As much as Hideki’s Songlist Offline started off from my needs (and still serving mostly for that reason…) this offline solution also comes from my desire to have offline access to the Hideki’s Songlist even when there is no Internet connection available.
Actually, both Lookup YouTube for text/songinfo and Lookup Last.fm for text/songinfo extensions for Google Chrome have already supported text/songinfo parsing. They essentially take text/song and convert it to queries (and API call, in case of Last.fm).
Hideki’s Songlist Offline takes same premise, however, I have decided to use AngularJS this time. This simplified JSONP parsing.
Once JSONP is loaded from Hideki’s Songlist web system, it is stored into local storage database. This essentially creates replicated copy of songdata library. Currently, when the update button is pressed, it drops whatever you have in current database and reload fresh copy of list from the server. This is ridiculously inefficient, so expansion is planned to deliver only updated information through the API.
Once data is loaded, subsequent loading of the Chrome app will load current contents within the database instead of one on the server, thus realizing offline functionality of Hideki’s Songlist.
I’ve created this project in 3 hours or so, thus still a lot to polish. The code is available from songlist-offline-client on GitHub. If you want to experiment plugging it with your own implementation of text/songinfo, please feel free to do so.
Improvements are planned. Stay tuned!