04_workshop_interactive circles

<!DOCTYPE html>

<head>
	<title>d3js workshop - circles 2</title>
	<script src="https://d3js.org/d3.v3.js"></script> 
</head>

<body>

// first let's draw 3 circles
		// this is how a circle looks like
		// <circle cx="40" cy="60" r="10"></circle>

// and this is what we want to create to get started
		/*
		<svg width="720" height="120">
  			<circle cx="40" cy="60" r="10"></circle>
  			<circle cx="80" cy="60" r="10"></circle>
  			<circle cx="120" cy="60" r="10"></circle>
		</svg>
		*/

// first we need to add an svg element to body
		svg = d3.select('body')
			.append('svg')
			.attr('width', '720px')
			.attr('height', '120px');
		
		// now let's append 3 circles to svg
		// I will use a data list with length of 3
		var data = [10, 20, 30];
		
		var circles = svg.selectAll('circle')
						.data(data)
						.enter()
						.append('circle')
							.attr('r', 10)
							.attr('cy', 60)
							.attr('cx', function(d){ return 4 * d});

// This is from example 03
		circles.transition()
			.delay(function(d, i){return i * 1000})
			.duration(2000)
			.style('fill', 'red')
			.attr('r', '15')
			.attr('cy', '80');

// let's make the circles to go back to where they came from
		// aka let's learn how to assign events in d3
		circles.on("mouseover", function(d){
			// say hi to the confusing 'this' in javascript
			var circle = this;

// set duration to make it pretty
			d3.select(circle)
				.style('fill', 'black')
				.attr('r', '10')
				.attr('cy', '60');
		})

// also add click event to disappear the circles
		// tip use on('click', function(d){'write the function here!'})

</script>
</body>

Modified http://d3js.org/d3.v3.js to a secure url

https://d3js.org/d3.v3.js