D3.js:这是数据DOM绑定的好习惯吗? [英] D3.js: Is this good practise for data-DOM-binding?
问题描述
我想要掌握D3的基本知识。我知道获得绑定权是至关重要的。
所以我做了一个简单的网页与更新,进入和退出操作。每次数据更改(修改,添加,删除)我调用一个函数,其中数据绑定到svg对象在更新,输入和退出方式。
不知道我的方法是否是好的?
< html>
< head>
< style>
.drawarea {border-style:solid; }
< / style>
< script src =https://d3js.org/d3.v4.min.js>< / script>
< script>
var data,drawArea;
function init(){
data = [{px:25,py:25,s:5},{px:25,py :50,s:5},{px:25,py:75,s:10}];
drawArea = d3.select(#drawareadiv)。append(svg:svg)
.attr(class,drawarea)
.attr width,500)
.attr(height,250);
draw();
}
function draw(){
var domRects = drawArea.selectAll(rect);
//更新
domRects
.data(data)
.attr(x,function(d){return d.px;})
.attr(y,function(d){return d.py;})
.attr(width,function(d){return ds;})
.attr height,function(d){return ds;});
//输入
domRects
.data(data)
.enter()
.append(svg:rect)
.attr(x,function(d){return d.px;})
.attr(y,function(d){return d.py;})
.attr宽度函数(d){return ds;})
.attr(height,function(d){return ds;});
// exit
domRects
.data(data)
.exit()
.remove();
}
function updateDataAndBinding(){
for(i = 0; i data [i] .px + = 10;
draw();
}
function enterDataAndBinding(){
var px = 25;
var py = 25 *(data.length + 1);
var s = Math.floor(data.length / 2)* 5 + 5;
data.push({px:px,py:py,s:s});
draw();
}
function exitDataAndBinding(){
data.splice(data.length-1,1);
draw();
}
< / script>
< / head>
< body onload =init()>
< div id =drawareadiv>< / div>
< button onclick =updateDataAndBinding()> updateDataAndBinding< / button>
< button onclick =enterDataAndBinding()> enterDataAndBinding< / button>
< button onclick =exitDataAndBinding()> exitDataAndBinding< / button>
< / body>
< / html>
我会建议两件事:
-
不要一次又一次绑定数据。这只是一次:
var domRects = drawArea.selectAll(rect)。
-
由于这是D3 v4.x,请使用
merge
一起处理输入和更新选择:
//输入+ update
domRects.enter()
.append(svg:rect)
.attr(x,function(d){return d.px;})
.attr y函数(d){return d.py;})
.attr(width,function(d){return ds;})
.attr d){return ds;})
.merge(domRects)
.attr(x,function(d){return d.px;})
.attr(y ,function(d){return d.py;})
.attr(width,function(d){return ds;})
.attr return ds;});
snippet):
< style& .drawarea {border-style:solid; }< / style>< script src =https://d3js.org/d3.v4.min.js>< / script>< script> var data,drawArea; function init(){data = [{px:25,py:25,s:5},{px:25,py:50,s:5},{px:25, py:75,s:10}]; drawArea = d3.select(#drawareadiv)。append(svg:svg).attr(class,drawarea).attr(width,500).attr(height,200); draw();} function draw(){var domRects = drawArea.selectAll(rect)。 // enter domRects.enter().append(svg:rect).attr(x,function(d){return d.px;}).attr(y,function(d){return d .attr(width,function(d){return ds;}).attr(height,function(d){return ds;}).merge(domRects) ,function(d){return d.px;}).attr(y,function(d){return d.py;}).attr(width,function(d){return ds;})。 attr(height,function(d){return ds;}); // exit domRects.exit().remove();} function updateDataAndBinding(){for(i = 0; i
除此之外,你的方法似乎是一个很好的(和标准的)一个。
I'm trying to grasp the D3 basics. I understand that it's crucial to get the binding right.
So I did a simple web page with update, enter and exit operations. Every time the data changes (modified, added, removed) I call a function where the data is bound to svg-objects in the update, enter and exit ways.
I wonder if my approach is a good one?
<html>
<head>
<style>
.drawarea { border-style: solid; }
</style>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>
var data, drawArea;
function init(){
data = [{"px" : 25, "py" : 25, "s" : 5}, {"px" : 25, "py" : 50, "s" : 5}, {"px" : 25, "py" : 75, "s" : 10} ];
drawArea = d3.select("#drawareadiv").append("svg:svg")
.attr("class", "drawarea")
.attr("width", 500)
.attr("height", 250);
draw();
}
function draw(){
var domRects = drawArea.selectAll("rect");
// update
domRects
.data(data)
.attr("x", function(d) { return d.px; })
.attr("y", function(d) { return d.py; })
.attr("width", function(d) { return d.s; })
.attr("height", function(d) { return d.s; });
// enter
domRects
.data(data)
.enter()
.append("svg:rect")
.attr("x", function(d) { return d.px; })
.attr("y", function(d) { return d.py; })
.attr("width", function(d) { return d.s; })
.attr("height", function(d) { return d.s; });
// exit
domRects
.data(data)
.exit()
.remove();
}
function updateDataAndBinding(){
for(i=0; i<data.length; i++)
data[i].px += 10;
draw();
}
function enterDataAndBinding(){
var px = 25;
var py = 25 * (data.length+1);
var s = Math.floor(data.length/2)*5+5;
data.push({"px" : px, "py" : py, "s" : s});
draw();
}
function exitDataAndBinding(){
data.splice(data.length-1, 1);
draw();
}
</script>
</head>
<body onload="init()">
<div id="drawareadiv"></div>
<button onclick="updateDataAndBinding()">updateDataAndBinding</button>
<button onclick="enterDataAndBinding()">enterDataAndBinding</button>
<button onclick="exitDataAndBinding()">exitDataAndBinding</button>
</body>
</html>
解决方案 I'd suggest two things:
Don't bind the data again and again. Do this just one time:
var domRects = drawArea.selectAll("rect").data(data);
As this is D3 v4.x, use merge
to deal with the "enter" and "update" selections together:
// enter + update
domRects.enter()
.append("svg:rect")
.attr("x", function(d) { return d.px; })
.attr("y", function(d) { return d.py; })
.attr("width", function(d) { return d.s; })
.attr("height", function(d) { return d.s; })
.merge(domRects)
.attr("x", function(d) { return d.px; })
.attr("y", function(d) { return d.py; })
.attr("width", function(d) { return d.s; })
.attr("height", function(d) { return d.s; });
Here is the demo (click "run code snippet"):
<style>
.drawarea { border-style: solid; }
</style>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>
var data, drawArea;
function init(){
data = [{"px" : 25, "py" : 25, "s" : 5}, {"px" : 25, "py" : 50, "s" : 5}, {"px" : 25, "py" : 75, "s" : 10} ];
drawArea = d3.select("#drawareadiv").append("svg:svg")
.attr("class", "drawarea")
.attr("width", 500)
.attr("height", 200);
draw();
}
function draw(){
var domRects = drawArea.selectAll("rect").data(data);
// enter
domRects.enter()
.append("svg:rect")
.attr("x", function(d) { return d.px; })
.attr("y", function(d) { return d.py; })
.attr("width", function(d) { return d.s; })
.attr("height", function(d) { return d.s; })
.merge(domRects)
.attr("x", function(d) { return d.px; })
.attr("y", function(d) { return d.py; })
.attr("width", function(d) { return d.s; })
.attr("height", function(d) { return d.s; });
// exit
domRects.exit()
.remove();
}
function updateDataAndBinding(){
for(i=0; i<data.length; i++)
data[i].px += 10;
draw();
}
function enterDataAndBinding(){
var px = 25;
var py = 25 * (data.length+1);
var s = Math.floor(data.length/2)*5+5;
data.push({"px" : px, "py" : py, "s" : s});
draw();
}
function exitDataAndBinding(){
data.splice(data.length-1, 1);
draw();
}
</script>
</head>
<body onload="init()">
<div id="drawareadiv"></div>
<button onclick="updateDataAndBinding()">updateDataAndBinding</button>
<button onclick="enterDataAndBinding()">enterDataAndBinding</button>
<button onclick="exitDataAndBinding()">exitDataAndBinding</button>
</body>
Other than that, your approach seems to be a good (and standard) one.
这篇关于D3.js:这是数据DOM绑定的好习惯吗?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!