I'm creating a PoC of an ASP.NET MVC 4 mobile application (tablets) for field operators that needs to support offline capabilities. It's a relatively simple data entry application with a WebAPI backend that will use a SQL database as persistent storage.
This is the first time I'll be implementing offline support, so I'm a bit unsure of which is the best way to design this. Right now I can think of two ways, and not sure which one is better or more correct.
What I want is that whenever there is internet connectivity, the information is retrieved from the server. If the connection is lost, I want the latest information to be cached/served and available to display to the user.
Based on a few tests that I've made, the way the HTML5 offline support appears to work is that as soon as any of the Views is loaded, the browser will check the manifest and cache the version of each page at that moment of time. If my understanding is correct, that means that if the user adds new entries after the browser downloaded the manifest files, then those records would not show in the offline version.
One way I can think to work around that is to change the manifest version (since I'm generating it dynamically) every time it is served, but i feel that would defeat the purpose..or at least be incredibly inefficient bandwidth-wise.
The only other alternative that I can think of is not using regular MVC (not passing the records/db information as the model property or a ViewBag property) to display the records, but just retrieve the json for the page information needed and save in local storage. Then, generate the view using a template or javascript based on the information in localstorage. That would work either online or offline, wouldn't it?
I'm not sure if I'm approaching this the wrong way. Would building an SPA or a simple HTML/javascript application be more appropiate? Maybe using a JS framework? At this point I have some ability to determine what technology or framework we'd use.
Any guidance is greatly appreciated.
Based on a few tests that I've made, the way the HTML5 offline support appears to work is that as soon as any of the Views is loaded, the browser will check the manifest and cache the version of each page at that moment of time. If my understanding is correct, that means that if the user adds new entries after the browser downloaded the manifest files, then those records would not show in the offline version.
This is why you shouldn't use server side rendering. When the server mixes data with formatting before sending to the browser it means that the browser can't tell the difference between the two. HTML5 and Javascript are perfectly capable of handling templating on their own so why not let them?
Write your MVC application as nothing but a series of controller methods. Do not use "views" per-say. Instead use straight HTML files that use javascript to make AJAX requests to the server for data. Populate the HTML view with the data and you're golden. Then you can cache the HTML files because they're static and you can save the data separately for offline mode.