---
title: "TransitioningPropertyValue | JavaScript maps SDK"
description: "Documentation for MapTiler SDK"
---

> For AI agents: a documentation index is available at [/llms.txt](https://docs.maptiler.com/llms.txt). Markdown versions of all pages are available by appending .md to any URL.

# Class TransitioningPropertyValue<T, R>

#### Type Parameters

-   T
-   R

##### Index

### Constructors[](#constructors)

[constructor](#constructor)

### Properties[](#properties)

[begin](#begin) [end](#end) [prior](#prior) [property](#property) [value](#value)

### Methods[](#methods)

[possiblyEvaluate](#possiblyevaluate)

## Constructors[](#constructors-1)

### constructor[](#constructor)

-   new TransitioningPropertyValue<[T](#constructortransitioningpropertyvaluet), [R](#constructortransitioningpropertyvaluer)\>(  
        property: [Property](https://docs.maptiler.com/sdk-js/api-reference/interfaces/Externals.Property/)<[T](#t), [R](#r)\>,  
        value: [PropertyValue](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.PropertyValue/)<[T](#t), [R](#r)\>,  
        prior: TransitioningPropertyValue<[T](#t), [R](#r)\>,  
        transition: [TransitionSpecification](https://docs.maptiler.com/sdk-js/api-reference/types/TransitionSpecification/),  
        now: number,  
    ): TransitioningPropertyValue<[T](#t), [R](#r)\>[](#constructortransitioningpropertyvalue)
    
    #### Type Parameters
    
    -   T
    -   R
    
    #### Parameters
    
    -   property: [Property](https://docs.maptiler.com/sdk-js/api-reference/interfaces/Externals.Property/)<[T](#t), [R](#r)\>
    -   value: [PropertyValue](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.PropertyValue/)<[T](#t), [R](#r)\>
    -   prior: TransitioningPropertyValue<[T](#t), [R](#r)\>
    -   transition: [TransitionSpecification](https://docs.maptiler.com/sdk-js/api-reference/types/TransitionSpecification/)
    -   now: number
    
    #### Returns TransitioningPropertyValue<[T](#t), [R](#r)\>
    

## Properties[](#properties-1)

### begin[](#begin)

begin: number

### end[](#end)

end: number

### prior[](#prior)

prior: TransitioningPropertyValue<[T](#t), [R](#r)\>

### property[](#property)

property: [Property](https://docs.maptiler.com/sdk-js/api-reference/interfaces/Externals.Property/)<[T](#t), [R](#r)\>

### value[](#value)

value: [PropertyValue](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.PropertyValue/)<[T](#t), [R](#r)\>

## Methods[](#methods-1)

### possiblyEvaluate[](#possiblyevaluate)

-   possiblyEvaluate(  
        parameters: [EvaluationParameters](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.EvaluationParameters/),  
        canonical: [CanonicalTileID](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.CanonicalTileID/),  
        availableImages: string\[\],  
    ): [R](#r)[](#possiblyevaluate-1)
    
    #### Parameters
    
    -   parameters: [EvaluationParameters](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.EvaluationParameters/)
    -   canonical: [CanonicalTileID](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.CanonicalTileID/)
    -   availableImages: string\[\]
    
    #### Returns [R](#r)