NPVariant

Summary

NPVariant is a struct that holds a value and the type of that value. The value is held in a union, and the type is one of types defined in the NPVariantType enumeration.

Syntax

typedef struct _NPVariant {
  NPVariantType type;
  union {
    bool boolValue;
    int32_t intValue;
    double_t doubleValue;
    NPString stringValue;
    NPObject *objectValue;
  } value;
} NPVariant;

Fields

The data structure has the following fields:

type

A member of the NPVariantType enumeration specifying the data type contained in the NPVariant.

value

The value contained in the NPVariant structure. It may be a boolean, integer, double, string, or object, depending on the variant type.

JavaScript type to NPVariantType enumeration mapping

When using NPVariants to access JavaScript objects in the browser, or vise versa, the mapping of JavaScript values to NPVariants is as follows:

Functions

• NPN_ReleaseVariantValue()
• NPN_GetStringIdentifier()
• NPN_GetStringIdentifiers()
• NPN_GetIntIdentifier()
• NPN_IdentifierIsString()
• NPN_UTF8FromIdentifier()
• NPN_IntFromIdentifier()

Macros

Plugin developers are not expected to directly manipulate or access the members of the NPVariant instance, instead, the function NPN_ReleaseVariantValue(), and the following macros are provided:

NPVARIANT_IS_VOID()

Evaluates to true if v is of type NPVariantType_Void.

NPVARIANT_IS_NULL()

Evaluates to true if v is of type NPVariantType_Null.

NPVARIANT_IS_BOOLEAN()

Evaluates to true if v is of type NPVariantType_Bool.

NPVARIANT_IS_INT32()

Evaluates to true if v is of type NPVariantType_Int32.

NPVARIANT_IS_DOUBLE()

Evaluates to true if v is of type NPVariantType_Double.

NPVARIANT_IS_STRING()

Evaluates to true if v is of type NPVariantType_String.

NPVARIANT_IS_OBJECT()

Evaluates to true if v is of type NPVariantType_Object.

NPVARIANT_TO_BOOLEAN()

Extracts the boolean value from v.

NPVARIANT_TO_INT32()

Extracts a signed 32-bit integer value from v.

NPVARIANT_TO_DOUBLE()

Extracts a double precision floating point value from v.

NPVARIANT_TO_STRING()

Extracts the NPString value from v.

NPVARIANT_TO_OBJECT()

Extracts the NPObject value from v.

VOID_TO_NPVARIANT()

Initialize v to a variant of type NPVariantType_Void.

NULL_TO_NPVARIANT()

Initialize v to a variant of type NPVariantType_Null.

BOOLEAN_TO_NPVARIANT()

Initialize v to a variant of type NPVariantType_Bool with the value val.

INT32_TO_NPVARIANT()

Initialize v to a variant of type NPVariantType_Int32 with the value val.

DOUBLE_TO_NPVARIANT()

Initialize v to a variant of type NPVariantType_Double with the value val.

STRINGZ_TO_NPVARIANT()

Initialize v to a variant of type NPVariantType_String with the value being an NPString holding the UTF-8 string value val.

STRINGN_TO_NPVARIANT()

Initialize v to a variant of type NPVariantType_String with the value being an NPString holding the UTF-8 string value val with the length len.

OBJECT_TO_NPVARIANT()

Initialize v to a variant of type NPVariantType_Object with the value val.