ReadArrayFromFile Method

In This Topic

ReadArrayFromFile reads raw bytes from a file into an UInt8Array.

Syntax

Javascript (Usage)
Javascript (Specification)

var value; // Type: UInt8Array

// Parameters
var FileName; // Type:  string

value = ReadArrayFromFile(FileName);

function ReadArrayFromFile( 
   FileName : string
) : UInt8Array;

Parameters

FileName: Absolute path and file name to read raw bytes from.

Example

HTML

<!DOCTYPE html>
<html>
    <head>
        <script src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
        <meta charset=utf-8 />
        <title>Chrome File API tester</title>

        <script>
            window.requestFileSystem  = window.requestFileSystem || window.webkitRequestFileSystem;

            // Handle errors
            function errorHandler(e) {
                var msg = '';

                switch (e.code) {
                    case FileError.QUOTA_EXCEEDED_ERR:
                        msg = 'QUOTA_EXCEEDED_ERR';
                        break;
                    case FileError.NOT_FOUND_ERR:
                        msg = 'NOT_FOUND_ERR';
                        break;
                    case FileError.SECURITY_ERR:
                        msg = 'SECURITY_ERR';
                        break;
                    case FileError.INVALID_MODIFICATION_ERR:
                        msg = 'INVALID_MODIFICATION_ERR';
                        break;
                    case FileError.INVALID_STATE_ERR:
                        msg = 'INVALID_STATE_ERR';
                        break;
                    default:
                        msg = 'Unknown Error';
                        break;
                };
                console.log('Error: ' + msg);
            }
        
            // Init and write some data to a file
            function onInitFs(fs) {
                fs.root.getFile('log-f-api.txt', {create: true}, function(fileEntry) {

                    fileEntry.isFile === true;
                    fileEntry.name == 'log-f-api.txt';
                    fileEntry.fullPath == '/log-f-api.txt';
                    // Create a FileWriter object for our FileEntry (log.txt).
                    fileEntry.createWriter(function(fileWriter) {

                        fileWriter.onwriteend = function(e) {
                            console.log('Write completed.');
                        };

                        fileWriter.onerror = function(e) {
                            console.log('Write failed: ' + e);
                        };

                        // Create a new Blob and write it to log.txt.
                        if (!window.BlobBuilder && window.WebKitBlobBuilder)
                            window.BlobBuilder = window.WebKitBlobBuilder; // in Chrome 12.
                        var bb = new BlobBuilder(); 
                        bb.append("some stuff");
                        console.log("bb size:"+bb.size);
                        bb.append('put some nice text in our file....');
                        var ourData = bb.getBlob('text/plain');
                        fileWriter.write(ourData); 
                    }, errorHandler);
                }, errorHandler);
            }

            // start the party
            $(function() {
                document.getElementById('hello').innerHTML = 'start the tests';
                window.requestFileSystem(window.PERSISTENT, 5*1024*1024, onInitFs,errorHandler);
            });
        
        </script>

    </head>
    <body>
        <p id="hello">Tester FIle API</p>

        <h4>Other links</h4>
        <ul>
            <li>http://code.google.com/chrome/extensions/trunk/fileBrowserHandler.html#event-onExecute</li>
            <li>http://html5rocks.com</li>
        </ul>

    </body>
</html>

Remarks

For more details please read Working with Blob and Uint8Array

Browser Compatibility

Introduction

Working with Blob and Uint8Array

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