File.md

File

Namespace: SpawnDev.SpawnJS.JSObjects
Inherits: Blob
Source: JSObjects/File.cs
MDN Reference: File on MDN

The File interface provides information about files and allows JavaScript in a web page to access their content. https://developer.mozilla.org/en-US/docs/Web/API/File

Constructors

Signature	Description
File(SpawnJSObjectReference _ref)	Deserialization constructor
File(IEnumerable<Union<ArrayBuffer, TypedArray, DataView, Blob, string, byte[]>> bits, string name)	The File() constructor creates a new File object instance. An iterable object such as an Array, having ArrayBuffers, TypedArrays, DataViews, Blobs, strings, or a mix of any of such elements, that will be put inside the File. Note that strings here are encoded as UTF-8, unlike the usual JavaScript UTF-16 strings. A string representing the file name or the path to the file.
File(IEnumerable<Union<ArrayBuffer, TypedArray, DataView, Blob, string, byte[]>> bits, string name, FileOptions options)	The File() constructor creates a new File object instance. An iterable object such as an Array, having ArrayBuffers, TypedArrays, DataViews, Blobs, strings, or a mix of any of such elements, that will be put inside the File. Note that strings here are encoded as UTF-8, unlike the usual JavaScript UTF-16 strings. A string representing the file name or the path to the file. An options object containing optional attributes for the file
File(IEnumerable<ArrayBuffer> bits, string name)	The File() constructor creates a new File object instance. An iterable object such as an Array, having ArrayBuffers, TypedArrays, DataViews, Blobs, strings, or a mix of any of such elements, that will be put inside the File. Note that strings here are encoded as UTF-8, unlike the usual JavaScript UTF-16 strings. A string representing the file name or the path to the file.
File(IEnumerable<ArrayBuffer> bits, string name, FileOptions options)	The File() constructor creates a new File object instance. An iterable object such as an Array, having ArrayBuffers, TypedArrays, DataViews, Blobs, strings, or a mix of any of such elements, that will be put inside the File. Note that strings here are encoded as UTF-8, unlike the usual JavaScript UTF-16 strings. A string representing the file name or the path to the file. An options object containing optional attributes for the file
File(IEnumerable<TypedArray> bits, string name)	The File() constructor creates a new File object instance. An iterable object such as an Array, having ArrayBuffers, TypedArrays, DataViews, Blobs, strings, or a mix of any of such elements, that will be put inside the File. Note that strings here are encoded as UTF-8, unlike the usual JavaScript UTF-16 strings. A string representing the file name or the path to the file.
File(IEnumerable<TypedArray> bits, string name, FileOptions options)	The File() constructor creates a new File object instance. An iterable object such as an Array, having ArrayBuffers, TypedArrays, DataViews, Blobs, strings, or a mix of any of such elements, that will be put inside the File. Note that strings here are encoded as UTF-8, unlike the usual JavaScript UTF-16 strings. A string representing the file name or the path to the file. An options object containing optional attributes for the file
File(IEnumerable<DataView> bits, string name)	The File() constructor creates a new File object instance. An iterable object such as an Array, having ArrayBuffers, TypedArrays, DataViews, Blobs, strings, or a mix of any of such elements, that will be put inside the File. Note that strings here are encoded as UTF-8, unlike the usual JavaScript UTF-16 strings. A string representing the file name or the path to the file.
File(IEnumerable<DataView> bits, string name, FileOptions options)	The File() constructor creates a new File object instance. An iterable object such as an Array, having ArrayBuffers, TypedArrays, DataViews, Blobs, strings, or a mix of any of such elements, that will be put inside the File. Note that strings here are encoded as UTF-8, unlike the usual JavaScript UTF-16 strings. A string representing the file name or the path to the file. An options object containing optional attributes for the file
File(IEnumerable<Blob> bits, string name)	The File() constructor creates a new File object instance. An iterable object such as an Array, having ArrayBuffers, TypedArrays, DataViews, Blobs, strings, or a mix of any of such elements, that will be put inside the File. Note that strings here are encoded as UTF-8, unlike the usual JavaScript UTF-16 strings. A string representing the file name or the path to the file.
File(IEnumerable<Blob> bits, string name, FileOptions options)	The File() constructor creates a new File object instance. An iterable object such as an Array, having ArrayBuffers, TypedArrays, DataViews, Blobs, strings, or a mix of any of such elements, that will be put inside the File. Note that strings here are encoded as UTF-8, unlike the usual JavaScript UTF-16 strings. A string representing the file name or the path to the file. An options object containing optional attributes for the file
File(IEnumerable<string> bits, string name)	The File() constructor creates a new File object instance. An iterable object such as an Array, having ArrayBuffers, TypedArrays, DataViews, Blobs, strings, or a mix of any of such elements, that will be put inside the File. Note that strings here are encoded as UTF-8, unlike the usual JavaScript UTF-16 strings. A string representing the file name or the path to the file.
File(IEnumerable<string> bits, string name, FileOptions options)	The File() constructor creates a new File object instance. An iterable object such as an Array, having ArrayBuffers, TypedArrays, DataViews, Blobs, strings, or a mix of any of such elements, that will be put inside the File. Note that strings here are encoded as UTF-8, unlike the usual JavaScript UTF-16 strings. A string representing the file name or the path to the file. An options object containing optional attributes for the file
File(IEnumerable<byte[]> bits, string name)	The File() constructor creates a new File object instance. An iterable object such as an Array, having ArrayBuffers, TypedArrays, DataViews, Blobs, strings, or a mix of any of such elements, that will be put inside the File. Note that strings here are encoded as UTF-8, unlike the usual JavaScript UTF-16 strings. A string representing the file name or the path to the file.
File(IEnumerable<byte[]> bits, string name, FileOptions options)	The File() constructor creates a new File object instance. An iterable object such as an Array, having ArrayBuffers, TypedArrays, DataViews, Blobs, strings, or a mix of any of such elements, that will be put inside the File. Note that strings here are encoded as UTF-8, unlike the usual JavaScript UTF-16 strings. A string representing the file name or the path to the file. An options object containing optional attributes for the file

Properties

Property	Type	Access	Description
Name	string	get	Returns the name of the file referenced by the File object.
LastModified	long	get	Returns the last modified time of the file, in millisecond since the UNIX epoch (January 1st, 1970 at Midnight).
WebkitRelativePath	string?	get	Returns the path the URL of the File is relative to.

Methods

Method	Return Type	Description
StartDownload()	Task	Start downloading the File using the File.Name

Example

// Create a File from string content using the Union-based constructor
var parts = new List<Union<ArrayBuffer, TypedArray, DataView, Blob, string, byte[]>>
{
    (Union<ArrayBuffer, TypedArray, DataView, Blob, string, byte[]>)"Hello, World!"
};
using var file = new File(parts, "greeting.txt", new FileOptions { Type = "text/plain" });

// Read file metadata
Console.WriteLine($"Name: {file.Name}");
Console.WriteLine($"Size: {file.Size} bytes");
Console.WriteLine($"Type: {file.Type}");
Console.WriteLine($"Last Modified: {file.LastModified}");

// Read the file content as text (inherited from Blob)
var content = await file.Text();
Console.WriteLine($"Content: {content}");

// Read the file content as binary (inherited from Blob)
using var buffer = await file.ArrayBuffer();
byte[] bytes = buffer.ReadBytes();

// Create a File from string parts (simpler constructor)
using var textFile = new File(new[] { "Line 1\n", "Line 2\n" }, "notes.txt");

// Create a File from byte arrays
using var binaryFile = new File(
    new[] { new byte[] { 0xFF, 0xD8, 0xFF } },
    "image.jpg",
    new FileOptions { Type = "image/jpeg" }
);

// Trigger a download using the file's own name
await file.StartDownload();