d3.js: why doesn't the data update? - d3.js

Question

I've got a fairly simple reusable chart built in D3.js -- some circles and some text.
I'm struggling to figure out how to update the chart with new data, without redrawing the entire chart.
With the current script, I can see that the new data is bound to the svg element, but none of the data-driven text or attributes is updating. Why isn't the chart updating?
Here's a fiddle: http://jsfiddle.net/rolfsf/em5kL/1/
I'm calling the chart like this:
d3.select('#clusters')
.datum({
Name: 'Total Widgets',
Value: 224,
Clusters: [
['Other', 45],
['FooBars', 30],
['Foos', 50],
['Bars', 124],
['BarFoos', 0]
]
})
.call( clusterChart() );
When the button is clicked, I'm simply calling the chart again, with different data:
$("#doSomething").on("click", function(){
d3.select('#clusters')
.datum({
Name: 'Total Widgets',
Value: 122,
Clusters: [
['Other', 14],
['FooBars', 60],
['Foos', 22],
['Bars', 100],
['BarFoos', 5]
]
})
.call( clusterChart() );
});
The chart script:
function clusterChart() {
var width = 450,
margin = 0,
radiusAll = 72,
maxRadius = radiusAll - 5,
r = d3.scale.linear(),
padding = 1,
height = 3 * (radiusAll*2 + padding),
startAngle = Math.PI / 2,
onTotalMouseOver = null,
onTotalClick = null,
onClusterMouseOver = null,
onClusterClick = null;
val = function(d){return d};
function chart(selection) {
selection.each(function(data) {
var cx = width / 2,
cy = height / 2,
stepAngle = 2 * Math.PI / data.Clusters.length,
outerRadius = 2*radiusAll + padding;
r = d3.scale.linear()
.domain([0, d3.max(data.Clusters, function(d){return d[1];})])
.range([50, maxRadius]);
var svg = d3.select(this).selectAll("svg")
.data([data])
.enter().append("svg");
//enter
var totalCircle = svg.append("circle")
.attr("class", "total-cluster")
.attr('cx', cx)
.attr('cy', cy)
.attr('r', radiusAll)
.on('mouseover', onTotalMouseOver)
.on('click', onTotalClick);
var totalName = svg.append("text")
.attr("class", "total-name")
.attr('x', cx)
.attr('y', cy + 16);
var totalValue = svg.append("text")
.attr("class", "total-value")
.attr('x', cx)
.attr('y', cy + 4);
var clusters = svg.selectAll('circle.cluster')
.data(data.Clusters)
.enter().append('circle')
.attr("class", "cluster");
var clusterValues = svg.selectAll("text.cluster-value")
.data(data.Clusters)
.enter().append('text')
.attr('class', 'cluster-value');
var clusterNames = svg.selectAll("text.cluster-name")
.data(data.Clusters)
.enter().append('text')
.attr('class', 'cluster-name');
clusters .attr('cx', function(d, i) { return cx + Math.cos(startAngle + stepAngle * i) * outerRadius; })
.attr('cy', function(d, i) { return cy + Math.sin(startAngle + stepAngle * i) * outerRadius; })
.attr("r", "10")
.on('mouseover', function(d, i, j) {
if (onClusterMouseOver != null) onClusterMouseOver(d, i, j);
})
.on('mouseout', function() { /*do something*/ })
.on('click', function(d, i){ onClusterClick(d); });
clusterNames
.attr('x', function(d, i) { return cx + Math.cos(startAngle + stepAngle * i) * outerRadius; })
.attr('y', function(d, i) { return cy + Math.sin(startAngle + stepAngle * i) * outerRadius + 16; });
clusterValues
.attr('x', function(d, i) { return cx + Math.cos(startAngle + stepAngle * i) * outerRadius; })
.attr('y', function(d, i) { return cy + Math.sin(startAngle + stepAngle * i) * outerRadius - 4; });
//update with data
svg .selectAll('text.total-value')
.text(val(data.Value));
svg .selectAll('text.total-name')
.text(val(data.Name));
clusters
.attr('class', function(d, i) {
if(d[1] === 0){ return 'cluster empty'}
else {return 'cluster'}
})
.attr("r", function (d, i) { return r(d[1]); });
clusterValues
.text(function(d) { return d[1] });
clusterNames
.text(function(d, i) { return d[0] });
$(window).resize(function() {
var w = $('.cluster-chart').width(); //make this more generic
svg.attr("width", w);
svg.attr("height", w * height / width);
});
});
}
chart.width = function(_) {
if (!arguments.length) return width;
width = _;
return chart;
};
chart.onClusterClick = function(_) {
if (!arguments.length) return onClusterClick;
onClusterClick = _;
return chart;
};
return chart;
}

Answer 1

I have applied the enter/update/exit pattern across all relevant svg elements (including the svg itself). Here is an example segment:
var clusterValues = svg.selectAll("text.cluster-value")
.data(data.Clusters,function(d){ return d[1];});
clusterValues.exit().remove();
clusterValues
.enter().append('text')
.attr('class', 'cluster-value');
...
Here is a complete FIDDLE with all parts working.
NOTE: I tried to touch your code as little as possible since you have carefully gone about applying a re-usable approach. This the reason why the enter/update/exit pattern is a bit different between the total circle (and text), and the other circles (and text). I might have gone about this using a svg:g element to group each circle and associated text.