So I need to create a filter that is presented from a UIPopoverController. The different lists to filter on go to the data manager (model) class and query the sqlite database. The problem I am having conceptualizing is how to do this for multiple UIPopoverControllers with the most reusability. What I mean by that is, if I have two filters, one for say fruits, and another for say vegetables. Each one needs to be presented in a popover.
What I have done is, I have a UITableView that has a generic array. In the class that presents the popover, depending on what filter was pressed, I present the popover with the UITableView and the corresponding fruit and vegetable list.
The tricky part for me is, the problems with the checkmarks. Since my list consists of “All”, plus each entry like “Apple” or “Orange”, when the user selects All, no other checkmarks are visible. If the user selects apple, then all is deselected, and apple is selected with a checkmark. If apple is selected again, then apple is deselcted, and All is reselected. The way I handle this is, in didSelectrowForIndexPath, I query the model class, get my NSDictionary of YES/NO values for each key, and set it. This also takes care of when the popover is closed, and then presented again, then the checkmarks are all there in the last state they were in since the model was already updated.
So my two questions are
(1) if this implementation is ‘ok,’ then how would I have a separate list for each UITableView? It seems like since the UITableView manages one list, I would need to create multiple UITableViews, one for each filter, so those specific calls to the data manager, like “All”, don’t mess up the other filters
(2) is there a better way to do this? I’m open to suggestions! Thanks!
You may want to reconsider the user interface. It may not be necessary to have “All” as an option, and it may even be preferable to leave it out.
I’ve checked out how such filters work in other apps, and I’ve found that “All” is often not an option. When the table first appears, all fruits, say, are shown by default. When one entry, say “Apple”, is selected, only apples are shown. When “Apple” is deselected, all results are shown once again.
This, of course, is the inverse of what is logical. Logically, if nothing is selected, nothing should be shown. However, I’ve found that when you’re using such a filter without the “All” option, you don’t realize the logical inconsistency and it somehow works very smoothly, as you would expect it to. On the other hand, it may appear more cumbersome for the user experience to have “All” being checked and unchecked automatically when the user is selecting an entirely different entry.
I’ve implemented a filter in just this way. In my opinion, it’s more user friendly even if it’s less logical.
As to the implementation, I just subclassed UITableViewController and set an array property for the filter entries. Then I re-use my subclass for different filters.