I need to display a table with in my iPhone app:
neither the number of cells nor the contents are known at compile time, but only at run time.
Views for each cell may differ, one cell has textField and another may have some other view control.
Should I consider Static or prototype cells?
Should I consider tableViewController or viewController with tableview in it?
Any thing I need to consider before I start coding? Thanks in advance
For The issue of dynamic Number of cell at Run time, you can call reload data for table view at any time you have the data source ready.
Prototype Cells should be used with no problem.
Simple Table View will be sufficient for the task.
You have to make cell, either in code or in storyboard, for each type of cell you want, 1 table View can have multiple types of prototype cells, Just name them differently and then make the objects of only the specific cell of which the data is best suited.
It is not that difficult but do handle the data source with extreme care.
Should I consider Static or prototype cells?
If you know all possible subview combinations that your cells might need to display the data appropriately, and they are relatively few, make one prototype for each. for example:
One text field,
Two labels,
One image view and a label,
...etc.
Otherwise, just use the plain-vanilla UITableViewCell (no subclassing) and remove/add subviews at runtime when reusing them (that is, inside the method -tableView:cellForRowAtIndexPath:).
Should I consider tableViewController or viewController with tableview
in it?
The only reason I would choose UIViewController + UITableView over UITableViewController is if -for example- I needed the table view to only take up part of the main view's bounds/screen, and display some other subview in the remainder. Otherwise, you get so much "for free" with UITableViewController that there's just no point in implementing all of that from scratch.
You have to choose prototype cell, u can create different types of cell depending upon your requirement.Any think ok for u, u can create tableview controller or view controller.
Related
I have a UIViewController with a collectionView inside it. The layout may seem confusing but I am making use of horizontal scrolling UICollectionViewCells, presented in 3 sections.
The main collection view is made up of 3 sections. I access 3 different UICollectionViewCell classes for each section becuase it is fetching different data for each one. Once the data is fetched, it dequeues another Cell class, which is the same one accessed for all the sections.
There are 2 buttons in each cell. When I press the button, a value changes within the database. When I re-run the program, the cell in which the button was pressed has moved to its corresponding section that it should be in as per the change. However, I want to achieve this as soon as I press the button. How can I move the cell from one section to another, baring in mind that they the cells presented are inside a collectionview cell making up the sections, which is then inside a greater UICollectionView.?
I've tried researching how to do this but no luck, and everyone seems to be using a drag and drop method which seems too complicated for what I am trying to achieve. Would appreciate any help.
Thanks
The approach I followed to achieve the above situation is using a custom Delegation when cell is removing from collectionviews. A container CollectionView has two sections with 2 different cells containing two different Horizontal UICollectionViews. These two collectionview's cells have UIButtons. When tap on one collectionView's button, that particular cell is removed, custom Delegate method calls and another CollectionView's cell is populated. This is the link of the project I have created for this particular scenario. For better understanding, here is a GIF for demonstration.
I have a tableview where a single prototype cell is used only 3 times. This cell has some buttons on it that trigger displaying and hiding content within the cell.
I could reuse the cells, but that requires a lot of resetting each cell so that if I expand A's content, B's content isn't expanded when it loads. Furthermore, this requires me to keep a state record in the Controller class, where I would prefer to have this all handled by the Cell itself for modularity. In other words, the amount of work to keep each cell in the correct stage seems inefficient.
What would be the best way to go about this? Do I use static cells? Is there a way to instance 3 separate cells of the same type and place them in the TableView?
You certainly can have the modular part of the code you need inside the cell itself. If you don't want to reuse the cells, then add a custom initializer with a case for each cell type. Inside your delegate method cellForRow:
return CustomCell(type: .myCustomType)
If you do it this way, you can add a switch inside the cell's initializer & set up the cells according to their types that way. And i'm assuming by "static" you mean just three instances. You "add" cells to the table by telling the delegate the number of cells that it will need, which will in turn call cellForRow x times.
Imagine this scenario:
I've 10 different and custom UITableViewCell: one with a textfield,
one with a button, one with some labels, one with a textview, one
with an imageView and so on.
I've a ViewController with a tableView where I wanna display these cells.
The number of cell displayed can vary based on some conditions (and also the height, the background color and other parameters)
The user can interact with these cells
What is the best way to design this in respect of the MVC and maintain the ViewController lightweight and maintainable as possible?
How to take advantage of Swift language in doing this?
Is there any famous and consolidate design pattern to apply?
i will try to share some of my experience:
Create separate custom UITableViewCelll as per requirement like : textfield, textview, imageview, label etc. this class must not dependent on data calculation it is only for cosmetics UI. that means there must not be any method like updateCellWithData:(someDATAObj). This logic must go in some cetegory as discussed below.
Register separate custom UITableViewCelll with your tableview.
Create separate class (NSObject) as datasource and delegate for your UITableView.
Use category to populate data in your custom UITableView Cell. some thing like updateCellWithData:(someDATAObj).
Use constant file for your constants like height for tableView Cell, reuse identifier names, notification name.
try with some code atleast, then we can help you with best.
I want to access/update UITableView cell (using reusable cells) which is not in the current view . I know the table view cells are reusable, that can be the reason I am unable to fetch them but is there any way of virtually making and updating. OR I have to drop the reusable cell technique. Suppose tableview have total 20 cells but only say 7 are visible in the current view of iPhone. How will i update other 13 cells which are out of view bounds
Accessing and modifying cells (even if you could) would be a bad pattern. UITableViewCells are designed to be created and modified solely in the tableView:cellForRow:atIndexPath datasource method, where framework automatically asks you what to do with cells that are about to be displayed.
The whole idea behind reusability is that the system takes care of the view for you, and all you need to do is take care of your datasource and instruct the system, using the model, how to render cells, in its allocated datasource method.
This paradigm would be defeated if we started accessing cells manually and modifying them.
You can't access those cells because they are not added to the UITableView but are kept in a queue until user scrolls to them, then they are added to the UITableView. Instead update your model, which will reflect changes on the cells.
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.