[SPARK-7347] DAG visualization: add tooltips to RDDs

This is an addition to #5729.

Here's an example with ALS.
<img src="https://issues.apache.org/jira/secure/attachment/12731039/tooltip.png" width="400px"></img>

Author: Andrew Or <andrew@databricks.com>

Closes #5957 from andrewor14/viz-hover2 and squashes the following commits:

60e3758 [Andrew Or] Add tooltips for RDDs on job page

1 files changed, 16 insertions, 0 deletions

diff --git a/core/src/main/resources/org/apache/spark/ui/static/spark-dag-viz.js b/core/src/main/resources/org/apache/spark/ui/static/spark-dag-viz.js
index cda27cad7e..a0e3e914c2 100644
--- a/core/src/main/resources/org/apache/spark/ui/static/spark-dag-viz.js
+++ b/core/src/main/resources/org/apache/spark/ui/static/spark-dag-viz.js
@@ -218,6 +218,7 @@ function renderDagVizForJob(svgContainer) {
     });
   });
 
+  addTooltipsForRDDs(svgContainer);
   drawCrossStageEdges(crossStageEdges, svgContainer);
 }
 
@@ -424,6 +425,21 @@ function connectRDDs(fromRDDId, toRDDId, edgesContainer, svgContainer) {
   edgesContainer.append("path").datum(points).attr("d", line);
 }
 
+/* (Job page only) Helper function to add tooltips for RDDs. */
+function addTooltipsForRDDs(svgContainer) {
+  svgContainer.selectAll("g.node").each(function() {
+    var node = d3.select(this);
+    var tooltipText = node.attr("name");
+    if (tooltipText) {
+      node.select("circle")
+        .attr("data-toggle", "tooltip")
+        .attr("data-placement", "right")
+        .attr("title", tooltipText)
+    }
+  });
+  $("[data-toggle=tooltip]").tooltip({container: "body"});
+}
+
 /* Helper function to convert attributes to numeric values. */
 function toFloat(f) {
   if (f) {