From 107f9d8e86feef0bd886393edd40944c587ac2e7 Mon Sep 17 00:00:00 2001
From: Dan Vanderkam <danvk@google.com>
Date: Tue, 3 Jan 2012 18:52:24 -0500
Subject: [PATCH] Only show the secondary y-axis label when there is a
 secondary y-axis.

---
 auto_tests/tests/multiple_axes.js | 65 +++++++++++++++++++++++++++------------
 dygraph-canvas.js                 |  2 +-
 tests/two-axes.html               |  3 +-
 3 files changed, 48 insertions(+), 22 deletions(-)

diff --git a/auto_tests/tests/multiple_axes.js b/auto_tests/tests/multiple_axes.js
index 2c0f18f..bf75876 100644
--- a/auto_tests/tests/multiple_axes.js
+++ b/auto_tests/tests/multiple_axes.js
@@ -24,6 +24,17 @@ function getLegend() {
   return legend.textContent;
 }
 
+// returns all text in tags w/ a given css class, sorted.
+function getClassTexts(css_class) {
+  var texts = [];
+  var els = document.getElementsByClassName(css_class);
+  for (var i = 0; i < els.length; i++) {
+    texts[i] = els[i].textContent;
+  }
+  texts.sort();
+  return texts;
+}
+
 MultipleAxesTestCase.getData = function() {
   var data = [];
   for (var i = 1; i <= 100; i++) {
@@ -45,7 +56,7 @@ MultipleAxesTestCase.getData = function() {
 MultipleAxesTestCase.prototype.testBasicMultipleAxes = function() {
   var data = MultipleAxesTestCase.getData();
 
-  g = new Dygraph(
+  var g = new Dygraph(
     document.getElementById("graph"),
     data,
     {
@@ -71,7 +82,7 @@ MultipleAxesTestCase.prototype.testBasicMultipleAxes = function() {
 MultipleAxesTestCase.prototype.testNewStylePerAxisOptions = function() {
   var data = MultipleAxesTestCase.getData();
 
-  g = new Dygraph(
+  var g = new Dygraph(
     document.getElementById("graph"),
     data,
     {
@@ -101,7 +112,7 @@ MultipleAxesTestCase.prototype.testMultiAxisLayout = function() {
 
   var el = document.getElementById("graph");
 
-  g = new Dygraph(
+  var g = new Dygraph(
     el,
     data,
     {
@@ -178,7 +189,7 @@ MultipleAxesTestCase.prototype.testMultiChartLabels = function() {
   el.style.marginLeft = '200px';
   el.style.marginTop = '200px';
 
-  g = new Dygraph(
+  var g = new Dygraph(
     el,
     data,
     {
@@ -198,23 +209,37 @@ MultipleAxesTestCase.prototype.testMultiChartLabels = function() {
     }
   );
 
-  // returns all text in tags w/ a given css class, sorted.
-  function getTexts(css_class) {
-    var texts = [];
-    var els = document.getElementsByClassName(css_class);
-    for (var i = 0; i < els.length; i++) {
-      texts[i] = els[i].textContent;
-    }
-    texts.sort();
-    return texts;
-  }
-
   assertEquals(["Chart title", "x-axis", "y-axis", "y2-axis"],
-               getTexts("dygraph-label"));
-  assertEquals(["Chart title"], getTexts("dygraph-title"));
-  assertEquals(["x-axis"], getTexts("dygraph-xlabel"));
-  assertEquals(["y-axis"], getTexts("dygraph-ylabel"));
-  assertEquals(["y2-axis"], getTexts("dygraph-y2label"));
+               getClassTexts("dygraph-label"));
+  assertEquals(["Chart title"], getClassTexts("dygraph-title"));
+  assertEquals(["x-axis"], getClassTexts("dygraph-xlabel"));
+  assertEquals(["y-axis"], getClassTexts("dygraph-ylabel"));
+  assertEquals(["y2-axis"], getClassTexts("dygraph-y2label"));
 
   // TODO(danvk): check relative positioning here: title on top, y left of y2.
 };
+
+// Check that a chart w/o a secondary y-axis will not get a y2label, even if one
+// is specified.
+MultipleAxesTestCase.prototype.testNoY2LabelWithoutSecondaryAxis = function() {
+  var g = new Dygraph(
+    document.getElementById("graph"),
+    MultipleAxesTestCase.getData(),
+    {
+      labels: [ 'Date', 'Y1', 'Y2', 'Y3', 'Y4' ],
+      width: 640,
+      height: 350,
+      xlabel: 'x-axis',
+      ylabel: 'y-axis',
+      y2label: 'y2-axis',
+      title: 'Chart title'
+    }
+  );
+
+  assertEquals(["Chart title", "x-axis", "y-axis"],
+               getClassTexts("dygraph-label"));
+  assertEquals(["Chart title"], getClassTexts("dygraph-title"));
+  assertEquals(["x-axis"], getClassTexts("dygraph-xlabel"));
+  assertEquals(["y-axis"], getClassTexts("dygraph-ylabel"));
+  assertEquals([], getClassTexts("dygraph-y2label"));
+};
diff --git a/dygraph-canvas.js b/dygraph-canvas.js
index acf011f..5e6766d 100644
--- a/dygraph-canvas.js
+++ b/dygraph-canvas.js
@@ -551,7 +551,7 @@ DygraphCanvasRenderer.prototype._renderChartLabels = function() {
     this.container.appendChild(div);
     this.chartLabels.ylabel = div;
   }
-  if (this.attr_('y2label')) {
+  if (this.attr_('y2label') && this.dygraph_.numAxes() == 2) {
     div = createRotatedDiv(2, 'dygraph-label dygraph-y2label',
                            this.attr_('y2label'));
     this.container.appendChild(div);
diff --git a/tests/two-axes.html b/tests/two-axes.html
index bb4a34a..3f40b07 100644
--- a/tests/two-axes.html
+++ b/tests/two-axes.html
@@ -66,7 +66,8 @@
           {
             labels: [ 'Date', 'Y1', 'Y2', 'Y3', 'Y4' ],
             labelsKMB: true,
-            ylabel: 'Primary y-axis'
+            ylabel: 'Primary y-axis',
+            y2label: 'Secondary y-axis',
           }
       );
 
-- 
2.7.4