hello, ry!

how can I help you today?

Hi mark

I just have some questions relating to my app

I'm trying to extend the model fragment architecture from the tutorial

And i'm wondering if that's the best way to do it... because I have multiple screens which need to access its own instance of the model fragment

well, a model fragment is designed to help manage the model objects for one activity

you can say that you have several activities sharing the same model fragment class

Yes, same class, but its own instance of each model fragment

however, if they are all working off of the same model objects, that begs the question of why they are separate activities in the first place

I would typically expect different activities to need different model fragment classes, just because they would be working with different facets of your overall data

I want to enable the back button for users

and they are fragments not activities

ah, sorry -- when you wrote "multiple screens", I inferred that you meant multiple activities

so the user can go to a new screen, which is the same activity but different fragments, and i want each fragment to have its own model fragment instance

um, I don't know how you are going to do that

it all feels a bit messy... i'm not sure if this is a good way

the reason for a model fragment is to centralize activity-level things like configuration changes

off the cuff, I have not really thought about trying to have a model fragment per fragment in a multi-fragment activity

I suppose there is nothing stopping you from doing that, so long as you can keep track of unique tags for each model fragment instance

I'm not completely certain what you're gaining over having a single model fragment that happens to hold distinct portions of data for the active fragments

hmm... yea. youre right, i just need the model fragment to hold an arraylist for each fragment. so i could just put all those arrays in one model fragment instance

right

i'm also having trouble using findfragmentbytag inside of a fragment to get the instance of the model fragment that i've created in the activity. do you know off the top of your head if there's a common mistake i'm making?

are you using nested fragments (e.g., getChildFragmentManager())?

if yes, your model fragment is probably in the activity's FragmentManager, not one of the fragment's child FragmentManagers

all the fragments are created by that one activity, and i'm using getsupportfragmentmanager in my activity and in my fragments

then, off the cuff, I'm not sure what might be causing lookup problems, sorry

ok, i'll keep trying to debug it

thank you for the help

you are very welcome