From d855d74cdd051d3fe18152aa8ee3f185e838245c Mon Sep 17 00:00:00 2001
From: Stefan Borchert <stefan.borchert@undpaul.de>
Date: Sat, 4 Jun 2011 00:46:26 +0200
Subject: [PATCH] Issue #992020: Autocomplete caret position.

---
 includes/common.inc                 |   12 ++++++++----
 misc/autocomplete.js                |    6 +++---
 modules/taxonomy/taxonomy.pages.inc |   30 +++++++++++++++++++++---------
 3 files changed, 32 insertions(+), 16 deletions(-)

diff --git a/includes/common.inc b/includes/common.inc
index 4ec37dc..5cd9ddb 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -7069,17 +7069,21 @@ function drupal_explode_tags($tags) {
   // This regexp allows the following types of user input:
   // this, "somecompany, llc", "and ""this"" w,o.rks", foo bar
   $regexp = '%(?:^|,\ *)("(?>[^"]*)(?>""[^"]* )*"|(?: [^",]*))%x';
-  preg_match_all($regexp, $tags, $matches);
-  $typed_tags = array_unique($matches[1]);
+  preg_match_all($regexp, $tags, $matches, PREG_OFFSET_CAPTURE);
+  $typed_tags = array();
+  foreach ($matches[1] as $match) {
+    $typed_tags[$match[1]] = $match[0];
+  }
+  $typed_tags = array_unique($typed_tags);
 
   $tags = array();
-  foreach ($typed_tags as $tag) {
+  foreach ($typed_tags as $position => $tag) {
     // If a user has escaped a term (to demonstrate that it is a group,
     // or includes a comma or quote character), we remove the escape
     // formatting so to save the term into the database as the user intends.
     $tag = trim(str_replace('""', '"', preg_replace('/^"(.*)"$/', '\1', $tag)));
     if ($tag != "") {
-      $tags[] = $tag;
+      $tags[$position] = $tag;
     }
   }
 
diff --git a/misc/autocomplete.js b/misc/autocomplete.js
index 5e85be4..e39476c 100644
--- a/misc/autocomplete.js
+++ b/misc/autocomplete.js
@@ -200,7 +200,7 @@ Drupal.jsAC.prototype.populatePopup = function () {
 
   // Do search.
   this.db.owner = this;
-  this.db.search(this.input.value);
+  this.db.search(this.input.value, $input.get(0).selectionStart);
 };
 
 /**
@@ -264,7 +264,7 @@ Drupal.ACDB = function (uri) {
 /**
  * Performs a cached and delayed search.
  */
-Drupal.ACDB.prototype.search = function (searchString) {
+Drupal.ACDB.prototype.search = function (searchString, caretPosition) {
   var db = this;
   this.searchString = searchString;
 
@@ -290,7 +290,7 @@ Drupal.ACDB.prototype.search = function (searchString) {
     // Ajax GET request for autocompletion.
     $.ajax({
       type: 'GET',
-      url: db.uri + '/' + encodeURIComponent(searchString),
+      url: db.uri + '/' + encodeURIComponent(searchString) + '/' + caretPosition,
       dataType: 'json',
       success: function (matches) {
         if (typeof matches.status == 'undefined' || matches.status != 0) {
diff --git a/modules/taxonomy/taxonomy.pages.inc b/modules/taxonomy/taxonomy.pages.inc
index 3aed290..2672f81 100644
--- a/modules/taxonomy/taxonomy.pages.inc
+++ b/modules/taxonomy/taxonomy.pages.inc
@@ -76,15 +76,27 @@ function taxonomy_term_feed($term) {
 /**
  * Helper function for autocompletion
  */
-function taxonomy_autocomplete($field_name, $tags_typed = '') {
+function taxonomy_autocomplete($field_name, $tags_typed = '', $caret_position) {
   $field = field_info_field($field_name);
 
-  // The user enters a comma-separated list of tags. We only autocomplete the last tag.
-  $tags_typed = drupal_explode_tags($tags_typed);
-  $tag_last = drupal_strtolower(array_pop($tags_typed));
+  // The user enters a comma-separated list of tags.
+  $tags_typed_array = drupal_explode_tags($tags_typed);
+  // Try to find the tag based on the current caret position.
+  $tag_current = '';
+  $tag_positions = array_keys($tags_typed_array);
+  $tag_positions[] = drupal_strlen($tags_typed) + 1;
+  $position_last = -1;
+  foreach ($tag_positions as $position) {
+    if ($caret_position >= $position_last && $caret_position < $position) {
+      $tag_current = $tags_typed_array[$position_last];
+      break;
+    }
+    $position_last = $position;
+  }
+  unset($tags_typed_array[$position_last]);
 
   $matches = array();
-  if ($tag_last != '') {
+  if ($tag_current != '') {
 
     // Part of the criteria for the query come from the field's own settings.
     $vids = array();
@@ -98,19 +110,19 @@ function taxonomy_autocomplete($field_name, $tags_typed = '') {
     $query->addTag('term_access');
 
     // Do not select already entered terms.
-    if (!empty($tags_typed)) {
-      $query->condition('t.name', $tags_typed, 'NOT IN');
+    if (!empty($tags_typed_array)) {
+      $query->condition('t.name', $tags_typed_array, 'NOT IN');
     }
     // Select rows that match by term name.
     $tags_return = $query
       ->fields('t', array('tid', 'name'))
       ->condition('t.vid', $vids)
-      ->condition('t.name', '%' . db_like($tag_last) . '%', 'LIKE')
+      ->condition('t.name', '%' . db_like($tag_current) . '%', 'LIKE')
       ->range(0, 10)
       ->execute()
       ->fetchAllKeyed();
 
-    $prefix = count($tags_typed) ? implode(', ', $tags_typed) . ', ' : '';
+    $prefix = count($tags_typed_array) ? implode(', ', $tags_typed_array) . ', ' : '';
 
     $term_matches = array();
     foreach ($tags_return as $tid => $name) {
-- 
1.7.4