It has come to our attention that we are having issues with pdfs displaying correctly on IOS mobile devices. We are using the PDF embed module in Omeka S and to the best of our knowledge it displays fine on all desktop browsers and works fine on Android mobile. But I have tried accessing it on IOS in Safari and Firefox and in both cases the pdf controls do not appear and it renders as only the first page of the pdf. I’m hoping this is just a super obvious mistake that we’re missing, but would welcome any advice!
This is a restriction of how iOS works. When a page requests to embed a PDF using the normal embedding tags (which is what PDF Embed does), iOS does this “first page” thing, and has for a long time.
Your possible solutions vary a bit depending on how you’d want to solve it. Detecting iOS and just replacing the embed with a link to the PDF which would then open in an external PDF viewer is my preferred option for this, and doing that just requires a small update to the module.
If you want an actual in-page viewer for iOS then the only option is to use a library that will render it in the page using scripting, like the PDF.js library. For that you’d be looking at using a different module.