I have a UITableView, named Favorites section. If i add an entry to the favorites section, i can see it loaded correctly in the favorites section, but if i continue and try to add another entry, it will only work if i go to favorites section, then the original section and then back to the favorites section, as if something is holding her from refreshing.
I tried to put [UiTableView reloadData] in the viewWillAppear , but still no result. I even tried [self.tableView reloadData] and still. Any ideas what to do?
Note that i am using a tab bar
Please make sure you have properly added your record in datasource, and after that only u have reloaded data.
You can just reload a section if you know in which section you are adding else, you can use insertRows method to just update new record in your table, reloading entire table for a row is bad practice.
Hope this helps
Related
I have multiple data in my UITableView and when I delete one record.
Don't use didEndDisplayingCell to manipulate the cell or the data source array by the passed index path.
It's just a notification that the specified cell was removed from the table
The documentation also states:
Use this method to detect when a cell is removed from a table view, as opposed to monitoring the view itself to see when it appears or disappears.
The solution is to move the entire code in this method to the location where the cell / data source item is removed and use it before removing anything
The app is crashing because even though you have deleted the object( so now array will have one less element) but you have not told the table view to reset itself according to new datasource. Even cellforRowAt will crash if you delete the last element. One solution is to reload the tableview by calling:
<tableViewName>.reloadData()
but it will produce unnecessary flicker if tableViews are quite large and complex. And the Second thing, You should'nt be using didEndDisplayingCell
I'm very new to swift programming. I have been playing around with this for a while, but I am not getting anywhere so asking here.
I have a tableview which I can load the data into the view from CoreData no problem. I have an ADD button at the top that segue's to a new tableview, with a long list of options they can pick from. This tableview also works fine, and includes a search bar.
When the user selects an item row from the second tableview, it inserts that item into CoreData and segue's back to the first tableview. This is where my problem is, the data does NOT update on the visible view.
I call tableview.reloaddata() and I can see my code calling the fetchedResultsController with the new query that would return with the new data. But the code never gets to the cellForRowAtIndexPath func so therefore the visible data view never changes. It remains the same display that was visible when the add button was pressed.
How does the visible data get updated? What am I missing?
When using an NSFetchedResultsController, if you want it to "automatically" update the contents of the tableview then there are a couple of things you need to make sure of...
You have to become the NSFetchedResultsControllerDelegate and implements the methods necessary for the updating of the table view. These are quite lengthy and can be found on the Ray Wenderlich website. The code on here is in Objective-C but it's fairly easy to convert to Swift.
The second thing you need is to make sure that the core data update is done on a background thread. Again the website linked above shows this.
Once you've done that then you don't actually need to run [tableview reloadData] because the fetched results controller methods will manage everything for you.
A simple tableviewController, empty. A modal that can be launched from a button. No data in the data source for the tableview, and no rows displayed.
I open the modal, use it to add an item, and return to the tableview controller. The tableview updates itself automatically, and the new row is displayed.
I add a second item. The table view does NOT update automatically.
I can tell by logging inside numberOfSectionsInTableView that even if I go to add the first item and cancel, the tableview refreshes - it asks for the number of sections, rows, and the cell to display (if there is one). But not if there is one pre-existing row in the table.
I've scoured my code but can't find anything that would cause the tableview to know when the first item is added, but none afterwards.
Any ideas?
EDIT - I have further narrowed my issue so will close this shortly and have posted a more specific question at Why does an empty tableView check the number of sections but a non-empty one does not?
from Apple's documentation:
UITableView overrides the layoutSubviews method of UIView so that it
calls reloadData only when you create a new instance of UITableView or
when you assign a new data source.
maybe you are setting data source of table view after showing that modal? So at the second time data source does not changes and tableView does not update.
another key (I'm not sure about that) may be the showing of the modal first time. The method -addSubview for modal is causing -layoutSubviews.
I want to edit UITableView by calling EditTable method on a button click of some other class. In other words, I want to delete rows from UITableview from some other viewcontroller without navigating to that UITableView.
Please tell me the way to achieve this or any sample code for it.
If you want to delete rows from a tableview you just need to delete the corresponding rows from the datasource. When the table is next shown it should know how to reload it's data so the changes in the datasource are applied to the table.
Edit
You shouldn't rely on sending messages to view controllers that are deeper in the stack because they may have been unloaded already.
In my application, I have a UITableView with a few rows (let's call it TV1), now, at the bottom of these rows is a row that drills down into another (TV2). This new TV2 asks you which type of data you would like to add to the first view. Then, when the user selects which kind, they're brought to another view, in which they fill in some fields, the data is saved, and they're sent back to TV1, however, the data they entered, isn't loaded and I'm not really sure how to do this. Any ideas?
Maybe you did this already, but how about using [TV1 reloadData];? This forces the entire table to reload, yet there are also more specific methods for reloading just the cells that have been altered. See also the documentation: UITableView
Reload your table view by calling [self.tableView reloadData] in the viewcontroller's viewWillAppear: method. It will be called when the user switches back to your view. Right before it is actually put on screen.