I have a bunch of UITextFields living inside a collection view in different cells (around 7). I'm looking for a way to delegate the responsibility of validating these fields to an internal service class. Is there a way in which I can do this without causing controller bloat?
What I've partially tried is to create an object and then assign the Textfield delegates to this object. However I struggled on linking the two together (able to access the textField.text property to validate and add the output into a struct).
Is there a cleaner, more efficient way or am I looking at a long Controller?
Thanks
Features
- Save data from TextFields in cell
- Detect coordinates of editing TextField
- Locate TextFields handler in ViewController (MVC)
- Hide keyboard when scroll
Details
xCode 8.3, Swift 3.1
Full Example
ViewController.swift
import UIKit
fileprivate var textFieldsTexts = [IndexPath:String]()
class ViewController: UIViewController {
@IBOutlet weak var collectionView: UICollectionView!
override func viewDidLoad() {
super.viewDidLoad()
setupCollectionView()
}
}
extension ViewController: UICollectionViewDataSource {
func setupCollectionView() {
collectionView.dataSource = self
collectionView.delegate = self
}
func numberOfSections(in collectionView: UICollectionView) -> Int {
return 1
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 100
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CollectionViewCell", for: indexPath) as! CollectionViewCell
cell.textField.placeholder = "\(indexPath)"
cell.delegate = self
return cell
}
}
extension ViewController: UICollectionViewDelegate {
func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) {
let cell = cell as! CollectionViewCell
cell.textField.text = textFieldsTexts[indexPath]
}
func scrollViewWillBeginDecelerating(_ scrollView: UIScrollView) {
view.endEditing(true)
}
}
extension ViewController: CollectionViewCellDelegate {
func collectionViewCell(valueChangedIn textField: UITextField, delegatedFrom cell: CollectionViewCell) {
if let indexPath = collectionView.indexPath(for: cell), let text = textField.text {
print("textField text: \(text) from cell: \(indexPath))")
textFieldsTexts[indexPath] = text
}
}
func collectionViewCell(textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String, delegatedFrom cell: CollectionViewCell) -> Bool {
print("Validation action in textField from cell: \(String(describing: collectionView.indexPath(for: cell)))")
return true
}
}
CollectionViewCell.swift
import UIKit
class CollectionViewCell: UICollectionViewCell {
@IBOutlet weak var textField: UITextField!
var delegate: CollectionViewCellDelegate?
override func awakeFromNib() {
super.awakeFromNib()
textField.delegate = self
}
@IBAction func valueChanged(_ sender: UITextField) {
delegate?.collectionViewCell(valueChangedIn: textField, delegatedFrom: self)
}
}
extension CollectionViewCell: UITextFieldDelegate {
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
if let delegate = delegate {
return delegate.collectionViewCell(textField: textField, shouldChangeCharactersIn: range, replacementString: string, delegatedFrom: self)
}
return true
}
}
CollectionViewCellDelegate.swift
import UIKit
protocol CollectionViewCellDelegate {
func collectionViewCell(valueChangedIn textField: UITextField, delegatedFrom cell: CollectionViewCell)
func collectionViewCell(textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String, delegatedFrom cell: CollectionViewCell) -> Bool
}
Main.storyboard
<?xml version="1.0" encoding="UTF-8"?>
<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="12118" systemVersion="16D32" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" colorMatched="YES" initialViewController="BYZ-38-t0r">
<device id="retina4_7" orientation="portrait">
<adaptation id="fullscreen"/>
</device>
<dependencies>
<deployment identifier="iOS"/>
<plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="12086"/>
<capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
</dependencies>
<scenes>
<!--View Controller-->
<scene sceneID="tne-QT-ifu">
<objects>
<viewController id="BYZ-38-t0r" customClass="ViewController" customModule="stackoverflow_43143119" customModuleProvider="target" sceneMemberID="viewController">
<layoutGuides>
<viewControllerLayoutGuide type="top" id="y3c-jy-aDJ"/>
<viewControllerLayoutGuide type="bottom" id="wfy-db-euE"/>
</layoutGuides>
<view key="view" contentMode="scaleToFill" id="8bC-Xf-vdC">
<rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
<autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
<subviews>
<collectionView clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="scaleToFill" dataMode="prototypes" translatesAutoresizingMaskIntoConstraints="NO" id="KWt-KV-A2D">
<rect key="frame" x="0.0" y="28" width="375" height="639"/>
<color key="backgroundColor" white="1" alpha="1" colorSpace="calibratedWhite"/>
<collectionViewFlowLayout key="collectionViewLayout" minimumLineSpacing="10" minimumInteritemSpacing="10" id="WoG-le-dkA">
<size key="itemSize" width="100" height="50"/>
<size key="headerReferenceSize" width="0.0" height="0.0"/>
<size key="footerReferenceSize" width="0.0" height="0.0"/>
<inset key="sectionInset" minX="0.0" minY="0.0" maxX="0.0" maxY="0.0"/>
</collectionViewFlowLayout>
<cells>
<collectionViewCell opaque="NO" clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="center" reuseIdentifier="CollectionViewCell" id="w5c-mF-XjG" customClass="CollectionViewCell" customModule="stackoverflow_43143119" customModuleProvider="target">
<rect key="frame" x="0.0" y="0.0" width="100" height="50"/>
<autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMaxY="YES"/>
<view key="contentView" opaque="NO" clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="center">
<rect key="frame" x="0.0" y="0.0" width="100" height="50"/>
<autoresizingMask key="autoresizingMask"/>
<subviews>
<textField opaque="NO" clipsSubviews="YES" contentMode="scaleToFill" contentHorizontalAlignment="left" contentVerticalAlignment="center" borderStyle="roundedRect" placeholder="text" textAlignment="natural" minimumFontSize="17" translatesAutoresizingMaskIntoConstraints="NO" id="HAy-QM-Eqi">
<rect key="frame" x="0.0" y="10" width="100" height="30"/>
<nil key="textColor"/>
<fontDescription key="fontDescription" type="system" pointSize="14"/>
<textInputTraits key="textInputTraits"/>
<connections>
<action selector="valueChanged:" destination="w5c-mF-XjG" eventType="editingChanged" id="qDf-D2-X1l"/>
</connections>
</textField>
</subviews>
</view>
<color key="backgroundColor" white="0.66666666666666663" alpha="1" colorSpace="calibratedWhite"/>
<constraints>
<constraint firstItem="HAy-QM-Eqi" firstAttribute="centerY" secondItem="w5c-mF-XjG" secondAttribute="centerY" id="JCH-09-Hsr"/>
<constraint firstItem="HAy-QM-Eqi" firstAttribute="leading" secondItem="w5c-mF-XjG" secondAttribute="leading" id="YvF-Qw-sOW"/>
<constraint firstAttribute="trailing" secondItem="HAy-QM-Eqi" secondAttribute="trailing" id="kPK-6X-Aug"/>
</constraints>
<connections>
<outlet property="textField" destination="HAy-QM-Eqi" id="3tf-0f-agX"/>
</connections>
</collectionViewCell>
</cells>
</collectionView>
</subviews>
<color key="backgroundColor" red="1" green="1" blue="1" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
<constraints>
<constraint firstItem="KWt-KV-A2D" firstAttribute="top" secondItem="y3c-jy-aDJ" secondAttribute="bottom" constant="8" symbolic="YES" id="5Fe-R9-7li"/>
<constraint firstItem="KWt-KV-A2D" firstAttribute="bottom" secondItem="wfy-db-euE" secondAttribute="top" id="Rjm-Ij-0Pe"/>
<constraint firstAttribute="trailing" secondItem="KWt-KV-A2D" secondAttribute="trailing" id="kZ0-HK-x0Z"/>
<constraint firstItem="KWt-KV-A2D" firstAttribute="leading" secondItem="8bC-Xf-vdC" secondAttribute="leading" id="zQM-Za-bkN"/>
</constraints>
</view>
<connections>
<outlet property="collectionView" destination="KWt-KV-A2D" id="SR1-Cn-p5v"/>
</connections>
</viewController>
<placeholder placeholderIdentifier="IBFirstResponder" id="dkx-z0-nzr" sceneMemberID="firstResponder"/>
</objects>
<point key="canvasLocation" x="133.59999999999999" y="137.18140929535232"/>
</scene>
</scenes>
</document>
Result
来源：https://stackoverflow.com/questions/43143119/swift-uicollectionview-textfields