ExpressionChangedAfterItHasBeenCheckedException class

An error thrown if application changes model breaking the top-down data flow.

This exception is only thrown in dev mode.

Example

@Component({
  selector: 'parent',
  template: `
    <child [prop]="parentProp"></child>
  `,
  directives: [forwardRef(() => Child)]
})
class Parent {
  parentProp = "init";
}

@Directive({selector: 'child', inputs: ['prop']})
class Child {
  constructor(public parent: Parent) {}

  set prop(v) {
    // this updates the parent property, which is disallowed during change detection
    // this will result in ExpressionChangedAfterItHasBeenCheckedException
    this.parent.parentProp = "updated";
  }
}

Implemented types

• Exception

Constructors

ExpressionChangedAfterItHasBeenCheckedException(dynamic oldValue, dynamic currValue, dynamic context)

Properties

hashCode → int

The hash code for this object. [...]

read-only, inherited

runtimeType → Type

A representation of the runtime type of the object.

read-only, inherited

Methods

noSuchMethod(Invocation invocation) → dynamic

Invoked when a non-existent method or property is accessed. [...]

inherited

toString() → String

Returns a string representation of this object.

override

Operators

operator ==(Object other) → bool

The equality operator. [...]

inherited