I want to open a file in Javascript that the user selects from the local filesystem. I can get the file name but I don't know how to open it.
<form action='' method='POST' enctype='multipart/form-data'>
<input id="archiveFile" type='file' name='userFile'><br>
<script>
archiveFile.onchange = function (e)
{
console.log(archiveFile.value);
// open the file here
}
</script>
</form>
You need for the HTML5 FileReader Api, further information are there: https://developer.mozilla.org/en-US/docs/Web/API/FileReader
here is a polyfill using Flash: https://github.com/Jahdrien/FileReader
This is a very well-made article: http://www.html5rocks.com/en/tutorials/file/dndfiles/#toc-reading-files it explains almost everything.
working example:
function FileReaderCtrl() {
var self = this;
var field = document.getElementById('fieldFile');
var result = document.getElementById('result');
self.readFile = function(event) {
var res = event.target.result;
var image = '<img src="'+ (res || '') +'"/>';
result.innerHTML = image;
console.log(image);
};
field.onchange = function(event) {
var files = field.files;
var reader;
if(files.length < 1) {
return;
}
reader = new FileReader();
reader.onload = self.readFile;
reader.readAsDataURL(files[0]);
}
}
document.addEventListener('DOMContentLoaded', FileReaderCtrl);#result {
width: 200px;
height: 200px;
background: lightcoral;
margin: 1em auto;
}
img {max-width: 100% }<label for="fieldFile">Select an Image:<br><input type="file" id="fieldFile"/></label>
<div id="result"></div>Substitute archiveFile.files for archiveFile.value. The value of an input type="file" element is not a FileList or File object
For historical reasons, the
valueIDL attribute prefixes the file name with the string "C:\fakepath\"
archive.files would be the FileList object, from which you can iterate the selected File object or objects if multiple attribute is set at input type="file" element. For example, archiveFile.files[0] to view properties of individual File object
<form action='' method='POST' enctype='multipart/form-data'>
<input id="archiveFile" type='file' name='userFile'>
<br>
<script>
archiveFile.onchange = function(e) {
console.log(archiveFile.files, archiveFile.files[0]);
// open the file here
}
</script>
</form>