I'm programming a simple JavaScript page to get a file from the user and convert it to a data variable of either binary or text. When I use my code in a click event handler of a button, I get this error:
Uncaught TypeError: file.getAsText is not a function at HTMLButtonElement.sendfButton.onclick
First I browse and select a file, then click on send button.
This is my html input and button:
<tr>
<td>
<button type="button" class="control-button" id="send-file-button">SEND-FILE</button>
</td>
<td>
<input type='file' id='myfileinput' multiple><br>
<div id='output'>
</td>
</tr>
Here are my variables:
var sendfButton = document.getElementById("send-file-button");
var fileInput = document.getElementById("myfileinput");
And here is my click event handler:
sendfButton.onclick = function ()
{
var files = fileInput.files;
var accept = {
binary : ["image/png", "image/jpeg"],
text : ["text/plain", "text/css", "application/xml", "text/html" , "text/txt"]
};
var file;
if (conn && conn.open)
{
console.log('in1');
//convert a file to bytes then send it
for (var i = 0; i < files.length; i++)
{
console.log('in2');
file = files[i];
// if file type could be detected
if (file !== null)
{
console.log('in3');
if (accept.binary.indexOf(file.type) > -1)
{
console.log('in binary');
// file is a binary, which we accept
var data = file.getAsBinary();
console.log(data + 'dtat');
}
else if (accept.text.indexOf(file.type) > -1)
{
console.log('in text');
// file is of type text, which we accept
var data = file.getAsText();
console.log(data + 'dqata');
// modify data with string methods
}
}
}
console.log('out' + data);
conn.send(data);
console.log("fSent: " + data);
addMessage("<span class=\"selfMsg\">Self: </span> " + data);
}
else
{
console.log("failed fsend");
}
}
It seems to work when I run the code directly, but not when it is activated inside of the button event handler. Code 2 i add filereader but still there is a bug :
sendfButton.onclick = function ()
{
var files = fileInput.files;
var accept = {
binary : ["image/png", "image/jpeg"],
text : ["text/plain", "text/css", "application/xml", "text/html" , "text/txt"]
};
var file;
if (conn && conn.open)
{
console.log('in1');
//convert a file to bytes then send it
for (var i = 0; i < files.length; i++)
{
console.log('in2');
file = files[i];
var readers = new FileReader();
// if file type could be detected
if (file !== null)
{
console.log('in3');
if (accept.binary.indexOf(file.type) > -1)
{
console.log('in binary');
// file is a binary, which we accept
var data = readers.readAsBinaryString(file);
console.log(data + 'dtat');
}
else if (accept.text.indexOf(file.type) > -1)
{
console.log('in text');
// file is of type text, which we accept
var data = readers.readAsText(file);
console.log(data + 'dqata');
// modify data with string methods
}
}
}
console.log('out' + data);
conn.send(data);
console.log("fSent: " + data);
addMessage("<span class=\"selfMsg\">Self: </span> " + data);
}
else
{
console.log("failed fsend");
}
}
it returns undefined
The File.getAsText() method is obsolete. The File object is a specific kind of a Blob, so you can use the Blob.text() method instead. Replace file.getAsText() in your code with await file.text().
Edit: Another option that has better browser support is to use FileReader.readAsText(). Your code would look something like this:
var button = document.getElementById("send-file-button");
var fileInput = document.getElementById("myfileinput");
var output = document.getElementById("output");
button.onclick = function () {
var files = fileInput.files;
var reader = new FileReader();
reader.onload = function () {
output.innerText = reader.result;
};
if(files[0]) {
// This does not return the text. It just starts reading.
// The onload handler is triggered when it is done and the result is available.
reader.readAsText(files[0]);
}
};<input type='file' id='myfileinput' multiple>
<button type="button" class="control-button" id="send-file-button">SUBMIT-FILE</button>
<div id='output'>