jsinterop.annotations

Annotation Type JsEnum

@Retention(value=RUNTIME)
 @Target(value=TYPE)
 @Documented
public @interface JsEnum

JsEnum marks a Java enum as being represented as a Closure enum, either one that already exists from the external JavaScript environment, or one that will be accessible from the external JavaScript environment.

The underlying type of the Closure enum can be specified via hasCustomValue() and declaring an instance field named "value" of the desired type.

If the JsEnum is non-native and has custom values, a constructor is required to allow specifying the values for the enum constants, as in the following example

   @JsEnum(hasCustomValue=true)
   enum IntJsEnum {
     TEN(10),
     TWENTY(20);

     int value;

     IntJsEnum(int value) { this.value = value; }
   }
 

If the JsEnum is native and has custom values, the value field is still required but constructors are not needed nor allowed.

JsEnums do not support the full Java semantics:

• No instance fields are allowed other than value,
• Enum.name() and Enum#values() are not supported.
• Enum.ordinal() is supported only for non-native JsEnums that don't have custom values.
• The class is initialization might be delayed until a static field/method is accessed.

The JavaScript namespace and name can be specified in a manner similar to JsTypes via namespace() and name() respectively.

Methods and fields declared in the JsEnum are only accessible in Java code. Only the enum constants are accessible from JavaScript code.

This annotation is only supported by J2CL.

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
boolean	hasCustomValue When set to true, this JsEnum will have a custom value defined by a field named 'value'.
boolean	isNative When set to true, this JsEnum is a native Closure enum type.
java.lang.String	name Customizes the name of the type in generated JavaScript.
java.lang.String	namespace Customizes the namespace of the type in generated JavaScript.

Element Detail

name

public abstract java.lang.String name

Customizes the name of the type in generated JavaScript. If not provided, the simple Java name will be used.

Default:

"<auto>"

namespace

public abstract java.lang.String namespace

Customizes the namespace of the type in generated JavaScript.

Default:

"<auto>"

isNative

public abstract boolean isNative

When set to true, this JsEnum is a native Closure enum type.

Default:

false

hasCustomValue

public abstract boolean hasCustomValue

When set to true, this JsEnum will have a custom value defined by a field named 'value'. The only allowed types for the value field are String and primitive types with the exception of long.

Default:

false