This tutorial will help you to integrate Pivot Component with Google Charts charting library.

Supported chart types

Flexmonster supports the following Google Charts types:

• AreaChart (demo)
• BarChart (demo)
• ColumnChart (demo)
• LineChart (demo)
• PieChart (demo)
• Sankey (demo)

However, if chart type you want is not on the list it’s possible to use prepareDataFunction to preprocess the data in your own way.

Adding Google Charts

1. Add to your HTML page the following pivot table based on CSV file.

   <div id="pivotContainer">The component will appear here</div>
   <script src="flexmonster/flexmonster.js"></script>
   
   <script>
   	var pivot = new Flexmonster({
   		container: "pivotСontainer",
   		toolbar: true,
   		report: {
   			dataSource: {
   				filename: "data.csv"
   			},
   			slice: {
   				rows: [
   					{ uniqueName: "Country" }
   				],
   				columns: [
   					{ uniqueName: "[Measures]" }
   				],
   				measures: [
   					{ uniqueName: "Price" }
   				]
   			}
   		},
   		licenseKey: "XXXX-XXXX-XXXX-XXXX-XXXX"
   	});
   </script>
   

2. Add Google Charts.

   <script src="https://www.gstatic.com/charts/loader.js"></script>
   

3. Add our connector for Google Charts.

   <script src="flexmonster/lib/flexmonster.googlecharts.js"></script>
   

4. Add container for the chart.

   <div id="googlechartContainer"></div>
   

5. Add reportComplete event handler to know when the pivot table is ready to be a data provider.

   reportcomplete: function() {
   	pivot.off("reportcomplete");
   	pivotTableReportComplete = true;
   	createGoogleChart();
   }
   

6. Add function to create the chart. This function is using a connector for Google Charts from flexmonster.googlecharts.js. The connector extends Flexmonster API with the following call: googlecharts.getData(options, callbackHandler, updateHandler).

   var pivotTableReportComplete = false;
   var googleChartsLoaded = false;
   
   google.charts.load('current', {'packages':['corechart']});
   google.charts.setOnLoadCallback(onGoogleChartsLoaded);
   function onGoogleChartsLoaded() {
   	googleChartsLoaded = true;
   	if (pivotTableReportComplete) {
   		createGoogleChart();
   	}
   }
   
   function createGoogleChart() {
   	if (googleChartsLoaded) {
   		pivot.googlecharts.getData({ type: "column" }, 
   			drawChart, 
   			drawChart
   		);
   	}			
   }
   
   function drawChart(_data) {
   	var data = google.visualization.arrayToDataTable(_data.data);
   	var options = {
   		title: _data.options.title,
   		height: 300
   	};
   	var chart = new google.visualization
   		.ColumnChart(document.getElementById('googlechartContainer'));
   	chart.draw(data, options);
   }
   

You will see column chart that displays the same data that is shown in the pivot table instance pivot and it will react on updates. Try how it works on JSFiddle.

Connector for Google Charts

We added flexmonster.googlecharts.js as a connector between our component and Google Charts. googlecharts.getData() method requests data from the Pivot Table and preprocesses it to the appropriate format for the required type of chart.

googlecharts.getData(options:Object, callbackHandler:Function, updateHandler:Function) has the following parameters:

• options – Object. This object has the following parameters:
  • type (optional) – String. Chart type to prepare data for. Possible values: "area", "bar", "column", "line", "pie", "sankey". If type is not specified, data will be prepared the same way it is prepared for "sankey".
  • slice (optional) – Object. Defines the slice for which the data should be returned (for JSON, CSV and OCSV data sources only). If not defined, the API call will return data displayed in the pivot table.

    function createGoogleChart() {
    	if (googleChartsLoaded) {
    		pivot.googlecharts.getData({
    				slice: {
    					rows: [{uniqueName: "Country"}],
    					columns: [{uniqueName: "[Measures]"}],
    					measures: [{uniqueName: "Quantity"}]
    				}
    			}, 
    			drawChart, 
    			drawChart
    		);
    	}			
    }
    

  • prepareDataFunction (optional) – An external function. If the connector does not include the necessary type of chart or you need to preprocess the data in a different way – please use prepareDataFunction. prepareDataFunction gets two input parameters: rawData – raw data (check the structure of rawData in getData()); options – object with options set in googlecharts.getData(). Check the example on JSFiddle based on the data preprocessed with external function. One more example illustrates how the data can be prepared to show the deepest drill down level on Google Column Chart.
• callbackHandler – Function. Specifies what will happen once data is ready. Additional options can be specified and then data can be passed directly to the charting library. Gets two input parameters – data and rawData (rawData is passed just in case you need it, for example, for defining number formatting in the tooltip).
• updateHandler (optional) – Function. Gets two input parameters – data and rawData. Specifies what will happen once data in the pivot table is filtered/sorted/etc or a number format is changed.

The connector has several functions for defining number formatting for Google Charts. All these functions get the pivot table format object and return the formatting string in Google Charts format.

• flexmonster.googlecharts.getNumberFormat(format) – Object. Gets pivot format and returns format object for number formatting in Google Charts. This object can be used to format columns in DataTable.
• flexmonster.googlecharts.getNumberFormatPattern(format) – Object. Gets pivot format and returns Google Charts format pattern. This pattern can be used to format axes.

These functions can be used in callbackHandler and updateHandler functions to define a number formatting for axes and tooltips. Try it in JSFiddle.