public void createURLLinkDialog(){
    final AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
    final LayoutInflater inflater = getActivity().getLayoutInflater();

    builder.setView(inflater.inflate(R.layout.dialog_url, null))
            .setPositiveButton(R.string.OK, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int id) {
                    EditText et = (EditText) getActivity().findViewById(R.id.push_url_link);
                    //TODO: ERROR ON BUTTON CLICK!
                    urlToImage = et.getText().toString();
                }
            });
    builder.create();
    builder.show();
}

java.lang.NullPointerException: Attempt to invoke virtual method 'android.text.Editable android.widget.EditText.getText()' on a null object reference
                                                                           at ru.timuruktus.newsletters.View.Fragments.PushPostFragment$3.onClick(PushPostFragment.java:165)

final AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
final LayoutInflater inflater = getActivity().getLayoutInflater();

final View view = inflater.inflate(R.layout.dialog_url, null);
builder.setView(view)
        .setPositiveButton(R.string.OK, new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int id) {
                EditText et = (EditText) view.findViewById(R.id.push_url_link);
                urlToImage = et.getText().toString();
            }
        });
builder.create();
builder.show();