From cde821a30a510f957f9e9150f2e44f981c5f716c Mon Sep 17 00:00:00 2001
From: Pim Vernooij <pim.vernooij@gmail.com>
Date: Mon, 12 Dec 2016 23:29:19 +0100
Subject: [PATCH] implement conditional rendering in block

---
 src/personalisation/blocks.py | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/personalisation/blocks.py b/src/personalisation/blocks.py
index 105fa08..6f56113 100644
--- a/src/personalisation/blocks.py
+++ b/src/personalisation/blocks.py
@@ -3,10 +3,23 @@ from personalisation.models import Segment
 
 class PersonalisedStructBlock(blocks.StructBlock):
 
-    if Segment.objects.count() > 0:
-    	segment = blocks.ChoiceBlock(choices=[
-            (segment.pk, "{} ({})".format(segment.name, segment.status) ) \
-                for segment in Segment.objects.all()
+    segment = blocks.ChoiceBlock(choices=[
+        (segment.pk, "{} ({})".format(segment.name, segment.status) ) \
+            for segment in Segment.objects.all()
         ], required=False, label="Personalisation segment",
         help_text="Only show this content block for users in this segment")
 
+
+    def render(self, value, context=None):
+        """Only render block when the user is in the segment the block is
+        meant for"""
+
+        user_segments = context['request'].session['segments']
+
+        if value['segment']:
+            for segment in user_segments:
+                if segment['id'] == int(value['segment']):
+                    return super(PersonalisedStructBlock, self).render(value,
+                        context)
+
+        return ""