Tech and Design Blog

Mobile Safari: Image Resource Limit

By Rien | February 22nd, 2011 | No Comments

Thijs van der Vossen from Fingertips, developer of our new galleries for iPhone, iPad and other mobile devices, wrote a great post about a workaround for the limit of image data that can be loaded on a single HTML page in Mobile Safari. This limit is somewhere in between 8 and 10 mb.

When loading a gallery with 30 images of 500KB, Mobile Safari simply refuses to display the last 10 images. A problem that already occurred in a previous version of our mobile galleries.

To guarantee properly loading of images in larger galleries we are optimizing our images for Mobile use. Special more compressed images are generated, to solve the resource limit in Mobile Safari, but also to make loading on mobile networks much faster.

Check his post here: How to work around the Mobile Safari image resource limit

Mobile Safari: Offline Application Cache Limit

By Rien | February 22nd, 2011 | 4 Comments

Recently we’ve launched our new mobile galleries. I’ve experimented in an earlier stage with Mobile Safari’s Offline Application cache with a very simple idea: to give the user the option to locally store an image gallery for offline use. Great in combination with the ‘Add to Homescreen’ functionality that the iPhone an iPad provides.

Implementation was simple using the Apple Developer docs and the great tutorials here, all worked great. Except when downloading more than 5MB of data, the process simply hangs. Damn, that’s not a lot. Apple’s documentation does not say anything about a caching limit. Posted a question about a caching limit on StackOverflow, but found no definitive answer on the cache limit of Mobile Safari’s Offline Application cache.

After sending an e-mail to Apple Developer support I did not get a definite answer on the 5mb limit, but “that there is no supported way to achieve the desired functionality given the currently shipping system configurations” .

My e-mail:

Name: Rien Swagerman
E-mail: rien@viewbook.com
Company: viewbook.com
iPhone Developer Program Team ID: none
Follow-Up ID (if referring or responding to an open issue): none

DESCRIPTION OF PROBLEM
When using the manifest file for Safari Offline Application Cache there seems to be a limit of 5mb to cache (iPad and iPhone). Is this correct?

We want to provide offline image galleries to our users (on the iPad and iPhone), synced with their viewbook.com galleries, but this needs more data storage than 5mb. Is this possible (in the near future)?

For us it is a strategic choice to either use Safari, or if not possible create a native app for the iPad and iPhone.

STEPS TO REPRODUCE
Use manifest file that loads more than 5mb of files.

NOTES AND ATTACHMENTS
None.

———————————

Thanks,
Rien swagerman.

Apple’s response:

Hello Rien,

Thank you for contacting Apple Developer Technical Support (DTS). Our engineers have reviewed your request and have concluded that there is no supported way to achieve the desired functionality given the currently shipping system configurations.

If you would like for Apple to consider adding support for such features in the future, please submit an enhancement request via the Bug Reporter tool at <http://bugreport.apple.com>.

Thank you for taking the time to file this report.  We truly appreciate your help in discovering and isolating issues.

Best Regards,

Vanaja Pasumarthi
Apple Developer Support
Worldwide Developer Relations