Added dynamic labels example

Rathunter · Jan 14, 2013 · da3af13 · da3af13
1 parent f68f17e
commit da3af13
Showing 1 changed file with 212 additions and 0 deletions.
diff --git a/chapter_09/29_dynamic_labels.html b/chapter_09/29_dynamic_labels.html
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+<!DOCTYPE html>
+<html lang="en">
+	<head>
+		<meta charset="utf-8">
+		<title>D3 Demo: Adding and removing values from a chart (dynamic labels included)</title>
+		<script type="text/javascript" src="../d3/d3.v3.js"></script>
+		<style type="text/css">
+			/* No style rules here yet */
+		</style>
+	</head>
+	<body>
+
+		<p id="add">Add a new data value</p>
+		<p id="remove">Remove a data value</p>
+
+		<script type="text/javascript">
+
+			//Width and height
+			var w = 600;
+			var h = 250;
+
+			var dataset = [ { key: 0, value: 5 },		//dataset is now an array of objects.
+							{ key: 1, value: 10 },		//Each object has a 'key' and a 'value'.
+							{ key: 2, value: 13 },
+							{ key: 3, value: 19 },
+							{ key: 4, value: 21 },
+							{ key: 5, value: 25 },
+							{ key: 6, value: 22 },
+							{ key: 7, value: 18 },
+							{ key: 8, value: 15 },
+							{ key: 9, value: 13 },
+							{ key: 10, value: 11 },
+							{ key: 11, value: 12 },
+							{ key: 12, value: 15 },
+							{ key: 13, value: 20 },
+							{ key: 14, value: 18 },
+							{ key: 15, value: 17 },
+							{ key: 16, value: 16 },
+							{ key: 17, value: 18 },
+							{ key: 18, value: 23 },
+							{ key: 19, value: 25 } ];
+
+			var xScale = d3.scale.ordinal()
+							.domain(d3.range(dataset.length))
+							.rangeRoundBands([0, w], 0.05);
+
+			var yScale = d3.scale.linear()
+							.domain([0, d3.max(dataset, function(d) { return d.value; })])
+							.range([0, h]);
+
+			//Define key function, to be used when binding data
+			var key = function(d) {
+				return d.key;
+			};
+
+			//Create SVG element
+			var svg = d3.select("body")
+						.append("svg")
+						.attr("width", w)
+						.attr("height", h);
+
+			//Create bars
+			svg.selectAll("rect")
+			   .data(dataset, key)
+			   .enter()
+			   .append("rect")
+			   .attr("x", function(d, i) {
+			   		return xScale(i);
+			   })
+			   .attr("y", function(d) {
+			   		return h - yScale(d.value);
+			   })
+			   .attr("width", xScale.rangeBand())
+			   .attr("height", function(d) {
+			   		return yScale(d.value);
+			   })
+			   .attr("fill", function(d) {
+					return "rgb(0, 0, " + (d.value * 10) + ")";
+			   });
+
+			//Create labels
+			svg.selectAll("text")
+			   .data(dataset, key)
+			   .enter()
+			   .append("text")
+			   .text(function(d) {
+			   		return d.value;
+			   })
+			   .attr("text-anchor", "middle")
+			   .attr("x", function(d, i) {
+			   		return xScale(i) + xScale.rangeBand() / 2;
+			   })
+			   .attr("y", function(d) {
+			   		return h - yScale(d.value) + 14;
+			   })
+			   .attr("font-family", "sans-serif")
+			   .attr("font-size", "11px")
+			   .attr("fill", "white");
+
+
+
+
+			//On click, update with new data			
+			d3.selectAll("p")
+				.on("click", function() {
+
+					//See which p was clicked
+					var paragraphID = d3.select(this).attr("id");
+
+					//Decide what to do next
+					if (paragraphID == "add") {
+						//Add a data value
+						var maxValue = 25;
+						var newNumber = Math.floor(Math.random() * maxValue);
+						var lastKeyValue = dataset[dataset.length - 1].key;
+						console.log(lastKeyValue);
+						dataset.push({
+							key: lastKeyValue + 1,
+							value: newNumber
+						});
+					} else {
+						//Remove a value
+						dataset.shift();	//Remove one value from dataset
+					}
+
+					//Update scale domains
+					xScale.domain(d3.range(dataset.length));
+					yScale.domain([0, d3.max(dataset, function(d) { return d.value; })]);
+
+					//Select…
+					var bars = svg.selectAll("rect")
+						.data(dataset, key);
+
+					//Enter…
+					bars.enter()
+						.append("rect")
+						.attr("x", w)
+						.attr("y", function(d) {
+							return h - yScale(d.value);
+						})
+						.attr("width", xScale.rangeBand())
+						.attr("height", function(d) {
+							return yScale(d.value);
+						})
+						.attr("fill", function(d) {
+							return "rgb(0, 0, " + (d.value * 10) + ")";
+						});
+
+					//Update…
+					bars.transition()
+						.duration(500)
+						.attr("x", function(d, i) {
+							return xScale(i);
+						})
+						.attr("y", function(d) {
+							return h - yScale(d.value);
+						})
+						.attr("width", xScale.rangeBand())
+						.attr("height", function(d) {
+							return yScale(d.value);
+						});
+
+					//Exit…
+					bars.exit()
+						.transition()
+						.duration(500)
+						.attr("x", -xScale.rangeBand())
+						.remove();
+
+
+
+					//Update all labels
+
+					//Select…
+					var labels = svg.selectAll("text")
+						.data(dataset, key);
+
+					//Enter…
+					labels.enter()
+						.append("text")
+						.text(function(d) {
+							return d.value;
+						})
+						.attr("text-anchor", "middle")
+						.attr("x", w)
+						.attr("y", function(d) {
+							return h - yScale(d.value) + 14;
+						})						
+					   .attr("font-family", "sans-serif")
+					   .attr("font-size", "11px")
+					   .attr("fill", "white");
+
+					//Update…
+					labels.transition()
+						.duration(500)
+						.attr("x", function(d, i) {
+							return xScale(i) + xScale.rangeBand() / 2;
+						});
+
+					//Exit…
+					labels.exit()
+						.transition()
+						.duration(500)
+						.attr("x", -xScale.rangeBand())
+						.remove();
+
+				});
+
+
+		</script>
+	</body>
+</html>