TL;DR: I revised a plugin for Leaflet that allows for custom hash parameters! Leaflet Hash - Custom Params
It's been entirely too long since I've sat down to write, but the past six months have been fruitful - lots of work with mapping, new front-end frameworks, Node.JS, and of course plenty of code shipped.
Part of my work involved designing a mapping application to enable URL-sharing, not just for formal URL parameters, but also for exact center points and zooms for the map. A quick search of the plugin-list yielded the Leaflet-Hash plugin which updates the URL hash with x,y and zoom coordinates when the map moves.
This works really well - totally recommend it, but a side effect of the plugin is that it removes an other hash parameters you might be using. I wanted to include other selection options on the page including layers and filter parameters.
To do this, I forked the code and built a version of Leaflet-hash that names each parameter (no ordering required), allows the inclusion of additional hash params, and includes hash functions to add, update, and discover existing params. For Example:
This is my first plugin revision attempt - I welcome any suggestions and Pull Requests you want to throw at me.