Ecosyste.ms: Awesome
An open API service indexing awesome lists of open source software.
https://github.com/jeantimex/ios-swift-collapsible-table-section
:iphone: A simple iOS Swift project demonstrates how to implement collapsible table section.
https://github.com/jeantimex/ios-swift-collapsible-table-section
autosize collapse demo ios-swift swift4 tableview
Last synced: 3 days ago
JSON representation
:iphone: A simple iOS Swift project demonstrates how to implement collapsible table section.
- Host: GitHub
- URL: https://github.com/jeantimex/ios-swift-collapsible-table-section
- Owner: jeantimex
- License: mit
- Created: 2016-05-30T17:05:54.000Z (over 8 years ago)
- Default Branch: master
- Last Pushed: 2020-04-23T23:39:42.000Z (almost 5 years ago)
- Last Synced: 2025-01-13T09:04:40.191Z (10 days ago)
- Topics: autosize, collapse, demo, ios-swift, swift4, tableview
- Language: Swift
- Homepage:
- Size: 5.12 MB
- Stars: 1,214
- Watchers: 29
- Forks: 151
- Open Issues: 18
-
Metadata Files:
- Readme: README.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
Awesome Lists containing this project
README
# How to Implement Collapsible Table Section in iOS
[]()
[](#backers)
[](#sponsors)
A simple iOS swift project demonstrates how to implement collapsible table section programmatically, that is no main storyboard, no XIB, no need to register nib, just pure Swift!
In this project, the table view automatically resizes the height of the rows to fit the content in each cell, and the custom cell is also implemented programmatically.
## How to implement collapsible table sections? ##
#### Step 1. Prepare the Data ####
Let's say we have the following data that is grouped into different sections, each section is represented by a `Section` object:
```swift
struct Section {
var name: String
var items: [String]
var collapsed: Bool
init(name: String, items: [Item], collapsed: Bool = false) {
self.name = name
self.items = items
self.collapsed = collapsed
}
}
var sections = [Section]()
sections = [
Section(name: "Mac", items: ["MacBook", "MacBook Air"]),
Section(name: "iPad", items: ["iPad Pro", "iPad Air 2"]),
Section(name: "iPhone", items: ["iPhone 7", "iPhone 6"])
]
```
`collapsed` indicates whether the current section is collapsed or not, by default is `false`.
#### Step 2. Setup TableView to Support Autosizing ####
```swift
override func viewDidLoad() {
super.viewDidLoad()
// Auto resizing the height of the cell
tableView.estimatedRowHeight = 44.0
tableView.rowHeight = UITableViewAutomaticDimension
...
}
override func tableView(_ tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return UITableViewAutomaticDimension
}
```
#### Step 3. The Section Header ####
According to [Apple API reference](https://developer.apple.com/reference/uikit/uitableviewheaderfooterview), we should use `UITableViewHeaderFooterView`. Let's subclass it and implement the section header `CollapsibleTableViewHeader`:
```swift
class CollapsibleTableViewHeader: UITableViewHeaderFooterView {
let titleLabel = UILabel()
let arrowLabel = UILabel()
override init(reuseIdentifier: String?) {
super.init(reuseIdentifier: reuseIdentifier)
contentView.addSubview(titleLabel)
contentView.addSubview(arrowLabel)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
```
We need to collapse or expand the section when user taps on the header, to achieve this, let's borrow `UITapGestureRecognizer`. Also we need to delegate this event to the table view to update the `collapsed` property.
```swift
protocol CollapsibleTableViewHeaderDelegate {
func toggleSection(_ header: CollapsibleTableViewHeader, section: Int)
}
class CollapsibleTableViewHeader: UITableViewHeaderFooterView {
var delegate: CollapsibleTableViewHeaderDelegate?
var section: Int = 0
...
override init(reuseIdentifier: String?) {
super.init(reuseIdentifier: reuseIdentifier)
...
addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(CollapsibleTableViewHeader.tapHeader(_:))))
}
...
func tapHeader(_ gestureRecognizer: UITapGestureRecognizer) {
guard let cell = gestureRecognizer.view as? CollapsibleTableViewHeader else {
return
}
delegate?.toggleSection(self, section: cell.section)
}
func setCollapsed(_ collapsed: Bool) {
// Animate the arrow rotation (see Extensions.swf)
arrowLabel.rotate(collapsed ? 0.0 : .pi / 2)
}
}
```
Since we are not using any storyboard or XIB, how to do auto layout programmatically? The answer is `constraint anchors`.
```swift
override init(reuseIdentifier: String?) {
...
// Content View
contentView.backgroundColor = UIColor(hex: 0x2E3944)
let marginGuide = contentView.layoutMarginsGuide
// Arrow label
contentView.addSubview(arrowLabel)
arrowLabel.textColor = UIColor.white
arrowLabel.translatesAutoresizingMaskIntoConstraints = false
arrowLabel.widthAnchor.constraint(equalToConstant: 12).isActive = true
arrowLabel.topAnchor.constraint(equalTo: marginGuide.topAnchor).isActive = true
arrowLabel.trailingAnchor.constraint(equalTo: marginGuide.trailingAnchor).isActive = true
arrowLabel.bottomAnchor.constraint(equalTo: marginGuide.bottomAnchor).isActive = true
// Title label
contentView.addSubview(titleLabel)
titleLabel.textColor = UIColor.white
titleLabel.translatesAutoresizingMaskIntoConstraints = false
titleLabel.topAnchor.constraint(equalTo: marginGuide.topAnchor).isActive = true
titleLabel.trailingAnchor.constraint(equalTo: marginGuide.trailingAnchor).isActive = true
titleLabel.bottomAnchor.constraint(equalTo: marginGuide.bottomAnchor).isActive = true
titleLabel.leadingAnchor.constraint(equalTo: marginGuide.leadingAnchor).isActive = true
}
```
#### Step 4. The UITableView DataSource and Delegate ####
Now we implemented the header view, let's get back to the table view controller.
The number of sections is `sections.count`:
```swift
override func numberOfSectionsInTableView(in tableView: UITableView) -> Int {
return sections.count
}
```
Here is the key ingredient of implementing the collapsible table section, if the section is collapsed, then that section should not have any row:
```swift
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return sections[section].collapsed ? 0 : sections[section].items.count
}
```
Noticed that we don't need to render any cell for the collapsed section, this can improve the performance a lot if there are tons of cells in that section.
Next, we use tableView's viewForHeaderInSection function to hook up our custom header:
```swift
override func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
let header = tableView.dequeueReusableHeaderFooterViewWithIdentifier("header") as? CollapsibleTableViewHeader ?? CollapsibleTableViewHeader(reuseIdentifier: "header")
header.titleLabel.text = sections[section].name
header.arrowLabel.text = ">"
header.setCollapsed(sections[section].collapsed)
header.section = section
header.delegate = self
return header
}
```
Setup the normal row cell is pretty straightforward:
```swift
override func tableView(_ tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell") as UITableViewCell? ?? UITableViewCell(style: .default, reuseIdentifier: "Cell")
cell.textLabel?.text = sections[indexPath.section].items[indexPath.row]
return cell
}
```
In the above code, we use the plain `UITableViewCell`, if you would like to see how to make a autosizing cell, please take a look at our `CollapsibleTableViewCell` in the source code. The `CollapsibleTableViewCell` is a subclass of `UITableViewCell` that adds the name and detail labels, and the most important thing is that it supports autosizing feature, the key is to setup the autolayout constrains properly, make sure the subviews are proplery stretched to the top and bottom in the `contentView`.
#### Step 5. How to Toggle Collapse and Expand ####
The idea is pretty starightforward, reverse the `collapsed` flag for the section and tell the tableView to reload that section:
```swift
extension CollapsibleTableViewController: CollapsibleTableViewHeaderDelegate {
func toggleSection(_ header: CollapsibleTableViewHeader, section: Int) {
let collapsed = !sections[section].collapsed
// Toggle collapse
sections[section].collapsed = collapsed
header.setCollapsed(collapsed)
// Reload the whole section
tableView.reloadSections(NSIndexSet(index: section) as IndexSet, with: .automatic)
}
}
```
After the sections get reloaded, the number of cells in that section will be recalculated and redrawn.
That's it, we have implemented the collapsible table section! Please refer to the source code and see the detailed implementation.
## More Collapsible Demo ##
Sometimes you might want to implement the collapsible cells in a grouped-style table, I have a separate demo at [https://github.com/jeantimex/ios-swift-collapsible-table-section-in-grouped-section](https://github.com/jeantimex/ios-swift-collapsible-table-section-in-grouped-section). The implementation is pretty much the same but slightly different.
## Can I use it as a pod? ##
:tada: Yes! The CocoaPod is finally released, see [CollapsibleTableSectionViewController](https://github.com/jeantimex/CollapsibleTableSectionViewController).
## Support ##
## Contributors
This project exists thanks to all the people who contribute. [[Contribute](CONTRIBUTING.md)].
## Backers
Thank you to all our backers! 🙏 [[Become a backer](https://opencollective.com/ios-collapsible-table-section#backer)]
## Sponsors
Support this project by becoming a sponsor. Your logo will show up here with a link to your website. [[Become a sponsor](https://opencollective.com/ios-collapsible-table-section#sponsor)]
## License ##
MIT License
Copyright (c) 2019 Yong Su @jeantimex
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.