Why notify listeners in a content provider query method?
- by cbrulak
Vegeolla has this blog post about content providers and the snippet below (at the bottom) with this line:
cursor.setNotificationUri(getContext().getContentResolver(), uri);
I'm curious as to why one would want to notify listeners about a query operation. Am I missing something?
Thanks
@Override
public Cursor query(Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder) {
// Uisng SQLiteQueryBuilder instead of query() method
SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();
// Check if the caller has requested a column which does not exists
checkColumns(projection);
// Set the table
queryBuilder.setTables(TodoTable.TABLE_TODO);
int uriType = sURIMatcher.match(uri);
switch (uriType) {
case TODOS:
break;
case TODO_ID:
// Adding the ID to the original query
queryBuilder.appendWhere(TodoTable.COLUMN_ID + "="
+ uri.getLastPathSegment());
break;
default:
throw new IllegalArgumentException("Unknown URI: " + uri);
}
SQLiteDatabase db = database.getWritableDatabase();
Cursor cursor = queryBuilder.query(db, projection, selection,
selectionArgs, null, null, sortOrder);
// Make sure that potential listeners are getting notified
cursor.setNotificationUri(getContext().getContentResolver(), uri);
return cursor;
}
