PerformanceObserver extension type

The PerformanceObserver interface is used to observe performance measurement events and be notified of new PerformanceEntry as they are recorded in the browser's performance timeline.


API documentation sourced from MDN Web Docs.

on
Implemented types
Available extensions

Constructors

PerformanceObserver(PerformanceObserverCallback callback)
factory

Properties

hashCode int
The hash code for this object.
no setterinherited
isDefinedAndNotNull bool

Available on JSAny?, provided by the NullableUndefineableJSAnyExtension extension

no setter
isNull bool

Available on JSAny?, provided by the NullableUndefineableJSAnyExtension extension

Whether this value corresponds to JavaScript null.
no setter
isTruthy JSBoolean

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of !!this in JavaScript.
no setter
isUndefined bool

Available on JSAny?, provided by the NullableUndefineableJSAnyExtension extension

Whether this value corresponds to JavaScript undefined.
no setter
isUndefinedOrNull bool

Available on JSAny?, provided by the NullableUndefineableJSAnyExtension extension

no setter
not JSBoolean

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of !this in JavaScript.
no setter
runtimeType Type
A representation of the runtime type of the object.
no setterinherited

Methods

add(JSAny? any) JSAny

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this + any in JavaScript.
and(JSAny? any) JSAny?

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this && any in JavaScript.
callMethod<R extends JSAny?>(JSAny method, [JSAny? arg1, JSAny? arg2, JSAny? arg3, JSAny? arg4]) → R

Available on JSObject, provided by the JSObjectUnsafeUtilExtension extension

Calls method on this JSObject with up to four arguments.
callMethodVarArgs<R extends JSAny?>(JSAny method, [List<JSAny?>? arguments]) → R

Available on JSObject, provided by the JSObjectUnsafeUtilExtension extension

Calls method on this JSObject with a variable number of arguments.
dartify() Object?

Available on JSAny?, provided by the JSAnyUtilityExtension extension

Converts a JavaScript value to the Dart equivalent if possible.
delete(JSAny property) JSBoolean

Available on JSObject, provided by the JSObjectUnsafeUtilExtension extension

Deletes the property with key property from this JSObject.
disconnect() → void
The disconnect() method of the PerformanceObserver interface is used to stop the performance observer from receiving any PerformanceEntry events.
divide(JSAny? any) JSAny

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this / any in JavaScript.
equals(JSAny? any) JSBoolean

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this == any in JavaScript.
exponentiate(JSAny? any) JSAny

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this ** any in JavaScript.
getProperty<R extends JSAny?>(JSAny property) → R

Available on JSObject, provided by the JSObjectUnsafeUtilExtension extension

The value of the property key property of this JSObject.
greaterThan(JSAny? any) JSBoolean

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this > any in JavaScript.
greaterThanOrEqualTo(JSAny? any) JSBoolean

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this >= any in JavaScript.
has(String property) bool

Available on JSObject, provided by the JSObjectUnsafeUtilExtension extension

Shorthand helper for hasProperty to check whether this JSObject contains the property key property, but takes and returns a Dart value.
hasProperty(JSAny property) JSBoolean

Available on JSObject, provided by the JSObjectUnsafeUtilExtension extension

Whether or not this JSObject contains the property key property.
instanceof(JSFunction constructor) bool

Available on JSAny?, provided by the JSAnyUtilityExtension extension

Whether this JSAny? is an instanceof constructor.
instanceOfString(String constructorName) bool

Available on JSAny?, provided by the JSAnyUtilityExtension extension

Whether this JSAny? is an instanceof the constructor that is defined by constructorName, which is looked up in the globalContext.
isA<T extends JSAny?>() bool

Available on JSAny?, provided by the JSAnyUtilityExtension extension

Whether this JSAny? is an instance of the JavaScript type that is declared by T.
lessThan(JSAny? any) JSBoolean

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this < any in JavaScript.
lessThanOrEqualTo(JSAny? any) JSBoolean

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this <= any in JavaScript.
modulo(JSAny? any) JSAny

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this % any in JavaScript.
multiply(JSAny? any) JSAny

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this * any in JavaScript.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
notEquals(JSAny? any) JSBoolean

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this != any in JavaScript.
observe([PerformanceObserverInit options]) → void
The observe() method of the PerformanceObserver interface is used to specify the set of performance entry types to observe.
or(JSAny? any) JSAny?

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this || any in JavaScript.
setProperty(JSAny property, JSAny? value) → void

Available on JSObject, provided by the JSObjectUnsafeUtilExtension extension

Write the value of property key property of this JSObject.
strictEquals(JSAny? any) JSBoolean

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this === any in JavaScript.
strictNotEquals(JSAny? any) JSBoolean

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this !== any in JavaScript.
subtract(JSAny? any) JSAny

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this - any in JavaScript.
takeRecords() PerformanceEntryList
The takeRecords() method of the PerformanceObserver interface returns the current list of PerformanceEntry stored in the performance observer, emptying it out.
toString() String
A string representation of this object.
inherited
typeofEquals(String typeString) bool

Available on JSAny?, provided by the JSAnyUtilityExtension extension

Whether the result of typeof on this JSAny? is typeString.
unsignedRightShift(JSAny? any) JSNumber

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this >>> any in JavaScript.

Operators

operator ==(Object other) bool
The equality operator.
inherited
operator [](String property) JSAny?

Available on JSObject, provided by the JSObjectUnsafeUtilExtension extension

Shorthand helper for getProperty to get the value of the property key property of this JSObject, but takes and returns a Dart value.
operator []=(String property, JSAny? value) → void

Available on JSObject, provided by the JSObjectUnsafeUtilExtension extension

Shorthand helper for setProperty to write the value of the property key property of this JSObject, but takes a Dart value.

Static Properties

supportedEntryTypes JSArray<JSString>
The static supportedEntryTypes read-only property of the PerformanceObserver interface returns an array of the PerformanceEntry.entryType values supported by the user agent.
no setter