BLOB AND FILE APIs

One of the major pain points of web applications has been the inability to interact with files on a user's computer. Since before 2000, the only way to deal with files was to place <input type="file"> into a form and leave it at that. The Blob and File APIs are designed to give web developers access to files on the client computer in a secure manner that allows for better interaction with those files.

The File Type

The File API is still based around the file input field of a form but adds the ability to access the file information directly. HTML5 adds a files collection to DOM for the file input element. When one or more files are selected in the field, the files collection contains a sequence of File objects that represent each file. Each File object has several read-only properties, including:

• name—The file name on the local system.
• size—The size of the file in bytes.
• type—A string containing the MIME type of the file.
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