How to save data to sharedpreference in a flexible way

Question

I save chosen items into shared preference, but as the user during runtime get to remove any of these items (from any position), and as I use the saved size (in the code below) to loop through the items, and here's the problem

Say I have 5 items ( item_1 - item_2 - item_3 - item_4 - item_5 )

if the user removed item_2 I update chosen_items_size to be 4 and I remove item_2 from the shared preference.

but when I load the items later I use the (size = which is 4 now), which as in the code below will miss item_5, how to fix this, any suggestions or better approach to achieve what I need?

    mSharedPreference = getSharedPreferences("chosen_items", MODE_PRIVATE);
    int size = mSharedPreference.getInt("chosen_items_size", 0);
    for(int i = 1; i <= size; i++) {

       mSharedPreference.getString("item_" + i, null);

    }

Knowing that I want to enable drag and drop items, which using the above approach will make it pretty hard (if possible in the first place) to accomplish, any better approach to save & retrieve data / items?

Thank you

score 3 · Accepted Answer · answered Jan 24 '18 at 00:39

3

If you have a small amount of strings you can store them in one delimited string in SharedPreferences like so. You could also associate some metadata with each item and delimit that too.

answered Jan 24 '18 at 00:39

urgentx

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Or you could just use a JSON array instead of inventing your own encoding. – Jeffrey Blattman Jan 24 '18 at 00:55
Home small should it be? Is there a length limit? – Jack Jan 24 '18 at 03:48
The length is limited by the java.lang.String, or your free heap space, whichever is reached first. Typically it's in the order of megabytes. – urgentx Jan 24 '18 at 20:50

score 2 · Answer 2 · answered Jan 24 '18 at 00:36

2

You could utilize a built in SQL lite database.
Is this data that must persist between sessions? if not store it locally with a class and static variables/arrays.

answered Jan 24 '18 at 00:36

Notsileous

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Yes, it must persist between sessions. – Jack Jan 24 '18 at 00:52

How to save data to sharedpreference in a flexible way

2 Answers2