Allow quoted strings with spaces in Org keywords

Org keywords: #+HUGO_TAGS, #+HUGO_CATEGORIES, #+KEYWORDS

or

Org properties: :EXPORT_HUGO_TAGS:, :EXPORT_HUGO_CATEGORIES:, :EXPORT_KEYWORDS:

    !! This is a breaking change !!

Earlier, strings with spaces in those keywords had to be written as
abc__def. Now strings with spaces need to be written as "abc def"
instead, which is more intuitive.

This *does not* change the abc__def style required in Org
tags (e.g. :abc__def:), because Org tags cannot contain spaces. Note
that the same applies to the #+FILETAGS keyword too! In the
abc__def.

doc/ox-hugo-manual.org

@@ -1038,35 +1038,37 @@ export flow. So =#+FILETAGS= will have no effect in this flow.
 
 - To set tags, use =#+HUGO_TAGS=.
 - To set categories, use =#+HUGO_CATEGORIES=.
-**** Hyphens in tags (and categories)
-Hyphens are not allowed in Org tags. So =ox-hugo= converts *single
-underscores* to hyphens if =org-hugo-prefer-hyphen-in-tags= is set to
-non-nil (default). So an Org tag *abc_def* will be exported as /tag/
-*"abc-def"*. Similarly an Org tag *@abc_def* will be exported as
-/category/ *"abc-def"*.
+**** Hyphens and Spaces in Org tags (and categories)
+Hyphens and spaces are not allowed in Org tags (=* Heading :TAG:=).
+
+So =ox-hugo= converts:
+- *single underscores* to hyphens if =org-hugo-prefer-hyphen-in-tags=
+  is set to non-nil (default).
+- *double underscores* to spaces if =org-hugo-allow-spaces-in-tags= is
+  set to non-nil (default).
+
+So an Org tag *abc_def* will be exported as /tag/ *"abc-def"*, and
+*abc__def* will be exported as /tag/ *"abc def"*.
+
+The same applies to Org tags with prefix =@= which will be exported as
+/categories/. So *@abc_def* will be exported as /category/
+*"abc-def"*, and *@abc__def* as /category/ *"abc def"*.
 
 To export a tag or category with an underscore, use 3 consecutive
 underscores. So an Org tag *abc___def* will be exported as /tag/
-*"abc_def"*. If you rather prefer to always export single underscores
-as underscores, set =org-hugo-prefer-hyphen-in-tags= to nil.
-
-This variable does not affect the tags set via =#+HUGO_TAGS= keyword
-or the =EXPORT_HUGO_TAGS= property, because Org keywords and
-properties allow using the hyphen character. So underscores and
-hyphens in tags (or categories in =#+HUGO_CATEGORIES= /
-=EXPORT_HUGO_CATEGORIES=) remain untransformed on export.
-**** Spaces in tags (and categories)
-Spaces are not allowed in Org tags. So =ox-hugo= converts *double
-underscores* to spaces if =org-hugo-allow-spaces-in-tags= is set to
-non-nil (default). So an Org tag *abc__def* will be exported as /tag/
-*"abc def"*. Similarly an Org tag *@abc__def* will be exported as
-/category/ *"abc def"*.
-
-This variable *also affects* the tags set via =#+HUGO_TAGS= keyword or
-the =EXPORT_HUGO_TAGS= property, because it is not possible to
-distinguish in Org keywords and properties whether the space is part
-of the tag or used to separate two tags. The same applies to
-categories set via =#+HUGO_CATEGORIES= / =EXPORT_HUGO_CATEGORIES=.
+*"abc_def"* (and the same for categories). If you rather prefer to
+always export /single underscores/ as underscores, set
+=org-hugo-prefer-hyphen-in-tags= to nil.
+
+- NOTE :: These two variables *also affect* the tags set via
+          =#+FILETAGS= keyword (which is used only in subtree-based
+          exported Org files).
+
+These variables do not affect the tags set via keywords =#+HUGO_TAGS=,
+=#+HUGO_CATEGORIES= or =#+KEYWORDS= (or their respective subtree
+property forms), because Org keywords and properties allow using the
+hyphen and space (/in "double-quoted strings"/) characters. So the
+underscores in these keywords remain untransformed on export.
 **** Examples
 - [[https://raw.githubusercontent.com/kaushalmodi/ox-hugo/master/test/site/content-org/tags-and-categories.org][Org source]]
 - Exported Markdown -- [[https://raw.githubusercontent.com/kaushalmodi/ox-hugo/master/test/site/content/posts/inheriting-tags.md][=inheriting-tags.md=]], [[https://raw.githubusercontent.com/kaushalmodi/ox-hugo/master/test/site/content/posts/overriding-tags.md][=overriding-tags.md=]]

ox-hugo.el

@@ -2001,8 +2001,8 @@ string with just alphanumeric characters."
 (defun org-hugo--parse-property-arguments (str)
   "Return an alist converted from a string STR of Hugo property value.
 
-If STR is of type \":KEY VALUE\", the returned value is ((KEY
-. VALUE)).
+STR is of type \":KEY1 VALUE1 :KEY2 VALUE2 ..\".  Given that, the
+returned value is ((KEY1 . VALUE1) (KEY2 . VALUE2) ..).
 
 Example: Input STR \":foo bar :baz 1 :zoo \\\"two words\\\"\" would
 convert to ((foo . \"bar\") (baz . 1) (zoo . \"two words\"))."
@@ -2185,39 +2185,44 @@ Example: :some__tag:   -> \"some tag\"."
     (setq ret (cl-remove-if-not #'org-string-nw-p ret))
     ret))
 
-(defun org-hugo--delim-str-to-list (delim-str info &optional no-prefer-hyphen)
+(defun org-hugo--delim-str-to-list (delim-str)
   "Function to transform DELIM-STR string to a list.
 
 1. Trim leading/trailing spaces from DELIM-STR, replace spaces
    with `org-hugo--internal-list-separator'.
 2. Convert that string to a list using
    `org-hugo--internal-list-separator' as the separator.
-3. Pass that to `org-hugo--transform-org-tags' that does some string
-   transformation.  See that function for more info.
+3. Break up each element of that list into further string elements.
+   Space within quoted string is retained.  This is done using
+   `org-hugo--parse-quoted-string'.  If a string element if of
+   type \"VALUE1 \\\"QUOTED VALUE2\\\" ..\", that is converted to
+   \(\"VALUE1\" \"QUOTED VALUE2\" ..).
 4. Return the transformed list.
 
-Example: \"two__words hyphenated_word\" -> (\"two words\" \"hyphenated-word\").
-
-Note that when NO-PREFER-HYPHEN is non-nil, replacement of
-underscores in DELIM-STR with hyphens as shown in the above
-example will not happen.
+Example: \"one\n\\\"two words\\\" three\nfour\" -> (\"one\" \"two words\" \"three\" \"four\").
 
 This function can be applied to any string that uses
 `org-hugo--internal-list-separator' as delimiter, for example,
 parsing the tags, categories and keywords meta-data.
 
-INFO is a plist used as a communication channel.
-
 Return nil if DELIM-STR is not a string."
   (when (stringp delim-str)
     (let* ((delim-str (org-trim delim-str))
-           (delim-str (replace-regexp-in-string
-                       " +" org-hugo--internal-list-separator
-                       delim-str))
            (str-list (split-string delim-str org-hugo--internal-list-separator))
-           (str-list (org-hugo--transform-org-tags
-                      str-list info no-prefer-hyphen)))
-      str-list)))
+           ret)
+      (dolist (str str-list)
+        (let* ((format-str ":dummy '(%s)") ;The :dummy key is later discarded
+               (alist (org-babel-parse-header-arguments (format format-str str)))
+               (lst (cdr (car alist)))
+               (str-list2 (mapcar (lambda (elem)
+                                    (cond
+                                     ((symbolp elem)
+                                      (symbol-name elem))
+                                     (t
+                                      elem)))
+                                  lst)))
+          (setq ret (append ret str-list2))))
+      ret)))
 
 (defun org-hugo--category-p (tag)
   "Return non-nil if TAG begins with \"@\".
@@ -2284,8 +2289,7 @@ INFO is a plist used as a communication channel."
          (tags (or
                 ;; Look for tags set using #+HUGO_TAGS keyword, or
                 ;; EXPORT_HUGO_TAGS property if available.
-                (org-hugo--delim-str-to-list
-                 (plist-get info :hugo-tags) info :no-prefer-hyphen)
+                (org-hugo--delim-str-to-list (plist-get info :hugo-tags))
                 ;; Else use Org tags (the ones set in headlines
                 ;; and/or inherited) if any.
                 (let* ((tags-list (cl-remove-if #'org-hugo--category-p all-t-and-c))
@@ -2296,8 +2300,7 @@ INFO is a plist used as a communication channel."
                       ;; Look for categories set using
                       ;; #+HUGO_CATEGORIES keyword, or
                       ;; EXPORT_HUGO_CATEGORIES property if available.
-                      (org-hugo--delim-str-to-list
-                       (plist-get info :hugo-categories) info :no-prefer-hyphen)
+                      (org-hugo--delim-str-to-list (plist-get info :hugo-categories))
                       ;; Else use categories set using Org tags with
                       ;; "@" prefix (the ones set in headlines and/or
                       ;; inherited) if any.
@@ -2309,8 +2312,7 @@ INFO is a plist used as a communication channel."
                                                       categories-list)))
                         ;; (message "dbg: categories: categories-list = %s" categories-list)
                         categories-list)))
-         (keywords (org-hugo--delim-str-to-list
-                    (plist-get info :keywords) info :no-prefer-hyphen))
+         (keywords (org-hugo--delim-str-to-list (plist-get info :keywords)))
          (weight (let* ((wt (plist-get info :hugo-weight))
                         (auto-calc (and (stringp wt)
                                         (string= wt "auto")

test/site/content-org/all-posts.org

@@ -3735,7 +3735,7 @@ comma-separated.
 *** Multiple keywords in front-matter
 :PROPERTIES:
 :EXPORT_FILE_NAME: multiple-keywords-in-front-matter
-:EXPORT_KEYWORDS: abc def hyphenated-keyword underscored_keyword two__words these__are__four__words
+:EXPORT_KEYWORDS: abc def hyphenated-keyword underscored_keyword "two words" "these are four words"
 :END:
 *** Keywords set using multiple properties
 :PROPERTIES:

test/site/content-org/keyword-collection.org

@@ -10,7 +10,7 @@
 # https://ox-hugo.scripter.co/doc/tags-and-categories/#file-based-export
 
 # Tags
-#+HUGO_TAGS: mega__front-matter
+#+HUGO_TAGS: "mega front-matter"
 #+HUGO_TAGS: keys
 #+HUGO_TAGS: collection concatenation merging
 
@@ -54,7 +54,7 @@
 
 # Keywords
 #+KEYWORDS: keyword1 keyword2
-#+KEYWORDS: three__word__keywords3
+#+KEYWORDS: "three word keywords3"
 
 # Outputs
 #+HUGO_OUTPUTS: html

test/site/content-org/tags-and-categories.org

@@ -7,6 +7,7 @@
 
 #+FILETAGS: alpha beta
 #+FILETAGS: hyphened-tag
+#+FILETAGS: tag__with__lot__of__words
 
 # Categories
 #+FILETAGS: @cat1
@@ -37,7 +38,7 @@ added as Org tags to headlines as well as =#+FILETAGS=.
 :PROPERTIES:
 :EXPORT_HUGO_TAGS: overriding
 :EXPORT_HUGO_TAGS+: underscore_is_retained hyphenated-works
-:EXPORT_HUGO_CATEGORIES: cat3 3__word__cat
+:EXPORT_HUGO_CATEGORIES: cat3 "3 word cat"
 :EXPORT_FILE_NAME: overriding-tags
 :END:
 By using =EXPORT_HUGO_TAGS= in the property drawer, Org tags in the

test/site/content/posts/inheriting-tags.md

@@ -1,6 +1,6 @@
 +++
 title = "Inheriting tags"
-tags = ["hyphened-tag", "alpha", "beta", "super", "gamma", "delta", "two words"]
+tags = ["tag with lot of words", "hyphened-tag", "alpha", "beta", "super", "gamma", "delta", "two words"]
 categories = ["cat1", "cat2"]
 draft = false
 +++