diff --git a/piwik/indico_piwik/controllers.py b/piwik/indico_piwik/controllers.py
index 0835382..8a2bc2d 100644
--- a/piwik/indico_piwik/controllers.py
+++ b/piwik/indico_piwik/controllers.py
@@ -2,11 +2,10 @@ from flask import jsonify
 
 from indico.core.config import Config
 from indico.util.i18n import _
-from MaKaC.conference import ConferenceHolder
 from MaKaC.webinterface.rh.conferenceModif import RHConferenceModifBase
 
 from .views import WPStatistics
-from .reports import ReportCountries, ReportDevices, ReportDownloads, ReportGeneral, ReportVisitsPerDay
+from .reports import ReportCountries, ReportDevices, ReportDownloads, ReportGeneral, ReportMaterial, ReportVisitsPerDay
 
 
 class RHStatistics(RHConferenceModifBase):
@@ -62,76 +61,6 @@ class RHApiEventGraphDevices(RHApiEventBase):
         return jsonify(ReportDevices.get(**self._report_params))
 
 
-class RHApiMaterial(RHApiBase):
-    """
-    HTTP method for getting the Material dictionary of a Conference in
-    the format jqTree expects.
-    """
-
-    TREE_STR_LIMIT = 24
-
-    # @BaseStatisticsImplementation.memoizeReport
+class RHApiMaterial(RHApiEventBase):
     def _process(self):
-        confId = self._conf.getId()
-        conference = ConferenceHolder().getById(confId)
-        material = conference.getAllMaterialDict()
-
-        return self.formatForJQTree(material, returnAsList=True)
-
-    def formatForJQTree(self, child, returnAsList=False):
-        """
-        Wraps around the JSON output in Conference to the specific
-        format required by jqTree.
-        """
-
-        node = {}
-        node['label'] = child['title']
-        node['children'] = []
-
-        for key, value in child.iteritems():
-
-            if key not in ['children', 'material']:  # Performance only
-                continue
-
-            children = []
-
-            if key == 'children' and len(value) > 0:
-
-                for child in value:
-                    newNode = self.formatForJQTree(child)
-
-                    if newNode:
-                        children.append(newNode)
-
-            if key == 'material' and len(value) > 0:
-
-                for material in value:
-                    newNode = {}
-                    newNode['label'] = material['title']
-                    newNode['id'] = material['url']
-
-                    children.append(newNode)
-
-            if children:
-                node['children'].extend(children)
-
-        # If the node has no children (i.e. Sessions, Contributions & Material,
-        # then there is no point in displaying it in the tree.
-        if len(node['children']) > 0:
-
-            self.shortenNodeLabel(node)
-
-            for child in node['children']:
-                self.shortenNodeLabel(child)
-
-            return [node] if returnAsList else node
-        else:
-            return None
-
-    def shortenNodeLabel(self, node):
-        """
-        We don't want the strings to be massive in the labels, truncate them
-        to make the tree more manageable.
-        """
-        if len(node['label']) > self.TREE_STR_LIMIT:
-            node['label'] = node['label'][:self.TREE_STR_LIMIT] + '...'
+        return jsonify(ReportMaterial.get(**self._report_params))
diff --git a/piwik/indico_piwik/reports.py b/piwik/indico_piwik/reports.py
index eee56e2..d5e1dbd 100644
--- a/piwik/indico_piwik/reports.py
+++ b/piwik/indico_piwik/reports.py
@@ -20,8 +20,6 @@ class ReportBase(Serializer):
     default_report_interval = 14
 
     def __init__(self, event_id, contrib_id=None, start_date=None, end_date=None, **report_params):
-        self.graphs = {}
-        self.metrics = {}
         self.event_id = event_id
         self.contrib_id = contrib_id
         self._init_date_range(start_date, end_date)
@@ -74,21 +72,21 @@ class ReportCountries(ReportBase):
     __public__ = ['graphs']
 
     def _build_report(self):
-        self.graphs['countries'] = PiwikQueryReportEventGraphCountries(**self.params).get_result()
+        self.graphs = {'countries': PiwikQueryReportEventGraphCountries(**self.params).get_result()}
 
 
 class ReportDevices(ReportBase):
     __public__ = ['graphs']
 
     def _build_report(self):
-        self.graphs['devices'] = PiwikQueryReportEventGraphDevices(**self.params).get_result()
+        self.graphs = {'devices': PiwikQueryReportEventGraphDevices(**self.params).get_result()}
 
 
 class ReportDownloads(ReportBase):
     __public__ = ['metrics']
 
     def _build_report(self, download_url):
-        self.metrics['downloads'] = PiwikQueryReportEventMetricDownloads(**self.params).get_result(download_url)
+        self.metrics = {'downloads': PiwikQueryReportEventMetricDownloads(**self.params).get_result(download_url)}
 
 
 class ReportGeneral(ReportBase):
@@ -96,6 +94,7 @@ class ReportGeneral(ReportBase):
 
     def _build_report(self):
         """Build the report by performing queries to Piwik"""
+        self.metrics = {}
         queries = {'visits': PiwikQueryReportEventMetricVisits(**self.params),
                    'unique_visits': PiwikQueryReportEventMetricUniqueVisits(**self.params),
                    'visit_duration': PiwikQueryReportEventMetricVisitDuration(**self.params),
@@ -121,12 +120,57 @@ class ReportGeneral(ReportBase):
             self.contributions[contrib_id] = info
 
 
+class ReportMaterial(ReportBase):
+    __public__ = ['material']
+    tree_string_length = 24
+
+    def _build_report(self):
+        event = ConferenceHolder().getById(self.params['event_id'])
+        material = event.getAllMaterialDict()
+        self.material = {'tree': self._format_data(material, as_list=True)}
+
+    def _format_data(self, child, as_list=False):
+        node = {'label': child['title'],
+                'children': []}
+
+        for key, value in child.iteritems():
+            if key not in ['children', 'material']:
+                continue
+
+            children = []
+            if key == 'children' and value:
+                for child in value:
+                    new_node = self._format_data(child)
+                    if new_node:
+                        children.append(new_node)
+            if key == 'material' and value:
+                for material in value:
+                    new_node = {'label': material['title'],
+                                'id': material['url']}
+                    children.append(new_node)
+            if children:
+                node['children'].extend(children)
+
+        if not node['children']:
+            return None
+
+        self._truncate_node_label(node)
+        for child in node['children']:
+            self._truncate_node_label(child)
+
+        return [node] if as_list else node
+
+    def _truncate_node_label(self, node):
+        if len(node['label']) > self.tree_string_length:
+            node['label'] = node['label'][:self.tree_string_length] + '...'
+
+
 class ReportVisitsPerDay(ReportBase):
     __public__ = ['metrics']
 
     def _build_report(self):
-        self.metrics['unique'] = PiwikQueryReportEventMetricUniqueVisits(**self.params).get_result(reduced=False)
-        self.metrics['total'] = PiwikQueryReportEventMetricVisits(**self.params).get_result(reduced=False)
+        self.metrics = {'unique': PiwikQueryReportEventMetricUniqueVisits(**self.params).get_result(reduced=False),
+                        'total': PiwikQueryReportEventMetricVisits(**self.params).get_result(reduced=False)}
         self._reduce_metrics()
 
     def _reduce_metrics(self):