Updating RecyclerView Data when CheckBox is clicked

Question

I want to implement a CheckBox on a RecyclerView.Adapter But I don't know where to start right, I have previously read references from several articles related to the CheckBox on the RecyclerView but there are no articles that match my problem.

I have a response from an API like this :

{
    "results": [
        {
            "isNameChecked": false,
            "name": "Data A",
            "data": [
                {
                    "isChecked": false,
                    "id": "A1",
                    "name": "Data 1"
                },
                {
                    "isChecked": true,
                    "id": "A2",
                    "name": "Data 2"
                }
            ]
        },
        {
            "isNameChecked": true,
            "name": "Data B",
            "data": [
                {
                    "isChecked": true,
                    "id": "B1",
                    "name": "Data 1"
                },
                {
                    "isChecked": true,
                    "id": "B2",
                    "name": "Data 2"
                },
                {
                    "isChecked": true,
                    "id": "B3",
                    "name": "Data 2"
                }
            ]
        }
    ]
}

If the CheckBox All is true, all the existing CheckBox will be set true (isNameChecked and isChecked) automatically and save the id (A1, A2, B2, etc.) if the id is true from data into a Variable

Otherwise, if the All box is false, but isNameChecked set true, the data in the result will update isChecked as true

Answer 1

I don't know how you're displaying your checkboxes, but your adapter should have the data for all the items stored in it, and part of that data is whether the item is checked or not. I think you have two approaches:

• Make the All checkbox set/unset the checked status of all its child items (i.e. iterate through your list, map or whatever and change all the values) and then call notifyDataSetChanged() (or another notify method) so the display updates

• Don't change the children's checked states (so if you uncheck All, the others "remember" if they were checked or not) and just decide whether they should display as checked based on the top-level boxes

In your adapter's onBindViewHolder method (where it sets up the display for an item, including whether it shows as checked or not) you can find the parent checkbox, and if it's checked you can display the child as checked too. Otherwise show its actual state (the real value set in the data).

That's just the basic idea, you'll have to work out how to fit it in with what you're actually doing and how you're representing that hierarchy in your data, but it's one way you can approach it!