Make bar styling options scriptable

docs/charts/bar.md

@@ -61,31 +61,69 @@ var myBarChart = new Chart(ctx, {
 ```
 
 ## Dataset Properties
-The bar chart allows a number of properties to be specified for each dataset. These are used to set display properties for a specific dataset. For example, the colour of the bars is generally set this way.
 
-Some properties can be specified as an array. If these are set to an array value, the first value applies to the first bar, the second value to the second bar, and so on.
+The bar chart allows a number of properties to be specified for each dataset.
+These are used to set display properties for a specific dataset. For example,
+the color of the bars is generally set this way.
 
-| Name | Type | Description
-| ---- | ---- | -----------
-| `label` | `String` | The label for the dataset which appears in the legend and tooltips.
-| `xAxisID` | `String` | The ID of the x axis to plot this dataset on. If not specified, this defaults to the ID of the first found x axis.
-| `yAxisID` | `String` | The ID of the y axis to plot this dataset on. If not specified, this defaults to the ID of the first found y axis.
-| `backgroundColor` | `Color/Color[]` | The fill color of the bar. See [Colors](../general/colors.md#colors).
-| `borderColor` | `Color/Color[]` | The color of the bar border. See [Colors](../general/colors.md#colors).
-| `borderWidth` | `Number/Number[]` | The stroke width of the bar in pixels.
-| `borderSkipped` | `String` | Which edge to skip drawing the border for. [more...](#borderskipped)
-| `hoverBackgroundColor` | `Color/Color[]` | The fill colour of the bars when hovered.
-| `hoverBorderColor` | `Color/Color[]` | The stroke colour of the bars when hovered.
-| `hoverBorderWidth` | `Number/Number[]` | The stroke width of the bars when hovered.
-
-### borderSkipped
-This setting is used to avoid drawing the bar stroke at the base of the fill. In general, this does not need to be changed except when creating chart types that derive from a bar chart.
+| Name | Type | [Scriptable](../general/options.md#scriptable-options) | [Indexable](../general/options.md#indexable-options) |  Default
+| ---- | ---- | :----: | :----: | ----
+| [`backgroundColor`](#styling) | [`Color`](../general/colors.md) | Yes | Yes | `'rgba(0,0,0,0.1)'`
+| [`borderColor`](#styling) | [`Color`](../general/colors.md) | Yes | Yes | `'rgba(0,0,0,0.1)'`
+| [`borderSkipped`](#borderskipped) | `String` | Yes | Yes | `'bottom'`
+| [`borderWidth`](#styling) | `Number` | Yes | Yes | `0`
+| [`data`](#data-structure) | `Object[]` | - | - | **required**
+| [`hoverBackgroundColor`](#interactions) | [`Color`](../general/colors.md) | - | - | `undefined`
+| [`hoverBorderColor`](#interactions) | [`Color`](../general/colors.md) | - | - | `undefined`
+| [`hoverBorderWidth`](#interactions) | `Number` | - | - | `1`
+| [`label`](#general) | `String` | - | - | `''`
+| [`xAxisID`](#general) | `String` | - | - | first x axis
+| [`yAxisID`](#general) | `String` | - | - | first y axis
+
+### General
+
+| Name | Description
+| ---- | ----
+| `label` | The label for the dataset which appears in the legend and tooltips.
+| `xAxisID` | The ID of the x axis to plot this dataset on.
+| `yAxisID` | The ID of the y axis to plot this dataset on.
+
+### Styling
+
+The style of each bar can be controlled with the following properties:
+
+| Name | Description
+| ---- | ----
+| `backgroundColor` | The bar background color.
+| `borderColor` | The bar border color.
+| [`borderSkipped`](#borderskipped) | The edge to skip when drawing bar.
+| `borderWidth` | The bar border width (in pixels).
+
+All these values, if `undefined`, fallback to the associated [`elements.rectangle.*`](../configuration/elements.md#rectangle-configuration) options.
+
+#### borderSkipped
+
+This setting is used to avoid drawing the bar stroke at the base of the fill.
+In general, this does not need to be changed except when creating chart types
+that derive from a bar chart.
 
 Options are:
-* 'bottom'
-* 'left'
-* 'top'
-* 'right'
+* `'bottom'`
+* `'left'`
+* `'top'`
+* `'right'`
+
+### Interactions
+
+The interaction with each bar can be controlled with the following properties:
+
+| Name | Description
+| ---- | -----------
+| `hoverBackgroundColor` | The bar background color when hovered.
+| `hoverBorderColor` | The bar border color hovered.
+| `hoverBorderWidth` | The bar border width when hovered (in pixels).
+
+All these values, if `undefined`, fallback to the associated [`elements.point.*`](../configuration/elements.md#point-configuration) options.
 
 ## Configuration Options
 

gulpfile.js

@@ -186,16 +186,16 @@ function lintHtmlTask() {
 }
 
 function docsTask(done) {
-  const script = require.resolve('gitbook-cli/bin/gitbook.js');
-  const cmd = process.execPath;
+  var script = require.resolve('gitbook-cli/bin/gitbook.js');
+  var cmd = '"' + process.execPath + '"';
 
   exec([cmd, script, 'install', './'].join(' ')).then(() => {
     return exec([cmd, script, argv.watch ? 'serve' : 'build', './', './dist/docs'].join(' '));
-  }).catch((err) => {
-    console.error(err.stdout);
   }).then(() => {
     done();
-  });
+  }).catch((err) => {
+    done(new Error(err.stdout || err));
+  })
 }
 
 function unittestTask(done) {

samples/samples.js

@@ -176,6 +176,9 @@
 	}, {
 		title: 'Scriptable',
 		items: [{
+			title: 'Bar Chart',
+			path: 'scriptable/bar.html'
+		}, {
 			title: 'Bubble Chart',
 			path: 'scriptable/bubble.html'
 		}]

samples/scriptable/bar.html

@@ -0,0 +1,95 @@
+<!DOCTYPE html>
+<html lang="en-US">
+<head>
+	<meta charset="utf-8">
+	<meta http-equiv="X-UA-Compatible" content="IE=Edge">
+	<meta name="viewport" content="width=device-width, initial-scale=1">
+	<title>Scriptable > Bar | Chart.js sample</title>
+	<link rel="stylesheet" type="text/css" href="../style.css">
+	<script src="../../dist/Chart.js"></script>
+	<script src="../utils.js"></script>
+</head>
+<body>
+	<div class="content">
+		<div class="wrapper"><canvas id="chart-0"></canvas></div>
+		<div class="toolbar">
+			<button onclick="randomize(this)">Randomize</button>
+			<button onclick="addDataset(this)">Add Dataset</button>
+			<button onclick="removeDataset(this)">Remove Dataset</button>
+		</div>
+	</div>
+
+	<script>
+		var DATA_COUNT = 16;
+
+		var utils = Samples.utils;
+
+		utils.srand(110);
+
+		function colorize(opaque, ctx) {
+			var v = ctx.dataset.data[ctx.dataIndex];
+			var c = v < -50 ? '#D60000'
+				: v < 0 ? '#F46300'
+				: v < 50 ? '#0358B6'
+				: '#44DE28';
+
+			return opaque ? c : utils.transparentize(c, 1 - Math.abs(v / 150));
+		}
+
+		function generateData() {
+			return utils.numbers({
+				count: DATA_COUNT,
+				min: -100,
+				max: 100
+			});
+		}
+
+		var data = {
+			labels: utils.months({count: DATA_COUNT}),
+			datasets: [{
+				data: generateData()
+			}]
+		};
+
+		var options = {
+			legend: false,
+			tooltips: false,
+			elements: {
+				rectangle: {
+					backgroundColor: colorize.bind(null, false),
+					borderColor: colorize.bind(null, true),
+					borderWidth: 2
+				}
+			}
+		};
+
+		var chart = new Chart('chart-0', {
+			type: 'bar',
+			data: data,
+			options: options
+		});
+
+		// eslint-disable-next-line no-unused-vars
+		function randomize() {
+			chart.data.datasets.forEach(function(dataset) {
+				dataset.data = generateData();
+			});
+			chart.update();
+		}
+
+		// eslint-disable-next-line no-unused-vars
+		function addDataset() {
+			chart.data.datasets.push({
+				data: generateData()
+			});
+			chart.update();
+		}
+
+		// eslint-disable-next-line no-unused-vars
+		function removeDataset() {
+			chart.data.datasets.shift();
+			chart.update();
+		}
+	</script>
+</body>
+</html>

samples/utils.js

@@ -11,7 +11,7 @@ window.chartColors = {
 };
 
 (function(global) {
-	var Months = [
+	var MONTHS = [
 		'January',
 		'February',
 		'March',
@@ -106,7 +106,7 @@ window.chartColors = {
 			var i, value;
 
 			for (i = 0; i < count; ++i) {
-				value = Months[Math.ceil(i) % 12];
+				value = MONTHS[Math.ceil(i) % 12];
 				values.push(value.substring(0, section));
 			}
 

src/controllers/controller.bar.js

@@ -213,35 +213,32 @@ module.exports = function(Chart) {
 
 		updateElement: function(rectangle, index, reset) {
 			var me = this;
-			var chart = me.chart;
 			var meta = me.getMeta();
 			var dataset = me.getDataset();
-			var custom = rectangle.custom || {};
-			var rectangleOptions = chart.options.elements.rectangle;
+			var options = me._resolveElementOptions(rectangle, index);
 
 			rectangle._xScale = me.getScaleForId(meta.xAxisID);
 			rectangle._yScale = me.getScaleForId(meta.yAxisID);
 			rectangle._datasetIndex = me.index;
 			rectangle._index = index;
-
 			rectangle._model = {
+				backgroundColor: options.backgroundColor,
+				borderColor: options.borderColor,
+				borderSkipped: options.borderSkipped,
+				borderWidth: options.borderWidth,
 				datasetLabel: dataset.label,
-				label: chart.data.labels[index],
-				borderSkipped: custom.borderSkipped ? custom.borderSkipped : rectangleOptions.borderSkipped,
-				backgroundColor: custom.backgroundColor ? custom.backgroundColor : helpers.valueAtIndexOrDefault(dataset.backgroundColor, index, rectangleOptions.backgroundColor),
-				borderColor: custom.borderColor ? custom.borderColor : helpers.valueAtIndexOrDefault(dataset.borderColor, index, rectangleOptions.borderColor),
-				borderWidth: custom.borderWidth ? custom.borderWidth : helpers.valueAtIndexOrDefault(dataset.borderWidth, index, rectangleOptions.borderWidth)
+				label: me.chart.data.labels[index]
 			};
 
-			me.updateElementGeometry(rectangle, index, reset);
+			me._updateElementGeometry(rectangle, index, reset);
 
 			rectangle.pivot();
 		},
 
 		/**
 		 * @private
 		 */
-		updateElementGeometry: function(rectangle, index, reset) {
+		_updateElementGeometry: function(rectangle, index, reset) {
 			var me = this;
 			var model = rectangle._model;
 			var vscale = me.getValueScale();
@@ -472,6 +469,47 @@ module.exports = function(Chart) {
 
 			helpers.canvas.unclipArea(chart.ctx);
 		},
+
+		/**
+		 * @private
+		 */
+		_resolveElementOptions: function(rectangle, index) {
+			var me = this;
+			var chart = me.chart;
+			var datasets = chart.data.datasets;
+			var dataset = datasets[me.index];
+			var custom = rectangle.custom || {};
+			var options = chart.options.elements.rectangle;
+			var resolve = helpers.options.resolve;
+			var values = {};
+			var i, ilen, key;
+
+			// Scriptable options
+			var context = {
+				chart: chart,
+				dataIndex: index,
+				dataset: dataset,
+				datasetIndex: me.index
+			};
+
+			var keys = [
+				'backgroundColor',
+				'borderColor',
+				'borderSkipped',
+				'borderWidth'
+			];
+
+			for (i = 0, ilen = keys.length; i < ilen; ++i) {
+				key = keys[i];
+				values[key] = resolve([
+					custom[key],
+					dataset[key],
+					options[key]
+				], context, index);
+			}
+
+			return values;
+		}
 	});
 
 	Chart.controllers.horizontalBar = Chart.controllers.bar.extend({

src/controllers/controller.bubble.js

@@ -103,12 +103,14 @@ module.exports = function(Chart) {
 		setHoverStyle: function(point) {
 			var model = point._model;
 			var options = point._options;
+
 			point.$previousStyle = {
 				backgroundColor: model.backgroundColor,
 				borderColor: model.borderColor,
 				borderWidth: model.borderWidth,
 				radius: model.radius
 			};
+
 			model.backgroundColor = helpers.valueOrDefault(options.hoverBackgroundColor, helpers.getHoverColor(options.backgroundColor));
 			model.borderColor = helpers.valueOrDefault(options.hoverBorderColor, helpers.getHoverColor(options.borderColor));
 			model.borderWidth = helpers.valueOrDefault(options.hoverBorderWidth, options.borderWidth);
@@ -167,6 +169,7 @@ module.exports = function(Chart) {
 				dataset.radius,
 				options.radius
 			], context, index);
+
 			return values;
 		}
 	});