Using formatted labels

• Introduction
• Example
• What macros are available?

Introduction

Formatted labels are available to you as of version 6.0 of RGraph for both canvas and SVG charts and allow you to specify a single template string as the label which has certain macros in it and RGraph will replace those macros with the correct values.

Label templates are very similar to tooltip templates in their appearance albeit with fewer macros available to them (because only strings are permitted - not HTML).

Here's an example of a chart that uses label templates. In the download archive there's a demo called demos/activity-radial2.html which shows off label templates to good effect. It's not by any means a complicated demo - but it's effective.

Example

<script>
    data   = [28,19,39,45];
    values = RGraph.clone(data);
    labels = ['John','Fred','Mark','Andy'];

    new RGraph.Activity({
        id: 'cvs',
        min: 0,
        max: 100,
        value: data,
        options: {
            marginInner: 2,
            backgroundColor: 'transparent',
            backgroundGrid: false,
            backgroundGridRadials: false,
            backgroundRings: false,
            colors: ['red','blue','#aaa','black'],
            labels: '%{global:labels[%{index}]} (%{value_formatted})',
            labelsFormattedUnitsPost: '%',
            labelsSize: 10,
            labelsBold: true,
            labelsItalic: true,
            labelsColor: '#333',
            labelsOffsetx: -20,
            labelsFormattedUnitsPost:'%'
        }
    }).draw().responsive([
        {maxWidth: null, css: {cssFloat: 'right'}},
        {maxWidth: 600, css: {cssFloat: 'none'}}
    ]);
</script>

What macros are available?

You can use these macros when you're creating your template label string. Note that because there's no concept of a group or sequential index there's only one index macro available.

• %{index}
  This is the index of the label. Remember that counting starts at zero just like an array in JavaScript.
• %{property:title}
%{property:names[%{index}]}
  This macro allows you to reference your object properties from the template string. This means that you can set arbitrary properties (eg the names property as shown above) and reference them from your template string (similarly to the example chart shown above).
• %{value}
%{value_formatted}
  These two properties allow you to show the value in your labels. The formatted value uses other properties that allow you to control the styling of the resulting number - these are shown below. The xxx in the property names should be replaced with the correct prefix for your chosen labels - so you'll need to check the correct API documentation [canvas] [SVG] page for your chosen chart type.

  Property	Description	Default
  xxxFormattedPoint	This character is used as the decimal point.	.
  xxxFormattedThousand	This character is used as the thousand separator.	,
  xxxFormattedDecimals	This specifies the number of decimals that are shown.
  xxxFormattedUnitsPre	These units are prepended to the number.	(an empty string)
  xxxFormattedUnitsPost	These units are appended to the number.	(an empty string)

  xxxFormattedPoint
  This character is used as the decimal point.
  Default: .
  
  xxxFormattedThousand
  This character is used as the thousand separator.
  Default: ,
  
  xxxFormattedDecimals
  This specifies the number of decimals that are shown.
  Default:
  
  xxxFormattedUnitsPre
  These units are prepended to the number.
  Default: (an empty string)
  
  xxxFormattedUnitsPost
  These units are appended to the number.
  Default: (an empty string)
  
  
• %{global:myVariable}
%{global:myVariable[%{index}]}
  This macro allows you to reference global variables from the template string. This might be easier for you than setting your data as properties on the chart object.
• %{function:myFunction()}
%{function:myFunction(%{index})}
  This macro allows you to call a function. The return value is used as the text that you will see in the label. Note that you can call your function without passing any arguments and you can also pass in the index as an argument.