Javascript 将null传递给d3.selection.on函数
我试着结合bl.ocks和上d3示例中的两个示例。目前,我有一个来自后端的AJAX响应,它传入了显示choropleth所需的us.json之类的内容 风格 JavascriptJavascript 将null传递给d3.selection.on函数,javascript,jquery,svg,d3.js,choropleth,Javascript,Jquery,Svg,D3.js,Choropleth,我试着结合bl.ocks和上d3示例中的两个示例。目前,我有一个来自后端的AJAX响应,它传入了显示choropleth所需的us.json之类的内容 风格 Javascript response = parseJSON(response); var us = response['us']; var data = response['data']; var reportID = response['reportID']; var thresholds = response['thresholds
response = parseJSON(response);
var us = response['us'];
var data = response['data'];
var reportID = response['reportID'];
var thresholds = response['thresholds'];
var colorScheme = response['colorScheme'];
var max = response['max'];
var options = response['options'];
var name = options['name'];
var width = 900, height = 500, centered;
//define the display threshold
var color = d3.scale.threshold()
.domain(thresholds)
// .range(["#f2f0f7", "#dadaeb", "#bcbddc", "#9e9ac8", "#756bb1", "#54278f"]); //purple
.range(colorScheme); //all colors
var rateById = {};
for(var i in data){
rateById[data[i]['id']] = +data[i]['value'];
}
var projection = d3.geo.albersUsa()
.scale(1070)
.translate([width / 2, height / 2]);
var path = d3.geo.path()
.projection(projection);
var svg = d3.select("#" + rowID + " .choropleth:nth-of-type(" + (parseInt(options['i']) + 1) + ")").append("svg")
.attr("width", width)
.attr("height", height)
var g = svg.append("g");
svg.append("g")
.attr("class", "counties")
.selectAll("path")
.data(topojson.feature(us, us.objects.counties).features)
.enter().append("path")
.attr("d", path)
.style("fill", function(d) { return color(rateById[d.id]); });
g.append("g")
.attr("id", "states")
.selectAll("path")
.data(topojson.feature(us, us.objects.states).features)
.enter().append("path")
.attr("d", path)
g.append("path")
.datum(topojson.mesh(us, us.objects.states, function(a, b) { return a !== b; }))
.attr("id", "state-borders")
.attr("d", path);
svg.append("rect")
.attr("class", "background")
.attr("width", width)
.attr("height", height)
.on("click", clicked);
function clicked(d){
console.log(typeof d);
var x, y, k;
if(d && centered !== d){
var centroid = path.centroid(d);
x = centroid[0];
y = centroid[1];
k = 4;
centered = d;
}else{
x = width / 2;
y = height / 2;
k = 1;
centered = null;
}
console.log(x + "\n" + y + "\n" + k + "\n" + centered);
g.transition()
.duration(750)
.attr("transform", "translate(" + width / 2 + "," + height / 2 + ")scale(" + k + ")translate(" + -x + "," + -y + ")")
.style("stroke-width", 1.5 / k + "px");
}
我把控制台放在d的logtyped上;要检查传递给click函数的参数的状态是否为null,但如果我取出添加到county行中的块,则click函数将传递适当的值,缩放函数将按预期工作。我尝试重新排列按SVG元素顺序添加的各个块,但没有成功。我找不到关于传递给click函数的参数的确切来源的任何文档,因此我不知道是什么导致它为空。我通过移动创建该函数的块解决了这个问题
svg.append("g")
.attr("class", "counties")
.selectAll("path")
.data(topojson.feature(us, us.objects.counties).features)
.enter().append("path")
.attr("d", path)
.style("fill", function(d) { return color(rateById[d.id]); })
.on("click", clicked);
在我定义clicked函数并将click事件处理程序放在该元素上而不是rect上之前的右端。d指绑定到被单击元素的数据,您没有将任何数据绑定到rect元素。但是如果我去掉创建县的块,那么它工作正常,并且该块的存在不应该影响rect是否有数据。不,不应该,我不知道您是如何得到这种行为的。你能提供一个完整的例子来演示这个问题吗?我在上面的JS部分中提供的是所有与显示choropleth相关的代码。唯一缺少的是us中的数据以及us.json和id/值对的数据,就像choropleth bl.ock中包含的数据文件一样。默认情况下,colorScheme是其上方注释掉的行中包含的颜色。
svg.append("g")
.attr("class", "counties")
.selectAll("path")
.data(topojson.feature(us, us.objects.counties).features)
.enter().append("path")
.attr("d", path)
.style("fill", function(d) { return color(rateById[d.id]); })
.on("click", clicked);