UITableViewController edit by cell identifier

The ChatViewController of acaniChat has two different types of cells with cell identifiers: @"MessageCellID" and @"TimestampCellID". How do I make it so that only the message cells are editable?

Here's what I did. It kinda wor开发者_JS百科ks, but only the message cells on screen are editable.

- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath {
    return [[chatContent cellForRowAtIndexPath:indexPath] reuseIdentifier] == MessageCellId;
}

This works for all cells, but is it the correct practice?

- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath {
    return [[cellMap objectAtIndex:[indexPath row]] isKindOfClass:[Message class]];
}

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My "answer" is more of a recommendation that you use a data source check vs a cell check to determine whether the cell is editable. The tableView:canEditRowAtIndexPath: is a UITableViewDataSource protocol message. The reason it's part of the data source is b/c generally it is data model logic that determines whether or not the data in a particular cell should be editable. In both of your examples, you are using the type of cell as a proxy for the type of data in the cell.

A better check would be similar to the logic you must be using in tableView:cellForRowAtIndexPath: to determine which kind of cell to use.

Without knowing the specifics of the data model I can't give you the exact code but it's something like:

- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath {
    return [self chatDataTypeAtIndexPath:indexPath] == ChatDataTypeMessage;
}

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You should fix the first option, the '==' operator will check for pointer comparison, and will not compare the strings themselves which is done by isEqualToString:

So it should look like:

return[ [[chatContent cellForRowAtIndexPath:indexPath] reuseIdentifier] isEqualToString:MessageCellId];