dataviz: truncate horizontal bar labels in narrow graphs (#39920)

combo/apps/dataviz/models.py

@@ -26,6 +26,7 @@ from django.conf import settings
 from jsonfield import JSONField
 from requests.exceptions import HTTPError
 import pygal
+import pygal.util
 
 from combo.data.models import CellBase
 from combo.data.library import register_cell_class
@@ -272,6 +273,9 @@ class ChartNgCell(CellBase):
                 chart.add(serie_label, values)
             if width and width < 500:
                 chart.legend_at_bottom = True
+                if self.chart_type == 'horizontal-bar':
+                    # truncate labels
+                    chart.x_labels = [pygal.util.truncate(x, 15) for x in chart.x_labels]
         else:
             # pie, create a serie by data, to get different colours
             values = data