feat(search): add search assistance for simple queries

This add some search assistance to simple, single-word search queries
which may be restricted to a single namespace.

Further improvements:
* better styling
* trigger events for other plugins
* set namespaces directly from fulltext search results
* some more config options

3 files changed, 84 insertions, 0 deletions

diff --git a/lib/exe/js.php b/lib/exe/js.php
index ee017a41e..4c614f080 100644
--- a/lib/exe/js.php
+++ b/lib/exe/js.php
@@ -47,6 +47,7 @@ function js_out(){
                 DOKU_INC.'lib/scripts/cookie.js',
                 DOKU_INC.'lib/scripts/script.js',
                 DOKU_INC.'lib/scripts/qsearch.js',
+                DOKU_INC.'lib/scripts/search.js',
                 DOKU_INC.'lib/scripts/tree.js',
                 DOKU_INC.'lib/scripts/index.js',
                 DOKU_INC.'lib/scripts/textselection.js',
diff --git a/lib/scripts/search.js b/lib/scripts/search.js
new file mode 100644
index 000000000..0c9dca76a
--- /dev/null
+++ b/lib/scripts/search.js
@@ -0,0 +1,67 @@
+jQuery(function () {
+    'use strict';
+
+    const $searchForm = jQuery('.search-results-form');
+    if (!$searchForm.length) {
+        return;
+    }
+    if (!$searchForm.find('#search-results-form__show-assistance-button').length){
+        return;
+    }
+    const $toggleAssistanceButton = $searchForm.find('#search-results-form__show-assistance-button');
+    const $queryInput = $searchForm.find('[name="id"]');
+    const $termInput = $searchForm.find('[name="searchTerm"]');
+
+    $toggleAssistanceButton.on('click', function () {
+        jQuery('.js-advancedSearchOptions').toggle();
+        $queryInput.toggle();
+        $termInput.toggle();
+    });
+
+
+    const $matchTypeSwitcher = $searchForm.find('[name="matchType"]');
+    const $namespaceSwitcher = $searchForm.find('[name="namespace"]');
+    const $refiningElements = $termInput.add($matchTypeSwitcher).add($namespaceSwitcher);
+    $refiningElements.on('input change', function () {
+        $queryInput.val(
+            rebuildQuery(
+                $termInput.val(),
+                $matchTypeSwitcher.filter(':checked').val(),
+                $namespaceSwitcher.filter(':checked').val()
+            )
+        );
+    });
+
+    /**
+     * Rebuild the search query from the parts
+     *
+     * @param {string} searchTerm the word which is to be searched
+     * @param {enum} matchType the type of matching that is to be done
+     * @param {string} namespace list of namespaces to which to limit the search
+     *
+     * @return {string} the query string for the actual search
+     */
+    function rebuildQuery(searchTerm, matchType, namespace) {
+        let query = '';
+
+        switch (matchType) {
+        case 'contains':
+            query = '*' + searchTerm + '*';
+            break;
+        case 'starts':
+            query = '*' + searchTerm;
+            break;
+        case 'ends':
+            query = searchTerm + '*';
+            break;
+        default:
+            query = searchTerm;
+        }
+
+        if (namespace && namespace.length) {
+            query += ' @' + namespace;
+        }
+
+        return query;
+    }
+});
diff --git a/lib/tpl/dokuwiki/css/_search.css b/lib/tpl/dokuwiki/css/_search.css
index a8972ae72..8da2652a2 100644
--- a/lib/tpl/dokuwiki/css/_search.css
+++ b/lib/tpl/dokuwiki/css/_search.css
@@ -12,6 +12,22 @@
     margin-bottom: 1.4em;
 }
 
+.search-results-form .search-results-form__fieldset {
+    width: 80vw;
+}
+
+.search-results-form__show-assistance-button {
+    float: right;
+}
+
+.search-results-form__no-assistance-message {
+    color: grey;
+    float: right;
+    font-size: 80%;
+    margin-top: -0.3em;
+}
+
+
 /*____________ matching pagenames ____________*/
 
 .dokuwiki div.search_quickresult {