Pie chart API reference

• Example
• The angles (coordinates) properties
• Properties
• Methods
• Data properties that are used on the segments
• Events
• Effects

Example

<script>
    data = [280,45,133,152,278,221,56];

    new RGraph.SVG.Pie({
        id: 'chart-container',
        data: data,
        options: {
            labels: ['Monday','Tuesday','Wednesday','Thursday','Friday','Saturday','Sunday'],
            shadow: true,
            colorsStroke: 'rgba(0,0,0,1)',
            linewidth: 0,
            exploded: [,,25],
            colors: ['#f66','pink','orange','gray','#fcc','green','#0f0'],
            tooltips: '%{key}',
            tooltipsFormattedKeyLabels: ['Monday','Tuesday','Wednesday','Thursday','Friday','Saturday','Sunday'],
            tooltipsFormattedUnitsPost: '%',
            tooltipsCss: {
                backgroundColor: '#333',
                fontWeight: 'bold',
                fontSize: '14pt',
                opacity: 0.85
            }
        }
    }).draw();
</script>

The angles property

The angles for the segments on the Pie chart are held in the obj.angles array. Each element in this array is an object that has the following properties:

• start - The start angle (measured in radians)
• end - The end angle (measured in radians)
• angle - The extent (the end minus the start) of the angle of the segment (measured in radians)
• halfway - The halfway point of the angle (measured in radians)
• cx - The center x-axis coordinate for the segment
• cy - The center y-axis coordinate for the segment
• radius - The radius of the segment (in a Pie chart all the radii of the segments are the same)
• object> - The RGraph Pie chart object
• element - The svg path element

Properties

You can use these properties to control how the chart appears. You can set them by including them in the options section of the configuration as shown above.

• Chart configuration properties
• Margin properties
• Color properties
• Other text properties
• Shadow properties
• Title properties
• Key properties
• Tooltip properties
• Highlight properties
• Other properties

tooltipsOverride: function (obj, opt)
{
    // Show tooltip
}

tooltipsFormattedKeyColorsCss : {
    border: "1px solid #ddd";
}

tooltipsFormattedListItems: [
    ['Bill','Jerry','Berty'], // First tooltip
    ['Gill','Carrie','Lucy'], // Second tooltip
    ['Pob','Nobby','Hilda']   // Third tooltip
]

.RGraph_tooltip ul#rgraph_formatted_tooltips_list li {
    text-align: left;
    color: yellow;
}

tooltips: {
    borderLeft: 'gray 2px solid',
    borderBottom: 'gray 2px solid'
}

tooltipsCss: {
    fontFamily: 'Verdana',
    fontSize: '20pt'
}

Methods

This can be used to get properties if necessary. It's normally used after the chart is drawn if you need to get parameters (if you're doing custom coding for example).

This can be used to set properties if necessary. It's normally used after the chart is drawn if you need to set additional parameters or change them.

This function adds an event listener (such as beforedraw or draw) to the chart object. For example:

obj.on('draw', function (obj)
{
    // Put your code here
});

This function can be used to execute a function (immediately). It's not event-based (ie it doesn't run when something happens) - it just runs immediately - and only once. You might use it when you need to get something from the chart when it's drawn and then call the redraw function. Because this function only runs once the RGraph.SVG.redraw function would not cause a loop - which would happen if you used the draw event.

obj.exec(function (obj)
{
    // Put your code here
});

The responsive function helps your charts respond to different browser window sizes and screen resolutions. For example, for smaller screens, you might want to have angled labels or show shorter versions of them completely.

Update: There is now the responsive configuration option available to you and this is now the preferred method of configuration.

The responsive function and configuration option are documented on their own page here.

Data properties that are used on the segments

The svg path elements that represent the segments on the Pie chart have various data attributes added to them that hold various bits of information. These are:

• data-index
• data-tooltip
• data-value
• data-start-angle
• data-end-angle
• data-radius

These can be retrieved by using standard dom methods:

obj.angles[0].element.getAttribute('data-index');

Events

RGraph supports custom events that allow you to easily add interactivity to your charts if required. The following events are available:

• beforedraw This event fires at the start of the draw method before anything has been done.
• draw This event fires at the end of the draw function.
• firstdraw This event fires at the end of the draw function - but only the first time and so it fires only once after the first draw call.
• beforetooltip This event fires at the start of the tooltip showing process.
• tooltip This event fires after a tooltip has been shown.

new RGraph.SVG.Pie({
    id: 'chart-container',
    data: [4,8,6,3,5,8,9],
    options: {
    }
}).on('tooltip', function (obj)
{
    console.log('The draw event has fired');
    
}).draw();

Effects

• The roundrobin effect (demo available in the download archive)

<script>
    //
    // An optional callback function that's called when the effect is completed
    //
    function myCallback (obj)
    {
        // ...
    }

    var obj = new RGraph.SVG.Pie({
        id: 'mySVG',
        data: [3,4,7,5,6,9,8],
        options: {
        }
    }).roundRobin({frames: 60}, myCallback);
</script>