RuntimeType<T> class

A non-opaque representation of a Type that can be used at runtime.

Normally, Type objects are opaque and cannot be used for actual logic. RuntimeType allows for operations such as sub- or super-type checking, type checks, and casting using a variable instead of a literal.

To use, replace your type literals with calls to the RuntimeType constructor:

// Before
final stringType = String;

// After
final stringType = RuntimeType<String>();

Though it adds support for some operations, RuntimeType is not a replacement for type literals. For example, it cannot be used as a type argument as they are required to be type literals. Additionally, RuntimeType can be used at runtime to perform operations on types but it cannot extract type information at runtime:

final something = 'foo' as dynamic;

RuntimeType<T> extractType<T>(T instance) => RuntimeType<T>();

final typeOfSomething = extractType(something); // Still dynamic
Available Extensions

Constructors

RuntimeType()
Create a new RuntimeType representing T.
RuntimeType.allowingDynamic()
Create a new RuntimeType representing T, allowing dynamic as a valid value for T.
const

Properties

hashCode → int
The hash code for this object.
no setteroverride
internalType → Type
The Type that this RuntimeType represents.
no setter
isNullable → bool
Whether this type is nullable.
no setter
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

acceptsInstance(dynamic instance) → bool
Whether instance can be assigned to this type.
castInstance(dynamic instance) → T
Cast instance to this type, throwing if the cast fails.
isEquivalentTo<U>(RuntimeType<U> other) → bool
Whether this type is equivalent to other.
isSubtypeOf<U>(RuntimeType<U> other) → bool
Whether this is a subtype of other.
isSupertypeOf<U>(RuntimeType<U> other) → bool
Whether this is a supertype of other.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
nullable() → RuntimeType<T?>
Return a nullable version of this RuntimeType.
run<R>(R callback<U>()) → R
Run callback, passing this type as a type parameter.
toString() → String
A string representation of this object.
override
withInstance<U, R>(U value, void process(T value), {void otherwise(U value)?}) → void
Run process with value if value is assignable to this type.

Operators

operator ==(Object other) → bool
The equality operator.
override