Combo Chart With MindFusion, a Free JS Chart Library
Combo Chart With MindFusion, a Free JS Chart Library
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Here, we will take a brief look at the steps you need to take to build this beautiful combo chart from scratch.
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<canvas id="combiChart" width="400" height="400"></canvas>
We create the chart control using a canvas HTML element:
var chartEl = document.getElementById('combiChart'); chartEl.width = chartEl.offsetParent.clientWidth; chartEl.height = chartEl.offsetParent.clientHeight; var chart = new Controls.BarChart(chartEl);
We create a bar chart, to which we will add line rendering capabilities. It is also possible to create a line chart and add rendering of bars to it.
Next, we add a title and a grid to the chart:
chart.title = "Corporate Sales"; chart.titleMargin = new Charting.Margins(0, 20, 0, 20); chart.gridType = GridType.Horizontal; chart.barSpacingRatio = 1.5;
barSpacingRatio indicates how much free space will be left between the group of bars relative to the bar width.
We create two serieses for the bars. MindFusion offers a variety of Series types to choose from, and we use two different series for the bars. The first one is a
BarSeries. We use it because it supports setting the X-labels by default:
var labels = new Collections.List([ "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" ]); var series1 = new Charting.BarSeries(new Collections.List([2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24]), null, null, labels);
The other series of type
SimpleSeries — it needs two parameters, a list with the necessary data and a list with the appropriate labels:
var series2 = new Charting.SimpleSeries(new Collections.List([1.4, 8, 13, 15, 13, 8, 2, 8, 13, 15, 13, 8]), null);
We don't have labels, so we set them to null. Then, we add the series to a collection:
var series = new Collections.ObservableCollection(new Array(series1, series2)); chart.series = series;
Then, we assign the collection to the series property of the chart. We create the line series as an instance of the Series2D class:
//the line series var series3 = new Charting.Series2D(new Collections.List([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]), new Collections.List([1.7, 6, 10.5, 11.5, 11.5, 10, 8, 12, 15.5, 17.5, 17.5, 16]), null); series3.title = "Average value"; var lseries = new Collections.ObservableCollection(new Array(series3));
After, we add it to another collection.
The chart renders with default bars. We will make it render a line series with the help of a
LineRenderer. We create an instance of the
LineRenderer class and provide it with the collection of serieses that we want to appear as lines. In our case it is just one:
//add a renderer for the line series var lRenderer = new Charting.LineRenderer(lseries); lRenderer.seriesStyle = new Charting.UniformSeriesStyle(lbrush, lstroke, 6); chart.plot.seriesRenderers.add(lRenderer);
Each chart has a plot, and the plot has a
seriesRenderers property that holds all renderers for the chart data. By default, a bar chart has a
BarRenderer. Now, we add the LineRenderer to this collection.
The chart legend is rendered when
showLegend is set to true:
//legend settings chart.showLegend = true; chart.legendMargin = new Charting.Margins(10, 10, 10, 10); chart.legendTitle = "Year";
We set the title of the legend to be "Year" and add some margins. The labels of the legend are taken from the title property of each Series. Since the series are rendered by two different renderers, we need to tell the legend which is the renderer, so it can take the labels from both of them and not only from the bar series. This is done with the content property of the
chart.legendRenderer.content = chart.plot.seriesRenderers;
The styling of the Series is done with different Style instances. For the bar chart, we use a
PerSeriesStyle instance. It colors all elements of a given series with the respective brush and stroke in the brushes and strokes instances that were provided as parameters:
var firstBrush = new Drawing.Brush("#8898B8"); var secondBrush = new Drawing.Brush("#4E567D"); var firstStroke = new Drawing.Brush("#60759f"); var secondStroke = new Drawing.Brush("#3b415e"); // assign one brush per series var brushes = new Collections.List([firstBrush, secondBrush]); var strokes = new Collections.List([firstStroke, secondStroke]); chart.plot.seriesStyle = new Charting.PerSeriesStyle(brushes, strokes);
We assign this style to the
seriesStyle property of the plot. The line series is colored with an instance of the
UniformSeriesStyle class. It applies one brush and one stroke to all elements in all series:
var lbrush = new Drawing.Brush("#F49B96"); var lstroke = new Drawing.Brush("#f07b75"); //add a renderer for the line series var lRenderer = new Charting.LineRenderer(lseries); lRenderer.seriesStyle = new Charting.UniformSeriesStyle(lbrush, lstroke, 6);
The third argument indicates stroke thickness. Note, that now we assign the new style to the
seriesStyle property of the
The rest of the settings for the chart appearance are in the theme property:
//theme settings for customizing the chart's appearance chart.theme.legendBackground = new Drawing.Brush("#f2f2f2"); chart.theme.legendTitleFontSize = 14; chart.theme.legendBorderStroke = new Drawing.Brush("#cecece"); chart.theme.axisTitleFontSize = 14; chart.theme.axisLabelsFontSize = 12; chart.theme.axisTitleFontName = "Verdana"; chart.theme.axisLabelsFontName = "Verdana"; chart.theme.dataLabelsFontName = "Verdana"; chart.theme.dataLabelsFontSize = 12; chart.theme.gridLineStyle = Drawing.DashStyle.Dash; chart.theme.gridColor1 = chart.theme.gridColor2 = new Drawing.Color("#ffffff"); chart.theme.gridLineColor = new Drawing.Color("#cecece"); chart.theme.highlightStroke = new Drawing.Brush("#F49B96"); chart.theme.highlightStrokeThickness = 4;
Here, we change the font for the labels and style the legend and the grid. Finally, we customize the stroke that highlights chart elements when the user hovers with the mouse over them.
We have reached the end of this tutorial. You can download the full source code of the sample with the libraries of Free JS Chart from this link.
You can find out more about MindFusion Free JS Chart library here.
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