Solution: Creating user table row
private fun TableBuilder.userRow(user: User) {
tr {
td { +user.id }
td { +user.name }
td { +user.points.toString() }
td { +user.category }
}
}
Example solution in playground
import org.junit.Test
import kotlin.test.assertEquals
data class User(val id: String, val name: String, val points: Int, val category: String)
fun userTable(users: List<User>): TableBuilder = table {
tr {
td { +"Id" }
td { +"Name" }
td { +"Points" }
td { +"Category" }
}
for (user in users) {
userRow(user)
}
}
private fun TableBuilder.userRow(user: User) {
tr {
td { +user.id }
td { +user.name }
td { +user.points.toString() }
td { +user.category }
}
}
fun main() {
val users = listOf(
User("1", "Randy", 2, "A"),
User("4", "Andy", 4, "B"),
User("3", "Mandy", 1, "C"),
User("5", "Cindy", 5, "A"),
User("2", "Lindy", 3, "B"),
)
// val table = userTable(users)
// println(table)
// <table>
// <tr><td>Id</td><td>Name</td>
// <td>Points</td><td>Category</td></tr>
// <tr><td>1</td><td>Randy</td><td>2</td><td>A</td></tr>
// <tr><td>4</td><td>Andy</td><td>4</td><td>B</td></tr>
// <tr><td>3</td><td>Mandy</td><td>1</td><td>C</td></tr>
// <tr><td>5</td><td>Cindy</td><td>5</td><td>A</td></tr>
// <tr><td>2</td><td>Lindy</td><td>3</td><td>B</td></tr>
// </table>
}
fun table(init: TableBuilder.() -> Unit): TableBuilder =
TableBuilder().apply(init)
data class TableBuilder(
var trs: List<TrBuilder> = emptyList()
) {
fun tr(init: TrBuilder.() -> Unit) {
trs += TrBuilder().apply(init)
}
override fun toString(): String =
"<table>${trs.joinToString(separator = "")}</table>"
}
data class TrBuilder(
var tds: List<TdBuilder> = emptyList()
) {
fun td(init: TdBuilder.() -> Unit) {
tds += TdBuilder().apply(init)
}
override fun toString(): String =
"<tr>${tds.joinToString(separator = "")}</tr>"
}
data class TdBuilder(var text: String = "") {
operator fun String.unaryPlus() {
text += this
}
override fun toString(): String = "<td>$text</td>"
}
class StudentTableTest {
@Test
fun `should work for empty list`() {
// when
val result = userTable(listOf())
// then
val expected = TableBuilder().apply {
trs += TrBuilder().apply {
tds += TdBuilder().apply { text = "Id" }
tds += TdBuilder().apply { text = "Name" }
tds += TdBuilder().apply { text = "Points" }
tds += TdBuilder().apply { text = "Category" }
}
}
assertEquals(expected, result)
}
@Test
fun `should work for a list with a single element`() {
// given
val users = listOf(
User("1", "Randy", 2, "A"),
)
// when
val result = userTable(users)
// then
val expected = TableBuilder().apply {
trs += TrBuilder().apply {
tds += TdBuilder().apply { text = "Id" }
tds += TdBuilder().apply { text = "Name" }
tds += TdBuilder().apply { text = "Points" }
tds += TdBuilder().apply { text = "Category" }
}
trs += TrBuilder().apply {
tds += TdBuilder().apply { text = "1" }
tds += TdBuilder().apply { text = "Randy" }
tds += TdBuilder().apply { text = "2" }
tds += TdBuilder().apply { text = "A" }
}
}
assertEquals(expected, result)
}
@Test
fun `should work for a list with multiple users`() {
// given
val users = listOf(
User("1", "Randy", 2, "A"),
User("4", "Andy", 4, "B"),
User("3", "Mandy", 1, "C"),
User("5", "Cindy", 5, "A"),
User("2", "Lindy", 3, "B"),
)
// when
val result = userTable(users)
// then
val expected = TableBuilder().apply {
trs += TrBuilder().apply {
tds += TdBuilder().apply { text = "Id" }
tds += TdBuilder().apply { text = "Name" }
tds += TdBuilder().apply { text = "Points" }
tds += TdBuilder().apply { text = "Category" }
}
for (user in users) {
trs += TrBuilder().apply {
tds += TdBuilder().apply { text = user.id }
tds += TdBuilder().apply { text = user.name }
tds += TdBuilder().apply { text = user.points.toString() }
tds += TdBuilder().apply { text = user.category }
}
}
}
assertEquals(expected, result)
}
}
