From cd64fb15e47a8ec1964dfb2726ff7caf34bfc161 Mon Sep 17 00:00:00 2001
From: Gordon Woodhull <gordon@woodhull.com>
Date: Thu, 11 Feb 2016 13:30:36 -0500
Subject: [PATCH] add percentages to pieChart example

workaround for #703

not enough data is currently available to write a `.label()`
function that displays percentages, so this demonstrates using a
pretransition hook to correct the labels
---
 web/examples/pie.html | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/web/examples/pie.html b/web/examples/pie.html
index 220d7dcd8..a43e25923 100644
--- a/web/examples/pie.html
+++ b/web/examples/pie.html
@@ -28,7 +28,13 @@
     .innerRadius(100)
     .dimension(runDimension)
     .group(speedSumGroup)
-    .legend(dc.legend());
+    .legend(dc.legend())
+    // workaround for #703: not enough data is accessible through .label() to display percentages
+    .on('pretransition', function(chart) {
+        chart.selectAll('text.pie-slice').text(function(d) {
+            return d.data.key + ' ' + dc.utils.printSingleValue((d.endAngle - d.startAngle) / (2*Math.PI) * 100) + '%';
+        })
+    });
 
   chart.render();
 });