Interactive World Map

Using the TopoJSON format in connection with D3 to create an interactive worldmap.

Click a country to center and zoom. Click again to zoom out. This example also allows you to freely pan and zoom with the mouse.

<!DOCTYPE html>
<meta charset="utf-8">
<style>
    .background {
        fill: none;
        pointer-events: all;
    }
    
    .stroke {
        fill: none;
        stroke: #000;
        stroke-width: 3px;
    }
    
    .graticule {
        fill: none;
        stroke: #777;
        stroke-width: .5px;
        stroke-opacity: .5;
    }
    
    .country {
        fill: #ccc;
    }
    
    .boundary {
        fill: none;
        stroke: #fff;
        stroke-width: .5px;
    }
    
    div.tooltip {
        position: absolute;
        text-align: center;
        color: black;
        font-weight: bold;
        padding: 2px;
        background: white;
        border: 2px solid;
        border-radius: 8px;
        pointer-events: none;
    }
</style>

var projection = d3.geo.mercator()
            .scale(150)
            .translate([width / 2, height / 1.5]);

var zoom = d3.behavior.zoom()
            .translate([0, 0])
            .scale(1)
            .scaleExtent([1, 8])
            .on("zoom", zoomed);

var path = d3.geo.path()
            .projection(projection);

var div = d3.select("body").append("div")
            .attr("class", "tooltip")
            .style("opacity", 0);

var svg = d3.select("body").append("svg")
            .attr("width", width)
            .attr("height", height)
            .on("click", stopped, true);

svg.append("rect")
            .attr("class", "background")
            .attr("width", width)
            .attr("height", height)
            .on("click", reset);

var g = svg.append("g");

svg.call(zoom).call(zoom.event);

d3.json("mapfile.json", function (error, world) {
            
            var countries = topojson.feature(world, world.objects.world);

g.selectAll(".country")
                .data(countries.features)
                .enter().append("path")
                .attr("class", function (d) {
                    return "country " + d.id;
                })
                .attr("d", path)
                .on("click", clicked)
                .on("mouseover", function (d) {
                    d3.select(this).transition().duration(300).style("fill", "#377eb8");
                    div.transition().duration(300)
                        .style("opacity", 1)
                    div.text(d.properties.name)
                        .style("left", (d3.event.pageX) + "px")
                        .style("top", (d3.event.pageY - 30) + "px");
                })
                .on("mouseout", function (d) {
                    d3.select(this).transition().duration(300).style("fill", "#ccc");
                    div.transition().duration(300)
                        .style("opacity", 0);
                });

g.append("path")
                .datum(topojson.mesh(world, world.objects.world, function (a, b) {
                    return a !== b;
                }))
                .attr("class", "boundary")
                .attr("d", path);
        });

function clicked(d) {
            if (active.node() === this) return reset(); // a second click returns to default zoom
            active.classed("active", false);
            active = d3.select(this).classed("active", true);

var bounds = path.bounds(d),
                dx = bounds[1][0] - bounds[0][0],
                dy = bounds[1][1] - bounds[0][1],
                x = (bounds[0][0] + bounds[1][0]) / 2,
                y = (bounds[0][1] + bounds[1][1]) / 2,
                scale = .9 / Math.max(dx / width, dy / height),
                translate = [width / 2 - scale * x, height / 2 - scale * y];

svg.transition()
                .duration(750)
                .call(zoom.translate(translate).scale(scale).event);
        }

function reset() {
            active.classed("active", false);
            active = d3.select(null);

svg.transition()
                .duration(750)
                .call(zoom.translate([0, 0]).scale(1).event);
        }

function zoomed() {
            g.style("stroke-width", 1.5 / d3.event.scale + "px");
            g.attr("transform", "translate(" + d3.event.translate + ")scale(" + d3.event.scale + ")");
        }

function stopped() {
            if (d3.event.defaultPrevented) d3.event.stopPropagation();
        }
    </script>
</body>

Modified http://d3js.org/d3.v3.min.js to a secure url

Modified http://d3js.org/d3.geo.projection.v0.min.js to a secure url

Modified http://d3js.org/topojson.v1.min.js to a secure url

https://d3js.org/d3.v3.min.js

https://d3js.org/d3.geo.projection.v0.min.js

https://d3js.org/topojson.v1.min.js