Module Ext_chart_Label

module Ext_chart_Label: sig .. end

Labels is a mixin to the Series class. Labels methods are implemented in each of the Series (Pie, Bar, etc) for label creation and placement.

The 2 methods that must be implemented by the Series are:

• onCreateLabel
• onPlaceLabel

The application can override these methods to control the style and location of the labels. For instance, to display the labels in green and add a '+' symbol when the value of a Line series exceeds 50:

 Ext.define('Ext.chart.series.MyLine', {
     extend: 'Ext.chart.series.Line',
     alias: ['series.myline', 'Ext.chart.series.MyLine'],
     type: 'MYLINE',

     onPlaceLabel: function(label, storeItem, item, i, display, animate){
         if (storeItem.data.y >= 50) {
             label.setAttributes({
                 fill: '#080',
                 text: "+" + storeItem.data.y
             }, true);
         }
         return this.callParent(arguments);
     }
 });

Note that for simple effects, like the example above, it is simpler for the application to provide a label.renderer function in the config:

  label: {
      renderer: function(value, label, storeItem, item, i, display, animate, index) {
          if (value >= 50) {
              label.setAttributes({fill:'#080'});
              value = "+" + value;
          }
          return value;
      }
  }

The rule of thumb is that to customize the value and modify simple visual attributes, it is simpler to use a renderer function, while overridding onCreateLabel and onPlaceLabel allows the application to take entire control over the labels.

class type t = object .. end

class type configs = object .. end

class type events = object .. end

class type statics = object .. end

val of_configs : configs Js.t -> t Js.t

val to_configs : t Js.t -> configs Js.t