Pie chart API reference

• Example
• Properties
• Methods
• The Horseshoe meter
• The Segmented donut
• The Activity meter
• The RadialProgress meter
• The coordinates properties
• Events
• Effects

Example

<script>
    labels = ['Fred','Rich','John','Paul','Jason','Hoolio','Kevin'];

    new RGraph.Pie({
        id: 'cvs',
        data: [564,155,499,611,322,568,389],
        options: {
            marginLeft: 100,
            marginRight: 100,
            tooltips: '<b>Results:</b><br />%{key}',
            tooltipsFormattedKeyLabels: labels,
            labels: labels,
            linewidth: 2,
            colorsStroke: 'white',
            shadow: false,
            tooltipsCss: {
                fontSize: '16pt',
                textAlign: 'left'
            },
            exploded: [25]
        }
    }).draw();
</script>

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.

obj.set('name', 'value');

• Chart configuration properties
• Margin properties
• Color properties
• Labels and text properties
• Title properties
• Shadow properties
• Interactive features properties
• Key properties
• Miscellaneous properties

<div style="margin-left: 50px; display: inline-block">
    <canvas id="cvs" width="650" height="250"></canvas>
</div>

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;
}

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

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

Methods

<script>
    pie.canvas.onclick = function (e)
    {
        RGraph.redraw();
    
        var canvas  = e.target,
            obj     = canvas.__object__,
            shape   = obj.getShape(e);

        if (shape) {
            
            var x      = shape.x,
                y      = shape.y,
                radius = shape.radius,
                start  = shape.angleStart,
                end    = shape.angleEnd;

            obj.path(
                'b m % % a % % % % % false c s black f red',
                x, y, x, y, radius, start, end
            );
        }
    }
</script>

The explode function allows you to programmatically trigger the exploding (ie the highlighting of) a particular segment. The explode method is used like so:

<script>
    pie = new RGraph.Pie({
        id: 'cvs',
        data: [8,9,4,6],
        options: {
        }
    }).draw();

    pie.explode(index, size);
</script>

The index argument is the zero-indexed segment to operate on (counting from the north axis). And the size is measured in pixels.

This method can be used to get an appropriate angle for a value using the "scale" of the Pie chart. So if your Pie chart is showing values that go from 0-100 and your requested value is 50, this method will return an angle for the bottom of the Pie chart (ie halfway around).

This method can be used to set an event listener on an object. It operates similarly to the jquery on function. The first argument is the event that you wish to attach to and the second is the handler function. For example:

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

The function is useful if you use method chaining when creating your charts:

new RGraph.Pie({
    id: 'cvs',
    data: [4,5,3,8,6,3],
    options: {
    }
}).on('draw', function (obj)

    // Put your draw event code here

}).on('click', function (e, shape)
{
    // Put your click event code here
}).draw()

The exec function is documented 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.

The Horseshoe meter

The Horseshoe meter is now (as of version 5.28) its own chart type and you can read about it on the Horseshoe meter documentation page.

The Segmented donut

The Segmented donut is now (as of version 5.28) its own chart type and you can read about it on the Segmented donut documentation page.

The Activity meter

The CActivity meter is now (as of version 5.28) its own chart type and you can read about it on the Activity meter documentation page.

The RadialProgress meter

The Radial Progress can be achieved by using the Activity meter class and configuring it as shown on the Activity meter documentation page.

The coordinates properties

There's two coordinates properties on the Pie chart and they're the obj.angles property and the obj.coordsText property.

• obj.angles This holds the information about the angles that make up the segments on the chart. The properties that each entry holds are:
  • start angle (measured in radians)
  • end angle (measured in radians)
  • center x coordinate
  • center y coordinate
• obj.coordsText This holds the coordinates of all of the text that has been added to the chart. Even if the text is blank (ie no text) then the coordinates will be added to this variable.

Events

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

• annotatebegin This event fires at the start of annotating - like the standard mousedown event.
• annotate This event fires (repeatedly) during annotating - like the standard mousemove event.
• annotateend This event fires at the end of annotating - like the standard mouseup event.
• annotateclear This event fires at the end of the RGraph.clearAnnotations function.
• beforeclear This event fires at the start of the RGraph.clear function.
• clear This event fires at the end of the RGraph.clear function.
• click This is similar to the standard canvas click event but this only fires when you click on a bar - not the whole canvas.
• crosshairs This event fires when you have the crosshairs feature enabled and you move the mouse.
• beforecontextmenu This event fires when you have the contextmenu enabled and it is about to appear.
• contextmenu This event fires when you have the contextmenu enabled and it has been displayed.
• beforedraw This event fires at the start of the draw method before anything has been done.
• firstdraw This event fires at the end of the draw function - but only the first time that the draw function is called.
• draw This event fires at the end of the draw function.
• beforeinteractivekey When you're using the interactive key this event fires just before the key and chart are highlighted.
• afterinteractivekey When you're using the interactive key this event fires just after the key and chart are highlighted.
• mousemove This event is similar to the standard mousemove event but only fires when you move the mouse over a bar on the chart.
• mouseover This event is similar to the standard mouseover event but only fires when you move the mouse over a bar on the chart.
• mouseout This event is similar to the standard mouseout event but only fires when you move the mouse away from a bar on the chart that you've previously hovered over.
• beforetooltip This event fires at the start of the tooltip showing process.
• tooltip This event fires after a tooltip has been shown.

new RGraph.Pie({
    id: 'cvs',
    data: [4,8,6],
    options: {
    }
}).on('draw', function (obj)
{
    console.log('The draw event has fired');
    
}).draw();

Effects

• The grow effect (effects-pie-grow.html in the download archive)
• The explode effect (effects-pie-explode.html in the download archive)
• The roundrobin effect (effects-pie-roundrobin.html in the download archive)
• The roundRobinSequential effect (effects-pie-roundrobinsequential.html in the download archive)

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

    new RGraph.Pie({
        id: 'cvs',
        data: [8,6,6,5,3,4,2],
        options: {
        }
    }).grow({frames: 60}, myCallback)
    // .implode({frames: 60}, myCallback)
    // .roundRobin({frames: 60}, myCallback)
    // .roundRobinSequential({frames: 90}, myCallback)
</script>