How can I add a parameter to the manifest file HTML5 for offline mode?

Question

Hello,

I have a web application and I want to make it run offline as well. In this application I just have a form and I am using PHP for submitting it. I am using a manifest.php file like the one described in http://building-iphone-apps.labs.oreilly.com/ch06.html .

The problem is that I need somehow to add the parameters from the form in the manifest, for caching the right file, for example the file welcome.php?name=aaaa and not the welcome.php . So I need to use a GET for the name in the manifest.php. But if I understood well the manifest file is created in the beginning before the form is submitted so the value on "name" is empty.

Is there a way to add these parameters in my manifest file for running the application offline as well?

Thanks

Answer 1

The only way you can do that is to list the files with their parameters in the manifest, so you would have to know all the possible parameters in advance and then use your manifest.php to spit them out, ending up with a manifest file that looks something like this:

CACHE MANIFEST
welcome.php?name=aaaa
welcome.php?name=aaab
welcome.php?name=aaac
...thousands more lines...
welcome.php?name=zzzz

NETWORK:
welcome.php

However, I strongly recommend you don't do it this way if (as it looks like) you want to present a personalised welcome page to the user. With this approach every user will download every welcome page, even though they only need to see one of them.

There are two approaches I think will work better:

1: Deliver personalised pages

If only thing which changes is this page, force the user to logon before accessing the welcome.php page, then use a session variable instead of a query parameter to deliver the personalised page. You then just need to specify welcome.php in your manifest and every user will cache one personalised version.

2: Write a full offline app

If your web app is going to have user specific data at every step you need to break down what are the common application components and what is the user data, and serve them separately. If your app is going to do anything offline it's going to be doing it with JavaScript, you should therefore use JavaScript to update the page in the browser rather than generating entire pages on the server side with PHP.

Most of your PHP pages are basically going to be templates which you will load with user data through JavaScript (you can still populate them the 'old' way for users who don't have offline capability in the browser). You will have at least one PHP page which delivers data in response to AJAX requests. For this approach you're going to need to learn about Local Storage and the various JavaScript APIs for managing the cache and detecting offline state. Once the user decides to install the offline version of your web app you download all of that user's data and put it in Local Storage, then use that data to update each page as it loads when the user is offline. Any changes made then need to be synced back to the server when the user is back online.