iOS Swift中如何结构化API数据实现TableView按日期分组

需求说明 #

我从API获取了如下格式的Appointments数据：

[ 
 Appointments(startTime:"2022-09-01",subject:"Clinic Appointment",activityid:"2343"),
  Appointments(startTime:"2022-09-01",subject:"Night Appointment",activityid:"5738"),
  Appointments(startTime:"2022-09-01",subject:"Regular checkup",activityid:"2975"),
  Appointments(startTime:"2022-09-02",subject:"High Fever",activityid:"9274"),
  Appointments(startTime:"2022-09-02",subject:"Virtual checkup",activityid:"5648"),
  Appointments(startTime:"2022-09-03",subject:"Regular Appointment",activityid:"1892")
]

同时有一个包含当月所有日期的数组，需要将数据按startTime字段分组到对应日期，生成如下格式的AppointmentsByDates数组（无预约的日期对应空数组），用于TableView的多节展示：

[ 
   AppointmentsByDates(title:"2022-09-01" , appointments: [
        Appointments(startTime:"2022-09-01",subject:"Night Appointment",activityid:"5738"),
        Appointments(startTime:"2022-09-01",subject:"Regular checkup",activityid:"2975"),
        Appointments(startTime:"2022-09-01",subject:"Clinic Appointment",activityid:"2343"),
      ]),
   AppointmentsByDates(title:"2022-09-02" , appointments: [
        Appointments(startTime:"2022-09-02",subject:"High Fever",activityid:"9274"),
        Appointments(startTime:"2022-09-02",subject:"Virtual checkup",activityid:"5648"),
      ]),
   AppointmentsByDates(title:"2022-09-03" , appointments: [
        Appointments(startTime:"2022-09-03",subject:"Regular Appointment",activityid:"1892")
      ]),
   AppointmentsByDates(title:"2022-09-04" , appointments: []),
   AppointmentsByDates(title:"2022-09-05" , appointments: []),
   ...
   AppointmentsByDates(title:"2022-09-30" , appointments: []),
]

Swift实现方案 #

1. 定义数据模型 #

先创建对应的数据结构体，适配API返回格式：

// 单个预约模型
struct Appointment: Codable {
    let startTime: String
    let subject: String
    let activityid: String
}

// 按日期分组后的容器模型
struct AppointmentsByDate {
    let title: String
    let appointments: [Appointment]
}

2. 对预约数据按日期分组 #

利用Swift原生的字典分组方法，把API返回的预约数组转换成以日期为键的字典：

// apiAppointments为从API获取的原始预约数组
let apiAppointments: [Appointment] = [...]

// 按startTime字段分组
let groupedAppointments = Dictionary(grouping: apiAppointments) { $0.startTime }

3. 遍历日期数组生成目标结构 #

假设你已经有了当月所有日期的数组monthDates（格式为"yyyy-MM-dd"），遍历数组匹配分组数据：

// monthDates为包含当月所有日期的数组，例如["2022-09-01", "2022-09-02", ..., "2022-09-30"]
let monthDates: [String] = [...]

// 生成最终的分组数组
let appointmentsByDates = monthDates.map { date in
    // 匹配对应日期的预约，无预约则返回空数组
    let matchedAppointments = groupedAppointments[date] ?? []
    return AppointmentsByDate(title: date, appointments: matchedAppointments)
}

4. 可选：给单日期下的预约排序 #

如果需要对每个日期内的预约排序（比如按主题名称），可以在生成匹配数组时添加排序逻辑：

let matchedAppointments = groupedAppointments[date]?.sorted { $0.subject < $1.subject } ?? []

TableView适配使用 #

生成的appointmentsByDates可直接作为TableView数据源：

• 节数：appointmentsByDates.count
• 单节行数：appointmentsByDates[indexPath.section].appointments.count
• 节标题：appointmentsByDates[indexPath.section].title

内容的提问来源于stack exchange，提问作者Ankit Mahindrakar