JSON - what am I missing

I am trying to understand how to create dynamic content for HTML5 apps. I think I am right in understanding that when you phonegap an app and submit it to the apple store, it can't have php code, so therefore you need to create a JSON file to hold the dynamic content which your HTML5 page then use to populate the page.

Am I right so far?

If so, I assume that I have to have a php page sitting on a remote server that connects to a mysql DB, and this php then spits out the requested databasse content as JSON which is loaded into an HTML5 template as and when it is required.

If I am still right, then I am missing a part of the puzzle. I don't understand how to get the content from a php page to a JSON file/array without having to have some form of php code in the app. So, how do I get the JSON array into the app without using php in it?

I can create a JSON array in a php page and have successfully returned results, but I am concerned that I will spend a lot time making an HTML5 app with dynamic content only to have it rejected by Apple because it has php in it! What is it I am missing or don't fully understand?

Basically, I am hoping to create an app that will load the latest content when connected to wifi, but also hold the last loaded content in the device memory/database should wifi not be available. Simply put, saved content for off-line reading later.

Thanks in advance.