However, all the browsers do not have HTML 5 support so it is important to test the browser compatibility before using the File API. Once File is selected in FileUpload control, it is read as Binary data and then the Binary data is read using the xlsx Excel plugin. Parameters: fileName - the name of the file to read from Throws: FileNotFoundException - if the named file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading. The FileReader object must be the event target for all events in this specification. Found inside – Page 193... showBuffer); function getFileInfo(e){ fileReader.readAsArrayBuffer(e.target.files[0]); //creating the arrayBuffer based on the loaded file }; function ... The FileReader() constructor creates a new FileReader.. For details about how to use FileReader, see Using files from web applications. Found insideA Hands-On Guide to the Fundamentals of Modern JavaScript Tim Wright ... type = file.type, reader = new FileReader(); // initialize the FileReader Object ... Internet Explorer 10 and 11+, Mozilla FireFox, Google Chrome and Opera. If you would like to follow along with this article, you will need: An understanding of JavaScript methods, EventListener, and Promises will be helpful. Found insidegetFileAsync("textfile.txt") .then(function (textFileBlob) { var reader = new FileReader(); reader.readAsText(textFileBlob); reader.onload = function (evt) ... To encode a Blob object to Base64 in JavaScript you can use the FileReader.readAsDataURL() method. Found inside – Page 543FileIO, PathIO, and WinJS Helpers (plus FileReader) Simplicity is a good thing ... which can also be found in the RawFileWrite example (js/default.js): ... var fileReader = new FileReader(); // We declare an event of the fileReader class (onload event) and we register an anonimous function that will be executed when the event is raised. Found inside – Page 117The operation required to read a file back in memory is very similar (and equally convoluted). We are going to create a FileReader object and we are going ... Parameters: fileName - the name of the file to read from Throws: FileNotFoundException - if the named file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading. The JavaScript is one of the client side scripting language is also dynamic computer programming language the user browsers interprets from browser to browser it may varied upon the … FileReader is used to read the contents of a Blob or File. Found inside – Page 304FILEREADER. API. There are many reasons why it may be useful to process a file with JavaScript rather than simply submitting it to the server: ➤ It allows ... Found inside – Page 287