File extension type

The File interface provides information about files and allows JavaScript in a web page to access their content.

File objects are generally retrieved from a FileList object returned as a result of a user selecting files using the input element, or from a drag and drop operation's DataTransfer object.

A File object is a specific kind of Blob, and can be used in any context that a Blob can. In particular, FileReader, URL.createObjectURL_static, createImageBitmap, the body option to fetch, and XMLHttpRequest accept both Blobs and Files.

See Using files from web applications for more information and examples.

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API documentation sourced from MDN Web Docs.

on

• JSObject

Implemented types

• Blob
• JSObject

Available extensions

• JSAnyExtension
• JSAnyNullableExtension
• JSAnyOperatorExtension
• JSAnyUtilityExtension
• JSObjectExtension
• JSObjectUnsafeUtilExtension
• JSObjectWebExtension
• NullableUndefineableJSAnyExtension

Constructors

File(JSArray<BlobPart> fileBits, String fileName, [FilePropertyBag options])

factory

Properties

asString → String

Available on JSAny, provided by the JSAnyExtension extension

no setter

asString → String?

Available on JSAny?, provided by the JSAnyNullableExtension extension

no setter

entries → Iterable<MapEntry<String, dynamic>>

Available on JSObject, provided by the JSObjectExtension extension

no setter

hashCode → int

The hash code for this object.

no setter, inherited

isDefinedAndNotNull → bool

Available on JSAny?, provided by the NullableUndefineableJSAnyExtension extension

no setter

isElement → bool

Available on JSObject?, provided by the JSObjectWebExtension extension

no setter

isHTMLElement → bool

Available on JSObject?, provided by the JSObjectWebExtension extension

no setter

isNode → bool

Available on JSObject?, provided by the JSObjectWebExtension 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

keys → Iterable<String>

Available on JSObject, provided by the JSObjectExtension extension

no setter

lastModified → int

The lastModified read-only property of the File interface provides the last modified date of the file as the number of milliseconds since the Unix epoch (January 1, 1970 at midnight). Files without a known last modified date return the current date.

no setter

name → String

The name read-only property of the File interface returns the name of the file represented by a File object. For security reasons, the path is excluded from this property.

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 setter, inherited

size → int

The size read-only property of the Blob interface returns the size of the Blob or File in bytes.

no setter, inherited

type → String

The type read-only property of the Blob interface returns the of the file.

no setter, inherited

webkitRelativePath → String

The webkitRelativePath read-only property of the File interface contains a string which specifies the file's path relative to the directory selected by the user in an input element with its webkitdirectory attribute set.

no setter

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.

arrayBuffer() → JSPromise<JSArrayBuffer>

The arrayBuffer() method of the Blob interface returns a Promise that resolves with the contents of the blob as binary data contained in an ArrayBuffer.

inherited

as<T extends JSObject>() → T?

Available on JSObject, provided by the JSObjectExtension extension

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 JSON-like 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.

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.

get(String key) → Object?

Available on JSObject, provided by the JSObjectExtension extension

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.

or(JSAny? any) → JSAny?

Available on JSAny?, provided by the JSAnyOperatorExtension extension

The result of this || any in JavaScript.

put(Object key, Object? value) → void

Available on JSObject, provided by the JSObjectExtension extension

setProperty(JSAny property, JSAny? value) → void

Available on JSObject, provided by the JSObjectUnsafeUtilExtension extension

Write the value of property key property of this JSObject.

slice([int start, int end, String contentType]) → Blob

The slice() method of the Blob interface creates and returns a new Blob object which contains data from a subset of the blob on which it's called.

inherited

stream() → ReadableStream

The stream() method of the Blob interface returns a ReadableStream which upon reading returns the data contained within the Blob.

inherited

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.

text() → JSPromise<JSString>

The text() method of the Blob interface returns a Promise that resolves with a string containing the contents of the blob, interpreted as UTF-8.

inherited

toMap() → Map<String, dynamic>

Available on JSObject, provided by the JSObjectExtension extension

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 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.