我正在使用强制布局图来显示网络，但在更新数据时遇到问题。
我已经从D3.js检查How to update elements of D3 force layout when the underlying data changes，当然还有“修改力布局”以及“ mbostock ”的“一般更新模式”（不幸的是，我最多只能发布两个链接......）。
我的代码基于“移动专利套装”示例，并有一些修改和差异。 你可以在这里查看我的完整代码：
<!DOCTYPE html>
<meta charset="utf-8">
<style>
.link {
fill: none;
stroke: #666;
stroke-width: 1.5px;
}
#licensing {
fill: green;
}
.link.licensing {
stroke: green;
}
.link.resolved {
stroke-dasharray: 0,2 1;
}
circle {
fill: #ccc;
stroke: #333;
stroke-width: 1.5px;
}
text {
font: 10px sans-serif;
pointer-events: none;
text-shadow: 0 1px 0 #fff, 1px 0 0 #fff, 0 -1px 0 #fff, -1px 0 0 #fff;
}
</style>
<body>
<!-- add an update button -->
<div id="update">
<input name="updateButton" type="button" value="Update" onclick="newData()"/>
</div>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script>
var width = 960,
height = 500;
var force = d3.layout.force()
.size([width, height])
.linkDistance(60)
.charge(-300)
.on("tick", tick);
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height)
.style("border", "1px solid black");
var dataset = [
{source: "Microsoft", target: "Amazon", type: "licensing"},
{source: "Microsoft", target: "HTC", type: "licensing"},
{source: "Samsung", target: "Apple", type: "suit"},
{source: "Motorola", target: "Apple", type: "suit"},
{source: "Nokia", target: "Apple", type: "resolved"},
{source: "HTC", target: "Apple", type: "suit"},
{source: "Kodak", target: "Apple", type: "suit"},
{source: "Microsoft", target: "Barnes & Noble", type: "suit"},
{source: "Microsoft", target: "Foxconn", type: "suit"},
{source: "Oracle", target: "Google", type: "suit"},
{source: "Apple", target: "HTC", type: "suit"},
{source: "Microsoft", target: "Inventec", type: "suit"},
{source: "Samsung", target: "Kodak", type: "resolved"},
{source: "LG", target: "Kodak", type: "resolved"},
{source: "RIM", target: "Kodak", type: "suit"},
{source: "Sony", target: "LG", type: "suit"},
{source: "Kodak", target: "LG", type: "resolved"},
{source: "Apple", target: "Nokia", type: "resolved"},
{source: "Qualcomm", target: "Nokia", type: "resolved"},
{source: "Apple", target: "Motorola", type: "suit"},
{source: "Microsoft", target: "Motorola", type: "suit"},
{source: "Motorola", target: "Microsoft", type: "suit"},
{source: "Huawei", target: "ZTE", type: "suit"},
{source: "Ericsson", target: "ZTE", type: "suit"},
{source: "Kodak", target: "Samsung", type: "resolved"},
{source: "Apple", target: "Samsung", type: "suit"},
{source: "Kodak", target: "RIM", type: "suit"},
{source: "Nokia", target: "Qualcomm", type: "suit"}
];
var path = svg.append("g").selectAll("path"),
circle = svg.append("g").selectAll("circle"),
text = svg.append("g").selectAll("text"),
marker = svg.append("defs").selectAll("marker");
var nodes = {};
update(dataset);
function newData()
{
var newDataset = [
{source: "Microsoft", target: "Amazon", type: "licensing"},
{source: "Microsoft", target: "HTC", type: "licensing"},
{source: "Samsung", target: "Apple", type: "suit"},
];
update(newDataset);
}
function update(links)
{
// Compute the distinct nodes from the links.
links.forEach(function(link)
{
link.source = nodes[link.source] || (nodes[link.source] = {name: link.source});
link.target = nodes[link.target] || (nodes[link.target] = {name: link.target});
});
force
.nodes(d3.values(nodes))
.links(links)
.start();
// -------------------------------
// Compute the data join. This returns the update selection.
marker = marker.data(["suit", "licensing", "resolved"]);
// Remove any outgoing/old markers.
marker.exit().remove();
// Compute new attributes for entering and updating markers.
marker.enter().append("marker")
.attr("id", function(d) { return d; })
.attr("viewBox", "0 -5 10 10")
.attr("refX", 15)
.attr("refY", -1.5)
.attr("markerWidth", 6)
.attr("markerHeight", 6)
.attr("orient", "auto")
.append("line") // use ".append("path") for 'arrows'
.attr("d", "M0,-5L10,0L0,5");
// -------------------------------
// Compute the data join. This returns the update selection.
path = path.data(force.links());
// Remove any outgoing/old paths.
path.exit().remove();
// Compute new attributes for entering and updating paths.
path.enter().append("path")
.attr("class", function(d) { return "link " + d.type; })
.attr("marker-end", function(d) { return "url(#" + d.type + ")"; });
// -------------------------------
// Compute the data join. This returns the update selection.
circle = circle.data(force.nodes());
// Add any incoming circles.
circle.enter().append("circle");
// Remove any outgoing/old circles.
circle.exit().remove();
// Compute new attributes for entering and updating circles.
circle
.attr("r", 6)
.call(force.drag);
// -------------------------------
// Compute the data join. This returns the update selection.
text = text.data(force.nodes());
// Add any incoming texts.
text.enter().append("text");
// Remove any outgoing/old texts.
text.exit().remove();
// Compute new attributes for entering and updating texts.
text
.attr("x", 8)
.attr("y", ".31em")
.text(function(d) { return d.name; });
}
// Use elliptical arc path segments to doubly-encode directionality.
function tick()
{
path.attr("d", linkArc);
circle.attr("transform", transform);
text.attr("transform", transform);
}
function linkArc(d)
{
var dx = d.target.x - d.source.x,
dy = d.target.y - d.source.y,
dr = Math.sqrt(dx * dx + dy * dy);
return "M" + d.source.x + "," + d.source.y + "A" + dr + "," + dr + " 0 0,1 " + d.target.x + "," + d.target.y;
}
function transform(d)
{
return "translate(" + d.x + "," + d.y + ")";
}
</script>
我的代码的JSFiddle可以在这里找到：http://jsfiddle.net/5m8a9/
按“更新”按钮后，我想动态更新我的图表。到目前为止一直很好，问题是，只会更新路径但不会更新圆圈或文本（某些圆圈和相应的文本仍然保留，不会被删除），如您所见我的JSFiddle链接。 我试图在过去几天找出问题而没有成功。
我缺少什么，如何让我的代码按预期工作？
如果有人可以提供帮助，我将永远感激。
已修改为@AmeliaBR提供的最终解决方案：
以下是我最终解决方案的漏洞代码：
<!DOCTYPE html>
<meta charset="utf-8">
<style>
.link {
fill: none;
stroke: #666;
stroke-width: 1.5px;
}
#licensing {
fill: green;
}
.link.licensing {
stroke: green;
}
.link.resolved {
stroke-dasharray: 0,2 1;
}
circle {
fill: #ccc;
stroke: #333;
stroke-width: 1.5px;
}
text {
font: 10px sans-serif;
pointer-events: none;
text-shadow: 0 1px 0 #fff, 1px 0 0 #fff, 0 -1px 0 #fff, -1px 0 0 #fff;
}
</style>
<body>
<!-- add an update button -->
<div id="update">
<input name="updateButton" type="button" value="Update" onclick="newData()"/>
</div>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script>
var width = 960,
height = 500;
var force = d3.layout.force()
.size([width, height])
.linkDistance(60)
.charge(-300)
.on("tick", tick);
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height)
.style("border", "1px solid black");
var dataset = [
{source: "Microsoft", target: "Amazon", type: "licensing"},
{source: "Microsoft", target: "HTC", type: "licensing"},
{source: "Samsung", target: "Apple", type: "suit"},
{source: "Motorola", target: "Apple", type: "suit"},
{source: "Nokia", target: "Apple", type: "resolved"},
{source: "HTC", target: "Apple", type: "suit"},
{source: "Kodak", target: "Apple", type: "suit"},
{source: "Microsoft", target: "Barnes & Noble", type: "suit"},
{source: "Microsoft", target: "Foxconn", type: "suit"},
{source: "Oracle", target: "Google", type: "suit"},
{source: "Apple", target: "HTC", type: "suit"},
{source: "Microsoft", target: "Inventec", type: "suit"},
{source: "Samsung", target: "Kodak", type: "resolved"},
{source: "LG", target: "Kodak", type: "resolved"},
{source: "RIM", target: "Kodak", type: "suit"},
{source: "Sony", target: "LG", type: "suit"},
{source: "Kodak", target: "LG", type: "resolved"},
{source: "Apple", target: "Nokia", type: "resolved"},
{source: "Qualcomm", target: "Nokia", type: "resolved"},
{source: "Apple", target: "Motorola", type: "suit"},
{source: "Microsoft", target: "Motorola", type: "suit"},
{source: "Motorola", target: "Microsoft", type: "suit"},
{source: "Huawei", target: "ZTE", type: "suit"},
{source: "Ericsson", target: "ZTE", type: "suit"},
{source: "Kodak", target: "Samsung", type: "resolved"},
{source: "Apple", target: "Samsung", type: "suit"},
{source: "Kodak", target: "RIM", type: "suit"},
{source: "Nokia", target: "Qualcomm", type: "suit"}
];
var path = svg.append("g").selectAll("path"),
circle = svg.append("g").selectAll("circle"),
text = svg.append("g").selectAll("text"),
marker = svg.append("defs").selectAll("marker");
var nodes = {};
update(dataset);
function newData()
{
var newDataset = [
{source: "Microsoft", target: "Amazon", type: "licensing"},
{source: "Microsoft", target: "HTC", type: "licensing"},
{source: "Samsung", target: "Apple", type: "suit"},
];
update(newDataset);
}
function update(links)
{
d3.values(nodes).forEach(function(aNode){ aNode.linkCount = 0;});
// Reset the link count for all existing nodes by
// creating an array out of the nodes list, and then calling a function
// on each node to set the linkCount property to zero.
// Compute the distinct nodes from the links.
links.forEach(function(link)
{
link.source = nodes[link.source] || (nodes[link.source] = {name: link.source, linkCount:0}); // initialize new nodes with zero links
link.source.linkCount++;
// record this link on the source node, whether it was just initialized
// or already in the list, by incrementing the linkCount property
// (remember, link.source is just a reference to the node object in the
// nodes array, when you change its properties you change the node itself.)
link.target = nodes[link.target] || (nodes[link.target] = {name: link.target, linkCount:0}); // initialize new nodes with zero links
link.target.linkCount++;
});
d3.keys(nodes).forEach(
// create an array of all the current keys(names) in the node list,
// and then for each one:
function (nodeKey)
{
if (!nodes[nodeKey].linkCount)
{
// find the node that matches that key, and check it's linkCount value
// if the value is zero (false in Javascript), then the ! (NOT) operator
// will reverse that to make the if-statement return true,
// and the following will execute:
delete(nodes[nodeKey]);
//this deletes the object AND its key from the nodes array
}
}
);
force
.nodes(d3.values(nodes))
.links(links)
.start();
// -------------------------------
// Compute the data join. This returns the update selection.
marker = marker.data(["suit", "licensing", "resolved"]);
// Remove any outgoing/old markers.
marker.exit().remove();
// Compute new attributes for entering and updating markers.
marker.enter().append("marker")
.attr("id", function(d) { return d; })
.attr("viewBox", "0 -5 10 10")
.attr("refX", 15)
.attr("refY", -1.5)
.attr("markerWidth", 6)
.attr("markerHeight", 6)
.attr("orient", "auto")
.append("line") // use ".append("path") for 'arrows'
.attr("d", "M0,-5L10,0L0,5");
// -------------------------------
// Compute the data join. This returns the update selection.
path = path.data(force.links());
// Remove any outgoing/old paths.
path.exit().remove();
// Compute new attributes for entering and updating paths.
path.enter().append("path")
.attr("class", function(d) { return "link " + d.type; })
.attr("marker-end", function(d) { return "url(#" + d.type + ")"; });
// -------------------------------
// Compute the data join. This returns the update selection.
circle = circle.data(force.nodes());
// Add any incoming circles.
circle.enter().append("circle");
// Remove any outgoing/old circles.
circle.exit().remove();
// Compute new attributes for entering and updating circles.
circle
.attr("r", 6)
.call(force.drag);
// -------------------------------
// Compute the data join. This returns the update selection.
text = text.data(force.nodes());
// Add any incoming texts.
text.enter().append("text");
// Remove any outgoing/old texts.
text.exit().remove();
// Compute new attributes for entering and updating texts.
text
.attr("x", 8)
.attr("y", ".31em")
.text(function(d) { return d.name; });
}
// Use elliptical arc path segments to doubly-encode directionality.
function tick()
{
path.attr("d", linkArc);
circle.attr("transform", transform);
text.attr("transform", transform);
}
function linkArc(d)
{
var dx = d.target.x - d.source.x,
dy = d.target.y - d.source.y,
dr = Math.sqrt(dx * dx + dy * dy);
return "M" + d.source.x + "," + d.source.y + "A" + dr + "," + dr + " 0 0,1 " + d.target.x + "," + d.target.y;
}
function transform(d)
{
return "translate(" + d.x + "," + d.y + ")";
}
</script>
答案 0 :(得分：10)
通用节点链接图结构可以包含没有链接的节点，就像它可以有一个，两个或数百个链接的节点一样。您的更新方法会替换链接的数据，但不会查看节点数据以删除那些不再附加任何链接的数据。
他们现在已经设置了它，但是，有一个相当简单的解决方案。您可以从数据集初始化链接，并将节点初始化为空。然后在更新方法的这一部分中：
links.forEach(function(link)
{
link.source = nodes[link.source]
|| (nodes[link.source] = {name: link.source});
link.target = nodes[link.target]
|| (nodes[link.target] = {name: link.target});
});
在首先检查它是否已经在列表中之后，将所有提到的节点作为链接的源或目标添加到节点列表中。
（如果它不在列表中，nodes[link.source]将返回null，因此|| OR运算符将启动并评估语句的后半部分，创建对象，添加它到节点列表，然后将其连接到链接对象。）
现在，第一次运行更新方法时，这会用数据填充节点列表。然而，第二次，节点列表已经满了，你没有做任何事情来取走任何节点。
简单修复是在更新方法开始时将节点列表重置为空对象（nodes={};）。然后，只会添加当前链接集中的节点，因此当您重新计算圆圈和文本上的数据连接时，所有未使用的节点将被放入.exit()选择并删除
但是，我应该提一下，如果你要进行大量更新，并且每次只更改一些对象，还有其他方法可以做到这一点，需要更多代码，但更新速度会更快。此版本每次都会重新创建所有节点和链接数据对象。如果你有很多（数百个）复杂的数据节点并且只更改了每个更新，那么为节点对象添加额外的属性可能是值得的，它可以跟踪连接的链接数量，并且只能重置在更新方法开始时。然后，您可以使用过滤器来确定要在数据连接中包含哪些节点对象。
编辑添加：
这是我用于更保守的更新功能的方法（相对于数据的完全重置）。它不是唯一的选择，但它没有太多开销：
第一步（在更新方法中），将所有节点标记为零链接：
d3.values(nodes).forEach(function(aNode){ aNode.linkCount = 0;});
//Reset the link count for all existing nodes by
//creating an array out of the nodes list, and then calling a function
//on each node to set the linkCount property to zero.
第二步，更改links.forEach()方法以记录每个节点中的链接数：
links.forEach(function(link)
{
link.source = nodes[link.source]
|| (nodes[link.source] = {name: link.source, linkCount:0});
//initialize new nodes with zero links
link.source.linkCount++;
// record this link on the source node, whether it was just initialized
// or already in the list, by incrementing the linkCount property
// (remember, link.source is just a reference to the node object in the
// nodes array, when you change its properties you change the node itself.)
link.target = /* and then do the same for the target node */
});
第三步，选项一，使用filter仅包含至少包含一个链接的节点：
force
.nodes( d3.values(nodes).filter(function(d){ return d.linkCount;}) )
//Explanation: d3.values() turns the object-list of nodes into an array.
//.filter() goes through that array and creates a new array consisting of
//the nodes that return TRUE when passed to the callback function.
//The function just returns the linkCount of that node, which Javascript
//interprets as false if linkCount is zero, or true otherwise.
.links(links)
.start();
请注意，此不从nodes列表中删除未使用的节点，它只会过滤它们传递给布局。如果您不希望再次使用这些节点，则需要从节点列表中实际删除它们。
第三步，选项二，扫描节点列表并删除任何零链接的节点：
d3.keys(nodes).forEach(
//create an array of all the current keys(names) in the node list,
//and then for each one:
function (nodeKey) {
if (!nodes[nodeKey].linkCount) {
// find the node that matches that key, and check it's linkCount value
// if the value is zero (false in Javascript), then the ! (NOT) operator
// will reverse that to make the if-statement return true,
// and the following will execute:
delete(nodes[nodeKey]);
//this deletes the object AND its key from the nodes array
}
}//end of function
); //end of forEach method
/*then add the nodes list to the force layout object as before,
no filter needed since the list only includes the nodes you want*/