Gradually increment the opacity

Question

I would like to increment gradually the opacity of my circle in D3.js. I have two problems, the first is even if I put a static opacity, my circles doesn't appears. The second is I don't know how to have a clean method to have a gradually apparition of my circles :

    <!DOCTYPE html>
<meta charset="utf-8">
<style>
    text {
        font: 10px sans-serif;
    }
</style>
<body>
<script src="https://d3js.org/d3.v3.min.js" charset="utf-8"></script>
<script>

    var diameter = 960,
            format = d3.format(",d"),
            color = d3.scale.category20c();

    var bubble = d3.layout.pack()
            .sort(null)
            .size([diameter,diameter])
           .value(function(d) { console.log(d.size);return d.size; })
            .padding(1.5);

    var svg = d3.select("body").append("svg")
            .attr("width", diameter)
            .attr("height", diameter)
            .attr("class", "bubble");


    d3.json("./data.json", function(error, root) {
        if (error) throw error;

        var node = svg.selectAll(".node")
                .data(bubble.nodes(classes(root))
                 .filter(function(d) {   return !d.children; }))
                .enter().append("g")
                .attr("class", "node")
                .attr("transform", function(d) { return "translate(" + d.x + "," + d.y + ")"; });

        node.append("title")
                .text(function(d) { return d.className + ": " + format(d.value); });

        node.append("circle")
                .attr("r", function(d) {return d.r; })
                .style("fill", function(d) { return color(d.size); })
                .style("visibility","hidden");

        node.append("text")
                .attr("dy", ".3em")
                .style("text-anchor", "middle")
                .text(function(d) { return d.className.substring(0, d.r / 3); })
                .style("visibility","hidden");

                  setTimeout(myFunction, 3000);
        function myFunction() {
          for (var i = 0 ; i <= 1 ; i = i + 0.01){
            console.log(i);
            node.append("circle").style("opacity",i);
          }
            //At this time, circles should be appears !
        }
    });


    // Returns a flattened hierarchy containing all leaf nodes under the root.
    function classes(root) {
        var classes = [];
        function recurse(name, node) {
            if (node.children) node.children.forEach(function(child) { recurse(node.name, child); });
           else classes.push({packageName: name, className: node.name, value: node.size, size: node.size});
        }
        recurse(null, root);
        return {children: classes};
    }
    d3.select(self.frameElement).style("height", diameter + "px");

</script>
</body>

This is the Plunker : https://plnkr.co/edit/wrCk54GrDPpK8AkgWjCt?p=preview Thanks.

eko · Accepted Answer · 2016-04-26T13:25:05.370

Here's the result: https://plnkr.co/edit/SAf0BaUpJJQw5Vwp3T5P?p=preview

I think rather than visibility you want opacity for your circle and text elements like this:

node.append("circle")
                .attr("r", function(d) {return d.r; })
                .style("fill", function(d) { return color(d.size); })
                .style("opacity","0");

        node.append("text")
                .attr("dy", ".3em")
                .style("text-anchor", "middle")
                .text(function(d) { return d.className.substring(0, d.r / 3); })
                .style("opacity","0");

And your setTimeout callback should be:

  function myFunction() {
        node.selectAll("circle").transition().duration(1000).style("opacity","1");
        node.selectAll("text").transition().duration(1000).style("opacity","1");
    }

You can change the duration above for a slower effect.

A small note that it would be better to use `node.selectAll(...)` inside `myFunction` in case there are other `circle` and `text` elements outside of the chart (i.e. a toolbar/tooltip). — JSBob, Apr 26 '16 at 13:23

Gradually increment the opacity

1 Answers1