A JavaScript parser for the Protocol Buffer implementation used for the 'data' parameter in google maps URLs.
This is a fork of a great david-r-edgar/google-maps-data-parameter-parser. Only thing I've done is to make a package out of it that can be used in other projects. Much more can be done with it.
See examples of what this library does at the demonstration test page.
Google Maps directions URLs typically look something like this: https://www.google.co.uk/maps/dir/Bonn,+Germany/Berlin,+Germany/@51.6456171,7.9144552,7z/data=!3m1!4b1!4m13!4m12!1m5!1m1!1s0x47bee19f7ccbda49:0x86dbf8c6685c9617!2m2!1d7.0982068!2d50.73743!1m5!1m1!1s0x47a84e373f035901:0x42120465b5e3b70!2m2!1d13.404954!2d52.5200066?hl=en
While the user-specified waypoint inputs (Bonn and Berlin in this example) are named in the path, and the map centre coordinates are specified clearly following the @, other properties, including the actual coordinates of the waypoints, the type of map and the selected mode of transport are encoded in the 'data' parameter in a URL-safe string representation of a 'Protocol Buffer'.
Elements are separated by ! marks.
Each element consists of
- an integer id
- a single character alphabetic type
- a string value (whose format appears to vary according to the type, but is assumed to be composed of alphanumeric and URL-safe characters)
The meaning of an element depends on these properties, as well as the element's place in the tree.
Runtime: None!
Development: jest for testing
The parser extracts the data parameter and forms it into a tree of nodes, each representing one of the elements in the Protocol Buffer.
const data = new Gmdp(url);