Package org.graalvm.polyglot.proxy

Interface ProxyObject

All Superinterfaces:

Proxy

public interface ProxyObject
extends Proxy

Interface to be implemented to mimic guest language objects that contain members.

Since:

19.0

See Also:

• Proxy

Method Summary

Modifier and Type	Method	Description
static ProxyObject	fromMap(Map<String,Object> values)	Creates a proxy backed by a Map.
Object	getMember(String key)	Returns the value of the member.
Object	getMemberKeys()	Returns an array of member keys.
boolean	hasMember(String key)	Returns true if the proxy object contains a member with the given key, or else false.
void	putMember(String key, Value value)	Sets the value associated with a member.
default boolean	removeMember(String key)	Removes a member key and its value.

Method Details

getMember

Object getMember(String key)

Returns the value of the member.

Throws:

UnsupportedOperationException - if the operation is unsupported

Since:

19.0

getMemberKeys

Object getMemberKeys()

Returns an array of member keys. The returned array must be interpreted as having array elements using the semantics of Context.asValue(Object) and taking host access into consideration. Otherwise, an IllegalStateException is thrown. If one of the return values of the array is not a String then a ClassCastException is thrown. Examples for valid return values are:

• null for no member keys
• ProxyArray that returns String values for each array element
• List with exclusively String elements (HostAccess must allowListAccess)
• String[] (HostAccess must allowArrayAccess)
• A guest language object representing an array of strings.

Every member key returned by the getMemberKeys() method must return true for hasMember(String).

Since:

19.0

See Also:

• hasMember(String)
• Context.asValue(Object)

hasMember

boolean hasMember(String key)

Returns true if the proxy object contains a member with the given key, or else false. While not required ever member key which returns true for hasMember(String) should be returned by getMemberKeys() to allow guest members to list member keys.

Since:

19.0

See Also:

• getMemberKeys()

putMember

void putMember(String key,
 Value value)

Sets the value associated with a member. If the member does not exist then a new member is defined. If the definition of new members is not supported then an UnsupportedOperationException is thrown.

Throws:

UnsupportedOperationException - if the operation is unsupported

Since:

19.0

removeMember

default boolean removeMember(String key)

Removes a member key and its value. If the removal of existing members is not supported then an UnsupportedOperationException is thrown.

Returns:

true when the member was removed, false when the member didn't exist.

Throws:

UnsupportedOperationException - if the operation is unsupported

Since:

19.0

fromMap

static ProxyObject fromMap(Map<String,Object> values)

Creates a proxy backed by a Map. If the set values of the map are host values then the they will be unboxed.

Since:

19.0