# HG changeset patch
# User Ludovic Chabant <ludovic@chabant.com>
# Date 1408406027 25200
# Node ID dc72a288921fbd04b8662450668c8aca48289f18
# Parent  0170f449f924c651a188108f491ec557ab7ca5b7
Add the `paginate` filter to Jinja, activate `auto_reload`.

diff -r 0170f449f924 -r dc72a288921f piecrust/templating/jinjaengine.py
--- a/piecrust/templating/jinjaengine.py	Mon Aug 18 16:53:26 2014 -0700
+++ b/piecrust/templating/jinjaengine.py	Mon Aug 18 16:53:47 2014 -0700
@@ -9,6 +9,7 @@
 from pygments import highlight
 from pygments.formatters import HtmlFormatter
 from pygments.lexers import get_lexer_by_name, guess_lexer
+from piecrust.data.paginator import Paginator
 from piecrust.rendering import format_text
 from piecrust.routing import CompositeRouteFunction
 from piecrust.templating.base import TemplateEngine, TemplateNotFoundError
@@ -69,9 +70,11 @@
     def __init__(self, app, *args, **kwargs):
         super(PieCrustEnvironment, self).__init__(*args, **kwargs)
         self.app = app
+        self.auto_reload = True
         self.globals.update({
                 'fail': raise_exception})
         self.filters.update({
+                'paginate': self._paginate,
                 'formatwith': self._formatWith,
                 'markdown': lambda v: self._formatWith(v, 'markdown'),
                 'textile': lambda v: self._formatWith(v, 'textile'),
@@ -107,6 +110,15 @@
                                 "existing function or template data." %
                                 name)
 
+    def _paginate(self, value, items_per_page=5):
+        cpi = self.app.env.exec_info_stack.current_page_info
+        if cpi is None or cpi.page is None or cpi.render_ctx is None:
+            raise Exception("Can't paginate when no page has been pushed "
+                            "on the execution stack.")
+        return Paginator(cpi.page, value, cpi.render_ctx.uri,
+                page_num=cpi.render_ctx.page_num,
+                items_per_page=items_per_page)
+
     def _formatWith(self, value, format_name):
         return format_text(self.app, format_name, value)