I’m developing an offline web-app for a client of ours, designed to run on an iPad in airplane mode, mounted on a stand. It has no server-side dynamic pages, only a static HTML page, many JavaScript components to handle navigation and interactivity, and a bunch of small graphics assets. The whole website (static html + css + js + graphics) weighs exactly 8.3Mb.
I’m caching the whole site via an offline.manifest declared in my single HTML file, this manifest references absolutely all the files under the root directory, so that all files needed are cached.
I’m not using localStorage, IndexedDB or other offline-storage techs in my JS code. Apart from the “automatic” caching, I don’t store anything on-device.
So atfer checking my webserver logs, when my client installs the webapp on its iPad homescreen, it downloads all the files once, then never downloads anything from my server afterwards. That’s fine, exactly what he wanted in the first place : a full offline webapp.
Then, how comes that after several minutes of testing from my client, his iPad asks him to “increase local storage from 10Mb to 25Mb” ???
FYI, the app consists of a kind of quizz: one welcome screen, 19 question screens, one result screen ; the user can navigate backwards/forwards in the questions sequence, but they’re created and nullified on-the-fly so as to minimize memory footprint. Anyway I don’t believe this problem has to do with RAM access, only with “hard”, permanent, cached storage.
Seems like my client doesn’t have this problem anymore. As I’m not in direct, physical contact with him, I can’t tell what he did to get rid of it.