Quick question on all this. I'm making my model a KVO-compliant class, just to see what'll happen. The Apple guide says to implement methods, all of which include <key>. I've replaced <key> with TweetsTab, such as countOfTweetsTab, and I added tweetsTab (note the lowercase t) to my array controller in the Attributes Inspector. What I can't work out is how to tell the controller to *use* tweetsTab when it accesses the KVO methods in my model class.
When I go to the bindings inspector for my array controller, I can select a controller, set the path (which I set to the instance of my model in my view controller), but I can't set the controller key, because that text field is refusing to let me edit it. I thought I'd put tweetsTab in here, but that is apparently the wrong way to go about it, unless Xcode is doing something funny? I hope I'm making sense. > On Sep 7, 2015, at 08:25, Alex Hall <mehg...@icloud.com> wrote: > > >> On Sep 7, 2015, at 02:07, Ken Thomases <k...@codeweavers.com> wrote: >> >> On Sep 7, 2015, at 12:01 AM, Alex Hall <mehg...@icloud.com> wrote: >> >>> My first step is to make a KVO-compliant backing store, because Swift >>> arrays won't do the job. As you said, my goal of updating an array and >>> having my table automagically update itself to match the array just won't >>> happen. What I need is a class that implements the methods described in the >>> link you provided,so that bindings will work correctly. Obviously I can use >>> an array internally, but the interface of the class *must* offer the >>> necessary methods. I'll call this new class MyKVOCClass, because I'm >>> terrible at naming things. >> >> It's not particularly that the class must offer the necessary methods. It's >> that your code must use those methods to modify the array or KVO is not >> aware of the changes you make. > > That makes sense. I'd be able to just have the model class expose what it > needs to, handling all its internals by itself. There's no need for the > controller to care which tab is selected or which array something gets added > to, because the KVO methods will expose that. If I'm understanding correctly, > I would turn my model itself into a KVO-compliant class which would, in the > eyes of my array controller, have just one array. > >> It sounds like you're suggesting making a class just to be an array-like >> thing that is KVO-compliant. That sounds to me like you're heading down the >> wrong road. The class which needs to be KVO-compliant is the thing which >> currently holds the arrays (even if a bit indirectly). That brings us to >> the next point… >> >>> Next, remember that my model is a dictionary of arrays right now. The model >>> has a single variable that can change to point at any of the arrays in the >>> dictionary; the table is to display only that selected array (the table is >>> view-based, one column, no multi-selecting, no editing). >> >> Can you explain in some more concrete terms why this level of dynamism is >> required? What does the dictionary represent in some real-world sense or >> "business logic"? What do the various arrays represent? Is there a fixed >> set of arrays or is that variable? What makes one of the arrays current and >> what does that signify (other than that's the one shown in the table)? What >> other implications does it have? What do the arrays have in common? Why, >> other than happenstance or convenience, does it make sense for them to all >> be part of the same controller? > > Sure. This is a Twitter app, which shows one type of tweet at a time. That > is, the table can show one of home, mentions, DMs, favorites, RTs of the > user, Twitter searches, tweets from a different user, etc. When an array is > "active", right now it just shows its own tweets in the table, but I hope to > do a bit more in the future, like changing the window title to show the tab's > name. I'm just starting, so I know a lot of refactoring will have to happen; > I'm in the "just get it working" stage. > > My class is TweetDataController, and it currently does *everything* that > isn't related to my view. It holds my dictionary of tabs, but it also calls > the Twitter framework methods to download new tweets, it posts tweets, it > parses them for display, it replaces short URLs with expanded ones in tweet > text… I know it's not good to have all that logic in one place, and I was > going to refactor it soon, but as I said, I'm still getting things working > and seeing how the app--and its internals--will evolve and need to be changed. > > Anyway, the idea behind the dictionary of arrays is that each tab (list of > tweets) is an array of Tweet objects, and all the tabs are in the dictionary, > accessed by String constants. For instance, when the user hits cmd-4 to show > his favorites, the view controller calls > TweetDataController.getTabByName(TwitterDataController.favoritesTabName). In > the model, currentTab (a string) is set to the favoritesTabName string, and > then the view controller reloads the table. Since the active tab has changed, > reloading gets the array of tweets for favorites and my table shows favorites. > > I'm not bent on using this setup, it just made sense at the time, and I > needed something. This is why I said earlier that I'm using a dictionary, but > only need an array controller. It's also why I need that computed property, > so that the controller is always pointing at the correct array. I see what > you're saying, though: TweetDataController can implement the KVO-specific > methods and expose only what it needs to, no need to worry about the active > tab. As I said above, the model would then appear to the controller to just > be a KVO-ready array. >> >> I'm asking because this design strikes me as one which will cause trouble >> and I'm looking for handholds for a suggested refactoring. I'll wait for >> more info before getting into the other stuff. >> >> Regards, >> Ken >> > > > -- > Have a great day, > Alex Hall > mehg...@icloud.com > -- Have a great day, Alex Hall mehg...@icloud.com _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
