如何跟踪随日期移动的数据？

I have a school app that keeps track of your schedule. The app has a multitude of options for inputting the schedule. If the user has a four day schedule, then they will have A-D days. For my app. I’d like to keep track of what the current day is (for instance, whether or not it is an A day vs. a C day). The user will be able to specify what day it is when they set up the app, but then the app should keep track of this change day to day, minus weekends. I’m not sure what the best way to implement this is.

我有一个学校应用程序,可以跟踪您的日程安排。该应用程序有多种输入计划的选项。如果用户有四天的时间表,那么他们将有A-D天。对于我的应用程序我想跟踪当前的情况(例如,它是否是A日与C日)。用户可以指定他们设置应用程序的日期,但应用程序应该每天跟踪此更改,减去周末。我不确定实现这个的最佳方法是什么。

2 个解决方案

#1

If the configuration allows completely arbitrary day assignments, you would only need a simple dictionary in the form [Date:String].

如果配置允许完全任意的日期分配,则只需要[Date:String]形式的简单字典。

If you want to let your users specify repeating patterns of day identifiers (letters), the configuration parameters and process will need to be more sophisticated and will depend on how far you're willing to go in processing exceptions (i.e. non school days). Weekends can be automatic but holidays and scheduled "off days" would require that you define some kind of rule (hard coded or user configurable).

如果您想让您的用户指定日标识符(字母)的重复模式,配置参数和过程将需要更复杂,并取决于您愿意处理异常(即非上学日)的程度。周末可以是自动的,但假期和预定的“休息日”将要求您定义某种规则(硬编码或用户可配置)。

In all cases, I would suggest creating a function that converts any date into its day identifier based on the configured parameters. Depending on the complexity of the rules and the range of dates you are working with, it may be a good idea to dynamically build a global dictionary of date identifiers (e.g. [Date:String]) and only compute identifiers once per date.

在所有情况下,我建议创建一个函数,根据配置的参数将任何日期转换为日期标识符。根据规则的复杂程度和您使用的日期范围,动态构建日期标识符的全局字典(例如[Date:String])并且每个日期仅计算一次标识符可能是个好主意。

For example:

// your configuration parameters could be something like this:

let firstSchoolDay:Date     = // read from configuration
let lastSchoolDay           = // read from configuration
let dayIdentifiers:[String] = // read from configuration 
let skippedDates:Set<Date>  = // read from configuration 

// The global dictionary and function could work like this:

var dayIdentifiers:[Date:Sting] = [:] // global scope (or singleton)
func dayIdentifier(for date:Date) -> String
{
    if let dayID = dayIdentifiers[date]
    { return dayID  }

    let dayID:String = // compute your day ID once according to parameters.
                       // you could use an empty string as a convention for
                       // non school days

                       // a simple way to compute this is to start from
                       // the last computed date (or firstSchoolDay)
                       // and move forward using Calendar.enumerateDates
                       // applying the weekend and offdays rules
                       // and saving day identifiers as you
                       // move forward up to the requested date

    dayIdentifiers[date] = dayID
    return dayID         
}

#2

I figured out how to keep track of the moving dates, while also not accounting for weekends and updating the value every time it is checked.

我想出了如何跟踪移动日期,同时也没有考虑周末和每次检查时更新值。

func getCurrentDay() -> Int {

    let lastSetDay = //Get the last value of the set day
    let lastSetDayDate = //Get the last time the day was set
    var numberOfDays: Int! //Calculate number of recurring days, for instance an A, B, C, D day schedule would be 4

    var currentDay = lastSetDay
    var currentIteratedDate = lastSetDayDate

    while Calendar.current.isDate(currentIteratedDate, inSameDayAs: Date()) == false {
        currentIteratedDate = Calendar.current.date(byAdding: .day, value: 1, to: currentIteratedDate)!
        if !Calendar.current.isDateInWeekend(currentIteratedDate) {
            currentDay += 1
        }
        if currentDay > numberOfDays {
            currentDay = 1
        }
    }

    if Calendar.current.isDate(currentIteratedDate, inSameDayAs: Date()) == false {
        //Save new day
        //Save new date
    }

    return currentDay
}

#1