From 0777933d7dd73a2b91af5577a7c8a9407a6c5629 Mon Sep 17 00:00:00 2001
From: hvelarde <hector.velarde@gmail.com>
Date: Wed, 27 Aug 2014 19:23:12 -0300
Subject: [PATCH] Implement automatic loading of new micro-updates using AJAX
 calls

---
 src/collective/liveblog/browser/__init__.py   |   3 +
 .../liveblog/browser/add_microupdate.py       |  39 +++++++
 .../liveblog/browser/configure.zcml           |   7 ++
 .../liveblog/browser/templates/updates.pt     |  22 ++++
 .../liveblog/{ => browser}/templates/view.pt  |  41 ++++---
 src/collective/liveblog/browser/updates.py    |  38 +++++++
 .../liveblog/{browser.py => browser/view.py}  |  41 ++-----
 src/collective/liveblog/configure.zcml        |   1 +
 .../tests/test_add_microupdate_view.py        |  39 +++++++
 src/collective/liveblog/tests/test_views.py   | 102 ++++++++++++++----
 src/collective/liveblog/utils.py              |   9 ++
 11 files changed, 277 insertions(+), 65 deletions(-)
 create mode 100644 src/collective/liveblog/browser/__init__.py
 create mode 100644 src/collective/liveblog/browser/add_microupdate.py
 create mode 100644 src/collective/liveblog/browser/configure.zcml
 create mode 100644 src/collective/liveblog/browser/templates/updates.pt
 rename src/collective/liveblog/{ => browser}/templates/view.pt (53%)
 create mode 100644 src/collective/liveblog/browser/updates.py
 rename src/collective/liveblog/{browser.py => browser/view.py} (61%)
 create mode 100644 src/collective/liveblog/tests/test_add_microupdate_view.py
 create mode 100644 src/collective/liveblog/utils.py

diff --git a/src/collective/liveblog/browser/__init__.py b/src/collective/liveblog/browser/__init__.py
new file mode 100644
index 0000000..9d624b5
--- /dev/null
+++ b/src/collective/liveblog/browser/__init__.py
@@ -0,0 +1,3 @@
+# -*- coding: utf-8 -*-
+from .view import View  # noqa
+from .add_microupdate import AddMicroUpdateView  # noqa
diff --git a/src/collective/liveblog/browser/add_microupdate.py b/src/collective/liveblog/browser/add_microupdate.py
new file mode 100644
index 0000000..e074e46
--- /dev/null
+++ b/src/collective/liveblog/browser/add_microupdate.py
@@ -0,0 +1,39 @@
+# -*- coding: utf-8 -*-
+from collective.liveblog import _
+from collective.liveblog.adapters import IMicroUpdateContainer
+from collective.liveblog.adapters import MicroUpdate
+from collective.liveblog.interfaces import IBrowserLayer
+from collective.liveblog.interfaces import ILiveblog
+from five import grok
+from plone import api
+from zope.event import notify
+from zope.lifecycleevent import ObjectModifiedEvent
+
+grok.templatedir('templates')
+
+
+class AddMicroUpdateView(grok.View):
+
+    """Add a micro-update to the Liveblog."""
+
+    grok.context(ILiveblog)
+    grok.layer(IBrowserLayer)
+    grok.name('add-microupdate')
+    grok.require('collective.liveblog.AddMicroUpdate')
+
+    def render(self):
+        title = self.request.form.get('title', None)
+        text = self.request.form.get('text', None)
+        if not text:
+            msg = _(u'There were some errors. Required input is missing.')
+            api.portal.show_message(msg, self.request, type='error')
+        else:
+            adapter = IMicroUpdateContainer(self.context)
+            adapter.add(MicroUpdate(title, text))
+
+            # notify the Liveblog has a new micro-update
+            notify(ObjectModifiedEvent(self.context))
+            msg = _(u'Item published.')
+            api.portal.show_message(msg, self.request)
+
+        self.request.response.redirect(self.context.absolute_url())
diff --git a/src/collective/liveblog/browser/configure.zcml b/src/collective/liveblog/browser/configure.zcml
new file mode 100644
index 0000000..d5fb2df
--- /dev/null
+++ b/src/collective/liveblog/browser/configure.zcml
@@ -0,0 +1,7 @@
+<configure
+    xmlns="http://namespaces.zope.org/zope"
+    xmlns:browser="http://namespaces.zope.org/browser"
+    xmlns:i18n="http://namespaces.zope.org/i18n"
+    i18n_domain="collective.liveblog">
+
+</configure>
diff --git a/src/collective/liveblog/browser/templates/updates.pt b/src/collective/liveblog/browser/templates/updates.pt
new file mode 100644
index 0000000..55ce3df
--- /dev/null
+++ b/src/collective/liveblog/browser/templates/updates.pt
@@ -0,0 +1,22 @@
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en"
+    xmlns:tal="http://xml.zope.org/namespaces/tal"
+    xmlns:i18n="http://xml.zope.org/namespaces/i18n"
+    tal:omit-tag=""
+    i18n:domain="collective.liveblog">
+<body tal:omit-tag="">
+    <div id="micro-updates" tal:omit-tag="">
+      <div class="microupdate" data-timestamp=""
+          tal:repeat="update view/updates_since_timestamp"
+          tal:attributes="data-timestamp update/timestamp">
+        <p class="microupdate-title">
+          <strong tal:content="update/title" />
+        </p>
+        <div class="microupdate-text" tal:content="structure update/text" />
+        <p class="microupdate-byline" i18n:translate="">
+          By <span tal:content="update/creator" />
+          <span tal:content="update/time_only" tal:attributes="title update/created" />
+        </p>
+      </div>
+    </div>
+</body>
+</html>
diff --git a/src/collective/liveblog/templates/view.pt b/src/collective/liveblog/browser/templates/view.pt
similarity index 53%
rename from src/collective/liveblog/templates/view.pt
rename to src/collective/liveblog/browser/templates/view.pt
index 49fe3fb..f1d9f6d 100644
--- a/src/collective/liveblog/templates/view.pt
+++ b/src/collective/liveblog/browser/templates/view.pt
@@ -5,6 +5,7 @@
     xmlns:i18n="http://xml.zope.org/namespaces/i18n"
     i18n:domain="collective.liveblog">
 <body>
+  <!-- TODO: https://schema.org/BlogPosting -->
   <metal:block fill-slot="content-core">
     <div tal:condition="view/can_add_microupdate">
       <h2 i18n:translate="">Add micro-update</h2>
@@ -28,21 +29,37 @@
       </form>
     </div>
 
-    <div tal:condition="view/has_updates" tal:repeat="update view/updates">
-      <div>
-        <strong tal:content="update/title" />
+    <div id="micro-updates">
+      <div class="microupdate" data-timestamp=""
+          tal:repeat="update view/updates"
+          tal:attributes="data-timestamp update/timestamp">
+        <p class="microupdate-title">
+          <strong tal:content="update/title" />
+        </p>
+        <div class="microupdate-text" tal:content="structure update/text" />
+        <p class="microupdate-byline" i18n:translate="">
+          By <span tal:content="update/creator" />
+          <span tal:content="update/time_only" tal:attributes="title update/created" />
+        </p>
       </div>
-      <div>
-        <p tal:content="structure update/text" />
-      </div>
-      <div i18n:translate="">
-        By <span tal:content="update/creator" />
-        <span tal:content="update/time_only" tal:attributes="title update/created" />
+      <div class="microupdate" data-timestamp=""
+          tal:condition="not:view/has_updates"
+          tal:attributes="data-timestamp view/now">
+        <p class="microupdate-title">
+          <strong i18n:translate="">No micro-updates yet for this Liveblog.</strong>
+        </p>
+        <div class="microupdate-text" />
+        <p class="microupdate-byline" />
       </div>
     </div>
-    <p tal:condition="not:view/has_updates" i18n:translate="">
-        No micro-updates yet for this Liveblog.
-    </p>
+    <script type="text/javascript">
+        setInterval(function() {
+            var timestamp = $(".microupdate").attr("data-timestamp");
+            $.get("updates?timestamp=" + timestamp, function(data) {
+                $("#micro-updates").prepend(data).fadeIn("slow");
+            });
+        }, 1000 * 60);
+    </script>
   </metal:block>
 </body>
 </html>
diff --git a/src/collective/liveblog/browser/updates.py b/src/collective/liveblog/browser/updates.py
new file mode 100644
index 0000000..9a5abdd
--- /dev/null
+++ b/src/collective/liveblog/browser/updates.py
@@ -0,0 +1,38 @@
+# -*- coding: utf-8 -*-
+from collective.liveblog.interfaces import IBrowserLayer
+from collective.liveblog.interfaces import ILiveblog
+from five import grok
+from plone.memoize import ram
+from time import time
+
+grok.templatedir('templates')
+
+
+class Updates(grok.View):
+
+    """Helper view for Liveblog."""
+
+    grok.context(ILiveblog)
+    grok.layer(IBrowserLayer)
+    grok.require('zope2.View')
+
+    def _updates_since_timestamp(self):
+        """Return the list of micro-updates since the specified timestamp."""
+        timestamp = self.request.get('timestamp', None)
+
+        # timestamp should a string representing a float
+        try:
+            float(timestamp)
+        except (TypeError, ValueError):
+            return []
+
+        updates = self.context.restrictedTraverse('view').updates()
+        updates = [u for u in updates if u['timestamp'] > timestamp]
+        return updates
+
+    @ram.cache(lambda *args: time() // 20)
+    def updates_since_timestamp(self):
+        """Return the list of micro-updates since the specified timestamp;
+        the list is cached for 20 seconds.
+        """
+        return self._updates_since_timestamp()
diff --git a/src/collective/liveblog/browser.py b/src/collective/liveblog/browser/view.py
similarity index 61%
rename from src/collective/liveblog/browser.py
rename to src/collective/liveblog/browser/view.py
index e66c032..6d14f9c 100644
--- a/src/collective/liveblog/browser.py
+++ b/src/collective/liveblog/browser/view.py
@@ -1,14 +1,12 @@
 # -*- coding: utf-8 -*-
-from collective.liveblog import _
 from collective.liveblog.adapters import IMicroUpdateContainer
-from collective.liveblog.adapters import MicroUpdate
 from collective.liveblog.interfaces import IBrowserLayer
 from collective.liveblog.interfaces import ILiveblog
+from collective.liveblog.utils import _timestamp
+from datetime import datetime
 from five import grok
 from plone import api
 from plone.memoize import ram
-from zope.event import notify
-from zope.lifecycleevent import ObjectModifiedEvent
 
 grok.templatedir('templates')
 
@@ -42,6 +40,7 @@ def _updates(self):
             updates.append(dict(
                 id=id + 1,
                 creator=update.creator,
+                timestamp=_timestamp(update.created),
                 created=api.portal.get_localized_time(update.created, True),
                 time_only=api.portal.get_localized_time(update.created, time_only=True),
                 title=update.title,
@@ -52,35 +51,17 @@ def _updates(self):
 
     @ram.cache(_render_updates_cachekey)
     def updates(self):
+        """Return the list of micro-updates in the Liveblog in reverse order;
+        the list is cached until a new update is published.
+        """
         return self._updates()
 
     @property
     def has_updates(self):
+        """Return True if Liveblog has updates."""
         return len(self.updates()) > 0
 
-
-class AddMicroUpdateView(grok.View):
-
-    """Add a micro-update to the Liveblog."""
-
-    grok.context(ILiveblog)
-    grok.layer(IBrowserLayer)
-    grok.name('add-microupdate')
-    grok.require('collective.liveblog.AddMicroUpdate')
-
-    def render(self):
-        title = self.request.form.get('title', None)
-        text = self.request.form.get('text', None)
-        if not text:
-            msg = _(u'There were some errors. Required input is missing.')
-            api.portal.show_message(msg, self.request, type='error')
-        else:
-            adapter = IMicroUpdateContainer(self.context)
-            adapter.add(MicroUpdate(title, text))
-
-            # notify the Liveblog has a new micro-update
-            notify(ObjectModifiedEvent(self.context))
-            msg = _(u'Item published.')
-            api.portal.show_message(msg, self.request)
-
-        self.request.response.redirect(self.context.absolute_url())
+    @property
+    def now(self):
+        """Return a timestamp for the current date and time."""
+        return _timestamp(datetime.now())
diff --git a/src/collective/liveblog/configure.zcml b/src/collective/liveblog/configure.zcml
index 995267b..68b1637 100644
--- a/src/collective/liveblog/configure.zcml
+++ b/src/collective/liveblog/configure.zcml
@@ -30,6 +30,7 @@
   <include file="profiles.zcml" />
 
   <browser:resourceDirectory name="collective.liveblog" directory="static" />
+  <include package=".browser" />
 
   <adapter
       for=".interfaces.ILiveblog"
diff --git a/src/collective/liveblog/tests/test_add_microupdate_view.py b/src/collective/liveblog/tests/test_add_microupdate_view.py
new file mode 100644
index 0000000..be27eea
--- /dev/null
+++ b/src/collective/liveblog/tests/test_add_microupdate_view.py
@@ -0,0 +1,39 @@
+# -*- coding: utf-8 -*-
+from collective.liveblog.interfaces import IBrowserLayer
+from collective.liveblog.testing import FUNCTIONAL_TESTING
+from plone import api
+from Products.statusmessages.interfaces import IStatusMessage
+from zope.interface import alsoProvides
+
+import unittest
+
+
+class AddMicroUpdateViewTestCase(unittest.TestCase):
+
+    layer = FUNCTIONAL_TESTING
+
+    def setUp(self):
+        self.portal = self.layer['portal']
+        self.request = self.layer['request']
+        alsoProvides(self.request, IBrowserLayer)
+        with api.env.adopt_roles(['Manager']):
+            self.liveblog = api.content.create(
+                self.portal, 'Liveblog', 'liveblog')
+
+    def test_add_microupdate_no_parameters(self):
+        # invoke the view and check the status message
+        self.liveblog.unrestrictedTraverse('add-microupdate')()
+        msg = IStatusMessage(self.request).show()
+        self.assertEqual(len(msg), 1)
+        expected = u'There were some errors. Required input is missing.'
+        self.assertEqual(msg[0].message, expected)
+
+    def test_add_microupdate(self):
+        self.request.form['title'] = ''
+        self.request.form['text'] = 'Extra! Extra! Read All About It!'
+        # invoke the view and check the status message
+        self.liveblog.unrestrictedTraverse('add-microupdate')()
+        msg = IStatusMessage(self.request).show()
+        self.assertEqual(len(msg), 1)
+        expected = u'Item published.'
+        self.assertEqual(msg[0].message, expected)
diff --git a/src/collective/liveblog/tests/test_views.py b/src/collective/liveblog/tests/test_views.py
index 9cd2637..7aec011 100644
--- a/src/collective/liveblog/tests/test_views.py
+++ b/src/collective/liveblog/tests/test_views.py
@@ -1,39 +1,95 @@
 # -*- coding: utf-8 -*-
+from collective.liveblog.adapters import IMicroUpdateContainer
+from collective.liveblog.adapters import MicroUpdate
 from collective.liveblog.interfaces import IBrowserLayer
-from collective.liveblog.testing import FUNCTIONAL_TESTING
+from collective.liveblog.testing import INTEGRATION_TESTING
+from datetime import datetime
 from plone import api
-from Products.statusmessages.interfaces import IStatusMessage
-from zope.interface import directlyProvides
+from time import sleep
+from zope.interface import alsoProvides
 
 import unittest
 
 
-class AddMicroUpdateViewTestCase(unittest.TestCase):
+class ViewTestCase(unittest.TestCase):
 
-    layer = FUNCTIONAL_TESTING
+    layer = INTEGRATION_TESTING
+
+    def _create_updates(self):
+        """Create 20 micro-updates. Note the use of the sleep method to avoid
+        doing this so fast that we ended with the same timestamp on different
+        updates."""
+        adapter = IMicroUpdateContainer(self.liveblog)
+        for i in range(1, 11):
+            sleep(0.01)
+            adapter.add(MicroUpdate(str(i), str(i)))
+
+        self.timestamp = datetime.now()
+
+        for i in range(11, 21):
+            sleep(0.01)
+            adapter.add(MicroUpdate(str(i), str(i)))
 
     def setUp(self):
         self.portal = self.layer['portal']
         self.request = self.layer['request']
-        directlyProvides(self.request, IBrowserLayer)
+        alsoProvides(self.request, IBrowserLayer)
         with api.env.adopt_roles(['Manager']):
             self.liveblog = api.content.create(
                 self.portal, 'Liveblog', 'liveblog')
 
-    def test_add_microupdate_no_parameters(self):
-        # invoke the view and check the status message
-        self.liveblog.unrestrictedTraverse('add-microupdate')()
-        msg = IStatusMessage(self.request).show()
-        self.assertEqual(len(msg), 1)
-        expected = u'There were some errors. Required input is missing.'
-        self.assertEqual(msg[0].message, expected)
-
-    def test_add_microupdate(self):
-        self.request.form['title'] = ''
-        self.request.form['text'] = 'Extra! Extra! Read All About It!'
-        # invoke the view and check the status message
-        self.liveblog.unrestrictedTraverse('add-microupdate')()
-        msg = IStatusMessage(self.request).show()
-        self.assertEqual(len(msg), 1)
-        expected = u'Item published.'
-        self.assertEqual(msg[0].message, expected)
+
+class DefaultViewTestCase(ViewTestCase):
+
+    def setUp(self):
+        super(DefaultViewTestCase, self).setUp()
+        self.view = api.content.get_view('view', self.liveblog, self.request)
+
+    def test_can_add_microupdate(self):
+        with api.env.adopt_roles(['Manager']):
+            self.assertTrue(self.view.can_add_microupdate)
+        with api.env.adopt_roles(['Reader']):
+            self.assertFalse(self.view.can_add_microupdate)
+        with api.env.adopt_roles(['Reviewer']):
+            self.assertFalse(self.view.can_add_microupdate)
+
+    def test_updates(self):
+        self.assertEqual(len(self.view._updates()), 0)
+        self._create_updates()
+        self.assertEqual(len(self.view._updates()), 20)
+
+    def test_has_updates(self):
+        self.assertFalse(self.view.has_updates)
+        self._create_updates()
+        self.assertTrue(self.view.has_updates)
+
+
+class UpdatesViewTestCase(ViewTestCase):
+
+    def setUp(self):
+        super(UpdatesViewTestCase, self).setUp()
+        self.view = api.content.get_view('updates', self.liveblog, self.request)
+
+    def test_updates_since_timestamp(self):
+        from collective.liveblog.utils import _timestamp
+
+        timestamp = datetime.now()
+        self._create_updates()
+
+        # before all elements were created
+        self.request['timestamp'] = _timestamp(timestamp)
+        self.assertEqual(len(self.view._updates_since_timestamp()), 20)
+        # middle of the creation
+        self.request['timestamp'] = _timestamp(self.timestamp)
+        self.assertEqual(len(self.view._updates_since_timestamp()), 10)
+        # after all elements were created
+        self.request['timestamp'] = _timestamp(datetime.now())
+        self.assertEqual(len(self.view._updates_since_timestamp()), 0)
+
+        self.request['timestamp'] = _timestamp(self.timestamp)
+        updates = self.view._updates_since_timestamp()
+        updates = [u['title'] for u in updates]
+        self.assertIn('20', updates)
+        self.assertIn('11', updates)
+        self.assertNotIn('10', updates)
+        self.assertNotIn('1', updates)
diff --git a/src/collective/liveblog/utils.py b/src/collective/liveblog/utils.py
new file mode 100644
index 0000000..8a5d8e2
--- /dev/null
+++ b/src/collective/liveblog/utils.py
@@ -0,0 +1,9 @@
+# -*- coding: utf-8 -*-
+from datetime import datetime
+
+
+def _timestamp(dt):
+    """Return a timestamp from a datetime object."""
+    epoch = datetime.utcfromtimestamp(0)
+    delta = dt - epoch
+    return str(delta.total_seconds())