When would you use a factory constructor flutter?

In Factory pattern, we create object without exposing the creation logic to the client and refer to newly created object using a common interface.

Factory method is a creational design pattern which solves the problem of creating product objects without specifying their concrete classes . Factory Method defines a method, which should be used for creating objects instead of direct constructor call ( new operator).

A factory constructor is a constructor that can be used when you don’t necessarily want a constructor to create a new instance of your class . This might be useful if you hold instances of your class in memory and don’t want to create a new one each time (or if the operation of creating an instance is costly).

A factory constructor invokes another constructor . Since a factory constructor does not directly create a new instance, it cannot use a constructor initializer list. A normal constructor always returns a new instance of the class.