Use these date related top-level Kotlin functions to show sections like "Today", "Yesterday" and so on

README.md

Date header top-level Kotlin functions

There are several apps which show a list with sections like "Today", "Yesterday" and so on like Inbox Android app

I wrote few top-level functions which are helpful to check if the date is upcoming, tomorrow, today, yesterday, this month, this week or older to show sections in my app

PS: I used SectionedRecyclerView library to show sections in my app.

Dependency:

• Joda-time

DateHeaderHelper.kt

import org.joda.time.LocalDate

/**
 * @return true if the supplied date is in the future else false
 */
fun isUpcoming(millis: Long): Boolean {
    return !isTomorrow(millis) && LocalDate(millis).isAfter(LocalDate.now())
}

/**
 * @return true if the supplied date is tomorrow else false
 */
fun isTomorrow(millis: Long): Boolean {
    return LocalDate.now().plusDays(1).compareTo(LocalDate(millis)) == 0
}

/**
 * @return true if the supplied date is today else false
 */
fun isToday(millis: Long): Boolean {
    return LocalDate.now().compareTo(LocalDate(millis)) == 0
}

/**
 * @return true if the supplied when is yesterday else false
 */
fun isYesterday(millis: Long): Boolean {
    return LocalDate.now().minusDays(1).compareTo(LocalDate(millis)) == 0
}

/**
 * @return true if the supplied when is this week else false
 */
fun isThisWeek(millis: Long): Boolean {
    return LocalDate.now().minusWeeks(1) <= LocalDate(millis)
}

/**
 * @return true if the supplied when is this month else false
 */
fun isThisMonth(millis: Long): Boolean {
    return LocalDate.now().minusMonths(1) <= LocalDate(millis)
}

TimeHelperTest.kt

import org.junit.Assert.assertEquals
import org.junit.Test
import org.junit.runner.RunWith
import org.junit.runners.JUnit4

@RunWith(JUnit4::class)
class TimeHelperTest {


    @Test
    fun isTodayTest() {
        // 21/01/2018 : 14:22
        assertEquals(true, isToday(1516524740355))
    }

    @Test
    fun isYesterdayTest() {
        // 20/01/2018 : 20:00
        assertEquals(true, isYesterday(1516458600000))
    }

    @Test
    fun isThisWeekTest() {
        // 18/01/2018 : 20:00
        assertEquals(true, isThisWeek(1516285800000))
    }

    @Test
    fun isThisMonthTest() {
        // 11/01/2018 : 20:00
        assertEquals(true, isThisMonth(1515681000000))
    }

}

Usage.kt

// Example usage
when {
    isUpcoming(time) -> {}
    isTomorrow(time) -> {}
    isToday(time) -> {}
    isYesterday(time) -> {}
    isThisWeek(time) -> {}
    isThisMonth(time) -> {}
    else -> {
      // Else branch means the date is older
    }
}