Group UITableView sections by date - ios

Question

I have a JSON file with Title, startDate, and endDate. I would like to group my sections in my UITableView by dates and to add the date of each group as the header. I am unsure of how to retrieve the data from my groupByDate function to populate the specific sections. Would I have to create a new array from my groupByDate function.
var eventList: [Event] = []
var eventGroup: [[Event]] = []
func numberOfSections(in tableView: UITableView) -> Int {
return eventGroup.count
}
func tableView(_ tableView: UITableView, viewForFooterInSection section: Int) -> UIView? {
v.backgroundColor = .darkGray
return v
}
func tableView(_ tableView: UITableView, heightForFooterInSection section: Int) -> CGFloat {
return 3.0
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "myCell", for: indexPath) as! MyTableCell
cell.titleLabel.textColor = .red
}else{
cell.titleLabel.textColor = .black
}
return cell
}

Answer 1

You need to get the idea first. Imagine you just have one section of all your events. What would you have as your model?
A title
An array of events
Right?
Okay if the above makes sense, you then would need multiple of that said models. Right again? Now break that into more specific terms. Like actual model type.
struct Event {
let title: String
let startDate: Date
// maybe an endDate object too
}
struct Section {
let title: String
let events: [Event]
}
So now you will need to provide an array of Section object to the table view.
But before that you will need to group your sections by the startDate object. Swift has a pretty convenience initializer of Dictionary type that allows us to group an array by choosing a particular property's value from the object in the array. Pay attention to the function below:
func groupedSectionsByDate(from events: [Event]) -> [Section] {
let grouped = Dictionary(grouping: events) { $0.startDate }
// here you will need a date formatter object that will be used to convert
// the Date type to String type. It's left as an assignment for the reader
let dateFormatter: DateFormatter // init and configure it yourself
let sections = grouped.map { Section(title: dateFormatter.string(from: $0.key), events: $0.value) }
return sections
}
The above function should get you the sections with titles as grouped by date.
Now how would you use it with the table view?
class TableViewController: UITableViewController {
. . .
let sections = [Section]()
. . .
. . .
func numberOfSections(in tableView: UITableView) -> Int {
return sections.count
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return sections[section].count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
. . .
let event = sections[indexPath.section].events[indexPath.row]
. . .
}
. . .
. . .
}

Answer 2

update
The initial data of the hypothesis is like this
[
{
"title": "Bicycling with Friends",
"start": "11-01-2018"
},
{
"title": "Yoga",
"start": "11-01-2018"
},
{
"title": "Yoga",
"start": "11-02-2018"
}
]
If you want to group display, you need to assemble the array into dates like this, each group of titles can use start
[
[
{
"title": "Bicycling with Friends",
"start": "11-01-2018"
},
{
"title": "Yoga",
"start": "11-01-2018"
}
],
[
{
"title": "Yoga",
"start": "11-02-2018"
}
]
]
I think your data source can hold a two-dimensional array eventGroup, or a dated dictionary [dateString : [event]]. Only use eventGroup can be modified to be like this
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return eventGroup[section].count
}
func numberOfSections(in tableView: UITableView) -> Int {
return eventGroup.count
}
func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
let events = eventGroup[section]
let event = events.first
return event?.title //Replace with the header title you want
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "myCell", for: indexPath) as! MyTableCell
let events = eventGroup[indexPath.section]
let dateRow = events[indexPath.row].start
let dateRowEnd = events[indexPath.row].end
let formatter = DateFormatter()
formatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
let myString = formatter.string(from: dateRow)
let yourDate = formatter.date(from: myString)
formatter.dateFormat = "MM-dd-yyyy h:mm a"
let myStringafd = formatter.string(from: yourDate!)
cell.titleLabel.text = eventList[indexPath.row].title
cell.dateStartLabel.text = "Start date: \(myStringafd)"
if events[indexPath.row].conflict == true {
cell.titleLabel.textColor = .red
}else{
cell.titleLabel.textColor = .black
}
return cell
}