FirebaseListAdapter with filtered data

[Michael Huber]

Hi,

I try to implement the FirebaseListAdapter with a SearchView based on Android. Everything works well, but I can't filter my list of customers to the input text the user types in. Is there any way to filter the ListView-data to the string the user is typing? For example: There is a listview with many entries. The user is going to type : "Paul Miller" in the searchview, so the listview should just show every entry with the name "Paul Miller". 

I tried to implement the Filterable Class to my own FirebaseListAdapter. The problem is I can't change the dataset (Query) like in an arraylist. So, notifydatasetchanged() is not working.

public class FirebaseCustomerAdapter extends FirebaseListAdapter<Customer> implements Filterable {

    private CustomerFilter customerFilter;
    private Query query;

    public FirebaseCustomerAdapter(Activity activity, Query ref) {
        super(activity, Customer.class, R.layout.fragment_customer_list_row, ref);
    }

    @Override
    protected void populateView(View view, Customer customer, int position) {

        TextView name = (TextView) view.findViewById(R.id.customer_list_row_name_textview);
        TextView zip = (TextView) view.findViewById(R.id.customer_list_row_plz_city_textview);

        if (customer.getName() != null) {
            name.setText(customer.getName());
        }
        String zipCity = "";
        if (customer.getZipCode() != null) {
            zipCity = customer.getZipCode() + " ";
        }
        if (customer.getCity() != null) {
            zipCity += customer.getCity();
        }
        zip.setText(zipCity);
    }

    @Override
    public Filter getFilter() {
        if (customerFilter == null) {
            customerFilter = new CustomerFilter();
        }
        return customerFilter;
    }

    private class CustomerFilter extends Filter {

        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
            FilterResults filterResults = new FilterResults();
            Query query;
            if (constraint != null && constraint.length() > 0) {
                query = FirebaseHelper.getCustomerRef().orderByChild("name").equalTo(constraint.toString());
            } else {
                query = FirebaseHelper.getCustomerRef().orderByChild("name");
            }
            filterResults.values = query;
            return filterResults;
        }

        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) {
            query = (Query) results.values;
        }
    }
}

Would be great to get your feedback.

Thanks

Michael

[Frank van Puffelen]

The FirebaseUI adapters for Android don't yet have support for client-side filtering. The request to add this is tracked in [this Github issue](https://github.com/firebase/FirebaseUI-Android/issues/15).

Adding support for client-side filtering with a Filterable seems like a beautiful idea. I had never seen that interface, so thanks for pointing me to it. I've added a note to the issue about the possibility of using  Filterable. Keep in mind though that we keep the functionality of FirebaseUI in sync between Android and iOS. So knowing a beautiful approach for Android does not necessarily mean we'll be able to add it soon.

      puf