Made several changes to query method: - len(objs) retrieves all objects. The recommended approach is   objs.count() - Added some error checking and warnings if loads of data is being   downloaded - Fixed error: if page but not page_size, None error when multiplying,   line 47 (old version) - Made it slightly more pythonic
Made several changes to query method:
- len(objs) retrieves all objects. The recommended approach is
  objs.count()
- Added some error checking and warnings if loads of data is being
  downloaded
- Fixed error: if page but not page_size, None error when multiplying,
  line 47 (old version)
- Made it slightly more pythonic

zhounanshu/Flask-AppBuilder,rpiotti/Flask-AppBuilder,dpgaspar/Flask-AppBuilder,dpgaspar/Flask-AppBuilder,rpiotti/Flask-AppBuilder,rpiotti/Flask-AppBuilder,qpxu007/Flask-AppBuilder,qpxu007/Flask-AppBuilder,zhounanshu/Flask-AppBuilder,rpiotti/Flask-AppBuilder,dpgaspar/Flask-AppBuilder,qpxu007/Flask-AppBuilder,zhounanshu/Flask-AppBuilder,zhounanshu/Flask-AppBuilder,dpgaspar/Flask-AppBuilder,qpxu007/Flask-AppBuilder