How does AirBnb create a collection view with different cells? - ios

I noticed in the Airbnb app when you click on a specific cell on the home screen, they have a complex collection view displaying various items in different looking collection view cells. I have attached 4 pics below:
In those pictures you have different sections like About your host, Availability, Reviews, Group size up to 2 guests, Guest requirement, Contact Host, etc. How does one go about organizing a view like this?
Is this just a bunch of different cells in a TableView or CollectionView? Since every single item I click on the home screen has a very similar layout with the exact same sections. Or are these just views placed on a scrollview?

It's probably a UITableView or UICollectionView with a set of different cells. So their cellForRowAtIndexPath: cellForItemAtIndexPath: functions would return a different cell class for each different section.
They'll have an AboutYourHostCell class, an AvailabilityCell class, a ReviewsCell class, etc.
It would be possible to do this by adding Views into a UIScrollView, but it would be a lot of work, and you'd lose some nice behaviour that UITableView or UICollectionView provides - like highlighting cells when you press and hold, and animating changes.

Related

Move CollectionViewCell to another section

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.

How to create a complex scrolling view in iOS similar to yelp?

Yelp has this View show up when you click on a specific restaurant or some event:
In the picture above there is the Cascal label, then Write a Review button, then three buttons (Photo or Video, Check in, Bookmark) all in a row, then a map, and some cells underneath (Directions, Call, Explore the menu, etc.).
How can you make a complex scrolling view similar to this (do you have to use a collection view or table view?)? Since in both a tableview and collectionview you are reusing the same cells again and again (with the same layout) so it is difficult to create a view with so many heterogeneous elements like in the picture above.
Use a table view and a bunch of different cell classes each with their unique design (XIB or Storyboard) and height.
Select the cell class and height depending on index path and let table view delegate methods return accordingly.
Very basic stuff actually.
You only reuse cell classes if you need to. In the Yelp example the Directions, Call, Explore the Menu and More Info cells may have used the same design because the layout seems to be identical, only the image and text differs.

Issue with programmatically added buttons

I have a cell in the UITableView. The cell has a UITableViewCell class. In this class I programmatically add few buttons.
Note: the cell is located in the very end of the table view.
Issue:
If I'm using simulator iphone 5 > the buttons will be shown.
But if I'm using simulator iphone 6+ > the buttons will NOT be shown.
Note: when i'm opening it on iphone 5 I need to scroll to see that particular cell. on iphone 6+ i don't need to scroll there, the cell is visible right away.
So I think the issue is somewhere here. May be with the place where I do my 'buttons adding'.
Where should I call the method that sets up the buttons?
Or how can I solve this problem?
TL;DR: If you have different cell types in your table view, you should make sure they have different identifiers.
Explanation:
Table cells are re-used within the UITableView and when the table is first being displayed it won't have any re-usable cells yet. It gets the cells to display by calling on its data source through the UITableViewDataSource protocol.
The thing providing the cells will first ask the table view if it has any re-usable cells (of a particular type), before creating a new one. The way it determines the particular type is from the reuseIdentifier in the table cell.
So, if you have two different classes of table cell, but they share the same reuseIdentifier you will sometimes get one class and sometimes the other - if you get the one without buttons when you're expecting the buttons then this will be a problem!
The answer is to make sure your different cell types have a unique reuseIdentifier.

Paging through different diagrams in a table view cell

I'm looking for a method to page or slide through up to 6 different views in one table view cell. What's the best approach to do that?
I already experiment with a Collection View and a Page View Control. But the diagrams are represented by different classes, so that the standard tutorials setting up a label, are not working for me.
Thank for any feedback on this topic.
Based on what you are doing, I would use a UICollectionView with different UICollectionViewCells for your different diagrams. That should allow you to use different classes for the content of each cell.
So first go and create a UICollectionViewCell for each diagram.
Then you are going to want to go into your UICollectionViewController (or wherever you are implementing your collection view) and in the cellForItemAtIndexPath method tell it which cell to display for each indexPath.

When to use UICollectionView instead of UITableView?

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

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