RBLHTMLView spinning the run loop

[alanjrogers]

https://github.com/github/Rebel/blob/master/Rebel/RBLHTMLView.m#L118-L120

RBLHTMLView spins the current run loop while it waits for the HTML to render.

I haven't dug into it too far yet, but I've seen this cause an intermittent crash if the HTML for the view has been assigned inside of a 'transaction' such as the begin/endUpdates calls used in view based NSTableViews.

For example:

- (NSView *)tableView:(NSTableView *)tableView viewForTableColumn:(NSTableColumn *)tableColumn row:(NSInteger)row {
    if ((NSUInteger)row >= self.cellCount) return nil;

    if (row == 0) {
       MYCellView *cellView = [[MYCellView alloc] initWithNibName:@"MYCellView" bundle:nil];
         cellView.rblHTMLView = self.htmlString;
    }
}

This method is called when rows are inserted into the table view, so usually after a call to [tableView beginUpdates]. My theory is that spinning the run loop is implicitly calling endUpdates resulting in unbalanced calls.

[jspahrsummers]

I think this is done to avoid a flash when the page reloads (by simply not returning control to the renderer until the page is ready).

Maybe we could instead do this in a block asynchronously dispatched to the main thread. It'd introduce an imperceptible delay before starting to render, but would ensure that it occurs outside of any transactional behavior.

[joshaber]

This was to ensure that it rendered the new content as soon as it was set, as you'd expect a label to do. Introducing a queue hop doesn't seem like it'd solve the problem :\