I'm building a dashboard and using d3.js to add a world map that will plot tweets in real time based on geo location.
The world.json file referenced in the d3.json() line is downloadable HERE (it's called world-countries.json).
The map is on the page as an SVG container and is rendered using d3.
Below are the relevant code slices.
<div id="mapContainer">
<svg xmlns="http://www.w3.org/2000/svg" width="100%" height="500"></svg>
</div>
#mapContainer svg {
display:block;
margin:0 auto;
}
#mapContainer path {
fill:#DDD;
stroke:#FFF;
}
// generate US plot
function draw() {
var map = d3.select("svg");
var width = $("svg").parent().width();
var height = $("svg").parent().height();
var projection = d3.geo.equirectangular().scale(185).translate([width/2, height/2]);
var path = d3.geo.path().projection(projection);
d3.json('plugins/maps/world.json', function(collection) {
map.selectAll('path').data(collection.features).enter()
.append('path')
.attr('d', path)
.attr("width", width)
.attr("height", height);
});
}
draw();
latestLoop();
$(window).resize(function() {
draw();
});
I have scaled the map to an acceptable size (for my particular browser size), but it still will not scale and center when I change the size of the window. If, however, I resize the window, then hit refresh, then the map will be centered once the page is reloaded. However, since the scale is static, it is not scaled properly.
COMPLETE SOLUTION:
Here's the solution which will resize the map AFTER the user has released the edge of the window to resize it, and center it in the parent container.
<div id="mapContainer"></div>
function draw(ht) {
$("#mapContainer").html("<svg id='map' xmlns='http://www.w3.org/2000/svg' width='100%' height='" + ht + "'></svg>");
map = d3.select("svg");
var width = $("svg").parent().width();
var height = ht;
// I discovered that the unscaled equirectangular map is 640x360. Thus, we
// should scale our map accordingly. Depending on the width ratio of the new
// container, the scale will be this ratio * 100. You could also use the height
// instead. The aspect ratio of an equirectangular map is 2:1, so that's why
// our height is half of our width.
projection = d3.geo.equirectangular().scale((width/640)*100).translate([width/2, height/2]);
var path = d3.geo.path().projection(projection);
d3.json('plugins/maps/world.json', function(collection) {
map.selectAll('path').data(collection.features).enter()
.append('path')
.attr('d', path)
.attr("width", width)
.attr("height", width/2);
});
}
draw($("#mapContainer").width()/2);
$(window).resize(function() {
if(this.resizeTO) clearTimeout(this.resizeTO);
this.resizeTO = setTimeout(function() {
$(this).trigger('resizeEnd');
}, 500);
});
$(window).bind('resizeEnd', function() {
var height = $("#mapContainer").width()/2;
$("#mapContainer svg").css("height", height);
draw(height);
});