I am just starting to learn D3 and currently working through understanding this example.
I am trying to get text to display next to each node in the graph. In the JSON data, there is a key named name, which contains the name of a character from Les Misérables. I am trying to display this text next to each node using this code:
var node = svg.selectAll(".node")
.data(graph.nodes)
.enter().append("circle")
.attr("class", "node")
.attr("r", 5)
.style("fill", "black")
.text(function(d) { return d.name;}).style("font-family", "Arial").style("font-size", 12)
.call(force.drag);
I've basically just altered the .text to try and display text. Can anyone explain how I can get text to display? Thanks in advance.
The SVG <circle> element will not display any text that you place inside it using the .text function. A way to display the text would be to make the nodes of the graph SVG <g> elements. These can then contain a <circle> and a <text> child elements.
This could look like this :
\\create graph nodes using groups
var node = svg.selectAll(".node")
.data(graph.nodes)
.enter().append("g").call(force.drag);
node.append("circle")
.attr("class", "node")
.attr("r", 5)
.style("fill", function (d) { return color(d.group); });
node.append("text")
.text(function (d) { return d.name; });
You would also need to change the force so that it transforms the group <g> on a tick.
force.on("tick", function () {
...
node.attr("transform", function (d) { return "translate(" + d.x + "," + d.y + ")"; });
});
You can see it in action for a small graph at http://jsfiddle.net/vrWDc/19/. This method may not be very efficient when applied to a large graph due to the amount of text that needs to be rendered.
Related
I am trying to make a stacked bar graph through d3js and have it update when new data is passed through an update function. I call this update function to initially call the graph and it works fine. However, when I change the data and call it again, it erases all the "rect" elements from the graph (When I console log the data, it appears to be passing through). How can I make the graph be redrawn appropriately? I have tried experimenting with the .remove() statement at the beginning, but without it the data doesn't pass through when the bars are redrawn.
function update(my_data) {
svg.selectAll(".year").remove();
var year = svg.selectAll(".year")
.data(my_data)
.enter().append("g")
.attr("class", "year")
.attr("transform", function(d) { return "translate(" + x0(d.Year) + ",0)"; });
var bar = year.selectAll(".bar")
.data( function(d){ return d.locations; });
bar
.enter().append("rect")
.attr("class", "bar")
.attr("width", x0.rangeBand())
.attr("y", function(d) { return y(d.y1); })
.attr("height", function(d) { return y(d.y0) - y(d.y1); })
.style("fill", function(d) { return color(d.name); });
}
update(data);
It's hard to tell exactly what you're doing cause your question doesn't include the data or the DOM. It would help if you included a link to a work-in-progress jsFiddle or something.
If I had to guess what's going wrong, it looks like you're doing a nested join where each year gets bound to a g element and then each location gets bound to a rect inside each g element.
The issue is likely you are only specifying the enter behavior, but not the update behavior or the exit behavior. As a result, when you try to redraw, nothing updates and nothing exits - but new data elements will get added.
It would seem that is why you have to add the selectAll().remove() to get anything to redraw. By removing everything, all the data elements will trigger the enter condition and get added again.
Take a look at these tutorials to better understand how the enter/update/exit pattern works and how nested joins work.
General Update Pattern: https://bl.ocks.org/mbostock/3808218
Nested Selections: https://bost.ocks.org/mike/nest/
Also, here is a jsFiddle I wrote some time ago to demonstrate how to use nested selections and the general update pattern together:
https://jsfiddle.net/reblace/bWp8L/
var series = svg.selectAll("g.row").data(data, function(d) { return d.key; });
/*
* This section handles the "enter" for each row
*/
// Adding a g element to wrap the svg elements of each row
var seriesEnter = series.enter().append("g");
seriesEnter
.attr("class", "row")
.attr("transform", function(d, i){
return "translate(" + margin.left + "," + (margin.top + (span*i)) + ")";
})
.attr("opacity", 0).transition().duration(200).attr("opacity", 1);
// Adding a text label for each series
seriesEnter.append("text")
.style("text-anchor", "end")
.attr("x", -6)
.attr("y", boxMargin + (boxDim/2))
.attr("dy", ".32em")
.text(function(d){ return d.key; });
// nested selection for the rects associated with each row
var seriesEnterRect = seriesEnter.selectAll("rect").data(function(d){ return d.values; });
// rect enter. don't need to worry about updates/exit when a row is added
seriesEnterRect.enter().append("rect")
.attr("fill", function(d){ return colorScale(d)})
.attr("x", function(d, i){ return i*span + boxMargin; })
.attr("y", boxMargin)
.attr("height", boxDim)
.attr("width", boxDim);
/*
* This section handles updates to each row
*/
var seriesUpdateRect = series.selectAll("rect").data(function(d){ return d.values});
// rect update (Will handle updates after enter)
// rect enter
seriesUpdateRect.enter().append("rect")
.attr("x", function(d, i){ return i*span + boxMargin; })
.attr("y", boxMargin)
.attr("height", boxDim)
.attr("width", boxDim);
// rect enter + update
seriesUpdateRect
.attr("fill", function(d){ return colorScale(d)});
// Exit
seriesUpdateRect.exit();
/*
* This section handles row exit
*/
series.exit()
.attr("opacity", 1)
.transition().duration(200).attr("opacity", 0)
.remove();
I would like to make the text in the D3.js nodes submit a GET request upon click.
The jsfiddle for the code can be found here: https://jsfiddle.net/ft5107wo/2/
I would like the GET request to be on the id key in node's JSON.
I have attempted this solution, but it did not work.
The relevant code for creating the rectangles and appending node text is from lines 191 to 218, and is as follows:
// Create the node rectangles.
nodes.append("rect")
.attr("class", "node")
.attr("height", 40)
.attr("width", 40)
.attr("id", function (d) {
return d.id;
})
.attr("display", function (d) {
if (d.hidden) {
return "none"
} else {
return ""
};
})
.attr("x", kx)
.attr("y", ky);
// Create the node text label.
nodes.append("text")
.text(function (d) {
return d.name;
}).attr("transform", "translate(0," + 5 + ")")
.style("text-anchor", "middle")
.attr("x", tx)
.attr("y", ty)
.attr("dy", 0)
.call(wrap, 40);
How can this be achieved?
It turns out one needs to use this hack to have it work correctly and avoid problems with namespaces.
I'm living updating nodes and links. I also want to change the radius of existing nodes(circles). how can i update eg a specific circle?
When i do this below it updates all circles.
node.select("circle").attr("r", circleradius);
when i update the node array nothing changes in the viz.
nodes[index].size = 2000;
this is how the outputted html looks like
this is the function update code:
function update() {
// Restart the force layout.
force
.nodes(nodes)
.links(links)
.start();
// Update links.
link = link.data(links, function(d) { return d.target.id; });
link.exit().remove();
link.enter().insert("line", ".node")
.attr("class", "link");
// Update nodes.
node = node.data(nodes, function(d) { return d.id; });
node.exit().remove();
var nodeEnter = node.enter().append("g")
.attr("class", "node")
.on("click", click)
.call(force.drag);
nodeEnter.append("circle")
.attr("r", function(d) { return Math.sqrt(d.size) / 2 || 24.5; });
nodeEnter.append("text")
.attr("dy", ".35em")
.text(function(d) { return d.name; });
node.select("circle")
.style("fill", color);
}
Child elements are not automatically updated until you use d3.select. It's a bit of a hard thing to wrap your head around which I won't get into here.
But for practical purposes, what you need to do is, after you've created your force-directed layout and elements and such, if you want to change a data value used for size element 0 and see it update, the code needs to read like this:
nodes[0].size = 2000;
d3.selectAll("g").select("circle")
.attr("r", function(d) { return Math.sqrt(d.size) / 2 || 24.5; });
I'm using a range slider to add/remove points from a line which follows an histogram.
Without updating the data, the text labels are shown correctly, when I update the values with the slider I'd like that the text-labels follow the line, so they show the values of the points correctly.
The update for the line works, but I am not able to update the text labels correctly.
Right now the laberls are plotted like so outside of the on-change function:
var SerifText = svg.append("g")
.attr("id", "serif-labels")
.selectAll("text")
.data(histogSerif)
.enter()
.append("text")
.text(function (d) { return d.y >= 1 ? d.y : null; })
.attr("text-anchor", "middle")
.attr("font-size", 10 + "px")
.attr("fill", "#f0027f")
.attr("x", function (d) { return x(d.x)})
.attr("y", function (d) { return y(d.y) - padding; })
.attr("visibility", "hidden"); //the hidden & visible is managed by an external checkbox
And then on the on-change function I put this code:
SerifText.selectAll("text").remove();
/* If I do SerifText.remove() it does remove the text but also the group of course,
but as it is it doesn't work */
SerifText.selectAll("text")
.data(histogSerif)
.enter()
.append("text")
.text(function (d) { return d.y >= 1 ? d.y : null; })
.attr("text-anchor", "middle")
.attr("font-size", 10 + "px")
.attr("fill", "#f0027f")
.attr("x", function (d) { return x(d.x)})
.attr("y", function (d) { return y(d.y) - padding; });
But this doesn't work unfortunately. I'd like also to be able to retain the manage of the visible/hidden status by the external checkbox if possible.
Full code is here
Instead of trying to save a reference to the labels that you are going to delete, and then re-selecting them, how about just use a variable that references the SerifText element selection, e.g.:
var SerifTextGroup = svg.append("g")
.attr("id", "serif-labels");
SerifTextGroup.selectAll("text")
.data(histogSerif)
.enter()
//... and so on
Then the rest of your code should work as written (just change SerifText to SerifTextGroup).
I am new to this kind of chord visualization. I am working on a sample http://bl.ocks.org/mbostock/4062006:
I would like to add "black", "blonde","brown","red" as labels in the respective chord. How is this possible.
I tried something like this but is not working:
var textLabel = d3.scale.ordinal().range(['Black','Blonde','Brown','Red']);
svg.append("g").selectAll("path")
.data(chord.groups)
.enter()
.append("path")
.style("fill", function(d) { return fill(d.index); })
.style("stroke", function(d) { return fill(d.index); })
.attr("d", d3.svg.arc().innerRadius(innerRadius).outerRadius(outerRadius))
svg.append("g").append("svg:text")
.attr("x", 6)
.attr("dy", 15)
.append("svg:textPath")
.text(function(d,i) { return textLabel(i+1); })
.on("mouseover", fade(.1))
.on("mouseout", fade(1));
You have forgotten to use the enter selection and also do not link the svg:textPath to an actual path in the SGV. To do this the path you want the text to follow needs to have been given an id attribute and you need to reference this in the textPath with an href attribute.
So you want to add the id attribute to the path you want the text to follow
.attr("id", function(d, i){return "group-" + i;})
You then want to do something like this to add textPath elements
svg.append("g").selectAll("text")
.data(chord.groups)
.enter()
.append("sgv:text")
.attr("x", 6)
.attr("dy", 15)
.append("svg:textPath")
.attr("xlink:href", function(d, i){return "#group-" + i;})
.text(function(d,i) {return textLabel(i+1);});
Finally with the colour black you will probably want to invert the text so you don't end up with black on black text.
.filter(function(d, i){return i === 0 ? true : false;})
.attr("style", "fill:white;");