Suggested patch for max issues per recipe

src/calibre/gui2/actions/fetch_news.py

@@ -58,6 +58,16 @@ class FetchNewsAction(InterfaceAction):
             self.scheduler.recipe_download_failed(arg)
             return self.gui.job_exception(job)
         id = self.gui.library_view.model().add_news(pt.name, arg)
+
+        # Arg may contain a "keep_issues" variable.  if it is non-zer, delete all but newest x issues.
+        try:
+            ikeep_issues = int(arg['keep_issues'])
+        except:
+            ikeep_issues = 0
+        if ikeep_issues > 0:
+            ids2delete = self.gui.library_view.model().db.get_most_recent_by_tag(arg['keep_issues'], arg['title'])
+            self.gui.library_view.model().delete_books_by_id(ids2delete)
+                                                                                     
         self.gui.library_view.model().reset()
         sync = self.gui.news_to_be_synced
         sync.add(id)

src/calibre/gui2/dialogs/scheduler.py

@@ -153,9 +153,10 @@ class SchedulerDialog(QDialog, Ui_Dialog):
             self.recipe_model.un_schedule_recipe(urn)
 
         add_title_tag = self.add_title_tag.isChecked()
+        keep_issues = unicode(self.keep_issues.text())
         custom_tags = unicode(self.custom_tags.text()).strip()
         custom_tags = [x.strip() for x in custom_tags.split(',')]
-        self.recipe_model.customize_recipe(urn, add_title_tag, custom_tags)
+        self.recipe_model.customize_recipe(urn, add_title_tag, custom_tags, keep_issues)
         return True
 
     def initialize_detail_box(self, urn):
@@ -215,9 +216,15 @@ class SchedulerDialog(QDialog, Ui_Dialog):
             if d < timedelta(days=366):
                 self.last_downloaded.setText(_('Last downloaded')+': '+tm)
 
-        add_title_tag, custom_tags = customize_info
+        add_title_tag, custom_tags, keep_issues = customize_info
         self.add_title_tag.setChecked(add_title_tag)
         self.custom_tags.setText(u', '.join(custom_tags))
+        try:
+            ikeep_issues = int(keep_issues)
+        except:
+            ikeep_issues = 0
+        self.keep_issues.setValue(ikeep_issues)
+
 
 
 class Scheduler(QObject):
@@ -299,7 +306,7 @@ class Scheduler(QObject):
             un = pw = None
             if account_info is not None:
                 un, pw = account_info
-            add_title_tag, custom_tags = customize_info
+            add_title_tag, custom_tags, keep_issues = customize_info
             script = self.recipe_model.get_recipe(urn)
             pt = PersistentTemporaryFile('_builtin.recipe')
             pt.write(script)
@@ -312,6 +319,7 @@ class Scheduler(QObject):
                     'recipe':pt.name,
                     'title':recipe.get('title',''),
                     'urn':urn,
+                    'keep_issues':keep_issues
                    }
             self.download_queue.add(urn)
             self.start_recipe_fetch.emit(arg)

src/calibre/gui2/dialogs/scheduler.ui

@@ -245,6 +245,36 @@
                </item>
               </layout>
              </item>
+             <item>
+              <layout class="QHBoxLayout" name="horizontalLayout_3">
+               <item>
+                <widget class="QLabel" name="label_6">
+                 <property name="toolTip">
+                  <string>Maximum number of copies (issues) of this recipe to keep.  Set to 0 to keep all (disable).</string>
+                 </property>
+                 <property name="text">
+                  <string>Maximum copies (0 to keep all): </string>
+                 </property>
+                </widget>
+               </item>
+               <item>
+                <widget class="QSpinBox" name="keep_issues"/>
+               </item>
+               <item>
+                <spacer name="horizontalSpacer_2">
+                 <property name="orientation">
+                  <enum>Qt::Horizontal</enum>
+                 </property>
+                 <property name="sizeHint" stdset="0">
+                  <size>
+                   <width>40</width>
+                   <height>20</height>
+                  </size>
+                 </property>
+                </spacer>
+               </item>
+              </layout>
+             </item>
              <item>
               <widget class="QLabel" name="last_downloaded">
                <property name="text">

src/calibre/library/database2.py

@@ -1476,6 +1476,18 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
 
     ############# End get_categories
 
+    def get_most_recent_by_tag(self, number_to_keep, tag):
+        #Based on tag and number passed in, create a list of books matching that tag, keeping only the newest X versions
+        tag = tag.lower().strip()
+        idlist = []
+        mycount = 0
+        for myid in (self.conn.get('select a.book id from books_tags_link a inner join books b on a.book = b.id where a.tag in (select tags.id from tags where tags.name = ?) order by b.timestamp desc', [tag])):
+            myid = myid[0]
+            mycount = mycount + 1
+            if mycount > int(number_to_keep):
+                idlist.append(myid)
+        return idlist
+
     def tags_older_than(self, tag, delta):
         tag = tag.lower().strip()
         now = nowf()

src/calibre/web/feeds/recipes/collection.py

@@ -201,12 +201,14 @@ class SchedulerConfig(object):
             self.root.append(sr)
             self.write_scheduler_file()
 
-    def customize_recipe(self, urn, add_title_tag, custom_tags):
+    # 'keep_issues' argument for recipe-specific number of copies to keep
+    def customize_recipe(self, urn, add_title_tag, custom_tags, keep_issues):
         with self.lock:
             for x in list(self.iter_customization()):
                 if x.get('id') == urn:
                     self.root.remove(x)
             cs = E.recipe_customization({
+                'keep_issues' : keep_issues,
                 'id' : urn,
                 'add_title_tag' : 'yes' if add_title_tag else 'no',
                 'custom_tags' : ','.join(custom_tags),
@@ -316,17 +318,20 @@ class SchedulerConfig(object):
                 if x.get('id', False) == urn:
                     return x.get('username', ''), x.get('password', '')
 
+    # 'keep_issues' element for recipe-specific number of copies to keep (default 0 == all)
     def get_customize_info(self, urn):
+        keep_issues = 0
         add_title_tag = True
         custom_tags = []
         with self.lock:
             for x in self.iter_customization():
                 if x.get('id', False) == urn:
+                    keep_issues = x.get('keep_issues',0)
                     add_title_tag = x.get('add_title_tag', 'yes') == 'yes'
                     custom_tags = [i.strip() for i in x.get('custom_tags',
                         '').split(',')]
                     break
-        return add_title_tag, custom_tags
+        return add_title_tag, custom_tags, keep_issues
 
     def get_schedule_info(self, urn):
         with self.lock:

src/calibre/web/feeds/recipes/model.py

@@ -354,9 +354,10 @@ class RecipeModel(QAbstractItemModel, SearchQueryParser):
         self.scheduler_config.schedule_recipe(self.recipe_from_urn(urn),
                 sched_type, schedule)
 
-    def customize_recipe(self, urn, add_title_tag, custom_tags):
+    # 'keep_issues' argument for recipe-specific number of copies to keep
+    def customize_recipe(self, urn, add_title_tag, custom_tags, keep_issues):
         self.scheduler_config.customize_recipe(urn, add_title_tag,
-                custom_tags)
+                custom_tags, keep_issues)
 
     def get_to_be_downloaded_recipes(self):
         ans = self.scheduler_config.get_to_be_downloaded_recipes()