Fixes the plugin for grafana 7.1.x

[craigching]

This fixes the plugin for Grafana 7.1.x. The return from ds.query() is an Observable, which can be converted to a promise with toPromise()

[craigching]

The one thing I'm not certain about his how backwards compatible this is. I am pretty sure the Observable change went in quite awhile ago, but this may need some love to support older versions of Grafana.

[Gauravshah]

Thanks @craigching for your contribution.
do you know which release added support for Observable ? I am unable to find it. That way we can update readme to state minimum grafana requirements

[Gauravshah]

fixes #104

[Gauravshah]

it was atleast added to mixed source in 6.4 grafana/grafana#19037

[Gauravshah]

@ShilpaSivanesan can you review and check basic compatibility ?

[craigching]

it was atleast added to mixed source in 6.4 grafana/grafana#19037

Yes, exactly. Thanks for taking the time to incorporate my PR! Let me know if you want any changes.

[craigching]

Any updates on getting this merged? I'd love to help in any way I can.

[Gauravshah]

team is stuck with internal projects, Will request @ShilpaSivanesan to have a look at it next week. Apologies for the delay

[zebardy]

Is there any update regarding this fix. Really keen for this as the plugin is currently unusable for us at the moment. Appreciate all of the work in producing and maintaining this plugin, and understand the pressure of competing priorities. Just keen for an update.

[ichiong]

Any updates on this? We are also in need of this plugin to be fixed for later versions of grafana so we can continue monitoring our systems... Thanks so much.

[ZyanKLee]

When installing the plugin with this patch within the Grafana v7.3.6 (ea06633c34) docker image there is an error message "ds.query(...).toPromise is not a function"

[Gauravshah]

seems to be compatibility issue with 7.3 vs 7.2 and previous versions. Looking into fixing further

[ShilpaSivanesan]

Thanks, @craigching for your contribution.
We had a compatibility issue with 7.3 vs 7.2. Have added the fix on top of your commits.
fix #118 works on all 7.x versions also tested on 6.5.2 and 6.7.5

[barbudor]

Hi
Is v0.0.4 going to be available from Grafana plugin repository ?
Thanks

[Gauravshah]

waiting on approval from grafana grafana/grafana-plugin-repository#827