Derive Macro bevy_reflect::FromReflect
source · #[derive(FromReflect)]
{
// Attributes available to this derive:
#[reflect]
}
Expand description
Derives the FromReflect
trait.
§Field Attributes
§#[reflect(ignore)]
The #[reflect(ignore)]
attribute is shared with the #[derive(Reflect)]
macro and has much of the same
functionality in that it denotes that a field will be ignored by the reflection API.
The only major difference is that using it with this derive requires that the field implements [Default
].
Without this requirement, there would be no way for FromReflect
to automatically construct missing fields
that have been ignored.
§#[reflect(default)]
If a field cannot be read, this attribute specifies a default value to be used in its place.
By default, this attribute denotes that the field’s type implements [Default
].
However, it can also take in a path string to a user-defined function that will return the default value.
This takes the form: #[reflect(default = "path::to::my_function")]
where my_function
is a parameterless
function that must return some default value for the type.
Specifying a custom default can be used to give different fields their own specialized defaults,
or to remove the Default
requirement on fields marked with #[reflect(ignore)]
.
Additionally, either form of this attribute can be used to fill in fields that are simply missing,
such as when converting a partially-constructed dynamic type to a concrete one.