agc*_*nti 5 javascript json d3.js
我一直试图运行Mike Bostock的See-Through Globe示例,但如果您尝试在本地重现它,则对其json文件的引用是不正确的.
问题来自这行代码:
d3.json("/mbostock/raw/4090846/world-110m.json", function(error, topo) {
var land = topojson.feature(topo, topo.objects.land),
grid = graticule();
});
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我遵循了这个例子: d3:我们在topojson格式文件中的状态太大了
并尝试将URL更改为这些变体,以便更好地为外部用户引用这些文件;
"https://raw.github.com/mbostock/topojson/master/examples/world-110m.json"
"https://render.github.com/mbostock/topojson/master/examples/world-110m.json"
"http://bl.ocks.org/mbostock/raw/4090846/world-110m.json"
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但我永远不允许访问.有关如何正确引用json文件的任何想法?
如果他的其他例子也尝试了一些,并且每次都遇到同样的问题.还有其他人在复制这些例子方面取得了成功吗
由于原始策略相同,您无法访问远程json文件.并且您将无法使用file:protocol检索JSON对象.除非您想通过直接嵌入JSON来对代码进行手术,否则您将不得不运行本地服务器.
运行本地Web服务器的简便方法是执行:
python -m SimpleHTTPServer 8888 &
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从您网站的"根"目录,然后通过它访问它 http://localhost:8888
您可以在此处直接访问数据:http://bl.ocks.org/mbostock/raw/4090846/world-110m.json
要使其工作,您需要在脚本中创建一个新变量并直接将json分配给它.
您提供的小提琴代码:
var topo = // Paste data from provided link here. It will be one big object literal.
var width = 960,
height = 960,
speed = -1e-2,
start = Date.now();
var sphere = {type: "Sphere"};
var projection = d3.geo.orthographic()
.scale(width / 2.1)
.translate([width / 2, height / 2])
.precision(.5);
var graticule = d3.geo.graticule();
var canvas = d3.select("body").append("canvas")
.attr("width", width)
.attr("height", height);
var context = canvas.node().getContext("2d");
var path = d3.geo.path()
.projection(projection)
.context(context);
// d3.json("https://render.github.com/mbostock/topojson/master/examples/world-110m.json", function(error, topo) {
var land = topojson.feature(topo, topo.objects.land), // topo var is now provided by pasted-in data instead of fetched json.
grid = graticule();
d3.timer(function() {
context.clearRect(0, 0, width, height);
projection.rotate([speed * (Date.now() - start), -15]).clipAngle(90);
context.beginPath();
path(sphere);
context.lineWidth = 3;
context.strokeStyle = "#000";
context.stroke();
context.fillStyle = "#fff";
context.fill();
projection.clipAngle(180);
context.beginPath();
path(land);
context.fillStyle = "#dadac4";
context.fill();
context.beginPath();
path(grid);
context.lineWidth = .5;
context.strokeStyle = "rgba(119,119,119,.5)";
context.stroke();
projection.clipAngle(90);
context.beginPath();
path(land);
context.fillStyle = "#737368";
context.fill();
context.lineWidth = .5;
context.strokeStyle = "#000";
context.stroke();
});
// });
d3.select(self.frameElement).style("height", height + "px");
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我本来可以直接修改小提琴,但json数据文件足够大,当我尝试粘贴它时,jsfiddle chokes.
希望这可以帮助.