Call class

Creates an Effect description that instructs the middleware to call the function fn with args and namedArgs as arguments.

• fn is a Generator function, or normal function which returns a Future as result, or any other value.

• args and namedArgs are values to be passed as arguments to fn

• Catch will be invoked for uncaught errors.

• Finally will be invoked in any case after call.

• name is an optional name for the task meta.

Notes

fn can be either a normal or a Generator function.

The middleware invokes the function and examines its result.

If the result is an Iterator object, the middleware will run that Generator function, just like it did with the startup Generators (passed to the middleware on startup). The parent Generator will be suspended until the child Generator terminates normally, in which case the parent Generator is resumed with the value returned by the child Generator. Or until the child aborts with some error, in which case an error will be thrown inside the parent Generator.

If fn is a normal function and returns a Future, the middleware will suspend the Generator until the Future is settled. After the future is resolved the Generator is resumed with the resolved value, or if the Future is rejected an error is thrown inside the Generator.

If the result is not an Iterator object nor a Future, the middleware will immediately return that value back to the saga, so that it can resume its execution synchronously.

When an error is thrown, if it has a Try block surrounding the current yield instruction, the control will be passed to the Catch block. Otherwise, the Generator aborts with the raised error, and if this Generator was called by another Generator, the error will propagate to the calling Generator.

Inheritance

• Object
• Effect
• EffectWithResult
• Call

Implementers

• Apply
• Try
• TryReturn

Constructors

Call(Function fn, {List? args, Map<Symbol, dynamic>? namedArgs, Function? Catch, Function? Finally, String? name, Result? result})

Creates an instance of a Call effect.

Properties

args → List?

Arguments of the function to call

final

Catch → Function?

A Generator function or a normal function to invoke for uncaught errors.

final

Finally → Function?

A Generator function or a normal function to invoke in any case after call.

final

fn → Function

A Generator function or a normal function to call.

final

hashCode → int

The hash code for this object.

no setter, inherited

name → String?

Meta name of function

final

namedArgs → Map<Symbol, dynamic>?

Named arguments of the function to call

final

result ↔ Result?

Result after effect is resolved.

getter/setter pair, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

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