Swift Accessing Data Structure Inside Cell Setup - ios

Question

I am appending a Firebase Data snapshot to a NSObject of items being a "customer", "employee", and "business". Set up like this:
var customerData = [CustomerData]()
var employeeData = [EmployeeData]()
var businessData = [BusinessData]()
func getCustomerData() {
Database.database().reference().child("user_profiles").observe(.childAdded, with: { snapshot in
self.customerData.append(CustomerData(snapshot: snapshot))
})
}
func getEmployeeData() {
Database.database().reference().child("employees").observe(.childAdded, with: { snapshot in
self.employeeData.append(EmployeeData(snapshot: snapshot))
})
}
func getBusinessData() {
Database.database().reference().child("Businesses").observe(.childAdded, with: { snapshot in
self.businessData.append(BusinessData(snapshot: snapshot))
})
}
Data structure is the same for customer, employees, and business as below
import UIKit
import Firebase
class CustomerData: NSObject {
var customerName: String?
var customerPicture: String?
var customerUID: String?
init(snapshot: DataSnapshot) {
if let dictionary = snapshot.value as? [String: AnyObject] {
customerName = dictionary["name"] as? String
customerUID = dictionary["uid"] as? String
customerPicture = dictionary["profPicString"] as? String
}
}
}
I just want to access this snapshot data inside the cell to keep my message details up-to-date, like the profile picture and name. Below is my cell set up:
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath) as! ChatMessageCell
cell.chatLogController = self
let customer = customerData
let employee = employeeData
let business = businessData
let message = messages[indexPath.row]
cell.message = message
cell.customer = customer
cell.employee = employee
cell.business = business
setupChatMessageCell(cell,message,customer,employee,business)
if let text = message.text {
cell.textView.text = text
cell.bubbleWidthAnchor?.constant = estimateSizeOfText(text).width + 32
cell.textView.isHidden = false
} else if message.imageUrl != nil {
cell.bubbleWidthAnchor?.constant = 200
cell.textView.isHidden = true
}
cell.playButton.isHidden = message.videoUrl == nil
return cell
}
private func setupChatMessageCell(_ cell: ChatMessageCell, _ message: GroupMessage, _ customer: CustomerData, _ employee: EmployeeData, _ business: BusinessData) {
if message.fromId == customer.customerUID {
//outgoing messages
cell.bubbleView.backgroundColor = ChatMessageCell.blueColor
cell.textView.textColor = .white
cell.bubbleLeftAnchor?.isActive = false
cell.bubbleRightAnchor?.isActive = true
cell.profileImageView.isHidden = true
cell.nameLabel.textColor = .gray
cell.nameRightAnchor?.isActive = true
cell.nameLeftAnchor?.isActive = false
cell.nameLabel.text = message.name?.description
//cell.nameLabel.text = message.customerName
} else if message.fromId == employee.employeeUID {
//incoming messagese
let customerImage = employee.employeePicture
cell.profileImageView.loadImageUsingCacheWithUrlString(customerImage!)
cell.profileImageView.isHidden = false
cell.bubbleView.backgroundColor = UIColor(red: 240, green: 240, blue: 240)
cell.textView.textColor = .black
cell.bubbleLeftAnchor?.isActive = true
cell.bubbleRightAnchor?.isActive = false
cell.profileImageView.isHidden = false
cell.nameRightAnchor?.isActive = false
cell.nameLeftAnchor?.isActive = true
cell.nameLabel.textColor = .black
cell.nameLabel.text = message.name?.description
} else if message.fromId == business.businessUID {
let customerImage = business.businessPicture
cell.profileImageView.loadImageUsingCacheWithUrlString(customerImage!)
cell.profileImageView.isHidden = false
cell.bubbleView.backgroundColor = UIColor(red: 240, green: 240, blue: 240)
cell.textView.textColor = .black
cell.bubbleLeftAnchor?.isActive = true
cell.bubbleRightAnchor?.isActive = false
cell.profileImageView.isHidden = false
cell.nameRightAnchor?.isActive = false
cell.nameLeftAnchor?.isActive = true
cell.nameLabel.textColor = .black
cell.nameLabel.text = message.name?.description
}
if let imageUrl = message.imageUrl {
cell.messageImageView.loadImageUsingCacheWithUrlString(imageUrl)
cell.messageImageView.isHidden = false
cell.bubbleView.backgroundColor = .clear
} else {
cell.messageImageView.isHidden = true
}
}
The problem is that I don't think accessing it as a "[index.path]" is the correct way just how I am doing with "messages". How can I access these data structures within the cell setup so I can keep my users information always up-to-date? I am getting errors like "Cannot assign value of type '[CustomerData]' to type 'CustomerData?'" so what is the proper way to access these data structures inside the cell?

Answer 1

The problem is that I don't think accessing it as a "[index.path]" is the correct way just how I am doing with "messages".
This is not true. Passing row or item property of IndexPath as index of element in data source array is correct way how to get certain element.
But, you're using UICollectionView, so you should use item property instead of row even if functionality is the same
UITableView
let item = dataSourceArray[indexPath.row]
UICollectionView
let item = dataSourceArray[indexPath.item]
But you should never pass certain cell as parameter for some other method where you're setting it.
Instead in your collection view cell subclass create method for setting cell's views etc.
class ChatMessageCell: UICollectionViewCell {
...
var message: Message!
...
func setupCell() {
... // here you can work with cell's properites e.g. message, ...
}
}
... and then call it in cellForItemAt
Inside this method you should change things connected with content. "Cosmetic" stuff like changing color of views, etc. you can set inside overridden UICollectionViewCell's method prepareForReuse()
override func prepareForReuse() {
super.prepareForReuse()
...
}