grafana/public/app/features/dashboard/repeat_option/repeat_option.ts

import { coreModule } from 'app/core/core';

const template = `
<div class="gf-form-select-wrapper max-width-18">
  <select class="gf-form-input" ng-model="panel.repeat" ng-options="f.value as f.text for f in variables" ng-change="optionChanged()">
  <option value=""></option>
</div>
`;

/** @ngInject */
function dashRepeatOptionDirective(variableSrv) {
  return {
    restrict: 'E',
    template: template,
    scope: {
      panel: '=',
    },
    link: (scope, element) => {
      element.css({ display: 'block', width: '100%' });

      scope.variables = variableSrv.variables.map(item => {
        return { text: item.name, value: item.name };
      });

      if (scope.variables.length === 0) {
        scope.variables.unshift({
          text: 'No template variables found',
          value: null,
        });
      }

      scope.variables.unshift({ text: 'Disabled', value: null });

      // if repeat is set and no direction set to horizontal
      if (scope.panel.repeat && !scope.panel.repeatDirection) {
        scope.panel.repeatDirection = 'h';
      }

      scope.optionChanged = () => {
        if (scope.panel.repeat) {
          scope.panel.repeatDirection = 'h';
        }
      };
    },
  };
}

coreModule.directive('dashRepeatOption', dashRepeatOptionDirective);