[elpa] externals/org f4b9f98 1/2: lisp/ox-html.el: make html meta tag builder nicer

[ELPA Syncer]

branch: externals/org
commit f4b9f98088924dd24d2bbfbe56d4f22de3fa9583
Author: TEC <tec@tecosaur.com>
Commit: Kyle Meyer <kyle@kyleam.com>

    lisp/ox-html.el: make html meta tag builder nicer
    
    * lisp/ox-html.el (org-html--build-meta-info): Multi-line repeated
    structure extracted to new function `org-html--build-meta-entry'.
    The keyword value formatting is changed from `org-export-data' to
    `org-html-encode-plain-text' to avoid potentially nesting HTML tags in
    meta tags and the <title> element, which would violate W3C.
---
 lisp/ox-html.el | 118 ++++++++++++++++++++++++++++----------------------------
 1 file changed, 60 insertions(+), 58 deletions(-)

diff --git a/lisp/ox-html.el b/lisp/ox-html.el
index 03145e3..f18f8a2 100644
--- a/lisp/ox-html.el
+++ b/lisp/ox-html.el
@@ -1835,78 +1835,80 @@ INFO is a plist used as a communication channel."
 
 ;;; Template
 
+(defun org-html--build-meta-entry
+    (label identity &optional content-format &rest content-formatters)
+  "Build a meta tag using the provided information.
+
+Construct <meta> tag of form <meta LABEL=\"IDENTITY\" />, or when 
CONTENT-FORMAT
+is present: <meta LABEL=\"IDENTITY\" content=\"{content}\" />
+
+Here {content} is determined by applying any CONTENT-FORMATTERS to the
+CONTENT-FORMAT and encoding the result as plain text."
+  (concat "<meta "
+         (format "%s=\"%s" label identity)
+         (when content-format
+           (concat "\" content=\""
+                   (replace-regexp-in-string
+                    "\"" "&quot;"
+                    (org-html-encode-plain-text
+                     (if content-formatters
+                         (apply #'format content-format content-formatters)
+                       content-format)))))
+         "\" />\n"))
+
 (defun org-html--build-meta-info (info)
   "Return meta tags for exported document.
 INFO is a plist used as a communication channel."
-  (let* ((protect-string
-          (lambda (str)
-            (replace-regexp-in-string
-             "\"" "&quot;" (org-html-encode-plain-text str))))
-         (title (org-export-data (plist-get info :title) info))
-         ;; Set title to an invisible character instead of leaving it
-         ;; empty, which is invalid.
-         (title (if (org-string-nw-p title) title "&lrm;"))
-         (author (and (plist-get info :with-author)
-                      (let ((auth (plist-get info :author)))
+  (let* ((title (org-html-plain-text
+                (org-element-interpret-data (plist-get info :title)) info))
+        ;; Set title to an invisible character instead of leaving it
+        ;; empty, which is invalid.
+        (title (if (org-string-nw-p title) title "&lrm;"))
+        (author (and (plist-get info :with-author)
+                     (let ((auth (plist-get info :author)))
                        ;; Return raw Org syntax.
-                        (and auth (org-element-interpret-data auth)))))
-         (description (plist-get info :description))
-         (keywords (plist-get info :keywords))
-         (charset (or (and org-html-coding-system
-                           (fboundp 'coding-system-get)
-                           (coding-system-get org-html-coding-system
-                                              'mime-charset))
-                      "iso-8859-1")))
+                       (and auth (org-html-plain-text
+                                  (org-element-interpret-data auth) info)))))
+        (charset (or (and org-html-coding-system
+                          (fboundp 'coding-system-get)
+                          (symbol-name
+                           (coding-system-get org-html-coding-system
+                                              'mime-charset)))
+                     "iso-8859-1")))
     (concat
      (when (plist-get info :time-stamp-file)
        (format-time-string
        (concat "<!-- "
                (plist-get info :html-metadata-timestamp-format)
                " -->\n")))
-     (format
-      (if (org-html-html5-p info)
-         (org-html-close-tag "meta" "charset=\"%s\"" info)
-       (org-html-close-tag
-        "meta" "http-equiv=\"Content-Type\" content=\"text/html;charset=%s\""
-        info))
-      charset) "\n"
+
+     (if (org-html-html5-p info)
+        (org-html--build-meta-entry "charset" charset)
+       (org-html--build-meta-entry "http-equiv" "Content-Type"
+                                  (concat "text/html;charset=" charset)))
+
      (let ((viewport-options
            (cl-remove-if-not (lambda (cell) (org-string-nw-p (cadr cell)))
                              (plist-get info :html-viewport))))
-       (and viewport-options
-           (concat
-            (org-html-close-tag
-             "meta"
-             (format "name=\"viewport\" content=\"%s\""
-                     (mapconcat
-                      (lambda (elm) (format "%s=%s" (car elm) (cadr elm)))
-                      viewport-options ", "))
-             info)
-            "\n")))
+       (if viewport-options
+          (org-html--build-meta-entry "name" "viewport"
+                                      (mapconcat
+                                       (lambda (elm)
+                                          (format "%s=%s" (car elm) (cadr 
elm)))
+                                       viewport-options ", "))))
+
      (format "<title>%s</title>\n" title)
-     (org-html-close-tag "meta" "name=\"generator\" content=\"Org mode\"" info)
-     "\n"
-     (and (org-string-nw-p author)
-         (concat
-          (org-html-close-tag "meta"
-                              (format "name=\"author\" content=\"%s\""
-                                      (funcall protect-string author))
-                              info)
-          "\n"))
-     (and (org-string-nw-p description)
-         (concat
-          (org-html-close-tag "meta"
-                              (format "name=\"description\" content=\"%s\"\n"
-                                      (funcall protect-string description))
-                              info)
-          "\n"))
-     (and (org-string-nw-p keywords)
-         (concat
-          (org-html-close-tag "meta"
-                              (format "name=\"keywords\" content=\"%s\""
-                                      (funcall protect-string keywords))
-                              info)
-          "\n")))))
+
+     (when (org-string-nw-p author)
+       (org-html--build-meta-entry "name" "author" author))
+
+     (when (org-string-nw-p (plist-get info :description))
+       (org-html--build-meta-entry "name" "description" (plist-get info 
:description)))
+
+     (when (org-string-nw-p (plist-get info :keywords))
+       (org-html--build-meta-entry "keywords" (plist-get info :keywords)))
+
+     (org-html--build-meta-entry "name" "generator" "Org Mode"))))
 
 (defun org-html--build-head (info)
   "Return information for the <head>..</head> of the HTML output.