Skip to content

Latest commit

 

History

History
127 lines (109 loc) · 4.7 KB

Value.md

File metadata and controls

127 lines (109 loc) · 4.7 KB
Raw

Value

Given

import advxml.data.*
import advxml.implicits.*

Key

Key is a case class that wrap a String instance and is used to describe the key concept. It exists to avoid unnamed string.

We can create it directly or using StringContext syntax ops.

val key: Key = Key("key")
// key: Key = Key(value = "key")
val keySyntax: Key = k"key"
// keySyntax: Key = Key(value = "key")

Value

Value is an ADT used to define a type different to String in order to provide data validation. Possible values are:

  • SimpleValue
  • ValidatedValue

SimpleValue represent a simple String wrapper, you can use get to access to the inner value. ValidatedValue represent also a simple String wrapper but, you can access to his data only validating the inner value through extract[F[_]] method or validated(just and alias for extract[ValidatedNelThrow]).

All Value instances have a method named validate that allows to specify a list of ValidationRule to validate the wrapped String instance, this method returns a ValidatedValue.

import scala.util.Try

val value: SimpleValue = v"TEST" // == Value("TEST") // == Value("TEST")
// value: SimpleValue = "TEST" // == Value("TEST") // == Value("TEST")
val valueUnboxed: String = value.get // == "TEST"
// valueUnboxed: String = TEST // == "TEST"
val valueExtracted: Try[String] = value.extract[Try] // == always Success("TEST") = Applicative[Try].pure(get)
// valueExtracted: Try[String] = Success(TEST) // == always Success("TEST") = Applicative[Try].pure(get)
val validatedValue: ValidatedValue = value.nonEmpty
  .validate(ValidationRule("MyCustomRule")(validator = _ == "TEST", errorReason = "Not equals to test")) // == always Success("TEST") = Applicative[Try].pure(get)
// validatedValue: ValidatedValue = "TEST" // == always Success("TEST") = Applicative[Try].pure(get)
val validatedValueTry: Try[String] = validatedValue.extract[Try] //Success("TEST")
// validatedValueTry: Try[String] = Success(TEST) //Success("TEST")

val validatedValueValidated: ValidatedNelThrow[String] = validatedValue.validated //Valid("TEST")
// validatedValueValidated: ValidatedNelThrow[String] = Valid(TEST)

AttributeData

AttributeData is a case class to bind a Key and a SimpleValue instance. It's used in advxml to contains write information for attributes. Advxml provides a fluent syntax to define an AttributeData instance.

val data: AttributeData = AttributeData(Key("key"), SimpleValue("value"))
// data: AttributeData = AttributeData(
//   key = Key(value = "key"),
//   value = SimpleValue(data = "value", ref = None)
// )
val dataWithSyntax: AttributeData = k"key" := "value"
// dataWithSyntax: AttributeData = AttributeData(
//   key = Key(value = "key"),
//   value = SimpleValue(data = "value", ref = None)
// )

Key-Value predicate

KeyValuePredicate is a case class to bind a Key and a predicate function Value => Boolean related to value. We can create it directly or using fluent syntax.

val p: KeyValuePredicate = KeyValuePredicate(Key("key"), _.get == "value")
// p: KeyValuePredicate = KeyValuePredicate(
//   key = Key(value = "key"),
//   valuePredicate = <function1>
// )
val pWithSyntax: KeyValuePredicate = k"key" -> (_.get == "value")
// pWithSyntax: KeyValuePredicate = KeyValuePredicate(
//   key = Key(value = "key"),
//   valuePredicate = <function1>
// )

Moreover, advxml provides multiple syntax method to easily create a KeyValuePredicate for the most common predicates. Each of these methods use an implicit Converter[Value, Try[T]] converter to safely convert SimpleValue into other compared instance type and PartialOrder from cats for comparisons (except for === and =!= that use Eq from cats). Please, keep in mind that if conversion fails predicate will result false.

val eq: KeyValuePredicate = k"key" === 1
// eq: KeyValuePredicate = KeyValuePredicate(
//   key = Key(value = "key"),
//   valuePredicate = === [1]
// )
val neq: KeyValuePredicate = k"key" =!= 1
// neq: KeyValuePredicate = KeyValuePredicate(
//   key = Key(value = "key"),
//   valuePredicate = =!= [1]
// )

val le: KeyValuePredicate = k"key" < 1
// le: KeyValuePredicate = KeyValuePredicate(
//   key = Key(value = "key"),
//   valuePredicate = < [1]
// )
val leEq: KeyValuePredicate = k"key" <= 1
// leEq: KeyValuePredicate = KeyValuePredicate(
//   key = Key(value = "key"),
//   valuePredicate = <= [1]
// )
val gt: KeyValuePredicate = k"key" > 1
// gt: KeyValuePredicate = KeyValuePredicate(
//   key = Key(value = "key"),
//   valuePredicate = > [1]
// )
val gtEq: KeyValuePredicate = k"key" >= 1
// gtEq: KeyValuePredicate = KeyValuePredicate(
//   key = Key(value = "key"),
//   valuePredicate = >= [1]
// )