HashTrack State Upgrades

[klassenjs]

It would be useful if HashTrack could restore the visible state of the map so that sharing the URL with someone else or bookmarking it for yourself would restore the map as it looked before.

Currently, the following are tracked:

• Map center and scale
• The list of visible layers

To restore the map to its previous visible state, at least the following would be, in addition, required:

• Layer Z-Order
• Layer Opacity
• Drawings
• Query results

While all of this state may be technically trackable, doing so is a lot of data and would produce exceptionally long URLs that in many instances would exceed the lengths allowed by the browsers. This could be somewhat mitigated by compressing the data but that wouldn't remove the length limitation and would also make testing and manual inspection/changing of the URL significantly more painful and thus may not be worth the complexity. Thus, we will not be able to reliably track everything and will need to be selective about what is and isn't tracked.