Develop Reference

Download file converted from Blob

In Javascript, test browser is Firefox. I have converted files to an array of bytes to store on my server and have used the subsequent code to convert the bytes back to a file, but I am unsure as to how to download the newly created file with appropriate file type can anyone please direct me?
to blob
$('input[type="file"]').change(function(e){
function convertFile(file){
return Array.prototype.map.call(new Uint8Array(file), x => ('00' + x.toString(16)).slice(-2)).join('');
}
file = event.target.files[0];
fileName = file.name;
fileSplit = fileName.split('.');
last = fileSplit.length-1;
let fileType = fileSplit[last];
$('#FileNameVisible').text(fileName);
var reader = new FileReader();
reader.readAsArrayBuffer(file);
reader.onload = function(e) {
fileData = e.target.result;
fileData = convertFile(e.target.result);
console.log(fileData);
};
reader.onerror = function() {
console.log(reader.error);
};
});
from Blob
var file = new File([dataUse], "File", {lastModified: Date.now()});
console.log(file);

Import xlsx file into html page via javascript

I want to read the data of a specific xlsx file into javascript to show them on a .html page.
For that i downloaded sheetjs. A .xlsx parser.
But now I realized that you kinda must choose a file in the html site to read it. But I only want to use one file the whole time. Also the html site will only run local. So is there any way to get going with setting up a absolute path in the js to the file. So something like
file= "C:\test.xlsx"
Code example from the documemtary:
function handleFile(e) {
var files = e.target.files;
var i,f;
for (i = 0, f = files[i]; i != files.length; ++i) {
var reader = new FileReader();
var name = f.name;
reader.onload = function(e) {
var data = e.target.result;
var workbook = XLSX.read(data, {type: 'binary'});
/* DO SOMETHING WITH workbook HERE */
};
reader.readAsBinaryString(f);
}
}
input_dom_element.addEventListener('change', handleFile, false);

ParseFile javascript - saved as bytes

I'm trying to save PDF file as ParseFile using Parse javascript SDK:
HTML
<input type="file" id="profilePhotoFileUpload" onchange="selectFile(event)">
JS
function selectFile(e) {
var fileUploadControl = $("#profilePhotoFileUpload")[0];
var file = fileUploadControl.files[0];
var parseFile = new Parse.File("doc.pdf", file);
parseFile.save().then(function(){
var test = new Parse.Object("TestObject");
test.set("file",parseFile);
test.save();
}, function(error) {
});
}
and i'm getting bytes result as:
http://files.parsetfss.com/637e62db-7116-473c-97dc-48ad15ce73ca/tfss-f5f522d0-0634-4e98-9f2a-be659e5dac00-asdasdas.pdf
any solution?

SOLVED
default file data is Text.
i used FileReader to get data as base64 and then i save data like this:
fr = new FileReader();
fr.onload = receivedText;
fr.readAsDataURL(file);
function receivedText() {
result = fr.result;
var res = result.split("base64,");
var name = "myFile.pdf";
var parseFile = new Parse.File(name, { base64: res[1] });
parseFile.save().then(function() {
console.log("object saved!");
}, function(error) {
// The file either could not be read, or could not be saved to Parse.
});
}

FileReader to String

Consider the following code
function readSingleFile(evt) {
//Retrieve the first (and only!) File from the FileList object
var myFile = evt.target.files[0];
var reader = new FileReader();
reader.readAsText(myFile);
var myString = reader.toString();
alert(myString); // print - "[object FileReader]"
}
I try to get all the file content into String , for example if the file content is
helloWorld1
helloWorld2
I will get alert of that's content .

That's not how you get the result of a FileReader. Modify your code to this:
function readSingleFile(evt) {
//Retrieve the first (and only!) File from the FileList object
var myFile = evt.target.files[0];
var reader = new FileReader();
reader.readAsText(myFile);
reader.onload=function(){alert(reader.result)}
}

Using HTML 5 File API to load a JSON file

I want the user to be be able to chose a JSON file on there computer, this JSON file should then be made available to the client side Javascript.
How would I do this using the FILE API, the ultimate goal is the the user selected JSON file to be available as an object which I can then play about with in Javascript. This is what I have so far:
JsonObj = null
function handleFileSelect(evt) {
var files = evt.target.files; // FileList object
f = files[0];
var reader = new FileReader();
// Closure to capture the file information.
reader.onload = (function(theFile) {
return function(e) {
// Render thumbnail.
JsonObj = e.target.result
console.log(JsonObj);
};
})(f);
// Read in the image file as a data URL.
reader.readAsDataURL(f);
}
document.getElementById('files').addEventListener('change', handleFileSelect, false);
FIDDLE: http://jsfiddle.net/jamiefearon/8kUYj/
How would I convert the variable JsonObj to a proper Json object, one can can add new fields to etc.

Don't load the data as a "DataUrl" via readAsDataURL, instead use readAsText then parse it via JSON.parse()
e.g.
JsonObj = null
function handleFileSelect(evt) {
var files = evt.target.files; // FileList object
f = files[0];
var reader = new FileReader();
// Closure to capture the file information.
reader.onload = (function(theFile) {
return function(e) {
// Render thumbnail.
JsonObj = JSON.parse(e.target.result);
console.log(JsonObj);
};
})(f);
// Read in the image file as a data URL.
reader.readAsText(f);
}
document.getElementById('files').addEventListener('change', handleFileSelect, false);