【发布时间】：2018-03-09 13:04:32
【问题描述】：
我一直在使用带有内置工具提示的 D3 svg 图表（使用 d3-tip 库）。原代码可以看这里：http://bl.ocks.org/Caged/6476579
我使用 Django 作为后端，我试图从日期时间开始按年填充日志计数。我成功地填充了除条形之外的图表的轴和标签。
这是我的名为graph.html的html模板：
<!DOCTYPE html>
<meta charset="utf-8">
<style>
body {
font: 10px sans-serif;
}
.axis path,
.axis line {
fill: none;
stroke: #000;
shape-rendering: crispEdges;
}
.bar {
fill: orange;
}
.bar:hover {
fill: orangered ;
}
.x.axis path {
display: none;
}
.d3-tip {
line-height: 1;
font-weight: bold;
padding: 12px;
background: rgba(0, 0, 0, 0.8);
color: #fff;
border-radius: 2px;
}
/* Creates a small triangle extender for the tooltip */
.d3-tip:after {
box-sizing: border-box;
display: inline;
font-size: 10px;
width: 100%;
line-height: 1;
color: rgba(0, 0, 0, 0.8);
content: "\25BC";
position: absolute;
text-align: center;
}
/* Style northward tooltips differently */
.d3-tip.n:after {
margin: -1px 0 0 0;
top: 100%;
left: 0;
}
</style>
<body>
<script src="http://d3js.org/d3.v3.js"></script>
<script src="http://labratrevenge.com/d3-tip/javascripts/d3.tip.v0.6.3.js"></script>
<script>
var margin = {top: 40, right: 20, bottom: 30, left: 40},
width = 960 - margin.left - margin.right,
height = 500 - margin.top - margin.bottom;
var parseDate = d3.time.format("%Y-%m-%dT00:00:00Z").parse; // for dates like "2014-01-01T00:00:00Z"
var x = d3.time.scale()
.range([0, width]);
var y = d3.scale.linear()
.range([height, 0]);
var xAxis = d3.svg.axis()
.scale(x)
.orient("bottom");
var yAxis = d3.svg.axis()
.scale(y)
.orient("left");
var tip = d3.tip()
.attr('class', 'd3-tip')
.offset([-10, 0])
.html(function(d) {
return "<strong>Log Count:</strong> <span style='color:red'>" + d.count_items + "</span>";
})
var svg = d3.select("body").append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
d3.json("{% url "log_count_by_year" %}", function(error, data) {
data.forEach(function(d) {
d.year = parseDate(d.year);
d.count_items = +d.count_items;
});
x.domain(d3.extent(data, function(d) { return d.year; }));
y.domain([0, d3.max(data, function(d) { return d.count_items; })]);
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(xAxis);
svg.append("g")
.attr("class", "y axis")
.call(yAxis)
.append("text")
.attr("transform", "rotate(-90)")
.attr("y", -38)
.attr("dy", ".71em")
.style("text-anchor", "end")
.text("Log count");
svg.selectAll(".bar")
.data(data)
.enter().append("rect")
.attr("class", "bar")
.attr("x", function(d) { return x(d.year); })
.attr("width", x.rangeBand())
.attr("y", function(d) { return y(d.count_items); })
.attr("height", function(d) { return height - y(d.count_items); })
.on('mouseover', tip.show)
.on('mouseout', tip.hide)
});
</script>
</body>
</html>
在views.py 我写了这段代码来成功找到每年的计数：
def graph(request):
return render(request, 'graph/graph.html')
def log_count_by_year(request):
data = log_runs.objects.all() \
.extra(select={'year': connections[log_runs.objects.db].ops.date_trunc_sql('year', 'RUN_DATETIME')}) \
.values('year') \
.annotate(count_items=Count('ID'))
return JsonResponse(list(data), safe=False)
当我进行 api 调用时，我能够成功获取 JSON 对象，这是我得到的 JSON 对象：
[{"count_items": 22, "year": "2017-01-01T00:00:00Z"}, {"count_items": 16, "year": "2016-01-01T00:00:00Z"}, {"count_items": 16, "year": "2015-01-01T00:00:00Z"}, {"count_items": 6, "year": "2014-01-01T00:00:00Z"}, {"count_items": 1, "year": "2013-01-01T00:00:00Z"}, {"count_items": 1, "year": "2012-01-01T00:00:00Z"}, {"count_items": 2, "year": "2011-01-01T00:00:00Z"}, {"count_items": 1, "year": "2010-01-01T00:00:00Z"}, {"count_items": 2, "year": "2009-01-01T00:00:00Z"}, {"count_items": 1, "year": "2008-01-01T00:00:00Z"}, {"count_items": 1, "year": "2007-01-01T00:00:00Z"}, {"count_items": 2, "year": "2006-01-01T00:00:00Z"}, {"count_items": 1, "year": "2005-01-01T00:00:00Z"}, {"count_items": 1, "year": "2004-01-01T00:00:00Z"}]
但在前端我只能看到轴和标签，没有条形图：Front end visualization 除了条形图和工具提示外，一切正常。有人可以帮我看看代码有什么问题吗？
【问题讨论】：
标签： javascript json django d3.js svg