I currently have a prototyped UITableView in my storyboard, which has many cell with very complex layout. Now, I need to convert it into a UICollectionView, because I always have some problem with the way UITableView handles cell layout(See my this question). I figured the code part to be the easy one, as I only need to tweak the inheritance of my cell classes, as well as switch the delegate and datasource with previously written code. However, I am a little stuck on the storyboard side, that is, given all my cells are complex in layout and even copying and pasting them from one cell to another would require many layout tweaking and IBOutlet/IBAction reconnecting. Is there a fast way to convert those UITableViewCells designed in storyboard into UICollectionViewCells?
I think, you save data into one class, In CollectionView, You get data from class. You remember, tableview and collection are reverse about cell and row.
I am wondering what exactly happens, when you dont use dequeueReusableCellWithIdentifier in the cellForRowAtIndexPath-method.
In one Project I am collaborating we have different types of custom UITableViewCells which all appear in one single tableview. So here we fill arrays with all TableCells that should be displayed. These arrays are not very big (10-15 Cells) so for us that way works even not using any identifiers for dequeueReusableCellWithIdentifier. The next question is how at all you could use identifiers resp. dequeueReusableCellWithIdentifier when using different Cells in one single section of an UITableView. Is someone here hwo can explain, what exactly happens in background? Regards Nils
The dequeueReusableCellWithIdentifier is something that reminds me of Flyweight pattern.
Since allocation and instantiation of a cell can be an expensive task, using this mechanism you have the opportunity to create only the first visible cells and later reuse them just changing their contents. Scrolling animation must be as fast as possible to give a good experience to the user.
Is it worth it? Yes and it basically comes for free, we just need to pay attention that some old data can be still present in a new visualization, the trick is to always implement the method -prepareForReuse() correctly, here, you can eventually wipe all displayed data before setting the new one.
If you want to use different cells in the same section is absolutely possible, also if they have different height. You just need to crate different cell identifiers, one for each cells and tie them somehow along with your data.
I usually map data to be displayed in struct (swift) or dictionaries along with a key for the cell identifier to be used.
If your type of cells are representing themselves while scrolling you should dequeue them.
I am have to show three different cells like (Facebook post) with all different size and design. The data is coming from server.What is the best way to deal with it. I have to use UITableview or UICollectionview there are three kinds of cells like:
News
Movies
Spots
Each cell type has different design, I want to identify each cell type from the data obtained from server and configure and display the correct cell.
The Cells Look Like This :
In the storyboard, add as many prototype cells you need. Then, to each create a different identifier (and its own class). Shape each to how you want it to look.
I found that UICollectionView is like an upgraded version of UITableView introduced in iOS6, but when should I choose UICollectionView instead of UITableView?
There are still Apps using UITableView, if UICollectionView can do anything UITableView can do , why people still use UITableView? Is there a difference as far as performance is concerned?
Thanks!
That depends on the requirements. How the application flows determines which type of UI to integrate into the application.
People mainly use the UICollectionview for creating types of UIs with multiple images shown in a grid. This would have complex logic using UITableView, but with UICollectionview, it would be easy.
When using UICollectionview, you don't need to set buttons with tags or other things by getting selected items values. You can simply get -(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath and in UITableViewDelegate:
`-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath`
You get the selected row instead of the item, so for creating grid or modified items, using UICollectionview is best.
For the listing details of each item, people use UITableView because it shows more info on each item.
Apple Docs:
UICollectionView Class Reference
The UICollectionView class manages an ordered collection of data items and presents them using customizable layouts. Collection views provide the same general function as table views except that a collection view is able to support more than just single-column layouts. Collection views support customizable layouts that can be used to implement multi-column grids, tiled layouts, circular layouts, and many more. You can even change the layout of a collection view dynamically if you want.
UITableView Class Reference
A table view displays a list of items in a single column. UITableView is a subclass of UIScrollView, which allows users to scroll through the table, although UITableView allows vertical scrolling only. The cells comprising the individual items of the table are UITableViewCell objects; UITableView uses these objects to draw the visible rows of the table. Cells have content—titles and images—and can have, near the right edge, accessory views. Standard accessory views are disclosure indicators or detail disclosure buttons; the former leads to the next level in a data hierarchy and the latter leads to a detailed view of a selected item. Accessory views can also be framework controls, such as switches and sliders, or can be custom views. Table views can enter an editing mode where users can insert, delete, and reorder rows of the table.
Here's my criteria:
If a UITableView can do it, use it
If a UITableView needs lots of code to do it or can't do it at all, use UICollectionView.
You have to consider the restrictions on UITableView before making a decision: It's a single column. And you can only customize the cells, but not section backgrounds and such. So if you have a straight-up list of things with no extra frills - that looks like a bog standard iOS view, basically - then use UITableview. If you have custom insets, or a border around each section, use UICollectionView.
I'm actually considering UICollectionView for all things simply because it's very expensive when you start developing your view as a table view, then later find out it can't do that one thing that you need it to do. 1st hand experience ;)
Edit after even more experience with the two: Disregard that last paragraph. UICollectionView requires a lot of boilerplate code to make it work like a UITableView. Use UICollectionView only when really needed. ;)
For simple lists and forwards/backwards navigtaion, use UITableView.
If you need a high degree of customisability, use UICollectionView.
Generally speaking, in software development, it's best to choose the approach which represents "The Simplest Possible Thing".
EDIT: As of iOS 14, UICollectionView can now do lists as well and is now the recommended approach. See this session from WWDC20 for more information and implementation details: https://developer.apple.com/videos/play/wwdc2020/10026/
According to my point of view main difference between collectionView and tableView is that
TABLEVIEW --> show list of items in only one column.
COLLECTION-VIEW -->show list of items in multiple column.
Hope it will help you.
If you choose UITableView for iPhone, make sure you have considered your iPad strategy first. If you want an iPad-specific layout, you may want that single-column layout to become a grid.
Although it's not required, I always use a collectionview. That way I can easily adapt how my collections are presented for differing resolutions. A plus is that it's ready to quickly add new types of cells when refactoring in the future.
I see no point of tableviews. It's very simple to use a collection view to represent a table. IMO.
From my personal experience the two elements should only be compared loosly.
TableView
A TableView is a UI element designed for showing data in a list format. There is certain functionality that comes as standard with a UITableView, such as:
Accessory View
Cell Selection Style
Editting Style (Delete and edit buttons).
The above elements enhance the usability of data when displaying and interacting in a list format. Such as viewing emails.
CollectionView
A CollectionView is a UI element designed for showing content using a custom layout (usually anything that isn't a list). CollectionViews improve functionality of displaying data in completely bespoke layout styles and also dynamically changing layouts on the fly. Some examples are:
Horizonal Lists
Photo Galleries
Thumbnail views
Carousels
Dials
Laying out elements on a map
etc.
CollectionViews also allow for multiple selections.
Conclusion
As you can see from the above, both have completely different use cases and are designed for enhancing the development and usability of their own specific data sets.
If you are looking at displaying anything in a list style with the followin interactions:
- Adding
- Deleting
- Re-ordering
Then a UITableView will simplify this process by providing the support straight out of the box.
Anything else, you should leverage the benefits of CollectionView as you have more flexibility.
Its totally dependent on how your data to be shown.
As mentioned by many above, if you require only single set of data and that too not complex, go for UITableView else use UICollectionView.
UICollectionView is customization friendly.
If you are dealing with multiple cell heights or so, then go for UICollectionView.
Both are depends on the requirements. Table Views also have support for a variety of editing scenarios. This support has not been implemented in the Collection View classes.
If you are converting from a Table View that relies on these methods, expect to do a little extra heavy lifting in the Collection View.
Collection View section headers can be placed anywhere within the view.
and UITableView don't need to set buttons with tags or other things by getting selected items values.
In practice, everyone uses UICollectionView that I've come across, when they only need a UITableView. "It's one-dimensional. It goes up and down. Why are you adding unnecessary delegate methods for layout AND data?". I once spent an extra 2 hours helping a startup find out why their UICollectionViewCell got squished because the owner, who didn't read the Animations manual, nor HIG, nor the UICollectionView guide, decided to use it and add variable heights and anims. Needless to say, he gave himself a headache and much lost time on a non-business-critical issue he could have avoided by simply using a table cell, since there's no extra layout delegate + Nib.
Let me get this straight, I am all for UICollectionView's when your data and display need it. They're very powerful. But in practice, most people I've seen have been using them on lists.
This brings up another flaw. They're also used on short, constant lists that won't change, ever. In this case, just make a Xib. Or write a custom view that stacks them. Why? Because you don't need the memory management for 5 sets of labels with a button or switch. If they might change, then yes, use a list. If you want physics, then UICollectionView works well with a some cool effects. But do you really need to add 5 delegate methods and a layout system for 5 labels that will never move?
Also, I'm not forgetting that iOS has a native stacking view now too. I can never get it to deform how I want, even though I'm quite adept at the 2D and animation systems, so I never use the built-in one.
All I'm saying is, define your requirements. Maybe you don't need either of these, if your UI isn't adding/removing items and refreshing itself. Or maybe you want to write a Card Game and throw them out virtually on a table, then use UICollectionView with a physics system for its layout guide.
Personally I think the UICollectionView can do most of the work which UITableview can do. well, at the same time, it's more complex to use.
I suggest you use UICollectionView as TableView just in case your manager change requirements in the future.
Based on our need we are choosing TableView or CollectionView.
Example:
For phone contacts tableView is best option.
For photo gallery, collection view will be best option.
I had this issue in my current project. Which to use. In my case it was simple really. I needed both. I needed my view to look like UITableView and also to change its change / layout. So, UICollectionView was used. I also use UITableView everywhere I don't need any extra customisation. Since UiTableView comes with a default layout that includes images and text - I use it for simplicity.
Based on our requirement we choose UITableView or UICollection view.
If we want to display images or items in grid type or if we need more customisability we use UICollectionview.
For listing each item with details and subdetails we use UITableView.
UICollectionView:
The UICollectionView class manages an ordered collection of data items and presents them using customizable layouts. Collection views provide the same general function as table views except that a collection view is able to support more than just single-column layouts.
UITableView: A table view displays a list of items in a single column. UITableView is a subclass of UIScrollView, which allows users to scroll through the table, although UITableView allows vertical scrolling only.
As per my view for Grid View display use UI Collection View.All other list view use UITable View
I have an app which will show over a 1000 items, all of those item details are local ( saved via coredaata) and will ship with the app.
In researching the UI mechanisms to show those items, I am in between choosing uicollectionview or tableviewcontroller with a customized cell.
My question is : Which choice would be more efficient and provide a smoother UI in terms of
dragging?
which one can I customize to load out the 1000 entries I have only enough the provide a smooth scroll, and load more cells as needed?
Thanks.
Both approachs will handle 1000 entries easily if you follow the good practices of view/cell reusing. Additionally both APIs are very similar, so jumping from one to the other is not that hard.
The main difference between the two is how you want to display those 1000 items. UITableView has a couple of styles of cells stacked one over the other. You should not try to bend it to do any other kind of things too much complex than that kind of layout. UICollectionView is a much more powerful set of classes that allow to modify almost every aspect of how your data will appear in screen, specially its layout, but also other things. You can see UITableViews in almost every iOS application (for example Contacts or iPod), while UICollectionViews are more difficult to see (the grid in Photos, but also the coverflow in iPod).
So, if you need something standard like most table views in iOS I will choose the UITableView, but if you need more control over your layout, go with UICollectionView.
It's slightly unclear what you're asking, so I have summerized the advantages of both.
UITableView
UITableView is the base mechanism for displaying sets of data on iOS. It's a simple list, which displays single-dimensional rows of data. It's smooth because of cell reuse and other magic.
UICollectionView
UICollectionView is the model for displaying multidimensional data - it was introduced just a year or two ago with iOS 6, I believe.
It's also smooth because of the same tactics used in UITableView - cell reuse, etc.