Make the search key used by the "find similar" searches able to be a grouped search term.

src/calibre/gui2/actions/similar_books.py

@@ -36,25 +36,28 @@ class SimilarBooksAction(InterfaceAction):
     def show_similar_books(self, type, *args):
         search, join = [], ' '
         idx = self.gui.library_view.currentIndex()
+        db = self.gui.library_view.model().db
         if not idx.isValid():
             return
         row = idx.row()
         if type == 'series':
             series = idx.model().db.series(row)
             if series:
-                search = ['series:"'+series+'"']
+                search = [db.prefs['similar_series_search_key'] + ':"'+series+'"']
         elif type == 'publisher':
             publisher = idx.model().db.publisher(row)
             if publisher:
-                search = ['publisher:"'+publisher+'"']
+                search = [db.prefs['similar_publisher_search_key'] + ':"'+publisher+'"']
         elif type == 'tag':
             tags = idx.model().db.tags(row)
             if tags:
-                search = ['tag:"='+t+'"' for t in tags.split(',')]
+                search = [db.prefs['similar_tags_search_key'] + ':"='+t+'"'
+                          for t in tags.split(',')]
         elif type in ('author', 'authors'):
             authors = idx.model().db.authors(row)
             if authors:
-                search = ['author:"='+a.strip().replace('|', ',')+'"' \
+                search = [db.prefs['similar_authors_search_key'] +
+                                    ':"='+a.strip().replace('|', ',')+'"' \
                                 for a in authors.split(',')]
                 join = ' or '
         if search:

src/calibre/gui2/preferences/search.py

@@ -12,6 +12,7 @@ from calibre.gui2.preferences import ConfigWidgetBase, test_widget, \
 from calibre.gui2.preferences.search_ui import Ui_Form
 from calibre.gui2 import config, error_dialog
 from calibre.utils.config import prefs
+from calibre.utils.icu import sort_key
 
 class ConfigWidget(ConfigWidgetBase, Ui_Form):
 
@@ -70,6 +71,12 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         self.gst_value.update_items_cache(fl)
         self.fill_gst_box(select=None)
 
+        self.set_similar_fields(initial=True)
+        self.similar_authors_search_key.currentIndexChanged[int].connect(self.something_changed)
+        self.similar_tags_search_key.currentIndexChanged[int].connect(self.something_changed)
+        self.similar_series_search_key.currentIndexChanged[int].connect(self.something_changed)
+        self.similar_publisher_search_key.currentIndexChanged[int].connect(self.something_changed)
+
         self.gst_delete_button.setEnabled(False)
         self.gst_save_button.setEnabled(False)
         self.gst_names.currentIndexChanged[int].connect(self.gst_index_changed)
@@ -86,6 +93,33 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         self.opt_grouped_search_make_user_categories.editingFinished.connect(
                                                         self.muc_box_changed)
 
+    def set_similar_fields(self, initial=False):
+        self.set_similar('similar_authors_search_key', first_item='author', initial=initial)
+        self.set_similar('similar_tags_search_key', first_item='tags', initial=initial)
+        self.set_similar('similar_series_search_key', first_item='series', initial=initial)
+        self.set_similar('similar_publisher_search_key', first_item='publisher', initial=initial)
+
+    def set_similar(self, name, first_item, initial=False):
+        field = getattr(self, name)
+        if not initial:
+            val = field.currentText()
+        else:
+            val = self.db.prefs[name]
+        field.blockSignals(True)
+        field.clear()
+        choices = [first_item]
+        choices.extend(sorted(self.gst.keys(), key=sort_key))
+        field.addItems(choices)
+        dex = field.findText(val)
+        if dex >= 0:
+            field.setCurrentIndex(dex)
+        else:
+            field.setCurrentIndex(0)
+        field.blockSignals(False)
+
+    def something_changed(self, dex):
+        self.changed_signal.emit()
+
     def muc_box_changed(self):
         self.muc_changed = True
 
@@ -121,6 +155,7 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         self.gst_changed = True
         self.gst[name] = val
         self.fill_gst_box(select=name)
+        self.set_similar_fields(initial=False)
         self.changed_signal.emit()
 
     def gst_delete_clicked(self):
@@ -133,9 +168,10 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
             self.fill_gst_box(select='')
             self.changed_signal.emit()
             self.gst_changed = True
+            self.set_similar_fields(initial=False)
 
     def fill_gst_box(self, select=None):
-        terms = sorted(self.gst.keys())
+        terms = sorted(self.gst.keys(), key=sort_key)
         self.opt_grouped_search_make_user_categories.update_items_cache(terms)
         self.gst_names.blockSignals(True)
         self.gst_names.clear()
@@ -168,6 +204,14 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         if self.gst_changed:
             self.db.prefs.set('grouped_search_terms', self.gst)
             self.db.field_metadata.add_grouped_search_terms(self.gst)
+        self.db.prefs.set('similar_authors_search_key',
+                          unicode(self.similar_authors_search_key.currentText()))
+        self.db.prefs.set('similar_tags_search_key',
+                          unicode(self.similar_tags_search_key.currentText()))
+        self.db.prefs.set('similar_series_search_key',
+                          unicode(self.similar_series_search_key.currentText()))
+        self.db.prefs.set('similar_publisher_search_key',
+                          unicode(self.similar_publisher_search_key.currentText()))
         return ConfigWidgetBase.commit(self)
 
     def refresh_gui(self, gui):

src/calibre/gui2/preferences/search.ui

@@ -201,6 +201,84 @@ to be shown as user categories</string>
      </layout>
     </widget>
    </item>
+   <item row="5" column="0">
+    <widget class="QGroupBox" name="groupBox22">
+     <property name="title">
+      <string>What to search when searching similar books</string>
+     </property>
+     <layout class="QGridLayout" name="gridLayout_22">
+      <item row="0" column="0" colspan="4">
+       <widget class="QLabel" name="label">
+        <property name="text">
+         <string>&lt;p&gt;When you search for similar books by author, series, etc,
+         calibre constructs a search using the column lookup names defined below.
+         By changing the lookup name to a grouped search term you can
+         search multiple columns.&lt;/p&gt;</string>
+        </property>
+        <property name="wordWrap">
+         <bool>true</bool>
+        </property>
+       </widget>
+      </item>
+      <item row="1" column="0">
+       <widget class="QLabel" name="label_221">
+        <property name="text">
+         <string>Similar authors: </string>
+        </property>
+       </widget>
+      </item>
+      <item row="1" column="1">
+       <widget class="QComboBox" name="similar_authors_search_key">
+        <property name="sizePolicy">
+         <sizepolicy hsizetype="Preferred" vsizetype="Fixed">
+          <horstretch>10</horstretch>
+          <verstretch>0</verstretch>
+         </sizepolicy>
+        </property>
+       </widget>
+      </item>
+      <item row="1" column="2">
+       <widget class="QLabel" name="label_222">
+        <property name="text">
+         <string>Similar series: </string>
+        </property>
+       </widget>
+      </item>
+      <item row="1" column="3">
+       <widget class="QComboBox" name="similar_series_search_key">
+        <property name="sizePolicy">
+         <sizepolicy hsizetype="Preferred" vsizetype="Fixed">
+          <horstretch>10</horstretch>
+          <verstretch>0</verstretch>
+         </sizepolicy>
+        </property>
+       </widget>
+      </item>
+      <item row="2" column="0">
+       <widget class="QLabel" name="label_223">
+        <property name="text">
+         <string>Similar tags: </string>
+        </property>
+       </widget>
+      </item>
+      <item row="2" column="1">
+       <widget class="QComboBox" name="similar_tags_search_key">
+       </widget>
+      </item>
+      <item row="2" column="2">
+       <widget class="QLabel" name="label_224">
+        <property name="text">
+         <string>Similar publishers: </string>
+        </property>
+       </widget>
+      </item>
+      <item row="2" column="3">
+       <widget class="QComboBox" name="similar_publisher_search_key">
+       </widget>
+      </item>
+     </layout>
+    </widget>
+   </item>
   </layout>
  </widget>
  <customwidgets>

src/calibre/library/database2.py

@@ -236,6 +236,10 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
         defs['categories_using_hierarchy'] = []
         defs['column_color_rules'] = []
         defs['grouped_search_make_user_categories'] = []
+        defs['similar_authors_search_key'] = 'author'
+        defs['similar_publisher_search_key'] = 'publisher'
+        defs['similar_tags_search_key'] = 'tags'
+        defs['similar_series_search_key'] = 'series'
 
         # Migrate the bool tristate tweak
         defs['bools_are_tristate'] = \