how to know the current Zoom level in D3.js

Question

I have a problem since a few days. I have a graph and when I use Zoom Behavior it works, but I need to know when I reach maximum zoom to load new given

// Specifies the zoom scale's allowed range, [min, max]
d3.behavior.zoom().x(x).scaleExtent([1,10]).on("zoom", draw)

See my code http://jsfiddle.net/albanlopez/D4MRP/

Answer 1

rect.call(zm=d3.behavior.zoom().x(x).scaleExtent([1,10]).on("zoom", draw));

After a new test i have the answer :

var currentZoom = d3.event.scale;

But only available/readable in the draw() function called by .on("zoom", draw)

rect.call( zm = d3.behavior.zoom().x(x).scaleExtent([1,10]).on("zoom", draw));

function draw() {
    // trace l'axe X
    svg.select("g.x.axis").call(xAxis);
    // trace l'axe Y
    svg.select("g.y.axis").call(yAxis);
    // trace la courbe
    svg.select("path.line").attr("d", line);

    console.log(zm.scale(), zm.translate()); // , zm.translate[1] = Y
    console.log(d3.event.scale, d3.event.translate[0]); // , d3.event.translate[1] = Y
}