echart2 add legend bind events

var ecConfig = echarts.config;

myChart.on(ecConfig.EVENT.LEGEND_SELECTED, function(params) { // legendselected   legendselectchanged

      console.log('obj', params)

      var selected = obj.selected;

      was legend = obj.name;

      // use legendToggleSelect Action will re-trigger legendselectchanged Event, resulting in repeated run this function

      // make no selected objects

      if (selected != undefined) {

         if (isFirstUnSelect(selected)) {

             triggerAction('legendToggleSelect', selected);

         } else if (isAllUnSelected(selected)) {

             triggerAction('legendSelect', selected);

         }

      }

    });