ldbws-ruby

I’ll write a proper readme/howto at some point, but short version is that this is a Ruby wrapper around Network Rail‘s Live Departure Board web service (LDBWS/OpenLDBWS)—I’ve trawled through their XSD files so you don’t have to =)

I built it for a project I’m hacking at + thought I’d release it into the world. It’s rough and ready right now, but it should be somewhat functional.

HOWTO

All operations are supported, in snake_case, thus:

“by require “ldbws”

service = Ldbws.service(YOUR_API_TOKEN) result = service.get_departure_board(crs: “CDF”)

puts “TIME PLAT TO” result.train_services.each do |service| printf( “%s %-2s %s (%s)\n”, service.std.strftime(“%H:%M”), service.platform || “-”, service.destination.first.name, service.operator ) end

TIME PLAT TO

17:32 - Penarth (Transport for Wales)

17:39 3 Swansea (Great Western Railway)

17:55 8 Barry (Transport for Wales)

17:56 2A Manchester Piccadilly (Transport for Wales)

18:01 6 Bargoed (Transport for Wales)

[etc]

“

A note about rate limiting

LDBWS uses rate-limiting for free access: while this probably isn’t going to be an issue for the casual user, you may want to consider using a cache in front of this gem, just in case.

Error-handling

This module is pretty decent at validating request parameters, but beyond that all it can really do is just echo what LDBWS says. To wit, there are three errors that can be raised:

Ldbws::Request::ParamValidationError

This is raised when parameter validation fails. Details about exactly which parameters and why can be found using the #messages, and is provided in hash format, thus:

“by begin service.get_departure_board rescue Ldbws::Request::ParamValidationError => e # e = { crs: “is missing” } end

“

Ldbws::RequestError

Raised when LDBWS returns an error message, usually because the request is bad (eg: invalid CRS). Unfortunately LDBWS’ error messages are pretty terrible, so it’s generally not too edifying to look at them.

Ldbws::ResponseParsingError

Raised when the response from LDBWS cannot be parsed.

Caveats

This is released into the world as-is. If you use it for something and end up missing your train, or do something that falls foul of the LDBWS terms of use, it’s not my fault :)

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