rhizicore: bug fix: draw links below nodes

bug introduced in cd7157955d15802f34dee6ac4578ae249f3e397d
before that we recreated the links and nodes every update, and since all
links were created before nodes the document order was
<link>
<link>
<node>
<node>

which per SVG rendering order [1] leads to nodes being drawn on top of
links.

But after that commit the new links and nodes where created as they were
being edited, so we got
<link>
<node>
<link>
<node>

With this commit all links are created in a single group, getting back
the correct order:

<g>
 <link>
 <link>
</g>
<node>
<node>

nodes are ungrouped but there is no need for that (except that it looks
strangely assymetrical).

[1] http://dev.w3.org/SVG/modules/renderorder/SVGRenderOrder.html

1 files changed, 5 insertions, 1 deletions

diff --git a/scripts/rhizicore.js b/scripts/rhizicore.js
index 10a42fb7..593121b7 100644
--- a/scripts/rhizicore.js
+++ b/scripts/rhizicore.js
@@ -388,6 +388,10 @@ function myGraph(el) {
         .attr("y", -$(el).innerHeight() * 5);
     $('.overlay').click(mousedown);
 
+    // SVG rendering order is last rendered on top, so to make sure
+    // all links are below the nodes we group them under a single g
+    vis.append("g").attr("id", "link-group");
+
     function zoom() {
         if (graphstate === "GRAPH") {
             vis.attr("transform", "translate(" + d3.event.translate + ")scale(" + d3.event.scale + ")");
@@ -500,7 +504,7 @@ function myGraph(el) {
     };
 
     var update = function() {
-        link = vis.selectAll(".link")
+        link = vis.select("#link-group").selectAll(".link")
             .data(links);
 
         link.enter().append("svg:defs").selectAll("marker")