Posts Tagged ‘charts’
Highcharts Support in a Native iOS App
There are many options available to display charts within your [native] iOS apps. You could write one yourself (why?) or use one of the many third party libraries that are available . Check out this GitHub repo for a list of charting libraries in swift/ ObjC.
However, if you are interested in using Highcharts within your app, then read on . Highcharts is a popular JS charting engine and you can learn more about it at http://www.highcharts.com.
This post will demonstrate how you can load a Highcharts based chart into a iOS native app. We will use the example charts available as part of the Highcharts library. A more interesting and complete example that demonstrates how you can dynamically load chart data is available at https://github.com/rajagp/iOS_Highcharts_Sample.
1) Download the sample xcode app project from http://www.priyaontech.com/wp-content/uploads/2017/01/HighchartDemo.zip. This is a simple single view application that will load a .html file into a WKWebView.
2) Download the Highcharts library from http://www.highcharts.com/download
3) Once downloaded , unzip its contents and examine it. You should see contents list similar to screenshot below
4) Navigate to the “examples” folder
5) Copy the “index.htm” file from any of the examples into your project. Make sure you copy it into your project
6) Your project should look something like this
7) In your xcode project, open and review the the index.htm file that you just copied over. It contains a JS function that creates a chart using the Highcharts chart API as defined in http://api.highcharts.com/highcharts/chart. The chart data and options are defined statically.
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$(function() { // Create the chart Highcharts.chart('container', { chart: { type: 'column' }, title: { text: 'Browser market shares. January, 2015 to May, 2015' }, ……… |
8) Now, open the “ChartViewController.swift” file and review it. This is a simple view controller that manages a WKWebview and loads the index.html into the web view.
Look for the “loadContainerPage” function . This is where the index.htm is loaded.
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fileprivate func loadContainerPage() { print(#function) // Loads the index.html that is the base page for loading the chart guard let filePath = Bundle(for: ChartViewController.self). path(forResource: "index", ofType: "htm") else{ print("Could not locate index.htm") return } do{ let currFrame = self.view.frame; let content = tryString(contentsOfFile:filePath) let formattedContent = String.init(format: content,currFrame.size.width,currFrame.size.height) let_= self.webView?.loadHTMLString(formattedContent, baseURL: URL.init(fileURLWithPath: Bundle(for: ChartViewController.self).bundlePath)) } catch{ print("Failed to load contents of index.html") } } |
9) That’s it ! Run the app and you should see the sample chart load …
A complete example that demonstrates how you can dynamically load chart data is available at https://github.com/rajagp/iOS_Highcharts_Sample.