D3.js: run a transition continuously?

Question

How can I run a transition continuously in D3.js?

For example, say I want to change the body colour from red to blue and back again, continuously (I don't, that would be horrendous, but go with it).

This is how I would do it once:

d3.select("body").transition().duration(1000).style("background-color", "red");

How would I do it continuously?

The closest examples I have seen use d3.timer, but I am not sure if there is a better way to do it.

Answer 1

For D3 version 4 you have to use .on instead of .each (based on Lars answer):

function myTrans() {
    d3.select("body").transition().duration(1000).style("background-color", "red")
      .on("end", function() {
        d3.select(this).transition().duration(1000).style("background-color", "blue")
          .on("end", function() { myTrans(); });
      });
}

Answer 2

You can use transition.each() and the "end" event. The code would look something like the following.

function myTrans() {
    d3.select("body").transition().duration(1000).style("background-color", "red")
      .each("end", function() {
        d3.select(this).transition().duration(1000).style("background-color", "blue")
          .each("end", function() { myTrans(); });
      });
}

Answer 3

You might want to check out this blog post (2 parts) on D3 transitions - http://blog.safaribooksonline.com/2013/07/11/reusable-d3-js-using-attrtween-transitions-and-mv/

I'm just beginning to work with D3 and this was helpful.

Answer 4

I faced the same problem and I used css animations to solve the problem. With simple html and css would be like this:

#cube {
  width: 120px; 
  height:120px;
  animation-duration: 3s;
  animation-name: transcolor;
  animation-iteration-count: infinite;
  animation-direction: alternate;
  }


@keyframes transcolor {
  from {
    background-color:#535455;
  }
  
  to {
   background-color:#bf2c23;
  }
}

<div id="cube">

</div>

With d3 and javascript :

d3.select("body")
  .style("animation", "transcolor 3s infinite linear alternate");

@keyframes transcolor {
  from {
    background-color:#535455;
  }
  
  to {
   background-color:#bf2c23;
  }
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>