--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/piecrust/sources/mixins.py	Wed Feb 18 18:35:03 2015 -0800
@@ -0,0 +1,139 @@
+import os
+import os.path
+import logging
+from piecrust.data.base import PaginationData
+from piecrust.data.filters import PaginationFilter
+from piecrust.sources.base import PageFactory
+from piecrust.sources.interfaces import IPaginationSource, IListableSource
+
+
+logger = logging.getLogger(__name__)
+
+
+class SourceFactoryIterator(object):
+    def __init__(self, source):
+        self.source = source
+
+        # This is to permit recursive traversal of the
+        # iterator chain. It acts as the end.
+        self.it = None
+
+    def __iter__(self):
+        return self.source.getPages()
+
+
+class DateSortIterator(object):
+    def __init__(self, it, reverse=True):
+        self.it = it
+        self.reverse = reverse
+
+    def __iter__(self):
+        return iter(sorted(self.it,
+                           key=lambda x: x.datetime, reverse=self.reverse))
+
+
+class PaginationDataBuilderIterator(object):
+    def __init__(self, it):
+        self.it = it
+
+    def __iter__(self):
+        for page in self.it:
+            if page is None:
+                yield None
+            else:
+                yield PaginationData(page)
+
+
+def page_setting_accessor(item, name):
+    return item.config.get(name)
+
+
+class SimplePaginationSourceMixin(IPaginationSource):
+    """ Implements the `IPaginationSource` interface in a standard way that
+        should fit most page sources.
+    """
+    def getItemsPerPage(self):
+        return self.config['items_per_page']
+
+    def getSourceIterator(self):
+        return SourceFactoryIterator(self)
+
+    def getSorterIterator(self, it):
+        return DateSortIterator(it)
+
+    def getTailIterator(self, it):
+        return PaginationDataBuilderIterator(it)
+
+    def getPaginationFilter(self, page):
+        conf = (page.config.get('items_filters') or
+                page.app.config.get('site/items_filters'))
+        if conf == 'none' or conf == 'nil' or conf == '':
+            conf = None
+        if conf is not None:
+            f = PaginationFilter()
+            f.addClausesFromConfig(conf)
+            return f
+        return None
+
+    def getSettingAccessor(self):
+        return page_setting_accessor
+
+
+class SimpleListableSourceMixin(IListableSource):
+    """ Implements the `IListableSource` interface for sources that map to
+        simple file-system structures.
+    """
+    def listPath(self, rel_path):
+        rel_path = rel_path.lstrip('\\/')
+        path = self._getFullPath(rel_path)
+        names = self._sortFilenames(os.listdir(path))
+
+        items = []
+        for name in names:
+            if os.path.isdir(os.path.join(path, name)):
+                if self._filterPageDirname(name):
+                    rel_subdir = os.path.join(rel_path, name)
+                    items.append((True, name, rel_subdir))
+            else:
+                if self._filterPageFilename(name):
+                    slug = self._makeSlug(os.path.join(rel_path, name))
+                    metadata = {'slug': slug}
+
+                    fac_path = name
+                    if rel_path != '.':
+                        fac_path = os.path.join(rel_path, name)
+                    fac_path = fac_path.replace('\\', '/')
+
+                    self._populateMetadata(fac_path, metadata)
+                    fac = PageFactory(self, fac_path, metadata)
+
+                    name, _ = os.path.splitext(name)
+                    items.append((False, name, fac))
+        return items
+
+    def getDirpath(self, rel_path):
+        return os.path.dirname(rel_path)
+
+    def getBasename(self, rel_path):
+        filename = os.path.basename(rel_path)
+        name, _ = os.path.splitext(filename)
+        return name
+
+    def _getFullPath(self, rel_path):
+        return os.path.join(self.fs_endpoint_path, rel_path)
+
+    def _sortFilenames(self, names):
+        return sorted(names)
+
+    def _filterPageDirname(self, name):
+        return True
+
+    def _filterPageFilename(self, name):
+        return True
+
+    def _makeSlug(self, rel_path):
+        return rel_path.replace('\\', '/')
+
+    def _populateMetadata(self, rel_path, metadata, mode=None):
+        pass
+