The endianness to apply, or a function that return the endianness based on the instance value.
Optionalopt: Partial<PrePostOptions>Optional configution.
The class or property decorator function.
Changing Endianness for individual properties
Use the @Endian decorator over a PrimitiveSymbol property to change it's endianness.
class Protocol {
@Endian(BinaryCursorEndianness.LittleEndian)
@Uint16
little_endian: number
@Uint32
big_endian: number
}
Changing Endianness for subtypes
By using the @Endian decorator over a subtype relation property to change
the endianness of the entire sub-type
class SubProtocol {
@Uint32
foo: number
@Uint32
bar: number
}
class Protocol {
@Endian(BinaryCursorEndianness.LittleEndian)
@Relation(SubProtocol)
sub_type: SubProtocol
@Uint32
big_endian: number // Because the default endianness is big endian this value will be read as a big endian number
}
Runtime Conditional Endianness:
If you need to set the endianness dynamically at runtime based on a class
property, you can pass a function to the @Endian decorator.
In the following example, the @Endian decorator uses the value of the
_value property passed as an argument of Protocol constructor whether
little-endian or big-endian byte order should be applied to the protocol.
@Endian(_ => _value > 0 ? BinaryCursorEndianness.LittleEndian : BinaryCursorEndianness.BigEndian)
class Protocol {
_value: number
@Uint32
foo: number
@Uint32
bar: number
constructor(value: number) {
this._value = value
}
}
The @Endian decorator is used to change endianness dynamically or based
on values known at runtime. If you want to describe the endianness of a
protocol that won't change use LittleEndian and BigEndian.
Because of the current architecture of the library, if multiple @Endian
that are based on values known at runtime are run in parallel it could
potentially mess up the result because they will all populate the 'post'
property metadata.
@Endiandecorator change the endianness dynamically of the decorated property or class and then set it back to the previous endianness once the decorated property/class has been fully processed.