#596 download remote resources on unpack

src/compiler/WebSharper.Compiler/commands/UnpackCommand.fs

@@ -23,9 +23,9 @@ namespace WebSharper.Compiler
 open FileSystem
 module PC = WebSharper.PathConventions
 module C = Commands
+module Re = WebSharper.Core.Resources 
 
 module UnpackCommand =
-
     type Config =
         {
             Assemblies : list<string>
@@ -79,6 +79,8 @@ module UnpackCommand =
             | errors -> C.ParseFailed errors
         | _ -> C.NotRecognized
 
+    let private localResTyp = typeof<Re.IDownloadableResource>
+
     let Exec env cmd =
         let baseDir =
             let pathToSelf = typeof<Config>.Assembly.Location
@@ -133,6 +135,30 @@ module UnpackCommand =
                 writeText script r.FileName r.Content
             for r in a.GetContents() do
                 writeBinary content r.FileName (r.GetContentData())
+
+            let rec printError (e: exn) =
+                if isNull e.InnerException then
+                    e.Message
+                else e.Message + " - " + printError e.InnerException 
+
+            try
+                let asm = 
+                    try
+                        System.Reflection.Assembly.LoadFile (Path.GetFullPath p)
+                    with e ->
+                        eprintfn "Failed to load assembly for unpacking local resources: %s - %s" p (printError e)     
+                        null
+                if not (isNull asm) then
+                    for t in asm.GetTypes() do
+                        if t.GetInterfaces() |> Array.contains localResTyp then
+                            try
+                                let res = Activator.CreateInstance(t) :?> Re.IDownloadableResource
+                                res.Unpack(cmd.RootDirectory)
+                            with e ->
+                                eprintfn "Failed to unpack local resource: %s - %s" t.FullName (printError e)     
+            with e ->
+                eprintfn "Failed to unpack local resources: %s" (printError e)     
+
         C.Ok
 
     let Description =

src/compiler/WebSharper.Core/Graph.fs

@@ -289,7 +289,7 @@ type Graph =
                                 member this.Render ctx =
                                     fun writer ->
                                         let writer = writer R.Scripts
-                                        writer.Write("<-- ")
+                                        writer.Write("<!-- ")
                                         writer.Write("Failed to load: {0}; because of: {1}", t, e.Message)
                                         writer.WriteLine(" -->")
                         }

src/compiler/WebSharper.Core/Resources.fs

@@ -25,6 +25,7 @@ open System.IO
 open System.Reflection
 open System.Web
 open System.Web.UI
+
 module CT = ContentTypes
 
 type Rendering =
@@ -60,6 +61,9 @@ type Context =
 and IResource =
     abstract member Render : Context -> ((RenderLocation -> HtmlTextWriter) -> unit)
 
+type IDownloadableResource =
+    abstract Unpack : string -> unit    
+
 let cleanLink dHttp (url: string) =
     if dHttp && url.StartsWith("//")
         then "http:" + url
@@ -218,49 +222,105 @@ let tryFindWebResource (t: Type) (spec: string) =
     t.Assembly.GetManifestResourceNames()
     |> Seq.tryFind ok
 
-type BaseResource(kind: Kind) =
-
+let tryGetUriFileName (u: string) =
+    try
+        let uri = System.Uri u
+        let parts = u.Split('/')
+        parts.[parts.Length - 1] |> Some
+    with _ -> None
+
+type BaseResource(kind: Kind) as this =
+
+    let self = this.GetType()
+    let name = self.FullName
+
     new () =
         new BaseResource(Ignore)
-
     new (spec: string) =
         new BaseResource(Basic spec)
 
     new (b: string, x: string, [<System.ParamArray>] xs: string []) =
         new BaseResource(Complex(b, x :: List.ofArray xs))
 
+    member this.GetLocalName() =
+        name.Replace('+', '.').Split('`').[0]
+
     interface IResource with
         member this.Render ctx =
             let dHttp = ctx.DefaultToHttp
+            let isLocal = ctx.GetSetting "UseDownloadedResources" |> Option.exists (fun s -> s.ToLower() = "true")
+            let localFolder isCss f =
+                (if isCss then "Content/WebSharper/" else "Scripts/WebSharper/") + this.GetLocalName() + "/" + f
             match kind with
             | Ignore ->
                 ignore
             | Basic spec ->
-                let self = this.GetType()
-                let id = self.FullName
                 let mt = if spec.EndsWith ".css" then Css else Js
                 let r =
-                    match ctx.GetSetting id with
+                    match ctx.GetSetting name with
                     | Some url -> RenderLink url
                     | None ->
                         match tryFindWebResource self spec with
                         | Some e -> Rendering.GetWebResourceRendering(ctx, self, e)
-                        | None -> RenderLink spec
+                        | None ->
+                            if isLocal then
+                                match tryGetUriFileName spec with
+                                | Some f ->
+                                    RenderLink (localFolder (mt = Css)  f)
+                                | _ ->
+                                    RenderLink spec
+                            else
+                                RenderLink spec
                 fun writer -> r.Emit(writer, mt, dHttp)
             | Complex (b, xs) ->
-                let id = this.GetType().FullName
-                let b = defaultArg (ctx.GetSetting id) b
+                let b = defaultArg (ctx.GetSetting name) b
                 let urls =
                     xs |> List.map (fun x ->
-                        let url = b.TrimEnd [| '/' |] + "/" + x.TrimStart [| '/' |]
+                        let url = b.TrimEnd('/') + "/" + x.TrimStart('/')
                         url, url.EndsWith ".css"     
-                    )     
+                    )  
+                let urls = 
+                    if isLocal then 
+                        urls |> List.map (fun (u, isCss) ->
+                            match tryGetUriFileName u with
+                            | Some f ->
+                                localFolder isCss f, isCss
+                            | _ ->
+                                u, isCss
+                        )
+                    else urls
                 fun writer ->
                     for url, isCss in urls do
                         if isCss then
                             link dHttp (writer Styles) url
                         else script dHttp (writer Scripts) url
 
+    interface IDownloadableResource with
+        member this.Unpack path =
+            use wc = new System.Net.WebClient()    
+            let localName = this.GetLocalName()
+            let cssDir = Path.Combine (path, "Content", "WebSharper", localName)
+            let jsDir = Path.Combine (path, "Scripts", "WebSharper", localName)
+            let download (url: string) =
+                match tryGetUriFileName url with
+                | Some f ->
+                    let localDir = if url.EndsWith ".css" then cssDir else jsDir
+                    let localPath = Path.Combine(localDir, f)
+                    if not (Directory.Exists localDir) then
+                        Directory.CreateDirectory localDir |> ignore
+                    let url = if url.StartsWith("//") then "http:" + url else url
+                    printfn "Downloading %A to %s" url localPath
+                    wc.DownloadFile(url, localPath)
+                | _ ->
+                    ()
+            match kind with
+            | Ignore -> ()
+            | Basic spec ->
+                download spec
+            | Complex (b, xs) ->
+                for x in xs do
+                    download (b.TrimEnd('/') + "/" + x.TrimStart('/'))
+
 [<Sealed>]
 type Runtime() =
     interface IResource with

src/compiler/WebSharper.Core/Resources.fsi

@@ -81,12 +81,15 @@ and IResource =
     /// Renders the resource to a given TextWriter.
     abstract member Render : Context -> ((RenderLocation -> HtmlTextWriter) -> unit)
 
+/// An interface for resources to execute custom unpack.
+type IDownloadableResource =
+
+    /// Gets the WebSharper output root directory.
+    abstract Unpack : string -> unit    
+
 /// A helper base class for resource-defining types.
 type BaseResource =
 
-    [<Obsolete "Do not call default constructor of BaseResource, it will do nothing.">]
-    new : unit -> BaseResource
-
     /// References an embedded resource from he current assembly.
     /// The string represents either a reference to an embedded
     /// resource from the current assembly, or a (possibly relative)
@@ -103,6 +106,7 @@ type BaseResource =
     new : string * string * [<ParamArray>] xs: string [] -> BaseResource
 
     interface IResource
+    interface IDownloadableResource
 
 /// Represents the runtime library resource required by all WebSharper code.
 [<Sealed>]

tests/Web/Web.config

@@ -23,5 +23,7 @@
   </runtime>
   <appSettings>
     <add key="WebSharperSharedMetadata" value="Full" />
+    <add key="UseDownloadedResources" value="True" />
+    <add key="WebSharper.JQuery.Resources.JQuery" value="/Scripts/jquery-3.1.1.min.js" />
   </appSettings>
 </configuration>