TryReturn class

An alias for Try/Call effect. It makes try/catch/finally code blocks more readable and returns value like Return. If you want to return from a returned value from a Try/Catch/Finally block then use TryReturn.

Example

In the following example the saga returns value returned

 saga() sync* {
   yield TryReturn(() sync* { //returns saga
     //...
     yield Return(somevalue1); //returns Try
   }, Catch: (e, s) sync* {
     //...
     yield Return(somevalue2); //returns Try
   });
 }

Equivalent code with Try

 saga() sync* {
   var result = Result();
   yield Try(() sync* {
     //...
     yield Return(somevalue1); //returns Try. Does not return saga
   }, Catch: (e, s) sync* {
     //...
     yield Return(somevalue2); //returns Try. Does not return saga
   }, result: result);
   yield Return(result.value); //returns saga
 }

In the following example, there is a simple checkout saga function. It tries to checkout the cart. If it successes returns a CheckoutSuccess action otherwise returns a CheckoutFailure action.

 import 'package:redux_saga/redux_saga.dart';
 import 'Api.dart';

 //...

 checkout() sync* {
   yield TryReturn(() sync* {
     var cart = Result<Cart>();
     yield Select(selector: getCart, result: cart);
     yield Call(buyProductsAPI, args: [cart.value]);
     yield Return(CheckoutSuccess(cart.value));
   }, Catch: (e, s) sync* {
     yield Return(CheckoutFailure(error));
   });
 }
Inheritance

Constructors

TryReturn(Function fn, {List? args, Map<Symbol, dynamic>? namedArgs, Function? Catch, Function? Finally, String? name, Result? result})
Creates an instance of a Try effect.

Properties

args → List?
Arguments of the function to call
finalinherited
Catch → Function?
A Generator function or a normal function to invoke for uncaught errors.
finalinherited
Finally → Function?
A Generator function or a normal function to invoke in any case after call.
finalinherited
fn → Function
A Generator function or a normal function to call.
finalinherited
hashCode → int
The hash code for this object.
no setterinherited
name → String?
Meta name of function
finalinherited
namedArgs → Map<Symbol, dynamic>?
Named arguments of the function to call
finalinherited
result ↔ Result?
Result after effect is resolved.
getter/setter pairinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

getDefinition() → Map<String, dynamic>
Returns all properties of effect as a dictionary object
override
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