Persistence

Attributes declared with the SDF_PERSIST flag are automatically saved and loaded by the framework via the callbacks registered at bootstrap.

The reference backend is localStorage (browser) via dbsimple.js.

Low-level dbsimple API¶

db_load_persistent_attrs(gobj, keys)
db_save_persistent_attrs(gobj, keys)
db_remove_persistent_attrs(gobj, keys)
db_list_persistent_attrs(gobj, keys)

These read/write directly from localStorage. Use them as the callbacks passed to gobj_start_up.

Via gobj (delegates to registered persistence fns)¶

gobj_load_persistent_attrs(gobj, keys)
gobj_save_persistent_attrs(gobj, keys)
gobj_remove_persistent_attrs(gobj, keys)
gobj_list_persistent_attrs(gobj, keys)

Application code normally calls these, not the low-level db_* functions. They dispatch to whichever backend was registered at gobj_start_up time.

Local storage helpers (no “store” parameter)¶

Also exposed for ad-hoc use outside the attribute persistence system:

kw_get_local_storage_value(key, default_value, create)   // create=false by default
kw_set_local_storage_value(key, value)
kw_remove_local_storage_value(key)

Plugging in a different backend¶

Pass your own callbacks to gobj_start_up — for example, an IndexedDB-backed store, an HTTP REST backend, or an in-memory mock for tests. The only contract is that each callback takes (gobj, keys) and either loads/saves/removes/lists the attributes whose names appear in the keys array.