I'm trying to create a tree using D3 and am having trouble changing the text of my nodes after changing dataset. My code for updating/creating the tree is pasted below:
function update(source) {
var duration = d3.event && d3.event.altKey ? 5000 : 500;
// Compute the new tree layout.
var nodes = tree.nodes(root).reverse();
// Normalize for fixed-depth.
nodes.forEach(function(d) { d.y = d.depth * 60; });
// Update the nodes…
var node = vis.selectAll("g.node")
.data(nodes, function(d) { return d.id || (d.id = ++i); });
// Enter any new nodes at the parent's previous position.
var nodeEnter = node.enter().append("svg:g")
.attr("class", "node")
.attr("transform", function(d) { return "translate(" + source.y0 + "," + source.x0 + ")"; })
.on("click", function(d) { toggle(d); update(d); });
nodeEnter.append("svg:circle")
.attr("r", 1e-6)
.style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
nodeEnter.append("svg:text")
.attr("x", function(d) { return d.children || d._children ? -10 : 10; })
.attr("dy", ".35em")
.attr("text-anchor", function(d) { return d.children || d._children ? "end" : "start"; })
.text(function(d) { console.log(d.name); return d.name; })
.style("fill-opacity", 1e-6);
// Transition nodes to their new position.
var nodeUpdate = node.transition()
.duration(duration)
.attr("transform", function(d) { return "translate(" + d.y + "," + d.x + ")"; });
nodeUpdate.select("circle")
.attr("r", function(d) {return d.size;} )//14.5)
.style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
nodeUpdate.select("text")
.style("fill-opacity", 1);
// Transition exiting nodes to the parent's new position.
var nodeExit = node.exit().transition()
.duration(duration)
.attr("transform", function(d) { return "translate(" + source.y + "," + source.x + ")"; })
.remove();
nodeExit.select("circle")
.attr("r", 1e-6);
nodeExit.select("text")
.style("fill-opacity", 1e-6);
// Update the links…
var link = vis.selectAll("path.link")
.data(tree.links(nodes), function(d) { return d.target.id; });
// Enter any new links at the parent's previous position.
link.enter().insert("svg:path", "g")
.attr("class", "link")
.attr("d", function(d) {
var o = {x: source.x0, y: source.y0};
return diagonal({source: o, target: o});
})
.transition()
.duration(duration)
.attr("d", diagonal);
// Transition links to their new position.
link.transition()
.duration(duration)
.attr("d", diagonal);
// Transition exiting nodes to the parent's new position.
link.exit().transition()
.duration(duration)
.attr("d", function(d) {
var o = {x: source.x, y: source.y};
return diagonal({source: o, target: o});
})
.remove();
// Stash the old positions for transition.
nodes.forEach(function(d) {
d.x0 = d.x;
d.y0 = d.y;
});
}
On tree one you can see the first tree with each node having a text.
On tree two you can see how of the same text names, where as tree two has completely different node texts than the first first. It creates a mix of node texts from tree one and tree two.
My new data HAS all the new texts I want to use, but when I use console.log() to print them out it only prints out the few that it actually uses on tree two.
How do I make it update the text on all nodes?
You are not updating the text in the update selection. To do that, use something like the following code:
nodeUpdate.select("text")
.text(function(d) { console.log(d.name); return d.name; })
.style("fill-opacity", 1);
Related
I am working on a project which needs a label for each of the levels of the collapsible tree in D3.js(https://bl.ocks.org/mbostock/4339083). I am facing tough time in adding the same. The label I require is added in the attached screenshot. The label should populate for each level as soon as click on each level and disappear as it the tree rolls back. Could anyone help me out with this.
Modify the update method to track the levels from the node items. Maintain a unique sorted hash of all the depth values from the node items used to plot the chart. Once you have the sorted depthHash array, plot the text on the top of your chart. Below is a fiddle i have modified for your reference.
http://jsfiddle.net/deepakpster/vomxqxov/3/
var margin = {top: 20, right: 120, bottom: 20, left: 120},
width = 960 - margin.right - margin.left,
height = 800 - margin.top - margin.bottom;
var i = 0,
duration = 750,
root;
var tree = d3.layout.tree()
.size([height, width]);
var diagonal = d3.svg.diagonal()
.projection(function(d) { return [d.y, d.x]; });
var svg = d3.select("body").append("svg")
.attr("width", width + margin.right + margin.left)
.attr("height", height + margin.top + margin.bottom)
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
flare = "http://rawgit.com/mbostock/1093025/raw/a05a94858375bd0ae023f6950a2b13fac5127637/flare.json"
d3.json(flare, function(error, flare) {
root = flare;
root.x0 = height / 2;
root.y0 = 0;
function collapse(d) {
if (d.children) {
d._children = d.children;
d._children.forEach(collapse);
d.children = null;
}
}
root.children.forEach(collapse);
update(root);
});
d3.select(self.frameElement).style("height", "800px");
function update(source) {
// Compute the new tree layout.
var nodes = tree.nodes(root).reverse(),
links = tree.links(nodes);
// Normalize for fixed-depth.
nodes.forEach(function(d) { d.y = d.depth * 180; });
// Showing the labels for the level of depths.
// Using underscore.js to do the pluck, uniq.
var depthHash = _.uniq(_.pluck(nodes, "depth")).sort();
svg.selectAll("g.levels-svg").remove();
var levelSVG = svg.append("g").attr("class", "levels-svg");
var levels = levelSVG.selectAll("g.level");
levels.data(depthHash)
.enter().append("g")
.attr("class", "level")
.attr("transform", function(d) { return "translate(" + d*180 + "," + 10 + ")"; })
.append("text")
.text(function(d){
return "level-" + d;
});
// Update the nodes…
var node = svg.selectAll("g.node")
.data(nodes, function(d) { return d.id || (d.id = ++i); });
// Enter any new nodes at the parent's previous position.
var nodeEnter = node.enter().append("g")
.attr("class", "node")
.attr("transform", function(d) { return "translate(" + source.y0 + "," + source.x0 + ")"; })
.on("click", click);
/*
nodeEnter.append("circle")
.attr("r", 1e-6)
.style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
*/
var ww = 30, hh = 20
nodeEnter.append("rect")
.attr("height", 1e-6)
.attr("width", 1e-6)
.attr("x", -ww/2)
.attr("y", -hh/2)
.attr("rx", 3)
.attr("ry", 3)
.style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
nodeEnter.append("text")
.attr("x", function(d) { return d.children || d._children ? -10 : 10; })
.attr("dy", ".35em")
.attr("text-anchor", function(d) { return d.children || d._children ? "end" : "start"; })
.text(function(d) { return d.name; })
.style("fill-opacity", 1e-6);
// Transition nodes to their new position.
var nodeUpdate = node.transition()
.duration(duration)
.attr("transform", function(d) { return "translate(" + d.y + "," + d.x + ")"; });
nodeUpdate.select("rect")
.attr("width", ww)
.attr("height", hh)
.style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
nodeUpdate.select("circle")
.attr("r", 4.5)
.style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
nodeUpdate.select("text")
.attr("dx", -10)
.style("fill-opacity", 1);
// Transition exiting nodes to the parent's new position.
var nodeExit = node.exit().transition()
.duration(duration)
.attr("transform", function(d) { return "translate(" + source.y + "," + source.x + ")"; })
.remove();
nodeExit.select("circle")
.attr("r", 1e-6);
nodeExit.select("text")
.style("fill-opacity", 1e-6);
// Update the links…
var link = svg.selectAll("path.link")
.data(links, function(d) { return d.target.id; });
// Enter any new links at the parent's previous position.
link.enter().insert("path", "g")
.attr("class", "link")
.attr("d", function(d) {
var o = {x: source.x0, y: source.y0};
return diagonal({source: o, target: o});
});
// Transition links to their new position.
link.transition()
.duration(duration)
.attr("d", diagonal);
// Transition exiting nodes to the parent's new position.
link.exit().transition()
.duration(duration)
.attr("d", function(d) {
var o = {x: source.x, y: source.y};
return diagonal({source: o, target: o});
})
.remove();
// Stash the old positions for transition.
nodes.forEach(function(d) {
d.x0 = d.x;
d.y0 = d.y;
});
}
// Toggle children on click.
function click(d) {
if (d.children) {
d._children = d.children;
d.children = null;
} else {
d.children = d._children;
d._children = null;
}
update(d);
}
I'm using the d3.js library to paint some nodes and link them, but they don't link them correctly. I have tried too many things but none of them has given me a solution.
Like you can see in the image the path are linking only in the enter position of the svg:rect.
nodeEnter.append("svg:rect")
.attr("x", 0)
.attr("y", 0)
.attr("width", 1)
.attr("height", 1)
.style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
nodeEnter.append("svg:text")
.attr("x", 30)
.attr("dy", ".35em")
.attr("text-anchor", "")
.text(function(d) { return d.name + " " + (d.occurences || ""); })
.style("fill-opacity", 1e-6);
nodeEnter.append("svg:image")
.attr('width', 0)
.attr('height', 0)
.style("fill-opacity", 1e-6)
.attr("xlink:href", function(d) {return d.icon; });
// Transition nodes to their new position.
var nodeUpdate = node.transition()
.duration(duration)
.attr("transform", function(d) { return "translate(" + d.y + "," + d.x + ")"; });
nodeUpdate.select("rect")
.attr("rx", 6)
.attr("ry", 6)
.attr("x", 0)
.attr("y", -12.5)
.attr("width", function(d){ return (getWidthOfText(d.name, 'Helvetica Neue', 14)+getWidthOfText(d.ocurrences, 'Helvetica Neue', 14))+30;})
.attr("height", 25)
//.style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
.style("filter", "url(#drop-shadow)");
nodeUpdate.select("text")
.style("fill-opacity", 1);
nodeUpdate.select("image")
.attr("x", 6)
.attr("y", -7)
.attr('width', 20)
.attr('height', 15)
.style("fill-opacity", 1);
// Transition exiting nodes to the parent's new position.
var nodeExit = node.exit().transition()
.duration(duration)
.attr("transform", function(d) { return "translate(" + source.y + "," + source.x + ")"; })
.remove();
nodeExit.select("rect")
.attr("x", 0)
.attr("y", 0)
.attr("width", 1)
.attr("height", 1)
.style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
nodeExit.select("text")
.style("fill-opacity", 1e-6);
vis.selectAll("image")
.append("svg:title")
.text(function(d) { return "Descripción: "+d.description+"\n\nComentarios: "+d.comment});
// Update the links…
var link = vis.selectAll("path.link")
.data(tree.links(nodes), function(d) { return d.target.id; });
// Enter any new links at the parent's previous position.
link.enter().insert("svg:path", "g")
.attr("class", "link")
.attr("d", function(d) {
var o = {x: source.x0, y: source.y0};
return diagonal({source: o, target: o});
})
.transition()
.duration(duration)
.attr("d", diagonal);
// Transition links to their new position.
link.transition()
.duration(duration)
.attr("d", diagonal);
// Transition exiting nodes to the parent's new position.
link.exit().transition()
.duration(duration)
.attr("d", function(d) {
var o = {x: source.x, y: source.y};
return diagonal({source: o, target: o});
})
.remove();
// Stash the old positions for transition.
nodes.forEach(function(d) {
d.x0 = d.x;
d.y0 = d.y;
});
Is there any way to move the paths to get the nodes correctly linked?
My understanding of d3 is currently rather limited and I am currently fiddling with a dendrogram example of D3.js. It can be found on several places:
on this interactive version for example.
When I implement it, all goes fine until you try to update a property like the circle diameter of the nodes. If I do (using an interactive framework like AngularJS which watches the parameter change): the nodes change in size. So no problem yet. However if I then click one of the nodes, the size is reset to the initialization size instead of the new one.
when a node gets clicked it follow the click function:
var nodeEnter = node.enter().append("g")
.attr("class", "dendrogramnode2")
.on("click", click);
The click function calls an update function.
function click(d) {
if (d.children) {
d._children = d.children;
d.children = null;
} else {
d.children = d._children;
d._children = null;
}
update(d);
}
Which then updates the dendrogram and opens or closes the necessary nodes.
function update(source) {
// Compute the new tree layout.
var nodes = tree.nodes(root),
links = tree.links(nodes);
// Normalize for fixed-depth.
nodes.forEach(function(d) { d.y = d.depth * 80; });
// Update the nodes…
var node = svg.selectAll("g.node")
.data(nodes, function(d) { return d.id || (d.id = ++i); });
// Enter any new nodes at the parent's previous position.
var nodeEnter = node.enter().append("g")
.attr("class", "node")
//.attr("transform", function(d) { return "rotate(" + (d.x - 90) + ")translate(" + d.y + ")"; })
.on("click", click);
nodeEnter.append("circle")
.attr("r", 1e-6)
.style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
nodeEnter.append("text")
.attr("x", 10)
.attr("dy", ".35em")
.attr("text-anchor", "start")
//.attr("transform", function(d) { return d.x < 180 ? "translate(0)" : "rotate(180)translate(-" + (d.name.length * 8.5) + ")"; })
.text(function(d) { return d.name; })
.style("fill-opacity", 1e-6);
// Transition nodes to their new position.
var nodeUpdate = node.transition()
.duration(duration)
.attr("transform", function(d) { return "rotate(" + (d.x - 90) + ")translate(" + d.y + ")"; })
nodeUpdate.select("circle")
.attr("r", 4.5)
.style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
nodeUpdate.select("text")
.style("fill-opacity", 1)
.attr("transform", function(d) { return d.x < 180 ? "translate(0)" : "rotate(180)translate(-" + (d.name.length + 50) + ")"; });
// TODO: appropriate transform
var nodeExit = node.exit().transition()
.duration(duration)
//.attr("transform", function(d) { return "diagonal(" + source.y + "," + source.x + ")"; })
.remove();
nodeExit.select("circle")
.attr("r", 1e-6);
nodeExit.select("text")
.style("fill-opacity", 1e-6);
// Update the links…
var link = svg.selectAll("path.link")
.data(links, function(d) { return d.target.id; });
// Enter any new links at the parent's previous position.
link.enter().insert("path", "g")
.attr("class", "link")
.attr("d", function(d) {
var o = {x: source.x0, y: source.y0};
return diagonal({source: o, target: o});
});
// Transition links to their new position.
link.transition()
.duration(duration)
.attr("d", diagonal);
// Transition exiting nodes to the parent's new position.
link.exit().transition()
.duration(duration)
.attr("d", function(d) {
var o = {x: source.x, y: source.y};
return diagonal({source: o, target: o});
})
.remove();
// Stash the old positions for transition.
nodes.forEach(function(d) {
d.x0 = d.x;
d.y0 = d.y;
});
}
This update function is thus called:
at initialization --> no problem (example: circle r = 5)
when a parameter get updated --> no problem, the parameter updates. (example: circle r = 10)
when you click a node --> problematic--> graph takes initial parameters.(example: circle r = 5)
All of this probably has a lot to do with scoping and how javascript handles databinding but I don't know how to do this properly. I either need to be able to access the new properties instead of the old ones.
Is there a way to either
adapt the code so the new parameter is taken instead of the old ones?
bind the parameters to the svg group as an object (probably not as efficient? ) so I
can manually reach for it from whatever scope using the d3 selectors?
I have set a property to the DOM element for those attributes which don't differ per datum.
function dograph(p){
//paramater object is passed and it's name is "p"
d3.select(elementid).selectAll("svg")[0][0]["p"] = p
//at some point update function gets called as part of an event and p is no longer available.
//someSvgElement
.on("mouseover"){update())}
function update(source) {
var p = d3.select(elementid).selectAll("svg")[0][0]["p"];
//stuff happens
}
}
might not be the perfect solution but it works for me.
Please see http://bl.ocks.org/mbostock/4339083
It loads data from flare.json and displays the nodes in a tree layout. I want to do the following:
1. Write a function to display only some of the nodes based on some conditions and reload the tree.
2. Write a function to add some nodes and reload the tree.
3. Write a function to remove some nodes and reload the tree.
I need to call these functions from outside
d3.json("/d/4063550/flare.json", function(error, flare)
in that sample.
Please let me know how to do it. I tried .children.splice method and again called upload(root). But it did not work.
Here is the relevant part of the code:
d3.json("/d/4063550/flare.json", function(error, flare) {
root = flare;
root.x0 = height / 2;
root.y0 = 0;
function collapse(d) {
if (d.children) {
d._children = d.children;
d._children.forEach(collapse);
d.children = null;
}
}
root.children.forEach(collapse);
update(root);
});
function update(source) {
// Compute the new tree layout.
var nodes = tree.nodes(root).reverse(),
links = tree.links(nodes);
// Update the nodes…
var node = svg.selectAll("g.node")
.data(nodes, function(d) { return d.id || (d.id = ++i); });
// Enter any new nodes at the parent's previous position.
var nodeEnter = node.enter().append("g")
.attr("class", "node")
.attr("transform", function(d) { return "translate(" + source.y0 + "," + source.x0 + ")"; })
nodeEnter.append("circle")
.attr("r", 1e-6)
.style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
// Transition nodes to their new position.
var nodeUpdate = node.transition()
.duration(duration)
.attr("transform", function(d) { return "translate(" + d.y + "," + d.x + ")"; });
nodeUpdate.select("circle")
.attr("r", 4.5)
.style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
// Transition exiting nodes to the parent's new position.
var nodeExit = node.exit().transition()
.duration(duration)
.attr("transform", function(d) { return "translate(" + source.y + "," + source.x + ")"; })
.remove();
nodeExit.select("circle")
.attr("r", 1e-6);
// Update the links…
var link = svg.selectAll("path.link")
.data(links, function(d) { return d.target.id; });
// Enter any new links at the parent's previous position.
link.enter().insert("path", "g")
.attr("class", "link")
.attr("d", function(d) {
var o = {x: source.x0, y: source.y0};
return diagonal({source: o, target: o});
});
// Transition links to their new position.
link.transition()
.duration(duration)
.attr("d", diagonal);
// Transition exiting nodes to the parent's new position.
link.exit().transition()
.duration(duration)
.attr("d", function(d) {
var o = {x: source.x, y: source.y};
return diagonal({source: o, target: o});
})
.remove();
// Stash the old positions for transition.
nodes.forEach(function(d) {
d.x0 = d.x;
d.y0 = d.y;
});
}
I changed your code a little bit and it works for me:
d3.json("flare.json", function(json) {
root = json;
root.fixed = true;
root.x = w / 2;
root.y = h / 2 - 80;
console.log("haha");
firstTimeRun();
update();
});
function firstTimeRun(){
flatten(root).forEach(collapse);
}
function collapse(d) {
if (d.children) {
d._children = d.children;
d.children = null;
}
}
I'm new to the d3.js library.
I'm trying to make a tree like this one, but with a link that goes to an external page on each node.
Is it possible?
I tried to add a "svg:a" to each node but in makes all the tree to disappear.
Update:
I'm taking this code from the html of the page linked above.
The libraries linked are:
d3.js
d3.layout.js
This is all the code:
<style type="text/css">
.node circle {
cursor: pointer;
fill: #fff;
stroke: steelblue;
stroke-width: 1.5px;
}
.node text {
font-size: 11px;
}
path.link {
fill: none;
stroke: #ccc;
stroke-width: 1.5px;
}
</style>
<script>
var m = [20, 120, 20, 120],
w = 1280 - m[1] - m[3],
h = 800 - m[0] - m[2],
i = 0,
root;
var tree = d3.layout.tree()
.size([h, w]);
var diagonal = d3.svg.diagonal()
.projection(function(d) { return [d.y, d.x]; });
var vis = d3.select("#body").append("svg:svg")
.attr("width", w + m[1] + m[3])
.attr("height", h + m[0] + m[2])
.append("svg:g")
.attr("transform", "translate(" + m[3] + "," + m[0] + ")");
d3.json("flare.json", function(json) {
root = json;
root.x0 = h / 2;
root.y0 = 0;
function toggleAll(d) {
if (d.children) {
d.children.forEach(toggleAll);
toggle(d);
}
}
// Initialize the display to show a few nodes.
root.children.forEach(toggleAll);
toggle(root.children[1]);
toggle(root.children[1].children[2]);
toggle(root.children[9]);
toggle(root.children[9].children[0]);
update(root);
});
function update(source) {
var duration = d3.event && d3.event.altKey ? 5000 : 500;
// Compute the new tree layout.
var nodes = tree.nodes(root).reverse();
// Normalize for fixed-depth.
nodes.forEach(function(d) { d.y = d.depth * 180; });
// Update the nodes…
var node = vis.selectAll("g.node")
.data(nodes, function(d) { return d.id || (d.id = ++i); });
// Enter any new nodes at the parent's previous position.
var nodeEnter = node.enter().append("svg:g")
.attr("class", "node")
.attr("transform", function(d) { return "translate(" + source.y0 + "," + source.x0 + ")"; })
.on("click", function(d) { toggle(d); update(d); });
nodeEnter.append("svg:circle")
.attr("r", 1e-6)
.style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
nodeEnter.append("svg:text")
.attr("x", function(d) { return d.children || d._children ? -10 : 10; })
.attr("dy", ".35em")
.attr("text-anchor", function(d) { return d.children || d._children ? "end" : "start"; })
.text(function(d) { return d.name; })
.style("fill-opacity", 1e-6);
// Transition nodes to their new position.
var nodeUpdate = node.transition()
.duration(duration)
.attr("transform", function(d) { return "translate(" + d.y + "," + d.x + ")"; });
nodeUpdate.select("circle")
.attr("r", 4.5)
.style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
nodeUpdate.select("text")
.style("fill-opacity", 1);
// Transition exiting nodes to the parent's new position.
var nodeExit = node.exit().transition()
.duration(duration)
.attr("transform", function(d) { return "translate(" + source.y + "," + source.x + ")"; })
.remove();
nodeExit.select("circle")
.attr("r", 1e-6);
nodeExit.select("text")
.style("fill-opacity", 1e-6);
// Update the links…
var link = vis.selectAll("path.link")
.data(tree.links(nodes), function(d) { return d.target.id; });
// Enter any new links at the parent's previous position.
link.enter().insert("svg:path", "g")
.attr("class", "link")
.attr("d", function(d) {
var o = {x: source.x0, y: source.y0};
return diagonal({source: o, target: o});
})
.transition()
.duration(duration)
.attr("d", diagonal);
// Transition links to their new position.
link.transition()
.duration(duration)
.attr("d", diagonal);
// Transition exiting nodes to the parent's new position.
link.exit().transition()
.duration(duration)
.attr("d", function(d) {
var o = {x: source.x, y: source.y};
return diagonal({source: o, target: o});
})
.remove();
// Stash the old positions for transition.
nodes.forEach(function(d) {
d.x0 = d.x;
d.y0 = d.y;
});
}
// Toggle children.
function toggle(d) {
if (d.children) {
d._children = d.children;
d.children = null;
} else {
d.children = d._children;
d._children = null;
}
}
</script>
Basically what I have tried was to add this piece of code just before the nodeEnter.append("svg:text")
nodeEnter.append("svg:a")
.attr("x", function(d) { return d.children || d._children ? -10 : 10; })
.attr("dy", ".35em")
.attr("text-anchor", function(d) { return d.children || d._children ? "end" : "start"; })
.text("http://example.com")
.style("fill-opacity", 1e-6);
Try adding the action on the node itself, like below, and change the cursor to pointer to give a hint to the user.
var node = vis.selectAll("g.node")
.data(nodes, function(d) { return d.id || (d.id = ++i); })
.style("cursor", "pointer")
.on("click", function() {
window.open("http://www.stackoverflow.com", '_blank').focus();
});
You should be able to add an HTML link to any of the objects that you want by adding an a tag as follows (this example is for the text that is associated with each node);
nodeEnter.append("a")
.attr("xlink:href", "http://example.com")
.append("svg:text")
.attr("x", function(d) { return d.children || d._children ? -10 : 10; })
.attr("dy", ".35em")
.attr("text-anchor", function(d) { return d.children || d._children ? "end" : "start"; })
.text(function(d) { return d.name; })
.style("fill-opacity", 1e-6);
If you had a seperate URL associated with each node (let's imagine that it's called link) it would just be a matter of retrieving the url with a function call similar to this;
nodeEnter.append("a")
.attr("xlink:href", function(d) { return d.link; })
.append("svg:text")
.attr("x", function(d) { return d.children || d._children ? -10 : 10; })
.attr("dy", ".35em")
.attr("text-anchor", function(d) { return d.children || d._children ? "end" : "start"; })
.text(function(d) { return d.name; })
.style("fill-opacity", 1e-6);
For a fuller description of adding a link see here: https://leanpub.com/D3-Tips-and-Tricks/read#leanpub-auto-adding-web-links-to-d3js-objects
For information on tree diagrams in general see here: https://leanpub.com/D3-Tips-and-Tricks/read#leanpub-auto-tree-diagrams