I am creating a settings menu and wanted to implement functionality so that when a user toggles any of the switches, it automatically saves their selection in my sqllite database.
I was thinking about putting each element into an outlet collection, iterating over each element, and adding each event to the same function.
Is there an easier way to do this or is that about it?
Thanks!
I'd put it in a tableview.
Then each cell manages its own UISwitch. The UISwitch also talks back to the cell.
Then in the cell you can call back to the table view controller to update it (with the row index) when the switch is updated.
Related
Is it possible to make changes to a particular UITableViewCell? For example, change the text in one cell of a table view with a button click?
It's possible, but you should not do that.
As you said in your comment, you can ask the table view for a cell and then make changes to that cell, but don't do that.
You should do what HHumorous said, and change your data model, then tell the table view to reload the affected cell.
If you simply change the appearance of the cell, then when the user scrolls that cell off-screen and then back on-screen the changes will be lost.
I have another question open where I'm trying to figure out how to reload the collectionView without auto-scrolling. I was also realizing there are a lot of other situations where I will need to change things in the collection view. Also I have some items that I will want to change the .alpha on and change the text of. Is there a way to do all of this in Swift? For example (to be specific) if I have a collection view with a view in each cell and that view has a textField in it, can I change the alpha and text, (change alpha with animation even) without reloading entire table?
Look at the documentation for UICollectionView. There are several "reload" methods:
reloadData()
reloadSections(_:)
reloadItems(at:)
If you just want to reload a single item, update your data source's data and then call reloadItems(at:) passing in the index path for the item.
Another option, if a cell is currently visible, is to use the cellForItem(at:) method to get a reference to an existing cell. Then you can directly access UI components of the cell as needed. You should also update your data model as needed so if the user scrolls and comes back, the cell will be rendered properly.
Most appropriate where you can update your custom view of a particular UIcollectionViewcell is reloadItemsAtIndexPaths.
You would be handling a particular item than whole collectionview with reloadData.
You can handle it via notifications or some call backs in your code where you can make decision when to update which cell.
Hope it will help you.
i have a tableview with form fields, and there is a row that use segue to call an UICollectionView, everything is works except that i can't keep the selected cells (the visual effect that i show when the cell is selected) after go back to the tableview.
I mean, i selected my UICollectionView cells, after that i go back to the form, but if i need to again to my UICollectionView Cells, to deselect o select more cells before submit the data, once the UICollectionView appear my previous selection are there (i print the array, and i see the values) but i cant see the effect that i did for selected cells.
How i can keep the effect for selected cells if I'm going back to select again o deselect cells?
One thing to realize is that this is not going to happen by itself. When you segue back to the table view and the form fields, the UICollectionView is completely destroyed. The next time you show the collection view, it is a new and different collection view.
So, if you want to maintain a knowledge of what the selection was in the collection view, you are going to have to maintain it yourself, deliberately, storing it somewhere when you know that the collection view is being destroyed.
That way, the next time you show your collection view, even though that will be a completely new and different collection view, you can pass the knowledge of what the selection was to that collection view as you create and show it. The user will have the illusion of "returning" to the collection view, in the same state, but in fact you will have saved and restored its state.
It is then just a matter of reflecting the selected state in the collection view's display of its items. To do that, you need to configure your model so that when cellForItemAtIndexPath: is called, each cell looks selected if that item is supposed to be selected.
Every time you use segue to call an UICollectionView a new instance of UICollectionView is created and hence states of selected cells doesn't get restored.
I believe u must have taken an array of index paths of selected indexes to show the visual changes in the cell.
Make your tableView class as delegate of UICollectionView. Using its delegate methods return the selected index array to tableView class .And before pushing to UICollectionView send the same array of index paths back to the UICollectionView. Hope it helps.. Happy Coding.. :)
I used to use static UITableView but the table is too long and overflow the memory.
I switched a dynamic prototype UITableView with 1 type of cell, which has an UISwitch in it.
One of the cell, when turning on the switch, will turn off the switch of another cell. These cells have fixed index.
The IBAction method is in my UITableViewCell subclass and I don't want to add the UITableView as a property in my UITableViewCell.
How do I achieve the above effect?
I'm planing to use an id or similar to distinguish between the cells as each cell's switch has different effects, that doesn't solve the above requirement.
Thanks,
I would add a block property to your cell which you can use to notify your controller of changes in the switch. See my answer below to a question on this:
How can I get index path of cell on switch change event in section based table view
All your logic can now be implemented in the view controller.
You are best to create a data model in the view controller which the cells simply provide views and controls onto. When you flick one switch and the block fires, update the data model and simply reload the table. Any cells affected will show the new data model positions for their switches. Avoid using one cell to adjust another. Just update the model and reload the cells.
In a core data app, I've got a UIViewController that has a "master" tableview on the left, with a set of detail controls (textfields, switches) and another UITableview on the right. (This is the iPad layout.) The tableviews are populated by NSFetchedResultsController instances. When the user selects a row on the leftmost tableview, it populates the details fields accordingly for editing, and the far right table is populated by another NSFetchedResultsController, displaying a set of related objects.
My problem is that for the master tableview, the one on the left, whenever I edit on of the fields related to the sort descriptors of the NSFetchedREsultsController, the table reorders and changes it's selection, which means the user would have to find the desired row and select it again to continue working. Is there a way I can prevent that selection from changing, or at least force it to reselect the proper row after it reorders the data?
It sounds like you are implementing the fetched results controller's delegate in only the most basic way, i.e. calling reloadData from within the controllerDidChangeContent: method. This will clear the table view's selection.
It you implement the fine-grained delegate methods, you should receive multiple changes of type NSFetchedResultsChangeMove during a reordering update, from which you can call moveRowAtIndexPath:toIndexPath:, which should preserve the table view's selection.
Otherwise you can store the model object that is selected in controllerWillChangeContent: and restore the selection from that model object in controllerDidChangeContent:.