Grafana is in the middle of converting from React to Angular and we are also building new plugin libraries so there are two ways to do this.
The old AngularJS way (here is a plugin using it):
See my previous answer:
The other similar way is to use the new @grafana/data library - which is still in alpha.
Example here:
https://github.com/grafana/grafana/blob/master/public/app/plugins/datasource/graphite/query_ctrl.ts#L11
and here:
https://github.com/grafana/grafana/blob/master/public/app/plugins/datasource/graphite/query_ctrl.ts#L109
