Created
July 17, 2012 14:41
-
-
Save gipi/3129800 to your computer and use it in GitHub Desktop.
Use Javascript typed array to read raw data from a file (original code from http://www.html5rocks.com/en/tutorials/file/dndfiles/)
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| <!DOCTYPE html> | |
| <html> | |
| <head> | |
| <title>POC</title> | |
| <body> | |
| <input type="file" id="files" name="files[]" multiple /> | |
| <output id="list"></output> | |
| <script> | |
| function handleFileSelect(evt) { | |
| var files = evt.target.files; // FileList object | |
| // Loop through the FileList and render image files as thumbnails. | |
| for (var i = 0, f; f = files[i]; i++) { | |
| var reader = new FileReader(); | |
| // Closure to capture the file information. | |
| reader.onload = (function(theFile) { | |
| return function(e) { | |
| var raw = e.target.result; | |
| // https://developer.mozilla.org/en/JavaScript_typed_arrays | |
| var rawBytes = new Uint8Array(raw); | |
| var hex = ""; | |
| for (var cycle = 0 ; cycle < raw.byteLength ; cycle++) { | |
| hex += rawBytes[cycle].toString(16) + " "; | |
| // TODO: more elegance | |
| if (!((cycle + 1) % 8)) | |
| hex += "\n"; | |
| } | |
| // Render thumbnail. | |
| var span = document.createElement('pre'); | |
| span.innerHTML = hex; | |
| document.getElementById('list').insertBefore(span, null); | |
| }; | |
| })(f); | |
| // Read in the image file as a data URL. | |
| reader.readAsArrayBuffer(f); | |
| } | |
| } | |
| document.getElementById('files').addEventListener('change', handleFileSelect, false); | |
| </script> | |
| </body> | |
| </html> |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment