            | Ok contentTemplate -> return Ok { updated with Content = Template.render contentTemplate updated }
+            | Ok contentTemplate -> return Ok { updated with Content = Template.render contentTemplate updated ctx.Data }
             | Error message -> return Error message
         else
             return Ok viewCtx 
@@ -210,7 +210,7 @@ let bareForTheme themeId template next ctx viewCtx = task {
         match! Template.Cache.get themeId "layout-bare" ctx.Data with
         | Ok layoutTemplate ->
             return!
-                (messagesToHeaders completeCtx.Messages >=> htmlString (Template.render layoutTemplate completeCtx))
+                (messagesToHeaders completeCtx.Messages >=> htmlString (Template.render layoutTemplate completeCtx ctx.Data))
                     next ctx
         | Error message -> return! Error.server message next ctx
     | Error message -> return! Error.server message next ctx

src/MyWebLog/Program.fs

@@ -27,7 +27,7 @@ type WebLogMiddleware(next: RequestDelegate, log: ILogger<WebLogMiddleware>) =
 
 
 /// Middleware to check redirects for the current web log
-type RedirectRuleMiddleware(next: RequestDelegate, log: ILogger<RedirectRuleMiddleware>) =
+type RedirectRuleMiddleware(next: RequestDelegate, _log: ILogger<RedirectRuleMiddleware>) =
 
     /// Shorthand for case-insensitive string equality
     let ciEquals str1 str2 =

src/MyWebLog/Template.fs

@@ -1,8 +1,14 @@
 module MyWebLog.Template
 
+open System
+open System.Collections.Generic
+open System.IO
+open System.Text
 open Fluid
 open Fluid.Values
 open Giraffe.ViewEngine
+open Microsoft.AspNetCore.Antiforgery
+open Microsoft.Extensions.FileProviders
 open MyWebLog
 open MyWebLog.ViewModels
 
@@ -48,10 +54,21 @@ module private Helpers =
 
 
 /// Fluid template options customized with myWebLog filters
-let options =
+let options () =
     let sValue = StringValue >> VTask<FluidValue>
+    
     let it = TemplateOptions.Default
     it.MemberAccessStrategy.MemberNameStrategy <- MemberNameStrategies.SnakeCase
+    [ // Domain types
+      typeof<CustomFeed>; typeof<Episode>; typeof<Episode option>; typeof<MetaItem>; typeof<Page>; typeof<RssOptions>
+      typeof<TagMap>;     typeof<WebLog>
+      // View models
+      typeof<AppViewContext>; typeof<DisplayCategory>; typeof<DisplayPage>; typeof<EditPageModel>; typeof<PostDisplay>
+      typeof<PostListItem>;   typeof<UserMessage>
+      // Framework types
+      typeof<AntiforgeryTokenSet>; typeof<DateTime option>; typeof<int option>;    typeof<KeyValuePair>
+      typeof<MetaItem list>;       typeof<string list>;     typeof<string option>; typeof<TagMap list> ]
+    |> List.iter it.MemberAccessStrategy.Register
     
     // A filter to generate an absolute link
     it.Filters.AddFilter("absolute_link", fun input _ ctx -> sValue (permalink input ctx.App.WebLog.AbsoluteUrl))
@@ -132,12 +149,14 @@ let options =
     // A filter to retrieve the value of a meta item from a list
     //   (shorter than `{% assign item = list | where: "Name", [name] | first %}{{ item.value }}`)
     it.Filters.AddFilter("value",
-        fun input args _ ->
+        fun input args ctx ->
-            let items = input.ToObjectValue() :?> MetaItem list
             let name = args.At(0).ToStringValue()
-            match items |> List.tryFind (fun it -> it.Name = name) with
+            let picker (value: FluidValue) =
-            | Some item -> item.Value
+                let item = value.ToObjectValue() :?> MetaItem
-            | None -> $"-- {name} not found --"
+                if item.Name = name then Some item.Value else None 
+            (input :?> ArrayValue).Values
+            |> Seq.tryPick picker
+            |> Option.defaultValue $"-- {name} not found --"
             |> sValue)
     
     it
@@ -234,11 +253,13 @@ let parser =
     
     it
 
+
+open MyWebLog.Data
+
 /// Cache for parsed templates
 module Cache =
     
     open System.Collections.Concurrent
-    open MyWebLog.Data
     
     /// Cache of parsed templates
     let private _cache = ConcurrentDictionary<string, IFluidTemplate> ()
@@ -277,6 +298,37 @@ module Cache =
         _cache.Clear()
 
 
+/// A file provider to retrieve files by theme 
+type ThemeFileProvider(themeId: ThemeId, data: IData) =
+    
+    interface IFileProvider with
+        
+        member _.GetDirectoryContents _ =
+            raise <| NotImplementedException "The theme file provider does not support directory listings"
+        
+        member _.GetFileInfo path =
+            match data.Theme.FindById themeId |> Async.AwaitTask |> Async.RunSynchronously with
+            | Some theme ->
+                match theme.Templates |> List.tryFind (fun t -> t.Name = path) with
+                | Some template ->
+                    { new IFileInfo with
+                        member _.Exists       = true
+                        member _.IsDirectory  = false
+                        member _.LastModified = DateTimeOffset.Now
+                        member _.Length       = int64 template.Text.Length
+                        member _.Name         = template.Name.Split '/' |> Array.last
+                        member _.PhysicalPath = null
+                        member _.CreateReadStream() =
+                            new MemoryStream(Encoding.UTF8.GetBytes template.Text) }
+                | None -> NotFoundFileInfo path
+            | None -> NotFoundFileInfo path
+        
+        member _.Watch _ =
+            raise <| NotImplementedException "The theme file provider does not support watching for changes"
+
+
 /// Render a template to a string
-let render (template: IFluidTemplate) (viewCtx: AppViewContext) =
+let render (template: IFluidTemplate) (viewCtx: AppViewContext) data =
-    template.Render(TemplateContext(viewCtx, options, true))
+    let opts = options ()
+    opts.FileProvider <- ThemeFileProvider(viewCtx.WebLog.ThemeId, data)
+    template.Render(TemplateContext(viewCtx, opts, true))

src/MyWebLog/appsettings.json

@@ -1,5 +1,5 @@
 {
-  "Generator": "myWebLog 2.2",
+  "Generator": "myWebLog 3",
   "Logging": {
     "LogLevel": {
       "MyWebLog.Handlers": "Information"