@gb-transit/dtd-schema

Declarative record layouts for the DTD fares, timetable, routeing guide and NFM64 feeds.

npm install @gb-transit/dtd-schema

The RSP publishes four feeds as zips of flat text files, each file a different fixed-width or delimited layout. This package is those layouts, written as data: which columns a record has, where they sit, what type each one is and which of them form its key.

It is the layouts only. Parsing them is @gb-transit/feed-parser; downloading the feeds is @gb-transit/dtd-source.

Usage

The default export holds one specification per feed, keyed by the file extension inside the zip:

import schema from "@gb-transit/dtd-schema";

const MSN = schema.timetable["MSN"];   // station names and coordinates
const MCA = schema.timetable["MCA"];   // schedules, associations, stop times
const FFL = schema.fares["FFL"];       // flow records

Each value is a FeedFile from @gb-transit/feed-parser, so a line becomes a record through the same interface whatever feed it came from.

import schema, {FeedConfig} from "@gb-transit/dtd-schema";

FeedConfig is the type of one feed's specification — a map of file extension to FeedFile.

What is covered

| Feed | Files | |---|---| | timetable | MSN, MCA, FLF, ZTR, ALF, CFA, TSI | | fares | DIS, FFL, FNS, FSC, LOC, NDF, NFO, RCM, RLC, RST, RTE, SUP, TAP, TOC, TPK, TRR, TSP, TTY, TVL | | routeing | RGC, RGD, RGE, RGF, RGG, RGH, RGK, RGL, RGM, RGN, RGP, RGR, RGS, RGX, RGY | | nfm64 | one record type, under the empty key |

downloadUrl is exported alongside, for the one feed that is fetched over HTTP rather than SFTP:

import {downloadUrl} from "@gb-transit/dtd-schema";

A note on what the layouts encode

The layouts carry decisions about the data, not just its shape. A numeric column of all spaces or all zeroes is usually the feed saying it has nothing to say, and which strings count as absent is set per column — an easting of 00000 is a missing coordinate, while an interchange status of 9 is a real value. Those choices are commented where they are made, because getting one wrong silently drops stations rather than failing.

Contributing

Issues, pull requests and the source live at planarnetwork/dtd2mysql. This is libs/dtd-schema in that repository.

License

This software is licensed under GNU GPLv3.

Copyright 2017 Linus Norton.