Refinements to publish the blog

* org-conf.el (durand-org-publish-sidebar)
(durand-org-publish-insert-sidebar): Use a sidebar for the navigation:
Instead of the built-in UP/HOME buttons, I want to go to sitemap files
for different types of blog posts quickly.  This is more convenient
for the readers I think.  This is inspired by the design of
Protesilaos' website.

(durand-org-publish-css-file): Add my own CSS file in the header.

(durand-org-publish-favicon): Add the favicon I produced by a simple C
program.

(org-publish-project-alist): Add a Math type of blog posts.

(durand-sitemap-custom-string-alist): Add a custom string to each
type's sitemap file.

(durand-org-publish-sitemap, durand-org-publish-sitemap-format): Use a
table instead of a list in the sitemap.  This is also inspired by the
design of Protesilaos' website.

(durand-org-publish-plist-get): The built-in `plist-get'
mal-functions, and this is a replacement.  After I update my Emacs,
this problem might be fixed, and this replcement might not be needed
anymore.

(durand-org-publish-convert-time): Convert the result of
`parse-time-string' to a time value.  The result may lack some
information, as the parsed string does not provide them.  So this
function supplies 0 for the missing values.  Note that it assumes the
year, month, and day cannot be missing, though.

(durand-org-index-entries-max-num): Show at most a fixed number of
entries on the index page.  This maximum is set to 10 now.

(durand-org-post-process): Shorten the date strings in the sitemap
files: I need the exact date for sorting, but I don't want to show
those information in the sitemap files.  So I convert the long form of
dates to comments, and use the shortened form for display.  Also this
generates a proper index page from the various sitemap files.  Right
now it will insert the entries to the index file each time this is
called, which is kind of inefficient.  I might adapt a more efficient
method later on.  I also want to generate Atom feeds in this function,
but right now I don't have such a need, and this is not fulfilled
yet.  This kind of imitates the behaviour of Protesilaos' website.

1 files changed, 322 insertions, 27 deletions

diff --git a/org-conf.el b/org-conf.el
index 019c033..68d4de7 100644
--- a/org-conf.el
+++ b/org-conf.el
@@ -546,13 +546,46 @@ If DESC is non-`nil', then it is the description of the new link."
 
 ;;; publishing settings
 
+;;;;; Custom preamble for the sidebar
+
+(defvar durand-org-publish-sidebar nil
+  "The sidebar that provides the navigation of the website.")
+
+(setq durand-org-publish-sidebar
+      "<div class=\"sidebar\">\n\
+<a href=\"math-sitemap.html\"> Math </a>\n\
+<a href=\"code-sitemap.html\"> Code </a>\n\
+<a  href=\"life-sitemap.html\"> Life </a>\n\
+<a href=\"index.html\"> Home </a></div>")
+
+;; REVIEW: This might be unnecessary.
+(defun durand-org-publish-insert-sidebar (_arg)
+  "Return the sidebar."
+  durand-org-publish-sidebar)
+
+;;;;;; Add a custom head
+
+(defvar durand-org-publish-css-file nil
+  "A custom css-file for publishing.")
+
+(setq durand-org-publish-css-file
+      "<link rel=\"stylesheet\" type=\"text/css\" \
+href=\"website.css\"/>")
+
+(defvar durand-org-publish-favicon nil
+  "A custom favicon for publishing.")
+
+(setq durand-org-publish-favicon
+      "<link rel='shortcut icon' \
+href='https://jsdurand.xyz/favicon.ico'/>")
+
 ;;;;; Projects settings
 
 (setq org-publish-project-alist
       (list
        (list
         "website"
-        :components (list "code" "life" "main"))
+        :components (list "math" "code" "life" "main"))
        (list
         "code"
         :base-directory (directory-file-name
@@ -575,11 +608,44 @@ If DESC is non-`nil', then it is the description of the new link."
         :sitemap-date-format "Published: %F %a %R"
         :sitemap-filename "code-sitemap.org"
         :sitemap-title "About coding"
-        :html-link-home "index.html"
         :sitemap-sort-files 'anti-chronologically
-        :html-head "<link rel=\"stylesheet\" type=\"text/css\"
-                       href=\"website.css\"/>"
-        :html-preamble t)
+        :html-head (concat durand-org-publish-css-file
+                           "\n"
+                           durand-org-publish-favicon)
+        :html-link-home ""
+        :html-link-up ""
+        :html-home/up-format ""
+        :html-preamble #'durand-org-publish-insert-sidebar)
+       (list
+        "math"
+        :base-directory (directory-file-name
+                         (expand-file-name
+                          "math" (expand-file-name
+                                  "blog" org-directory)))
+        :base-extension "org"
+        :publishing-directory (directory-file-name
+                               (expand-file-name
+                                "public" org-directory))
+        :publishing-function #'org-html-publish-to-html
+        :section-numbers nil
+        :with-toc nil
+        :with-email t
+        :with-creator t
+        :auto-sitemap t
+        :recursive t
+        :sitemap-function #'durand-org-publish-sitemap
+        :sitemap-format-entry #'durand-org-publish-sitemap-format
+        :sitemap-date-format "Published: %F %a %R"
+        :sitemap-filename "math-sitemap.org"
+        :sitemap-title "Mathematics"
+        :sitemap-sort-files 'anti-chronologically
+        :html-head (concat durand-org-publish-css-file
+                           "\n"
+                           durand-org-publish-favicon)
+        :html-link-home ""
+        :html-link-up ""
+        :html-home/up-format ""
+        :html-preamble #'durand-org-publish-insert-sidebar)
        (list
         "life"
         :base-directory (directory-file-name
@@ -602,11 +668,14 @@ If DESC is non-`nil', then it is the description of the new link."
         :sitemap-date-format "Published: %F %a %R"
         :sitemap-filename "life-sitemap.org"
         :sitemap-title "My life"
-        :html-link-home "index.html"
         :sitemap-sort-files 'anti-chronologically
-        :html-head "<link rel=\"stylesheet\" type=\"text/css\"
-                       href=\"website.css\"/>"
-        :html-preamble t)
+        :html-head (concat durand-org-publish-css-file
+                           "\n"
+                           durand-org-publish-favicon)
+        :html-link-home ""
+        :html-link-up ""
+        :html-home/up-format ""
+        :html-preamble #'durand-org-publish-insert-sidebar)
        (list
         "main"
         :base-directory (directory-file-name
@@ -623,24 +692,32 @@ If DESC is non-`nil', then it is the description of the new link."
         :with-creator t
         :auto-sitemap nil
         :recursive nil
-        :html-head "<link rel=\"stylesheet\" type=\"text/css\"
-                       href=\"website.css\"/>"
-        :html-preamble t)))
+        :html-head (concat durand-org-publish-css-file
+                           "\n"
+                           durand-org-publish-favicon)
+        :html-link-home ""
+        :html-link-up ""
+        :html-home/up-format ""
+        :html-preamble #'durand-org-publish-insert-sidebar)))
 
 ;;;;; Sitemap function
 
 ;;;;;; A hack to insert some string in the sitemap file.
 
-(defvar durand-sitemap-custom-string-alist
-  (list
-   (cons "About coding"
-         "This is the coding blog.  It contains my coding experiments, or \
-one might think of them as development diaries.")
-   (cons "My life"
-         "This is my casual blog.  It contains articles about my plain \
-life."))
+(defvar durand-sitemap-custom-string-alist nil
   "An association list that relates the title of the sitemap and the string to insert.")
 
+(setq durand-sitemap-custom-string-alist
+      (list
+       (cons "About coding"
+             "This is my coding blog.  It contains my coding experiments, or \
+one might think of them as development diaries.")
+       (cons "My life"
+             "This is my casual blog.  It contains articles about my plain \
+life.")
+       (cons "Mathematics"
+             "My Mathematics-related articles are put here.")))
+
 ;;;;;; Custom sitemap function
 
 (defun durand-org-publish-sitemap (title rep)
@@ -650,19 +727,237 @@ TITLE is the title of the sitemap.
 REP is a representation of the files and directories in the
 project.  Use such functions as `org-list-to-org' or
 `org-list-to-subtree' to transform it."
-  (format "#+TITLE: %s\n#+AUTHOR: JSDurand\n%s#+DATE: <%s>\n\n%s\n\n%s"
+  (format "#+TITLE: %s\n#+AUTHOR: JSDurand\n%s#+DATE: <%s>\n\n%s\n\n\
+#+ATTR_HTML: :border nil :rules nil :frame nil\n\
+%s"
           title
           "#+HTML_LINK_UP: index.html"
           (format-time-string "%F %a %R")
           (cdr (assoc title durand-sitemap-custom-string-alist #'string=))
-          (org-list-to-org rep)))
+          ;; generate a table
+          (org-list-to-generic
+           rep
+           '(:ustart "|---|"
+             :uend "|---|"
+             :isep "|---|"))))
 
 ;;;;;; Custom sitemap format
 
+;; NOTE: I use a table to style the entries.
+
+;; NOTE: This stores the date in an ugly long format.  But worry not:
+;; it will be replaced by a clean form in the post-processing phase.
+;; The long form is inserted here so that we can sort the entries
+;; precisely.
+
 (defun durand-org-publish-sitemap-format (entry _style project)
-  "Format the entry for the sitemap.
-A date is added."
-  (format "[[file:%s][(%s) %s]]"
-          entry (format-time-string
-                 "%F %R" (org-publish-find-date entry project))
+  "Format the entry for the sitemap as a table with a date.
+ENTRY is the entry file name to format.
+
+STYLE is either 'list or 'tree, which is ignored by us.
+
+PROJECT is the current project."
+  (format "| %s | [[file:%s][%s]] |"
+          (format-time-string
+           "%FT%T%z"
+           (org-publish-find-date entry project)
+           (current-time-zone))
+          entry
           (org-publish-find-title entry project)))
+
+;;;;; Post-processing
+
+;; I post-process the sitemaps in order to generate a section
+;; of "latest updates" on the index page.
+
+;;;;;; fix: plist-get not working
+
+;; For some reason the built-in `plist-get' does not work...
+(defun durand-org-publish-plist-get (prop plist)
+  (let (res)
+    (while (consp plist)
+      (cond
+       ((eq (car plist) prop)
+        (setq res (cadr plist))
+        (setq plist nil))
+       ((setq plist (cddr plist)))))
+    res))
+
+;;;;;; Helper for converting the format from `parse-time-string'
+
+(defun durand-org-publish-convert-time (spec)
+  "Convert SPEC to a valid time value.
+SPEC should be the result of `parse-time-string'.
+
+It is assumed that the year, the month, and the day components
+are present."
+  (let ((sec (car spec))
+        (minute (cadr spec))
+        (hour (caddr spec)))
+    (encode-time
+     (append
+      (list
+       (or sec 0)
+       (or minute 0)
+       (or hour 0))
+      (cdddr spec)))))
+
+;;;;;; Post process to generate the index page
+
+(defvar durand-org-index-entries-max-num 10
+  "The maximal number of entries to show on the index page.")
+
+(autoload #'durand-take (locate-user-emacs-file "common.el"))
+
+(defun durand-org-post-process (project)
+  "Generate a proper index page and Atom feeds.
+Also shorten the date strings in the sitemap files, and store the
+completion information in an attribute."
+  (let* ((project-plist (cdr (assoc project org-publish-project-alist #'string=)))
+         (components (durand-org-publish-plist-get
+                      :components project-plist))
+         (sitemap-file (durand-org-publish-plist-get
+                        :sitemap-filename project-plist))
+         ;; I cheat here
+         (publishing-dir (expand-file-name "~/org/public/"))
+         (publish-sitemap-file (cond
+                                (sitemap-file
+                                 (replace-regexp-in-string
+                                  "org$" "html"
+                                  (expand-file-name sitemap-file publishing-dir)))))
+         (index-file (expand-file-name "index.html" publishing-dir))
+         contents)
+    (cond
+     ;; depth-first recursion
+     (components
+      (setq contents (apply #'append
+                      (delete nil (mapcar #'durand-org-post-process components))))
+      ;; We only want some items
+      (setq contents
+            (durand-take
+             durand-org-index-entries-max-num
+             (sort contents
+                   (lambda (x y)
+                     (time-less-p
+                      (car y) (car x))))))
+      ;; If contents is non-nil, we need to process the info in the
+      ;; index page.
+      (cond
+       (contents
+        (with-temp-buffer
+          (insert-file-contents index-file)
+          (goto-char (point-min))
+          (search-forward "Latest updates")
+          (goto-char (line-end-position))
+          (while (search-forward "<table" nil t)
+            ;; delete existing tables
+            (delete-region
+             (match-beginning 0)
+             (progn (search-forward "</table>")
+                    (match-end 0))))
+          (insert "\n")
+          (insert "<table cellspacing=\"0\" cellpadding=\"6\">
+
+
+<colgroup>
+<col  class=\"org-right\" />
+
+<col  class=\"org-left\" />
+</colgroup>\n\n<tbody>\n")
+          (mapc
+           (lambda (entry)
+             (insert "<tr>")
+             (insert "<td class=\"org-right\">")
+             (insert (format-time-string "%F" (car entry)))
+             (insert "</td>\n")
+             (insert "<td class=\"org-left\">")
+             (insert (cdr entry))
+             (insert "</td>\n</tr>\n"))
+           contents)
+          (insert "</tbody>\n</table>")
+          (setq contents (buffer-substring-no-properties
+                          (point-min) (point-max))))
+        (write-region contents nil index-file))))
+     ((and publish-sitemap-file
+           (stringp publish-sitemap-file)
+           (file-exists-p publish-sitemap-file))
+      (with-temp-buffer
+        (insert-file-contents publish-sitemap-file)
+        (goto-char (point-min))
+        (search-forward "</colgroup>" nil t)
+        (let ((regexp (rx-to-string
+                       '(seq
+                         "<t" (any "hd")
+                         " "
+                         (one-or-more (not (or ">")))
+                         ">")
+                       t))
+              pos pos-2 temp temp-time)
+          (while (re-search-forward regexp nil t)
+            (setq pos (point))
+            ;; replace the first org-left by org-right
+            (save-excursion
+              (goto-char (match-beginning 0))
+              (setq pos-2 (match-end 0))
+              (save-match-data
+                (cond
+                 ((re-search-forward "left" pos-2 t)
+                  (replace-match "right")
+                  ;; fix pos
+                  (setq pos (1+ pos))))))
+            (search-forward "</t")
+            (setq pos-2 (match-beginning 0))
+            (forward-line 1)
+            (cond
+             ((re-search-forward 
+               (rx-to-string
+                '(seq
+                  (= 4 (any digit)) "-"
+                  (= 2 (any digit)) "-"
+                  (= 2 (any digit)) "T")
+                t)
+               (line-end-position) t)
+              (setq temp-time
+                    (durand-org-publish-convert-time
+                     (parse-time-string
+                      (buffer-substring-no-properties
+                       (match-beginning 0)
+                       (line-end-position))))))
+             (t
+              (setq
+               temp-time
+               (durand-org-publish-convert-time
+                (parse-time-string
+                 (buffer-substring-no-properties
+                  pos pos-2))))
+              (save-excursion
+                (goto-char pos)
+                (delete-region pos pos-2)
+                (insert (format-time-string "%F" temp-time)))
+              (insert
+               "<!--"
+               (format-time-string
+                "%FT%T%z\n" temp-time (current-time-zone))
+               "-->\n")
+              (write-region nil nil publish-sitemap-file)))
+            (setq
+             temp
+             (cons
+              (cons temp-time
+                    (progn
+                      (re-search-forward regexp)
+                      (setq pos (point))
+                      (search-forward "</t")
+                      (buffer-substring-no-properties
+                       pos (match-beginning 0))))
+              temp)))
+          (reverse temp)))))))
+
+;;;;; Atom feed
+
+;; The Atom feeds are generated in this function.
+
+(defun durand-org-generate-atom-feed (project)
+  "Generate an Atom feed for PROJECT."
+  ;; TODO 
+  )