From b7446e182ecf3f2c56f1db20415d670717a40898 Mon Sep 17 00:00:00 2001
From: Wolfgang Kinkeldei <wolfgang@kinkeldei.de>
Date: Sat, 17 Dec 2016 21:30:37 +0100
Subject: [PATCH] modified generated HTML files by downloading CDN-loaded
 assets

---
 build.fsx | 45 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/build.fsx b/build.fsx
index 99b39fcf..e159aefd 100644
--- a/build.fsx
+++ b/build.fsx
@@ -7,6 +7,8 @@
 
 #load "fsreveal.fsx"
 
+open System.Text.RegularExpressions
+
 // Git configuration (used for publishing documentation in gh-pages branch)
 // The profile where the project is posted
 let gitOwner = "myGitUser"
@@ -57,6 +59,45 @@ let copyPics() =
     with
     | exn -> traceImportant <| sprintf "Could not copy picture: %s" exn.Message
 
+let downloadAssets file =
+    let download (url:string) (filename:string) =
+        let content = (new System.Net.WebClient()).DownloadString(url)
+        File.WriteAllText((outDir </> filename), content)
+
+    let matchDownloadAndModifyAsset input tag attr subdir =
+        let regex = sprintf @"^(.*<%s.*%s\s*=\s*"")(//[^""]+?)(\?[^""]+?)?("".*)$" tag attr
+        let m = Regex.Match(input, regex)
+        if (m.Success)
+        then
+            let filePath = subdir </> Path.GetFileName(m.Groups.[2].Value)
+            let url = "http:" + m.Groups.[2].Value + m.Groups.[3].Value
+
+            download url filePath
+
+            Some (m.Groups.[1].Value + filePath + m.Groups.[4].Value)
+        else
+            None
+
+    let (|ScriptTag|_|) input =
+        matchDownloadAndModifyAsset input "script" "src" "js"
+
+    let (|LinkTag|_|) input =
+        matchDownloadAndModifyAsset input "link" "href" "css"
+
+    let downloadAssetIfNeeded line =
+        match line with
+        | ScriptTag l -> l
+        | LinkTag l -> l
+        | _ -> line
+
+    let oldFile = file + ".old"
+    File.Move(file, oldFile)
+
+    use stream = new StreamWriter(file);
+    File.ReadLines oldFile
+    |> Seq.map downloadAssetIfNeeded
+    |> Seq.iter stream.WriteLine
+ 
 let generateFor (file:FileInfo) = 
     try
         copyPics()
@@ -71,6 +112,10 @@ let generateFor (file:FileInfo) =
 
         tryGenerate 3
 
+        let outFile = outDir </> (System.IO.Path.ChangeExtension(file.Name, "html"))
+        trace <| sprintf "Created '%s', downloading CDN-loaded assets..." outFile
+        downloadAssets outFile
+
         copyStylesheet()
     with
     | :? FileNotFoundException as exn ->