cldfofflinebrowser

Provides a cldfbench plugin to create offline-browseable representations of the data in a CLDF dataset.

Notes on offline maps

cldfbench create --with-tiles […] allows you to predownload the world map at different zoom levels for offline viewing. These tiles are provided by the kind folk at OpenStreetMap – free of charge, no less. But obviously they're not wizards who can make bandwidth appear out of thin air. That's why we should all be nice to them and play by their rules to reduce strain on their servers.

This is why we would like to ask you to follow the following guidelines:

• Don't delete your offline/tiles folder unless you really, really have to!
  If you do you'll just end up re-downloading the same map tiles all over again, which is a waste of everybody's time and bandwidth.
• Keep your LanguageTable clean!
  Make sure it only contains languages that you have actual data points for, otherwise you'll end up downloading map tiles for regions that nobody will look at.
• Set --max-zoom to a reasonably low zoom level!
  This is especially true if your language sample spans over great distances. A map of that covers like half the planet will result in tens if not hundreds of thousands of tile downloads at higher zoom levels (10, 11, 12). So it's better to find a zoom-level that makes your data comfortable to look at and not go any deeper than that.
• Bulk-downloading map tiles for zoom level 13 or higher is forbidden!
  At these zoom levels, if you try to download more than 250 tiles at once, OSM will straight-up refuse your request. End of story.
• Don't run cldfbench offline.create multiple times at once!
  Whatever download speed you get is probably either your bandwidth limit or the server's. Either way, battering the server with more download requests isn't gonna make anything faster.

FAQ

Q: How to add sound files and transcriptions to an offline dataset?

A: If you want to make a new sound file and transcription browseable in an offline version:

1. Determine relevant language (LID) and parameter (PID) (aka concept) IDs.
2. Copy the sound file to ./parameter-<PID>/<LID>.mp3.
3. Add a corresponding row to cldf/media.csv.
4. Add a row to cldf/forms.csv.
5. Re-run cldfbench offline.create ....