Feature: support any tag separator

So it allows to have multiple words tags.

Breaking change: commas ',' are no longer a default separator.

Fixes #594

19 files changed, 191 insertions, 69 deletions

diff --git a/application/bookmark/Bookmark.php b/application/bookmark/Bookmark.php
index 4810c5e6..8aaeb9d8 100644
--- a/application/bookmark/Bookmark.php
+++ b/application/bookmark/Bookmark.php
@@ -60,11 +60,13 @@ class Bookmark
     /**
      * Initialize a link from array data. Especially useful to create a Bookmark from former link storage format.
      *
-     * @param array $data
+     * @param array  $data
+     * @param string $tagsSeparator Tags separator loaded from the config file.
+     *                              This is a context data, and it should *never* be stored in the Bookmark object.
      *
      * @return $this
      */
-    public function fromArray(array $data): Bookmark
+    public function fromArray(array $data, string $tagsSeparator = ' '): Bookmark
     {
         $this->id = $data['id'] ?? null;
         $this->shortUrl = $data['shorturl'] ?? null;
@@ -77,7 +79,7 @@ class Bookmark
         if (is_array($data['tags'])) {
             $this->tags = $data['tags'];
         } else {
-            $this->tags = preg_split('/\s+/', $data['tags'] ?? '', -1, PREG_SPLIT_NO_EMPTY);
+            $this->tags = tags_str2array($data['tags'] ?? '', $tagsSeparator);
         }
         if (! empty($data['updated'])) {
             $this->updated = $data['updated'];
@@ -348,7 +350,12 @@ class Bookmark
      */
     public function setTags(?array $tags): Bookmark
     {
-        $this->setTagsString(implode(' ', $tags ?? []));
+        $this->tags = array_map(
+            function (string $tag): string {
+                return $tag[0] === '-' ? substr($tag, 1) : $tag;
+            },
+            tags_filter($tags, ' ')
+        );
 
         return $this;
     }
@@ -420,11 +427,13 @@ class Bookmark
     }
 
     /**
-     * @return string Bookmark's tags as a string, separated by a space
+     * @param string $separator Tags separator loaded from the config file.
+     *
+     * @return string Bookmark's tags as a string, separated by a separator
      */
-    public function getTagsString(): string
+    public function getTagsString(string $separator = ' '): string
     {
-        return implode(' ', $this->getTags());
+        return tags_array2str($this->getTags(), $separator);
     }
 
     /**
@@ -444,19 +453,13 @@ class Bookmark
      *   - trailing dash in tags will be removed
      *
      * @param string|null $tags
+     * @param string      $separator Tags separator loaded from the config file.
      *
      * @return $this
      */
-    public function setTagsString(?string $tags): Bookmark
+    public function setTagsString(?string $tags, string $separator = ' '): Bookmark
     {
-        // Remove first '-' char in tags.
-        $tags = preg_replace('/(^| )\-/', '$1', $tags ?? '');
-        // Explode all tags separted by spaces or commas
-        $tags = preg_split('/[\s,]+/', $tags);
-        // Remove eventual empty values
-        $tags = array_values(array_filter($tags));
-
-        $this->tags = $tags;
+        $this->setTags(tags_str2array($tags, $separator));
 
         return $this;
     }
@@ -507,7 +510,7 @@ class Bookmark
      */
     public function renameTag(string $fromTag, string $toTag): void
     {
-        if (($pos = array_search($fromTag, $this->tags)) !== false) {
+        if (($pos = array_search($fromTag, $this->tags ?? [])) !== false) {
             $this->tags[$pos] = trim($toTag);
         }
     }
@@ -519,7 +522,7 @@ class Bookmark
      */
     public function deleteTag(string $tag): void
     {
-        if (($pos = array_search($tag, $this->tags)) !== false) {
+        if (($pos = array_search($tag, $this->tags ?? [])) !== false) {
             unset($this->tags[$pos]);
             $this->tags = array_values($this->tags);
         }
diff --git a/application/bookmark/BookmarkFileService.php b/application/bookmark/BookmarkFileService.php
index 3ea98a45..85efeea6 100644
--- a/application/bookmark/BookmarkFileService.php
+++ b/application/bookmark/BookmarkFileService.php
@@ -91,7 +91,7 @@ class BookmarkFileService implements BookmarkServiceInterface
             }
         }
 
-        $this->bookmarkFilter = new BookmarkFilter($this->bookmarks);
+        $this->bookmarkFilter = new BookmarkFilter($this->bookmarks, $this->conf);
     }
 
     /**
diff --git a/application/bookmark/BookmarkFilter.php b/application/bookmark/BookmarkFilter.php
index c79386ea..5d8733dc 100644
--- a/application/bookmark/BookmarkFilter.php
+++ b/application/bookmark/BookmarkFilter.php
@@ -6,6 +6,7 @@ namespace Shaarli\Bookmark;
 
 use Exception;
 use Shaarli\Bookmark\Exception\BookmarkNotFoundException;
+use Shaarli\Config\ConfigManager;
 
 /**
  * Class LinkFilter.
@@ -58,12 +59,16 @@ class BookmarkFilter
      */
     private $bookmarks;
 
+    /** @var ConfigManager */
+    protected $conf;
+
     /**
      * @param Bookmark[] $bookmarks initialization.
      */
-    public function __construct($bookmarks)
+    public function __construct($bookmarks, ConfigManager $conf)
     {
         $this->bookmarks = $bookmarks;
+        $this->conf = $conf;
     }
 
     /**
@@ -107,10 +112,14 @@ class BookmarkFilter
                     $filtered = $this->bookmarks;
                 }
                 if (!empty($request[0])) {
-                    $filtered = (new BookmarkFilter($filtered))->filterTags($request[0], $casesensitive, $visibility);
+                    $filtered = (new BookmarkFilter($filtered, $this->conf))
+                        ->filterTags($request[0], $casesensitive, $visibility)
+                    ;
                 }
                 if (!empty($request[1])) {
-                    $filtered = (new BookmarkFilter($filtered))->filterFulltext($request[1], $visibility);
+                    $filtered = (new BookmarkFilter($filtered, $this->conf))
+                        ->filterFulltext($request[1], $visibility)
+                    ;
                 }
                 return $filtered;
             case self::$FILTER_TEXT:
@@ -280,8 +289,9 @@ class BookmarkFilter
      *
      * @return string generated regex fragment
      */
-    private static function tag2regex(string $tag): string
+    protected function tag2regex(string $tag): string
     {
+        $tagsSeparator = $this->conf->get('general.tags_separator', ' ');
         $len = strlen($tag);
         if (!$len || $tag === "-" || $tag === "*") {
             // nothing to search, return empty regex
@@ -295,12 +305,13 @@ class BookmarkFilter
             $i = 0; // start at first character
             $regex = '(?='; // use positive lookahead
         }
-        $regex .= '.*(?:^| )'; // before tag may only be a space or the beginning
+        // before tag may only be the separator or the beginning
+        $regex .= '.*(?:^|' . $tagsSeparator . ')';
         // iterate over string, separating it into placeholder and content
         for (; $i < $len; $i++) {
             if ($tag[$i] === '*') {
                 // placeholder found
-                $regex .= '[^ ]*?';
+                $regex .= '[^' . $tagsSeparator . ']*?';
             } else {
                 // regular characters
                 $offset = strpos($tag, '*', $i);
@@ -316,7 +327,8 @@ class BookmarkFilter
                 $i = $offset;
             }
         }
-        $regex .= '(?:$| ))'; // after the tag may only be a space or the end
+        // after the tag may only be the separator or the end
+        $regex .= '(?:$|' . $tagsSeparator . '))';
         return $regex;
     }
 
@@ -334,14 +346,15 @@ class BookmarkFilter
      */
     public function filterTags($tags, bool $casesensitive = false, string $visibility = 'all')
     {
+        $tagsSeparator = $this->conf->get('general.tags_separator', ' ');
         // get single tags (we may get passed an array, even though the docs say different)
         $inputTags = $tags;
         if (!is_array($tags)) {
             // we got an input string, split tags
-            $inputTags = preg_split('/(?:\s+)|,/', $inputTags, -1, PREG_SPLIT_NO_EMPTY);
+            $inputTags = tags_str2array($inputTags, $tagsSeparator);
         }
 
-        if (!count($inputTags)) {
+        if (count($inputTags) === 0) {
             // no input tags
             return $this->noFilter($visibility);
         }
@@ -358,7 +371,7 @@ class BookmarkFilter
         }
 
         // build regex from all tags
-        $re = '/^' . implode(array_map("self::tag2regex", $inputTags)) . '.*$/';
+        $re = '/^' . implode(array_map([$this, 'tag2regex'], $inputTags)) . '.*$/';
         if (!$casesensitive) {
             // make regex case insensitive
             $re .= 'i';
@@ -378,7 +391,8 @@ class BookmarkFilter
                     continue;
                 }
             }
-            $search = $link->getTagsString(); // build search string, start with tags of current link
+            // build search string, start with tags of current link
+            $search = $link->getTagsString($tagsSeparator);
             if (strlen(trim($link->getDescription())) && strpos($link->getDescription(), '#') !== false) {
                 // description given and at least one possible tag found
                 $descTags = array();
@@ -390,9 +404,9 @@ class BookmarkFilter
                 );
                 if (count($descTags[1])) {
                     // there were some tags in the description, add them to the search string
-                    $search .= ' ' . implode(' ', $descTags[1]);
+                    $search .= $tagsSeparator . tags_array2str($descTags[1], $tagsSeparator);
                 }
-            };
+            }
             // match regular expression with search string
             if (!preg_match($re, $search)) {
                 // this entry does _not_ match our regex
@@ -422,7 +436,7 @@ class BookmarkFilter
                 }
             }
 
-            if (empty(trim($link->getTagsString()))) {
+            if (empty($link->getTags())) {
                 $filtered[$key] = $link;
             }
         }
@@ -537,10 +551,11 @@ class BookmarkFilter
      */
     protected function buildFullTextSearchableLink(Bookmark $link, array &$lengths): string
     {
+        $tagString = $link->getTagsString($this->conf->get('general.tags_separator', ' '));
         $content  = mb_convert_case($link->getTitle(), MB_CASE_LOWER, 'UTF-8') .'\\';
         $content .= mb_convert_case($link->getDescription(), MB_CASE_LOWER, 'UTF-8') .'\\';
         $content .= mb_convert_case($link->getUrl(), MB_CASE_LOWER, 'UTF-8') .'\\';
-        $content .= mb_convert_case($link->getTagsString(), MB_CASE_LOWER, 'UTF-8') .'\\';
+        $content .= mb_convert_case($tagString, MB_CASE_LOWER, 'UTF-8') .'\\';
 
         $lengths['title'] = ['start' => 0, 'end' => mb_strlen($link->getTitle())];
         $nextField = $lengths['title']['end'] + 1;
@@ -548,7 +563,7 @@ class BookmarkFilter
         $nextField = $lengths['description']['end'] + 1;
         $lengths['url'] = ['start' => $nextField, 'end' => $nextField + mb_strlen($link->getUrl())];
         $nextField = $lengths['url']['end'] + 1;
-        $lengths['tags'] = ['start' => $nextField, 'end' => $nextField + mb_strlen($link->getTagsString())];
+        $lengths['tags'] = ['start' => $nextField, 'end' => $nextField + mb_strlen($tagString)];
 
         return $content;
     }
diff --git a/application/bookmark/LinkUtils.php b/application/bookmark/LinkUtils.php
index 17c37979..9493b0aa 100644
--- a/application/bookmark/LinkUtils.php
+++ b/application/bookmark/LinkUtils.php
@@ -176,3 +176,49 @@ function is_note($linkUrl)
 {
     return isset($linkUrl[0]) && $linkUrl[0] === '?';
 }
+
+/**
+ * Extract an array of tags from a given tag string, with provided separator.
+ *
+ * @param string|null $tags      String containing a list of tags separated by $separator.
+ * @param string      $separator Shaarli's default: ' ' (whitespace)
+ *
+ * @return array List of tags
+ */
+function tags_str2array(?string $tags, string $separator): array
+{
+    // For whitespaces, we use the special \s regex character
+    $separator = $separator === ' ' ? '\s' : $separator;
+
+    return preg_split('/\s*' . $separator . '+\s*/', trim($tags) ?? '', -1, PREG_SPLIT_NO_EMPTY);
+}
+
+/**
+ * Return a tag string with provided separator from a list of tags.
+ * Note that given array is clean up by tags_filter().
+ *
+ * @param array|null $tags      List of tags
+ * @param string     $separator
+ *
+ * @return string
+ */
+function tags_array2str(?array $tags, string $separator): string
+{
+    return implode($separator, tags_filter($tags, $separator));
+}
+
+/**
+ * Clean an array of tags: trim + remove empty entries
+ *
+ * @param array|null $tags List of tags
+ * @param string     $separator
+ *
+ * @return array
+ */
+function tags_filter(?array $tags, string $separator): array
+{
+    $trimDefault = " \t\n\r\0\x0B";
+    return array_values(array_filter(array_map(function (string $entry) use ($separator, $trimDefault): string {
+        return trim($entry, $trimDefault . $separator);
+    }, $tags ?? [])));
+}
diff --git a/application/config/ConfigManager.php b/application/config/ConfigManager.php
index fb085023..a035baae 100644
--- a/application/config/ConfigManager.php
+++ b/application/config/ConfigManager.php
@@ -368,6 +368,7 @@ class ConfigManager
         $this->setEmpty('general.default_note_title', 'Note: ');
         $this->setEmpty('general.retrieve_description', true);
         $this->setEmpty('general.enable_async_metadata', true);
+        $this->setEmpty('general.tags_separator', ' ');
 
         $this->setEmpty('updates.check_updates', false);
         $this->setEmpty('updates.check_updates_branch', 'stable');
diff --git a/application/formatter/BookmarkDefaultFormatter.php b/application/formatter/BookmarkDefaultFormatter.php
index 149a3eb9..51bea0f1 100644
--- a/application/formatter/BookmarkDefaultFormatter.php
+++ b/application/formatter/BookmarkDefaultFormatter.php
@@ -68,15 +68,16 @@ class BookmarkDefaultFormatter extends BookmarkFormatter
      */
     protected function formatTagListHtml($bookmark)
     {
+        $tagsSeparator = $this->conf->get('general.tags_separator', ' ');
         if (empty($bookmark->getAdditionalContentEntry('search_highlight')['tags'])) {
             return $this->formatTagList($bookmark);
         }
 
         $tags = $this->tokenizeSearchHighlightField(
-            $bookmark->getTagsString(),
+            $bookmark->getTagsString($tagsSeparator),
             $bookmark->getAdditionalContentEntry('search_highlight')['tags']
         );
-        $tags = $this->filterTagList(explode(' ', $tags));
+        $tags = $this->filterTagList(tags_str2array($tags, $tagsSeparator));
         $tags = escape($tags);
         $tags = $this->replaceTokensArray($tags);
 
@@ -88,7 +89,7 @@ class BookmarkDefaultFormatter extends BookmarkFormatter
      */
     protected function formatTagString($bookmark)
     {
-        return implode(' ', $this->formatTagList($bookmark));
+        return implode($this->conf->get('general.tags_separator'), $this->formatTagList($bookmark));
     }
 
     /**
diff --git a/application/formatter/BookmarkFormatter.php b/application/formatter/BookmarkFormatter.php
index e1b7f705..124ce78b 100644
--- a/application/formatter/BookmarkFormatter.php
+++ b/application/formatter/BookmarkFormatter.php
@@ -267,7 +267,7 @@ abstract class BookmarkFormatter
      */
     protected function formatTagString($bookmark)
     {
-        return implode(' ', $this->formatTagList($bookmark));
+        return implode($this->conf->get('general.tags_separator', ' '), $this->formatTagList($bookmark));
     }
 
     /**
@@ -351,6 +351,7 @@ abstract class BookmarkFormatter
 
     /**
      * Format tag list, e.g. remove private tags if the user is not logged in.
+     * TODO: this method is called multiple time to format tags, the result should be cached.
      *
      * @param array $tags
      *
diff --git a/application/front/controller/admin/ManageTagController.php b/application/front/controller/admin/ManageTagController.php
index 2065c3e2..22fb461c 100644
--- a/application/front/controller/admin/ManageTagController.php
+++ b/application/front/controller/admin/ManageTagController.php
@@ -24,6 +24,12 @@ class ManageTagController extends ShaarliAdminController
         $fromTag = $request->getParam('fromtag') ?? '';
 
         $this->assignView('fromtag', escape($fromTag));
+        $separator = escape($this->container->conf->get('general.tags_separator', ' '));
+        if ($separator === ' ') {
+            $separator = '&nbsp;';
+            $this->assignView('tags_separator_desc', t('whitespace'));
+        }
+        $this->assignView('tags_separator', $separator);
         $this->assignView(
             'pagetitle',
             t('Manage tags') .' - '. $this->container->conf->get('general.title', 'Shaarli')
@@ -85,4 +91,31 @@ class ManageTagController extends ShaarliAdminController
 
         return $this->redirect($response, $redirect);
     }
+
+    /**
+     * POST /admin/tags/change-separator - Change tag separator
+     */
+    public function changeSeparator(Request $request, Response $response): Response
+    {
+        $this->checkToken($request);
+
+        $reservedCharacters = ['-', '.', '*'];
+        $newSeparator = $request->getParam('separator');
+        if ($newSeparator === null || mb_strlen($newSeparator) !== 1) {
+            $this->saveErrorMessage(t('Tags separator must be a single character.'));
+        } elseif (in_array($newSeparator, $reservedCharacters, true)) {
+            $reservedCharacters = implode(' ', array_map(function (string $character) {
+                return '<code>' . $character . '</code>';
+            }, $reservedCharacters));
+            $this->saveErrorMessage(
+                t('These characters are reserved and can\'t be used as tags separator: ') . $reservedCharacters
+            );
+        } else {
+            $this->container->conf->set('general.tags_separator', $newSeparator, true, true);
+
+            $this->saveSuccessMessage('Your tags separator setting has been updated!');
+        }
+
+        return $this->redirect($response, '/admin/tags');
+    }
 }
diff --git a/application/front/controller/admin/ShaareManageController.php b/application/front/controller/admin/ShaareManageController.php
index 2ed298f5..0b143172 100644
--- a/application/front/controller/admin/ShaareManageController.php
+++ b/application/front/controller/admin/ShaareManageController.php
@@ -125,7 +125,7 @@ class ShaareManageController extends ShaarliAdminController
             // To preserve backward compatibility with 3rd parties, plugins still use arrays
             $data = $formatter->format($bookmark);
             $this->executePageHooks('save_link', $data);
-            $bookmark->fromArray($data);
+            $bookmark->fromArray($data, $this->container->conf->get('general.tags_separator', ' '));
 
             $this->container->bookmarkService->set($bookmark, false);
             ++$count;
@@ -167,7 +167,7 @@ class ShaareManageController extends ShaarliAdminController
         // To preserve backward compatibility with 3rd parties, plugins still use arrays
         $data = $formatter->format($bookmark);
         $this->executePageHooks('save_link', $data);
-        $bookmark->fromArray($data);
+        $bookmark->fromArray($data, $this->container->conf->get('general.tags_separator', ' '));
 
         $this->container->bookmarkService->set($bookmark);
 
diff --git a/application/front/controller/admin/ShaarePublishController.php b/application/front/controller/admin/ShaarePublishController.php
index 18afc2d1..625a5680 100644
--- a/application/front/controller/admin/ShaarePublishController.php
+++ b/application/front/controller/admin/ShaarePublishController.php
@@ -113,7 +113,10 @@ class ShaarePublishController extends ShaarliAdminController
         $bookmark->setDescription($request->getParam('lf_description'));
         $bookmark->setUrl($request->getParam('lf_url'), $this->container->conf->get('security.allowed_protocols', []));
         $bookmark->setPrivate(filter_var($request->getParam('lf_private'), FILTER_VALIDATE_BOOLEAN));
-        $bookmark->setTagsString($request->getParam('lf_tags'));
+        $bookmark->setTagsString(
+            $request->getParam('lf_tags'),
+            $this->container->conf->get('general.tags_separator', ' ')
+        );
 
         if ($this->container->conf->get('thumbnails.mode', Thumbnailer::MODE_NONE) !== Thumbnailer::MODE_NONE
             && true !== $this->container->conf->get('general.enable_async_metadata', true)
@@ -128,7 +131,7 @@ class ShaarePublishController extends ShaarliAdminController
         $data = $formatter->format($bookmark);
         $this->executePageHooks('save_link', $data);
 
-        $bookmark->fromArray($data);
+        $bookmark->fromArray($data, $this->container->conf->get('general.tags_separator', ' '));
         $this->container->bookmarkService->set($bookmark);
 
         // If we are called from the bookmarklet, we must close the popup:
@@ -221,6 +224,11 @@ class ShaarePublishController extends ShaarliAdminController
 
     protected function buildFormData(array $link, bool $isNew, Request $request): array
     {
+        $link['tags'] = strlen($link['tags']) > 0
+            ? $link['tags'] . $this->container->conf->get('general.tags_separator', ' ')
+            : $link['tags']
+        ;
+
         return escape([
             'link' => $link,
             'link_is_new' => $isNew,
diff --git a/application/front/controller/visitor/BookmarkListController.php b/application/front/controller/visitor/BookmarkListController.php
index 78c474c9..cc3837ce 100644
--- a/application/front/controller/visitor/BookmarkListController.php
+++ b/application/front/controller/visitor/BookmarkListController.php
@@ -95,6 +95,10 @@ class BookmarkListController extends ShaarliVisitorController
             $next_page_url = '?page=' . ($page - 1) . $searchtermUrl . $searchtagsUrl;
         }
 
+        $tagsSeparator = $this->container->conf->get('general.tags_separator', ' ');
+        $searchTagsUrlEncoded = array_map('urlencode', tags_str2array($searchTags, $tagsSeparator));
+        $searchTags = !empty($searchTags) ? trim($searchTags, $tagsSeparator) . $tagsSeparator : '';
+
         // Fill all template fields.
         $data = array_merge(
             $this->initializeTemplateVars(),
@@ -106,7 +110,7 @@ class BookmarkListController extends ShaarliVisitorController
                 'result_count' => count($linksToDisplay),
                 'search_term' => escape($searchTerm),
                 'search_tags' => escape($searchTags),
-                'search_tags_url' => array_map('urlencode', explode(' ', $searchTags)),
+                'search_tags_url' => $searchTagsUrlEncoded,
                 'visibility' => $visibility,
                 'links' => $linkDisp,
             ]
@@ -119,8 +123,9 @@ class BookmarkListController extends ShaarliVisitorController
                 return '[' . $tag . ']';
             };
             $data['pagetitle'] .= ! empty($searchTags)
-                ? implode(' ', array_map($bracketWrap, preg_split('/\s+/', $searchTags))) . ' '
-                : '';
+                ? implode(' ', array_map($bracketWrap, tags_str2array($searchTags, $tagsSeparator))) . ' '
+                : ''
+            ;
             $data['pagetitle'] .= '- ';
         }
 
diff --git a/application/front/controller/visitor/TagCloudController.php b/application/front/controller/visitor/TagCloudController.php
index 76ed7690..560cad08 100644
--- a/application/front/controller/visitor/TagCloudController.php
+++ b/application/front/controller/visitor/TagCloudController.php
@@ -47,13 +47,14 @@ class TagCloudController extends ShaarliVisitorController
      */
     protected function processRequest(string $type, Request $request, Response $response): Response
     {
+        $tagsSeparator = $this->container->conf->get('general.tags_separator', ' ');
         if ($this->container->loginManager->isLoggedIn() === true) {
             $visibility = $this->container->sessionManager->getSessionParameter('visibility');
         }
 
         $sort = $request->getQueryParam('sort');
         $searchTags = $request->getQueryParam('searchtags');
-        $filteringTags = $searchTags !== null ? explode(' ', $searchTags) : [];
+        $filteringTags = $searchTags !== null ? explode($tagsSeparator, $searchTags) : [];
 
         $tags = $this->container->bookmarkService->bookmarksCountPerTag($filteringTags, $visibility ?? null);
 
@@ -71,8 +72,9 @@ class TagCloudController extends ShaarliVisitorController
             $tagsUrl[escape($tag)] = urlencode((string) $tag);
         }
 
-        $searchTags = implode(' ', escape($filteringTags));
-        $searchTagsUrl = urlencode(implode(' ', $filteringTags));
+        $searchTags = tags_array2str($filteringTags, $tagsSeparator);
+        $searchTags = !empty($searchTags) ? trim($searchTags, $tagsSeparator) . $tagsSeparator : '';
+        $searchTagsUrl = urlencode($searchTags);
         $data = [
             'search_tags' => escape($searchTags),
             'search_tags_url' => $searchTagsUrl,
@@ -82,7 +84,7 @@ class TagCloudController extends ShaarliVisitorController
         $this->executePageHooks('render_tag' . $type, $data, 'tag.' . $type);
         $this->assignAllView($data);
 
-        $searchTags = !empty($searchTags) ? $searchTags .' - ' : '';
+        $searchTags = !empty($searchTags) ? trim(str_replace($tagsSeparator, ' ', $searchTags)) .' - ' : '';
         $this->assignView(
             'pagetitle',
             $searchTags . t('Tag '. $type) .' - '. $this->container->conf->get('general.title', 'Shaarli')
diff --git a/application/front/controller/visitor/TagController.php b/application/front/controller/visitor/TagController.php
index de4e7ea2..7a3377a7 100644
--- a/application/front/controller/visitor/TagController.php
+++ b/application/front/controller/visitor/TagController.php
@@ -45,9 +45,10 @@ class TagController extends ShaarliVisitorController
             unset($params['addtag']);
         }
 
+        $tagsSeparator = $this->container->conf->get('general.tags_separator', ' ');
         // Check if this tag is already in the search query and ignore it if it is.
         // Each tag is always separated by a space
-        $currentTags = isset($params['searchtags']) ? explode(' ', $params['searchtags']) : [];
+        $currentTags = tags_str2array($params['searchtags'] ?? '', $tagsSeparator);
 
         $addtag = true;
         foreach ($currentTags as $value) {
@@ -62,7 +63,7 @@ class TagController extends ShaarliVisitorController
             $currentTags[] = trim($newTag);
         }
 
-        $params['searchtags'] = trim(implode(' ', $currentTags));
+        $params['searchtags'] = tags_array2str($currentTags, $tagsSeparator);
 
         // We also remove page (keeping the same page has no sense, since the results are different)
         unset($params['page']);
@@ -98,10 +99,11 @@ class TagController extends ShaarliVisitorController
         }
 
         if (isset($params['searchtags'])) {
-            $tags = explode(' ', $params['searchtags']);
+            $tagsSeparator = $this->container->conf->get('general.tags_separator', ' ');
+            $tags = tags_str2array($params['searchtags'] ?? '', $tagsSeparator);
             // Remove value from array $tags.
             $tags = array_diff($tags, [$tagToRemove]);
-            $params['searchtags'] = implode(' ', $tags);
+            $params['searchtags'] = tags_array2str($tags, $tagsSeparator);
 
             if (empty($params['searchtags'])) {
                 unset($params['searchtags']);
diff --git a/application/http/HttpAccess.php b/application/http/HttpAccess.php
index 646a5264..e80e0c01 100644
--- a/application/http/HttpAccess.php
+++ b/application/http/HttpAccess.php
@@ -29,14 +29,16 @@ class HttpAccess
         &$title,
         &$description,
         &$keywords,
-        $retrieveDescription
+        $retrieveDescription,
+        $tagsSeparator
     ) {
         return get_curl_download_callback(
             $charset,
             $title,
             $description,
             $keywords,
-            $retrieveDescription
+            $retrieveDescription,
+            $tagsSeparator
         );
     }
 
diff --git a/application/http/HttpUtils.php b/application/http/HttpUtils.php
index 28c12969..ed1002b0 100644
--- a/application/http/HttpUtils.php
+++ b/application/http/HttpUtils.php
@@ -550,7 +550,8 @@ function get_curl_download_callback(
     &$title,
     &$description,
     &$keywords,
-    $retrieveDescription
+    $retrieveDescription,
+    $tagsSeparator
 ) {
     $currentChunk = 0;
     $foundChunk = null;
@@ -568,6 +569,7 @@ function get_curl_download_callback(
      */
     return function ($ch, $data) use (
         $retrieveDescription,
+        $tagsSeparator,
         &$charset,
         &$title,
         &$description,
@@ -598,10 +600,10 @@ function get_curl_download_callback(
             if (! empty($keywords)) {
                 $foundChunk = $currentChunk;
                 // Keywords use the format tag1, tag2 multiple words, tag
-                // So we format them to match Shaarli's separator and glue multiple words with '-'
-                $keywords = implode(' ', array_map(function($keyword) {
-                    return implode('-', preg_split('/\s+/', trim($keyword)));
-                }, explode(',', $keywords)));
+                // So we split the result with `,`, then if a tag contains the separator we replace it by `-`.
+                $keywords = tags_array2str(array_map(function(string $keyword) use ($tagsSeparator): string {
+                    return tags_array2str(tags_str2array($keyword, $tagsSeparator), '-');
+                }, tags_str2array($keywords, ',')), $tagsSeparator);
             }
         }
 
diff --git a/application/http/MetadataRetriever.php b/application/http/MetadataRetriever.php
index ba9bd40c..2e1401ec 100644
--- a/application/http/MetadataRetriever.php
+++ b/application/http/MetadataRetriever.php
@@ -38,7 +38,6 @@ class MetadataRetriever
         $title = null;
         $description = null;
         $tags = null;
-        $retrieveDescription = $this->conf->get('general.retrieve_description');
 
         // Short timeout to keep the application responsive
         // The callback will fill $charset and $title with data from the downloaded page.
@@ -52,7 +51,8 @@ class MetadataRetriever
                 $title,
                 $description,
                 $tags,
-                $retrieveDescription
+                $this->conf->get('general.retrieve_description'),
+                $this->conf->get('general.tags_separator', ' ')
             )
         );
 
diff --git a/application/legacy/LegacyUpdater.php b/application/legacy/LegacyUpdater.php
index fe1a286f..ed949b1e 100644
--- a/application/legacy/LegacyUpdater.php
+++ b/application/legacy/LegacyUpdater.php
@@ -585,7 +585,7 @@ class LegacyUpdater
 
         $linksArray = new BookmarkArray();
         foreach ($this->linkDB as $key => $link) {
-            $linksArray[$key] = (new Bookmark())->fromArray($link);
+            $linksArray[$key] = (new Bookmark())->fromArray($link, $this->conf->get('general.tags_separator', ' '));
         }
         $linksIo = new BookmarkIO($this->conf);
         $linksIo->write($linksArray);
diff --git a/application/netscape/NetscapeBookmarkUtils.php b/application/netscape/NetscapeBookmarkUtils.php
index b83f16f8..6ca728b7 100644
--- a/application/netscape/NetscapeBookmarkUtils.php
+++ b/application/netscape/NetscapeBookmarkUtils.php
@@ -101,11 +101,11 @@ class NetscapeBookmarkUtils
 
         // Add tags to all imported bookmarks?
         if (empty($post['default_tags'])) {
-            $defaultTags = array();
+            $defaultTags = [];
         } else {
-            $defaultTags = preg_split(
-                '/[\s,]+/',
-                escape($post['default_tags'])
+            $defaultTags = tags_str2array(
+                escape($post['default_tags']),
+                $this->conf->get('general.tags_separator', ' ')
             );
         }
 
@@ -171,7 +171,7 @@ class NetscapeBookmarkUtils
             $link->setUrl($bkm['uri'], $this->conf->get('security.allowed_protocols'));
             $link->setDescription($bkm['note']);
             $link->setPrivate($private);
-            $link->setTagsString($bkm['tags']);
+            $link->setTags($bkm['tags']);
 
             $this->bookmarkService->addOrSet($link, false);
             $importCount++;
diff --git a/application/render/PageBuilder.php b/application/render/PageBuilder.php
index c2fae705..bf0ae326 100644
--- a/application/render/PageBuilder.php
+++ b/application/render/PageBuilder.php
@@ -161,6 +161,7 @@ class PageBuilder
         $this->tpl->assign('formatter', $this->conf->get('formatter', 'default'));
 
         $this->tpl->assign('links_per_page', $this->session['LINKS_PER_PAGE'] ?? 20);
+        $this->tpl->assign('tags_separator', $this->conf->get('general.tags_separator', ' '));
 
         // To be removed with a proper theme configuration.
         $this->tpl->assign('conf', $this->conf);