dataviz: add pie percent chart type (#71666)

combo/apps/dataviz/migrations/0011_auto_20200813_1100.py

@@ -45,6 +45,7 @@ class Migration(migrations.Migration):
                     ('stacked-bar-percent', 'Stacked Bar (%)'),
                     ('line', 'Line'),
                     ('pie', 'Pie'),
+                    ('pie-percent', 'Pie (%)'),
                     ('dot', 'Dot'),
                     ('table', 'Table'),
                     ('table-inverted', 'Table (inverted)'),

combo/apps/dataviz/models.py

@@ -241,6 +241,7 @@ class ChartNgCell(CellBase):
             ('stacked-bar-percent', _('Stacked Bar (%)')),
             ('line', _('Line')),
             ('pie', _('Pie')),
+            ('pie-percent', _('Pie (%)')),
             ('dot', _('Dot')),
             ('table', _('Table')),
             ('table-inverted', _('Table (inverted)')),
@@ -381,6 +382,7 @@ class ChartNgCell(CellBase):
             'stacked-bar-percent': pygal.StackedBar,
             'line': pygal.Line,
             'pie': pygal.Pie,
+            'pie-percent': pygal.Pie,
             'dot': pygal.Dot,
             'table': pygal.Bar,
             'table-inverted': pygal.Bar,
@@ -418,7 +420,7 @@ class ChartNgCell(CellBase):
                 data['series'][0]['data'] = self.process_one_dimensional_data(
                     chart, data['series'][0]['data']
                 )
-                if self.chart_type == 'pie':
+                if self.chart_type in ('pie', 'pie-percent'):
                     data['series'] = [
                         {'label': chart.config.x_value_formatter(label), 'data': [data]}
                         for label, data in zip(chart.x_labels, data['series'][0]['data'])
@@ -429,6 +431,9 @@ class ChartNgCell(CellBase):
 
             if self.chart_type == 'stacked-bar-percent':
                 self.make_percent([serie['data'] for serie in data['series']])
+            elif self.chart_type == 'pie-percent':
+                self.make_global_percent([serie['data'] for serie in data['series']])
+                chart.config.value_formatter = self.get_value_formatter(measure='percent')
 
             for serie in data['series']:
                 chart.add(serie['label'], serie['data'])
@@ -586,6 +591,9 @@ class ChartNgCell(CellBase):
         elif width:
             chart.truncate_legend = width // 20
 
+    def configure_pie_percent_chart(self, *args, **kwargs):
+        self.configure_pie_chart(*args, **kwargs)
+
     def configure_chart(self, chart, width, height):
         auto_height_scale = pygal.style.DefaultStyle.legend_font_size * 1.75
         chart.config.margin = 0
@@ -620,7 +628,7 @@ class ChartNgCell(CellBase):
         if hasattr(self, custom_configure_method_name):
             getattr(self, custom_configure_method_name)(chart, width, height)
 
-        if self.chart_type != 'pie':
+        if self.chart_type not in ('pie', 'pie-percent'):
             if width and width < 500:
                 chart.legend_at_bottom = True
                 # restore demanded chart's height
@@ -698,7 +706,7 @@ class ChartNgCell(CellBase):
             chart.add(gettext('Total'), line_totals)
 
     def add_data_to_chart(self, chart, data, y_labels):
-        if self.chart_type != 'pie':
+        if self.chart_type not in ('pie', 'pie-percent'):
             series_data = []
             for i, serie_label in enumerate(y_labels):
                 if chart.axis_count < 2:
@@ -718,7 +726,7 @@ class ChartNgCell(CellBase):
                 chart.add(label, value)
 
     @staticmethod
-    def get_value_formatter(unit, measure='duration'):
+    def get_value_formatter(unit=None, measure='duration'):
         if unit == 'seconds' or measure == 'duration':
 
             def format_duration(value):
@@ -743,6 +751,17 @@ class ChartNgCell(CellBase):
                 if values[i] is not None:
                     values[i] = round(values[i] * factor, 1)
 
+    def make_global_percent(self, series_data):
+        sum_values = sum(v for values in series_data for v in values if v is not None)
+        if sum_values == 0:
+            return
+
+        factor = 100 / sum_values
+        for serie in series_data:
+            for i, value in enumerate(serie):
+                if value is not None:
+                    serie[i] = round(value * factor, 1)
+
     @staticmethod
     def aggregate_data(data, interval):
         series_data = [serie['data'] for serie in data['series']]

tests/test_dataviz.py

@@ -1011,6 +1011,24 @@ def test_chartng_cell_new_api(app, new_api_statistics):
     assert chart.x_labels == []
     assert chart.raw_series == []
 
+    # pie with percent
+    cell.statistic = Statistic.objects.get(slug='two-series')
+    cell.chart_type = 'pie-percent'
+    cell.save()
+
+    chart = cell.get_chart()
+    assert chart.raw_series == [
+        ([None, 76.2, 9.5], {'title': 'Serie 1'}),
+        ([9.5, 4.8, None], {'title': 'Serie 2'}),
+    ]
+
+    cell.statistic = Statistic.objects.get(slug='no-data')
+    cell.save()
+
+    chart = cell.get_chart()
+    assert chart.x_labels == []
+    assert chart.raw_series == []
+
     cell.statistic = Statistic.objects.get(slug='not-found')
     cell.save()
     with pytest.raises(HTTPError):