CellExtension class

Annotation used to specify a class for which to generate a ValueCell extension.

When this annotation is applied to a class, an extension is generated for ValueCell's holding instances of the class. The extension extends ValueCell with an accessor for each property of the class. Each accessor returns a computed cell that accesses the property of the instance held in the cell on which the accessor was used.

NOTE: The live_cell_extension package does the actual code generation.

For example when the annotation is applied on the following class:

@CellExtension()
class Person {
   final String name;
   final int age;

   const Person({
     required this.name,
     required this.age
   });
}

ValueCell<Person> will be extended with accessors for the name and age properties:

final person = MutableCell(
  const Person(
    name: 'John Smith',
    age: 25
  )
);

// name and age are both ValueCell's
final name = person.name;
final age = person.age;

print(name.value); // Prints: John Smith
print(age.value);  // Prints: 25

person.value = Person(name: 'Bob', age: 49);

print(name.value); // Prints: Bob
print(age.value);  // Prints: 49

If mutable is true, MutableCell is also extended with accessors for the properties. Unlike the accessors created on ValueCell, these accessors return MutableCell's, which modify the value of the property of the object held in the cell on which the accessor was used. This is achieved by copying the instance with a new value for the modified property.

If the Person class was annotated with @CellExtension(mutable: true), the following accessors would be generated:

final person = MutableCell(
  const Person(
    name: 'John Smith',
    age: 25
  )
);

// name and age are both MutableCell's
final name = person.name;
final age = person.age;

name.value = 'Bob';
print('${person.value.name} - ${person.value.age}'); // Prints Bob 25

age.value = 49;
print('${person.value.name} - ${person.value.age}'); // Prints Bob 49

Constructors

CellExtension({Symbol? name, Symbol? mutableName, bool mutable = false, bool nullable = false})

Annotate a class to generate an extension on ValueCell for the class's properties.

const

Properties

hashCode → int

The hash code for this object.

no setter, inherited

mutable → bool

Should an extension on MutableCell be generated?

final

mutableName → Symbol?

Name of the MutableCell extension to generate.

final

name → Symbol?

Name of the ValueCell extension to generate.

final

nullable → bool

Should extension on cells holding a nullable type be generated?

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited