generate an atom feed

Makefile

@@ -3,19 +3,21 @@ cache := .cache
 www_root := _site
 www := $(www_root)/posts
 post_index := $(www_root)/posts.html
+feed := $(www_root)/feed.xml
 
 post_compiler := src/webcc.ml
 builddir := _build/default
 
 POSTCC := $(builddir)/$(patsubst %.ml,%.exe,$(post_compiler))
 INDEXCC := $(POSTCC) -i
+FEEDCC := $(POSTCC) -a
 
 post-sources := $(shell find $(src)/ -type f)
 post-htmls   := $(patsubst $(src)/%.md,$(www)/%.html,$(post-sources))
 
 .PHONY: all serve clean $(POSTCC)
 
-all: $(POSTCC) $(post-htmls) $(post_index) $(www_root)/static
+all: $(POSTCC) $(post-htmls) $(post_index) $(feed) $(www_root)/static
 	cp -R ~/www/* $(www_root)
 
 $(www):
@@ -27,6 +29,9 @@ $(www)/%.html: $(src)/%.md $(www)
 $(post_index): $(post-sources)
 	$(INDEXCC) $^ -o $@
 
+$(feed): $(post-sources)
+	$(FEEDCC) $^ -o $@
+
 $(www_root)/static: static
 	cp -R static $(www_root)
 

src/atom.ml

@@ -0,0 +1,44 @@
+open Post
+
+let format_entry ~title ~date ~url ~contents ~author =
+  String.concat ""
+    [
+{|<entry>
+  <title>|}; title; {|</title>
+  <id>|};
+    url;
+  {|</id>
+  <author>
+   <name>|}; author; {|</name>
+  </author>
+  <updated>|}; ISO8601.Permissive.string_of_datetime date;{|</updated>
+  <link href="|}; url ;{|" rel="alternate" />
+  <content type="xhtml">  <div xmlns="http://www.w3.org/1999/xhtml">|};
+    contents;
+{|  </div></content>
+</entry>
+|}]
+
+let format_feed ~title ~subtitle ~author ~feed_url ~site_url ~last_updated ~(entries: Post.t list) =
+  let opener =
+    String.concat "" [
+{|<?xml version="1.0" encoding="utf-8"?>
+<feed xmlns="http://www.w3.org/2005/Atom">
+  <title>|};  title; {|</title>
+  <id>|}; feed_url; {|</id>
+  <subtitle>|}; subtitle; {|</subtitle>
+  <updated>|}; ISO8601.Permissive.string_of_datetime last_updated; {|</updated>
+  <link href="|}; feed_url; {|" rel="self"/>
+  <link href="|}; site_url; {|"/>
+|}] in
+  opener ^
+  (String.concat "\n" @@ List.map
+                           (fun (md,contents) ->
+                             format_entry
+                               ~title:md.title
+                               ~date:md.date
+                               ~url:(site_url ^ md.filename)
+                               ~author
+                               ~contents)
+                          entries) ^
+  "</feed>"

src/dune

@@ -1,3 +1,4 @@
 (executable
  (name webcc)
- (libraries omd ISO8601 str))
+ (libraries omd ISO8601 str)
+ (modules_without_implementation post))

src/post.mli

@@ -0,0 +1,5 @@
+type date = float (* repr for the ISO8601 library *)
+type metadata = { title : string ; date : date ; tags : string list ;
+                  filename : string ;
+                  other : (string * string) list }
+type t = metadata * string

src/webcc.ml

@@ -1,21 +1,27 @@
+open Post
+
+let author = "Daniel"
+let site_url = "https://groupoid.moe"
+let feed_url = "https://groupoid.moe/feed.xml"
+let site_title = "groupoid.moe"
+let feed_title = "Recent posts"
 let input = ref []
 let output = ref ""
 let gen_index = ref false
+let gen_atom = ref false
 
 let spec =
   [
     ("-o", Arg.Set_string output,
      " file.html Specify the output file (default is stdout).");
     ("-i", Arg.Set gen_index,
-     " generate a post index instead of compiling individual posts.");
+     " generate the post index instead of compiling individual posts.");
+    ("-a", Arg.Set gen_atom,
+     " generate the atom feed.");
     ("--", Rest(fun s -> input := s :: !input),
      " Consider all remaining arguments as input file names.")
   ]
 
-type post_metadata = { title : string ; date : float ; tags : string list ;
-                       filename : string ;
-                       other : (string * string) list }
-
 (** Utitilies *)
 let with_open_in fn f =
   let ic = open_in fn in
@@ -29,7 +35,7 @@ let with_open_out fn f =
   | r -> close_out oc; r
   | exception e -> close_out_noerr oc; raise e
 
-let read_metadata filename ic : post_metadata =
+let read_metadata filename ic : Post.metadata =
   let rec go lst =
     let line =
       try input_line ic
@@ -46,12 +52,23 @@ let read_metadata filename ic : post_metadata =
     | None   -> "-"
   in
   let date = ISO8601.Permissive.date (lookup "date") in
+  (* TODO! Fix the paths here!!!!!! *)
+  let target_fname =
+      let open Str in
+      if string_match (regexp {|content/\(.*\)\.md|}) filename 0
+      then "/posts/" ^ matched_group 1 filename ^ ".html"
+      else filename
+  in
   { title = lookup "title";
     date  = date;
     tags  = String.split_on_char ',' (lookup "tags");
-    filename = filename;
+    filename = target_fname;
     other = md }
-    
+
+let read_post filename ic : Post.t =
+  let metadata = read_metadata filename ic in
+  let md = Omd.of_channel ic in
+  (metadata, Omd.to_html md)
 
 (** Functions for processing an individual post *)
 
@@ -77,7 +94,7 @@ let format_page ~title ~contents =
     <span class="menu-item"><a href="/feed.xml">atom feed</a></span>
   </div>
   <div id="wrapper">
-    <h1>|}; title; {|</h1>|}; 
+    <h1>|}; title; {|</h1>|};
     contents;
 {| </div>
   <hr />
@@ -97,41 +114,32 @@ let format_post ~title ~tags ~date ~contents =
 
 (* convert contents from [ic] to a post webpage, output to [oc] *)
 let process filename ic oc =
-  let metadata = read_metadata filename ic in
+  let (metadata, contents) = read_post filename ic in
-  let md = Omd.of_channel ic in
   let html = format_post
                ~title:(metadata.title)
                ~tags:(String.concat ", " metadata.tags)
                ~date:(ISO8601.Permissive.string_of_date metadata.date)
-               ~contents:(Omd.to_html md)
+               ~contents
   in
   output_string oc html
 
+(** Compile the posts to HTML *)
 let compile_posts oc =
   if !input = [] then process "<stdin>" stdin oc
   else begin
     let f filename = with_open_in filename @@ fun ic -> process filename ic oc in
     List.iter f !input
   end
-  
 
-(** Generating index of posts *)
+
+(** Generate the index of posts *)
 let generate_index oc =
   let f filename = with_open_in filename (read_metadata filename) in
   let mds = List.map f !input in
   let mds = List.sort (fun md1 md2 -> compare md2.date md1.date) mds in
-  (* TODO! Fix the paths here!!!!!! *)
   let format_item md =
-    (* path to the html file *)
-    let fname = md.filename in
-    let target_fname =
-      let open Str in
-      if string_match (regexp {|content/\(.*\)\.md|}) fname 0
-      then matched_group 1 fname ^ ".html"
-      else fname
-    in
     String.concat "" [
-        {|<li><a href="/posts/|}; target_fname; {|">|};
+        {|<li><a href="|}; md.filename; {|">|};
                  md.title;
               {|</a> - |}; ISO8601.Permissive.string_of_date md.date ; {|</li>|}]
   in
@@ -139,6 +147,28 @@ let generate_index oc =
   let html = format_page ~title:"Recent posts" ~contents in
   output_string oc html
 
+(** Generate the atom feed *)
+let generate_atom oc =
+  let f filename = with_open_in filename (read_post filename) in
+  let posts = List.map f !input in
+  let posts = List.sort (fun (md1,_) (md2,_) -> compare md2.date md1.date) posts in
+  let last_updated =
+    match posts with
+    | [] -> 0.
+    | (md,_)::_ -> md.date
+  in
+  let xml = Atom.format_feed
+              ~title:site_title
+              ~subtitle:feed_title
+              ~author
+              ~feed_url
+              ~site_url
+              ~last_updated
+              ~entries:posts
+  in
+  output_string oc xml
+
+
 (** main *)
 let main () =
   Arg.parse (Arg.align spec)
@@ -150,10 +180,14 @@ let main () =
     else
       with_open_out !output f
   in
-  with_output @@
+  begin
+    with_output @@
     if !gen_index
     then generate_index
     else compile_posts
+  end;
+  if !gen_atom then with_output generate_atom
+
 
 let () =
   try