[gnome-boxes] media-manager: Use correct tracker language property

[Zeeshan Ali Khattak <zeeshanak src gnome org>]

commit 348da74cb0ab8a288c063ce79c8c104acfb03908
Author: Zeeshan Ali (Khattak) <zeeshanak gnome org>
Date:   Thu May 8 14:27:26 2014 +0100

    media-manager: Use correct tracker language property
    
    In the end, it was decided not to make the existing 'nie:language'
    property multi-valued but rather introduce a new custom property for
    this case, 'osinfo:language'.
    
    This patch also:
    
    * moves the handling of Tracker SPARQL query into a seperate
      module/class, TrackerISOQuery.
    
    * ensures compatibility with older Tracker (that doesn't extract and
      expose the new 'osinfo:language' property) by using different queries,
      depending on whether or not 'osinfo:language' property is known to
      Tracker.
    
    * ensures language info is extracted from media if its available in case
      of older Tracker and therefore ensures that we don't end up using a
      locale that media doesn't support and break express installation.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=729122

 src/Makefile.am            |    1 +
 src/media-manager.vala     |   29 ++++++++-------------
 src/tracker-iso-query.vala |   59 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 71 insertions(+), 18 deletions(-)
---
diff --git a/src/Makefile.am b/src/Makefile.am
index 0af0520..4b3d6f4 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -138,6 +138,7 @@ gnome_boxes_SOURCES =                               \
        wizard.vala                             \
        downloader.vala                         \
        empty-boxes.vala                        \
+       tracker-iso-query.vala                  \
        $(NULL)
 
 gnome_boxes_LDADD =                            \
diff --git a/src/media-manager.vala b/src/media-manager.vala
index 04a830b..2fade9c 100644
--- a/src/media-manager.vala
+++ b/src/media-manager.vala
@@ -6,9 +6,6 @@ using Tracker;
 
 private class Boxes.MediaManager : Object {
     private static MediaManager media_manager;
-    private const string SPARQL_QUERY = "SELECT nie:url(?iso)   nie:title(?iso)     nie:language(?iso)" +
-                                        "       osinfo:id(?iso) osinfo:mediaId(?iso)" +
-                                        " { ?iso nfo:isBootable true }";
 
     public OSDatabase os_db { get; private set; }
     public Client client { get; private set; }
@@ -125,19 +122,15 @@ private class Boxes.MediaManager : Object {
 
         // Now ISO files
         try {
-            var cursor = yield connection.query_async (SPARQL_QUERY);
-            while (yield cursor.next_async ()) {
-                var file = File.new_for_uri (cursor.get_string (0));
-                var path = file.get_path ();
-                if (path == null)
-                    continue; // FIXME: Support non-local files as well
-                var title = cursor.get_string (1);
-                var languages = cursor.get_string (2);
-                var os_id = cursor.get_string (3);
-                var media_id = cursor.get_string (4);
-
-                var lang_list = (languages != null)? languages.split (",") : new string[]{};
-
+            var query = yield new TrackerISOQuery (connection);
+            string path, title, os_id, media_id;
+            string[] lang_list;
+
+            while (yield query.fetch_next_iso_data (out path,
+                                                    out title,
+                                                    out os_id,
+                                                    out media_id,
+                                                    out lang_list)) {
                 try {
                     var media = yield create_installer_media_from_iso_info (path, title, os_id, media_id, 
lang_list);
                     unowned GLib.List<InstallerMedia> dup_node = list.find_custom (media, 
compare_media_by_label);
@@ -226,12 +219,12 @@ private class Boxes.MediaManager : Object {
                                                                        string?  label,
                                                                        string?  os_id,
                                                                        string?  media_id,
-                                                                       string[] lang_list = new string[]{})
+                                                                       string[] lang_list)
                                                                        throws GLib.Error {
         if (!FileUtils.test (path, FileTest.EXISTS))
             throw new Boxes.Error.INVALID (_("No such file %s").printf (path));
 
-        if (label == null || os_id == null || media_id == null)
+        if (label == null || os_id == null || media_id == null || lang_list == null)
             return yield create_installer_media_for_path (path);
 
         var os = yield os_db.get_os_by_id (os_id);
diff --git a/src/tracker-iso-query.vala b/src/tracker-iso-query.vala
new file mode 100644
index 0000000..ba92064
--- /dev/null
+++ b/src/tracker-iso-query.vala
@@ -0,0 +1,59 @@
+// This file is part of GNOME Boxes. License: LGPLv2+
+
+using Tracker;
+
+private class Boxes.TrackerISOQuery {
+    private const string LANG_QUERY = "ASK { osinfo:language a 
<http://www.w3.org/1999/02/22-rdf-syntax-ns#Property> }";
+    private const string ISO_QUERY = "SELECT nie:url(?iso)   nie:title(?iso)\n" +
+                                     "       osinfo:id(?iso) osinfo:mediaId(?iso)\n" +
+                                     "{ ?iso nfo:isBootable true }";
+    private const string ISO_QUERY_LANG = "SELECT nie:url(?iso)   nie:title(?iso)\n" +
+                                          "       osinfo:id(?iso) osinfo:mediaId(?iso) 
osinfo:language(?iso)\n" +
+                                          "{ ?iso nfo:isBootable true }";
+
+    private Sparql.Cursor cursor;
+
+    public async TrackerISOQuery (Sparql.Connection connection) throws GLib.Error {
+        var iso_query = ISO_QUERY;
+        var cursor = yield connection.query_async (LANG_QUERY);
+        if ((yield cursor.next_async ()) && cursor.get_boolean (0))
+            iso_query = ISO_QUERY_LANG;
+        debug ("Tracker SPARQL query: %s", iso_query);
+
+        this.cursor = yield connection.query_async (iso_query);
+    }
+
+    public async bool fetch_next_iso_data (out string   path,
+                                           out string   title,
+                                           out string   os_id,
+                                           out string   media_id,
+                                           out string[] lang_list) throws GLib.Error {
+        path = title = os_id = media_id = null;
+        lang_list = null;
+
+        if (!(yield cursor.next_async ()))
+            return false;
+
+        var file = File.new_for_uri (cursor.get_string (0));
+        path = file.get_path ();
+        if (path == null) {
+            // FIXME: Support non-local files as well
+            return yield fetch_next_iso_data (out path,
+                                              out title,
+                                              out os_id,
+                                              out media_id,
+                                              out lang_list);
+        }
+
+        title = cursor.get_string (1);
+        os_id = cursor.get_string (2);
+        media_id = cursor.get_string (3);
+        if (cursor.n_columns > 4) {
+            var languages = cursor.get_string (4);
+
+            lang_list = (languages != null)? languages.split (",") : new string[]{};
+        }
+
+        return true;
+    }
+}