From 99043cde28fc633605a5b7b0e34336f5b10cfe64 Mon Sep 17 00:00:00 2001
From: Valentin Deniaud <vdeniaud@entrouvert.com>
Date: Wed, 12 Jan 2022 11:37:52 +0100
Subject: [PATCH 2/5] dataviz: turn dataviz graph into class based view
 (#60547)

---
 .../dataviz/templates/combo/dataviz-error.svg |  8 ++
 combo/apps/dataviz/views.py                   | 74 ++++++++++---------
 2 files changed, 48 insertions(+), 34 deletions(-)
 create mode 100644 combo/apps/dataviz/templates/combo/dataviz-error.svg

diff --git a/combo/apps/dataviz/templates/combo/dataviz-error.svg b/combo/apps/dataviz/templates/combo/dataviz-error.svg
new file mode 100644
index 00000000..ed6948cd
--- /dev/null
+++ b/combo/apps/dataviz/templates/combo/dataviz-error.svg
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg xmlns="http://www.w3.org/2000/svg" version="1.1"
+  viewBox="0 0 {{ width }} 30" width="{{ width }}" height="30">
+  <text
+       y="20"
+       x="10"
+       style="font-family: sans-serif; font-size: 16px; fill:#000000;">{{ text }}</text>
+</svg>
diff --git a/combo/apps/dataviz/views.py b/combo/apps/dataviz/views.py
index ca44ab52..8a5661b0 100644
--- a/combo/apps/dataviz/views.py
+++ b/combo/apps/dataviz/views.py
@@ -16,7 +16,9 @@
 
 from django.core.exceptions import PermissionDenied
 from django.http import Http404, HttpResponse
+from django.shortcuts import render
 from django.utils.translation import ugettext_lazy as _
+from django.views.generic import DetailView
 from requests.exceptions import HTTPError
 
 from combo.utils import get_templated_url, requests
@@ -30,40 +32,44 @@ def ajax_gauge_count(request, *args, **kwargs):
     return HttpResponse(response.content, content_type='text/json')
 
 
-def dataviz_graph(request, *args, **kwargs):
-    cell = ChartNgCell.objects.get(id=kwargs.get('cell'))
-    if not cell.page.is_visible(request.user):
-        raise PermissionDenied()
-    if not cell.is_visible(user=request.user):
-        raise PermissionDenied()
-    if not cell.statistic or not cell.statistic.url:
-        raise Http404('misconfigured cell')
-    error_text = None
-    try:
-        chart = cell.get_chart(
-            width=int(request.GET['width']) if request.GET.get('width') else None,
-            height=int(request.GET['height']) if request.GET.get('height') else int(cell.height),
-        )
-    except UnsupportedDataSet:
-        error_text = _('Unsupported dataset.')
-    except HTTPError as e:
-        if e.response.status_code == 404:
-            error_text = _('Visualization not found.')
-        else:
-            error_text = _('Unknown HTTP error: %s' % e)
+class DatavizGraphView(DetailView):
+    model = ChartNgCell
+    pk_url_kwarg = 'cell'
 
-    if error_text:
-        svg = """<?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<svg xmlns="http://www.w3.org/2000/svg" version="1.1"
-  viewBox="0 0 %(width)s 30" width="%(width)s" height="30">
-  <text
-       y="20"
-       x="10"
-       style="font-family: sans-serif; font-size: 16px; fill:#000000;">%(text)s</text>
-</svg>""" % {
-            'width': request.GET.get('width', 200),
+    def dispatch(self, request, *args, **kwargs):
+        self.cell = self.get_object()
+
+        if not self.cell.page.is_visible(request.user):
+            raise PermissionDenied()
+        if not self.cell.is_visible(user=request.user):
+            raise PermissionDenied()
+        if not self.cell.statistic or not self.cell.statistic.url:
+            raise Http404('misconfigured cell')
+
+        return super().dispatch(request, *args, **kwargs)
+
+    def get(self, request, *args, **kwargs):
+        try:
+            chart = self.cell.get_chart(
+                width=int(request.GET['width']) if request.GET.get('width') else None,
+                height=int(request.GET['height']) if request.GET.get('height') else int(self.cell.height),
+            )
+        except UnsupportedDataSet:
+            return self.svg_error(_('Unsupported dataset.'))
+        except HTTPError as e:
+            if e.response.status_code == 404:
+                return self.svg_error(_('Visualization not found.'))
+            else:
+                return self.svg_error(_('Unknown HTTP error: %s' % e))
+
+        return HttpResponse(chart.render(), content_type='image/svg+xml')
+
+    def svg_error(self, error_text):
+        context = {
+            'width': self.request.GET.get('width', 200),
             'text': error_text,
         }
-    else:
-        svg = chart.render()
-    return HttpResponse(svg, content_type='image/svg+xml')
+        return render(self.request, 'combo/dataviz-error.svg', context=context, content_type='image/svg+xml')
+
+
+dataviz_graph = DatavizGraphView.as_view()
-- 
2.30.2