Displaying User Comments in a UITableView like Instagram
In this article, we will explore the best way to structure a UITableView to display user comments similar to Instagram. We’ll cover the process of creating the table view cells, populating them with data from the backend, and adding functionality for users to click on “More Comments” buttons.
Understanding the Requirements
Before diving into the implementation, let’s understand what’s required. Instagram-style comment displays typically involve a combination of the following features:
- A list of comments with user names, comments text, and timestamps
- The ability to display more comments when a user clicks on the “More Comments” button next to each comment
- An efficient way to load and update data from the backend as users scroll through the comments
Setting Up the Table View
To create a UITableView like Instagram, we’ll use a combination of UITableViewCells with custom layouts and UITableViewDataSource and UITableViewDelegate protocols.
import UIKit
class CommentCell: UITableViewCell {
// Custom layouts for comment cells will go here
}
class CommentTableView: UITableView, UITableViewDataSource, UITableViewDelegate {
override func viewDidLoad() {
super.viewDidLoad()
// Initialize data source and delegate
self.dataSource = self
self.delegate = self
// Register cell classes
self.register(CommentCell.self, forCellReuseIdentifier: "commentCell")
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// Return the number of comments to display
return numberOfComments
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let commentCell = self.dequeueReusableCell(withIdentifier: "commentCell", for: indexPath)
// Configure cell data here
var data = CommentData()
data.username = "John Doe"
data.commentText = "This is a sample comment."
data.timestamp = Date(timeIntervalSinceNow: 0)
return commentCell
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
// Return the height of each row (comment cell)
return commentHeight
}
}
Populating Data from the Backend
To populate our table view with actual data from the backend, we’ll need to use a networking library like AFNetworking or Alamofire. We’ll make API calls to fetch comments and update them when necessary.
import Alamofire
class CommentService {
func loadComments(completion: @escaping ([CommentData]) -> Void) {
// Make an API call to fetch comments from the backend
let url = "https://example.com/comments"
AF.request(url, method: .GET)
.validate()
.responseJSON { response in
switch response.result {
case .success(let data):
// Parse JSON response and convert it into CommentData objects
do {
let comments = try JSONDecoder().decode([CommentData].self, from: data)
completion(comments)
} catch {
print("Error parsing JSON: \(error)")
}
case .failure(let error):
print("Error making request: \(error)")
}
}
}
}
class CommentTableView: UITableView, UITableViewDataSource, UITableViewDelegate {
var commentService: CommentService!
override func viewDidLoad() {
super.viewDidLoad()
// Initialize comment service
self.commentService = CommentService()
self.commentService.loadComments { [weak self] comments in
// Update the table view with new data
self?.numberOfComments = comments.count
self?.commentData = comments
// Notify the table view that the data has changed
self?.tableView.reloadData(toRow: 0, atSection: 0)
}
}
}
Implementing the “More Comments” Functionality
To implement the “More Comments” button functionality, we’ll need to create a new cell type for comments with more text and add it to our table view. We’ll also update our data source to handle the additional row.
class CommentCell: UITableViewCell {
// Custom layouts for comment cells will go here
class MoreCommentsCell: UITableViewCell {
override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
super.init(style: .detailDisclosed, reuseIdentifier: "moreCommentCell")
// Initialize the more comments cell layout
self.textLabel?.text = "More Comments"
self.detailTextLabel?.text = "View more comments"
}
required init?(coder: NSCoder) {
fatalError("MoreCommentsCell not implemented for storyboard/xeaglare.")
}
}
}
class CommentTableView: UITableView, UITableViewDataSource, UITableViewDelegate {
var commentData: [CommentData]!
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// Return the number of comments to display
return numberOfComments
// Check if we need more rows
if numberOfComments > maxRows {
return maxRows
} else {
return numberOfComments
}
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let commentCell = self.dequeueReusableCell(withIdentifier: "commentCell", for: indexPath)
// Check if we need more rows
if indexPath.row >= maxRows {
// Load the more comments cell
var data = CommentData()
data.username = "John Doe"
data.commentText = "This is a sample comment."
data.timestamp = Date(timeIntervalSinceNow: 0)
let moreCommentCell = self.dequeueReusableCell(withIdentifier: "moreCommentCell", for: indexPath)
moreCommentCell.textLabel?.text = "More Comments"
moreCommentCell.detailTextLabel?.text = "View more comments"
// Configure the cell data
return moreCommentCell
} else {
// Load the comment cell layout
var data = CommentData()
data.username = "John Doe"
data.commentText = "This is a sample comment."
data.timestamp = Date(timeIntervalSinceNow: 0)
commentCell.textLabel?.text = data.username + ": " + data.commentText
return commentCell
}
}
}
Adding Click Handling for the “More Comments” Button
We’ll add click handling to our more comments cell using the tableView(_:didSelectRowAt:) method.
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
// Check if we need more rows
if indexPath.row >= maxRows {
// Load additional comments from the backend
self.commentService.loadComments { [weak self] newComments in
do {
let updatedCommentData = try JSONDecoder().decode([CommentData].self, from: newComments)
// Update our table view with new data
self?.commentData.append(contentsOf: updatedCommentData)
self?.numberOfComments = self?.commentData.count
// Notify the table view that the data has changed
tableView.reloadData(toRow: 0, atSection: 0)
} catch {
print("Error parsing JSON: \(error)")
}
}
}
}
Last modified on 2024-11-19