Better default map positioning

[ohnorobo]

When there is no default 'center' position in the config use the median of the displayed points.

[beechnut]

Would it make sense to use the viewer's location as a default?

Clarifying question: How do you define median? Right now I'm thinking center of the bounding box.

[ohnorobo]

Viewer location doesn't make sense if all the data is in another city.
This is specifically motivated by http://timwis.github.io/finda-arcgis/ which uses data in Philly.

I also think the browser geolocation we have currently should get a config toggle and be off by default.

I don't really have an opinion about the details, median just seemed like an easy-to-implement heuristic that we could iterate on. (We may also eventually want a heuristic for initial zoom level.)
As long as we're getting a non-zero amount of data on the screen and avoiding the confusing scenario where a user loads the site for the first time and sees an empty map.

[beechnut]

Good point about other cities.

The center of the bounding box of the data is one spatial implementation of that heuristic (and a light-on-computation one at that, if I understand bounding boxes correctly).

If we're considering zoom, Leaflet has map.fitBounds(featureGroup) to zoom & pan to the extent of the data. This would make the whole dataset viewable on load, and would prevent even the worst Finda from presenting no data upon initial view.

I propose we implement #fitBounds.