I'm have a multi-list app that has an entity with several attributes for each list (i.e. List1 - item, description, qty...List2 - item, description, qty).
I have UITableView's for each list set to have two sections (section 0 "not checked" and section 1 "checked" with the didSelectRowAtIndexPath: method).
I want to use a button move the selected row's data to the second entity and remove it from the first.
I have put the button in a UIView in the footer of section 1 and made it segue to the destination viewController, just without any data transferred.
The only information I have found during google searching is on data migration and migrating assists of a business (fail), but I don't really think this is what I am looking for...is it? Or what is this process called? I am also using NSFetchedResultsController to manage the objectContext (I think I said that right).
Please keep in mind very new to coreData and that I'm still not able to convert Obj-c into Swift yet, so Swift is all I've been learning. Also, any explanation would be incredibly appreciated.
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I'm brand new to Swift but I want to create an app that has a table and each entry in that table will lead to a new screen (but this new screen is the same for all the table entries) but depending on which table cell you click on, that screen has different information posted on it.
What are the steps I need to do to complete this? I have my story board I'm just not sure how to put this all together with code
Thanks in advance!
Well your question is very broad and not very specific. Therefore it is not easy to give a helpful answer. What I would do:
Create a UITableViewController that holds your "table".
Define a UITableViewControllerDelegate for the UITableView that will be informed about UserInteractions (especially when the user
didSelect a certain row of the table).
Based on the specific row (that was selected) you can create a second UIViewController class the shows your intended information.
I can not show some code samples because your question is to broad and things depend on a lot of things (especially on the kind of data you want to show) and how you implement your UIElements on the ViewControllers in InterfaceBuilder.
And if you are not yet familiar with the concept of a UITableViewController and its Delegate, than you should find some tutorials first about that basic technique in developing iOS apps.
You want to use the master/detail pattern. I suggest doing a search on that.
My app is based on core data using MR.
I have 3 views. The three views are -
a table view where I can select an entity, when tapped it open the second view with all the relatives data and there I have a button that open the third view where the user can modify the data.
My problem is that to open the second view I have to pass from the table the row number to get the exact entity to be displayed, and here everything fine.
But if the selected entity is the last one in the table and the user modify some data that remove the last row(for example if change the category attribute of the entity), when I go back my app crash, because the row number relative that I passed from the first view doesn't exist anymore in my database.
I hope I explained it well. I know the problem, but I don't have any idea of how to solve it.
My problem is that to open the second view I have to pass from the table the row number to get the exact entity to be displayed
You should not pass the index into the table, since you know that it can change.
Alternatively, you can pass the managed object itself, or its objectID (taking into account that objectID is expensive).
In Xcode, in the left pane there's a breakpoint section (the one with the shape of an arrow… more or less). Open that section. If you hit the + button in the bottom left corner of that pane you can add an Exceptions Breakpoint. This will store the your app and highlight the section where it's crashing. From there you might be able to solve your problem fairly easily: you only need to understand why you're still trying to access that row, instead of the new index of the object. If you still need help at that point, please post the section of your code that's crashing and any related code of that class.
I solved my issue by passing the identifier of the entity instead of the row index. So now in the detail view I get my entity using the identifier instead the index.
In my iOS app, there are various Core Data entities that represent things like Appointments, Notes and Contacts.
I'd like the user to be able to edit selected attributes of each entity via a UITableView. Similar to the iOS Calendar app, when you click 'Edit', you're presented with a UITableView with editable values for Start Time, End Time, etc.
It's occurred to me that there could be a large amount of code re-use going on here, so I'm now considering creating a generic class, ManagedObjectEditorViewController that takes a managed object, displays selected attribute values within a table view, formatted according to their type, and allows them to be edited.
I can think of several neat ways of doing this, but before I spend a long time on this, I'm wondering if there's already something out there to accomplish this task? It seems like such a frequently used approach that I can't believe there isn't already some open source code out there.
Anyone heard of, or used anything similar?
I am about to do the same thing. Just started and works so far. A table that represents an NSManagedObject (Detail to a master view controller, has aspects of a master view controller itself.).
The whole table represents one NSManagedOjbect. There are fields and other controls that correspond with the simple properties.
There are to-one references where the referenced object is just displayed but can be changed.
There are to-one references which are editable NSObjects itself where 1 and exactly 1 of them exists.
There are to-many references which can be added, deleted and edited. Pretty similar to the calendar app or the address book app. (from a functional point of view. It looks different though).
For that I establish a delegate between the table cells and the view controller. This is mainly because I try to stick on the MVC pattern.
E.G. the cell serves as delegate for UITextViews, UITextFields or as target for Buttons etc.
The (Detail-) View controller which owns the NSManagedObject and all related objects serves as my delegate for the cells. It provides methods similar to IBActions to the cells so that the cell can 1) inform about the event and 2) hand over a related view, if required (I need that to display some popups accordingly) and 3) the object itself e.g. the object that is to be deleted or a person-object for which the data is to be fetched from the address book etc.
The View controller can then does its very own duties which is invoking other view controllers (Send Mail, select from Address Book, present a popover with options for the user to choose from, ...).
I just built that up yesterday evening. (It is a free-time project of mine).
I am happy so far but the concept is not really proven yet :) .
What is your current favorite approach?
I'm trying to create a UITableview that contains STATES and CITIES. To start with, I'd like the table to display only the STATES, with each value having a downward facing disclosure arrow on the right hand side of the cell which lets the user know it has values underneath it. If the user clicks the arrow, the table would expand to show the CITIES associated with the selected STATE. The user could then either select a CITY, or click on a upward facing disclosure arrow which would then "hide" the CITIES.
I've downloaded and reviewed Apples "Table View Animations and Gestures" example.
I was hoping someone might know a simpler way of accomplishing what I'm asking for.
http://developer.apple.com/library/ios/#samplecode/TableViewUpdates/Introduction/Intro.html
Good Job on explaining exactly what you want to do. This is how I would tackle this, I figure it would be easier to explain it without giving you meaningless code and answer any coding concerns you might have after.
I would set up the table view data source to be an array of arrays. The idea would be that every index in the array would represent a state and therefore contain a number of cities, hence ever index contains an array (array of cities). The parent array(of states) will be empty at the beginning, but the arrays(of cities) that will later fill it would be populated with the appropriate cities.
I would then set up the table view to contain sections (I a tempted to put code here, but read along). The sections would represent the cities. You can then fill out the table view with sections using (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section delegate. On the first run you can fill the actual table with one cell per section (maybe with the word "expand" or "more" and your down arrow). When the user touches that cell you can use the didselectrowatindexpath to know which section was touched (the indexpath object contains the section), now that you know which section it is, just modify the data source by adding the array of cities for that section of the array of arrays (parent array) and update the tableview.
This essentially gives your tableview an according style and feel. It is very easy to implement but requires a little bit of code. I have done this and am willing to provide the code you might need, the trickiest part would be to update the tableview in the correct way.
EDIT CODE:
I did a simple example following above explanation. The code is on Github , feel free to ask any questions about it.
I think a better way to represent this information would be to have a UITableView containing the states with each state showing a tiny arrow pointing to the right. Then, when a user clicks on the state, load the next UITableView that shows all of the cities in that particular state. Using a UIViewController for pushing the City list will allow users to easily return to the States list.
This approach will make much more sense to iOS Users, because this is how they expect Tables to work.
There are many tutorials explaining how to use UITableView. Here is a link to a site with many UITableView tutorials. The tutorial I linked to explains pushing a UIViewController on to the stack so that there is a simple back button back to the State list.
Normally such thing is done by seguing to another view and showing more details about cell.
What you want you could achieve by actually making custom UITableViewCell which would contain UIButton with arrow image and UITableView. In case button is clicked for the first time you could reload your cell and create inner UITableView which could show cities. Another click would simply reload cell again and not return inner UITableView at all. You also need to keep selected state somewhere because you may have to reload previous cell and hide inner table in case arrow in other cell is clicked.
I created an iOS app that allowed me to enter data into database and then display in tableview (using NSFetchedResultsController & tableView cellForRowAtIndexPath). This worked. Now, I added 3 one-to-many relationships and another entity and I need to load up the entity (on the one side of the one-to-many) from the db instead of pulling it directly from the db so that the data can be used in the relationships. Do I still use NSFetchedResultsController?
relationshipEntity2 is the one-to-many relationship between Entity1 & Entity2. The many point to Entity2
I know I'm supposed to use:
Entity2 *entity2 = [[self.entity1.relationshipEntity2 allObjects]
objectAtIndex:indexPath.row];
I am new to iOS development and even newer to Core Data but I must learn it. Any bit of help or pointing to a book or tutorial I haven't come across yet would be greatly appreciated. I haven't had much luck finding anything that does what I'm supposed to be doing.
Thanks and have a great week!
-------added for more description on project-------
I'm given the task of having a View Controller with a 3-part segmented button. There is also an add UIButton that pops up a view (bringing subview to the front, not a popover segue) with a UITextField for input to add to the table view on the view controller. There are 2 entities and three 1-to-many relationships. There is 1 relationship for each button on the segmented button. If the user, has the first part of the segmented button selected, adding a value to the popup textbox, should only add it to the table view seen when the first segmented button is selected. I have the CoreDataGeneratedAccessors created. I had this project saving data to database and fetching data to present in the table view but that was before the segmented part was added. Now I have to figure out out to separate the data into "collections" and then show all of say the first collection when the first segment of the segmented button is chosen. I'm just learning and just figured it out without the segmented part and now it's changed on me. I've worked with relational databases but in iOS it seems like it's new again.
Your question is by no means clear. You are not describing any problem, nor do you explain intelligibly what you want to accomplish.
Trying to infer your meaning: yes, you would continue to use your fetchedResultsController. This controller gives you the right object for each indexPath. When building your cell contents, you can easily get to the relationship entities with entity.relationship.
The code above will not work because entity.relationship returns an NSSet which is an unordered group of objects. (The additional allObjects does nothing and is redundant.) Therefore, objectAtIndex will not work (this only works for NSArray objects).
Hope this helps.