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Read Simple JSON file (almost done)

I have a input and when I load it shows the file right in console.log.
But how do I get the actual json data from the file??
$('#importFlow').change(function () {
var files = event.target.files;
var file = files[0];
console.log(file);
console.log(JSON.parse(file)); //doesn't work
});

You'd need to use the FileReader API.
$('#importFlow').change(function () {
var files = event.target.files;
var file = files[0];
var reader = new FileReader();
reader.onload = function(event) {
var jsonObject = JSON.parse(event.target.result);
console.log(jsonObject); // Logs the parsed JSON
}
reader.readAsText(file);
});

You can read actual file content like this:
$('#importFlow').change(function () {
var files = event.target.files;
var reader, fileContent;
if (this.files)
{
reader = new FileReader();
reader.onload = function (e)
{
fileContent = e.target.result;
}
reader.readAsDataURL(this.files[0]);
}
});
In the above code, you can get the actual file data in the "fileContent" variable.

how do you upload a filestream/buffer in winrt html/JavaScript?

I want to read a file from local storage and upload it via ajax. How is this done?

In most browsers, you can use FileReader to read data from file inputs. There are various functions for reading the data; this example uses the function that returns an ArrayBuffer containing all the bytes:
<script>
window.onload = function() {
document.getElementById('upload').onchange = function(e) {
var file = e.target.files[0];
var fileReader = new FileReader();
fileReader.onload = function(e) {
var bytes = e.target.result;
console.log(bytes);
};
fileReader.readAsArrayBuffer(file);
};
};
</script>
<input type = 'file' id = 'upload' />

I managed to figure it out. Here's the code for anyone interested.
var form = new FormData();
form.append("data", angular.toJson(message));
var bytes = new Uint8Array(audio.length); //audio is an IBuffer
var dataReader = Windows.Storage.Streams.DataReader.fromBuffer(audio);
dataReader.readBytes(bytes);
dataReader.close();
var media = new Blob([bytes], { type: "application/octet-stream" }); //application/octet-stream or audio/mpeg?
form.append("attached_files", media, "recording-aac.caf");
return $http.post(AppSettings.baseUri + "api/sendmessage", form, { headers: { "Content-Type": undefined } });

open excel file with xlsx.js by path

Hi i want to open excel file with xlsx extension with xlsx.js library.
I can open file by html input but i want to open it by using file path.
I have this code extracted from xlsx.js demo:
function handleFile(e) {
rABS = false;
use_worker = false;
console.log(e);
var files = e.target.files;
var f = files[0]; {
var reader = new FileReader();
var name = f.name;
reader.onload = function (e) {
if (typeof console !== 'undefined')
console.log("onload", new Date(), rABS, use_worker);
var data = e.target.result;
console.log("target result >>>>>>>>> " + e.target.result);
if (use_worker) {
xw(data, process_wb);
} else {
var wb;
if (rABS) {
wb = X.read(data, {
type : 'binary'
});
} else {
var arr = fixdata(data);
wb = X.read(btoa(arr), {
type : 'base64'
});
}
process_wb(wb);
}
};
if (rABS)
reader.readAsBinaryString(f);
else
reader.readAsArrayBuffer(f);
}
}
I want something like this:
var file = new File([""],"C:\\Users\\PalFS\\Downloads\\Fiverr_Example_List (1).xlsx");
var data = file;
How to do this or how can i convert this file into arraybuffer like it is returned from, var data = e.target.result;.
Thanks

You could use --allow-file-access-from-files flag at chrome, chromium with XMLHttpRequest , .responseType set to "arraybuffer" to retrieve .xlsx file from local filesystem as ArrayBuffer; set new File() data to returned ArrayBuffer. Second parameter at new File() constructor should set the .name property of created file.
Launch /path/to/chrome --allow-file-access-from-files
var request = new XMLHttpRequest();
// may be necessary to escape path string?
request.open("GET", "C:\\Users\\PalFS\\Downloads\\Fiverr_Example_List (1).xlsx");
request.responseType = "arraybuffer";
request.onload = function () {
// this.response should be `ArrayBuffer` of `.xlsx` file
var file = new File(this.response, "Fiverr_Example_List.xlsx");
// do stuff with `file`
};
request.send();

How can I console.log() a Blob object?

I have a Blob object I want to inspect by logging its value. All I can see are type and size properties. Is there a way to do this?

Basic example on using a FileReader to look at the content in a blob
var html= ['<a id="anchor">Hello World</a>'];
var myBlob = new Blob(html, { type: 'text/xml'});
var myReader = new FileReader();
myReader.onload = function(event){
console.log(JSON.stringify(myReader.result));
};
myReader.readAsText(myBlob);

First of all we should create a function for converting blob to base64:
const blobToBase64 = blob => {
const reader = new FileReader();
reader.readAsDataURL(blob);
return new Promise(resolve => {
reader.onloadend = () => {
resolve(reader.result);
};
});
};
Then we can use this function to use it for console.log:
blobToBase64(blobData).then(res => {
console.log(res); // res is base64 now
// even you can click on it to see it in a new tab
});

How do I write FileReader test in Jasmine?

I'm trying to make this test work, but I couldn't get my head around how to write a test with FileReader. This is my code
function Uploader(file) {
this.file = file;
}
Uploader.prototype = (function() {
function upload_file(file, file_contents) {
var file_data = new FormData()
file_data.append('filename', file.name)
file_data.append('mimetype', file.type)
file_data.append('data', file_contents)
file_data.append('size', file.size)
$.ajax({
url: "/upload/file",
type: "POST",
data: file_contents,
contentType: file.type,
success: function(){
// $("#thumbnail").attr("src", "/upload/thumbnail");
},
error: function(){
alert("Failed");
},
xhr: function() {
myXhr = $.ajaxSettings.xhr();
if(myXhr.upload){
myXhr.upload.addEventListener('progress',showProgress, false);
} else {
console.log("Upload progress is not supported.");
}
return myXhr;
}
});
}
return {
upload : function() {
var self = this,
reader = new FileReader(),
file_content = {};
reader.onload = function(e) {
file_content = e.target.result.split(',')[1];
upload_file(self.file, file_content);
}
}
};
})();
And this is my test
describe("Uploader", function() {
it("should upload a file successfully", function() {
spyOn($, "ajax");
var fakeFile = {};
var uploader = new Uploader(fakeFile);
uploader.upload();
expect($.ajax.mostRecentCall.args[0]["url"]).toEqual("/upload/file");
})
});
But it never gets to reader.onload.

The problem here is the use of reader.onload which is hard to test. You could use reader.addEventListener instead so you can spy on the global FileReader object and return a mock:
eventListener = jasmine.createSpy();
spyOn(window, "FileReader").andReturn({
addEventListener: eventListener
})
then you can fire the onload callback by yourself:
expect(eventListener.mostRecentCall.args[0]).toEqual('load');
eventListener.mostRecentCall.args[1]({
target:{
result:'the result you wanna test'
}
})

This syntax changed in 2.0. Code below gives an example based on Andreas Köberle's answer but using the new syntax
// create a mock object, its a function with some inspection methods attached
var eventListener = jasmine.createSpy();
// this is going to be returned when FileReader is instantiated
var dummyFileReader = { addEventListener: eventListener };
// pipe the dummy FileReader to the application when FileReader is called on window
// this works because window.FileReader() is equivalent to new FileReader()
spyOn(window, "FileReader").and.returnValue(dummyFileReader)
// your application will do something like this ..
var reader = new FileReader();
// .. and attach the onload event handler
reader.addEventListener('load', function(e) {
// obviously this wouldnt be in your app - but it demonstrates that this is the
// function called by the last line - onloadHandler(event);
expect(e.target.result).toEqual('url');
// jasmine async callback
done();
});
// if addEventListener was called on the spy then mostRecent() will be an object.
// if not it will be null so careful with that. the args array contains the
// arguments that addEventListener was called with. in our case arg[0] is the event name ..
expect(eventListener.calls.mostRecent().args[0]).toEqual('load');
// .. and arg[1] is the event handler function
var onloadHandler = eventListener.calls.mostRecent().args[1];
// which means we can make a dummy event object ..
var event = { target : { result : 'url' } };
// .. and call the applications event handler with our test data as if the user had
// chosen a file via the picker
onloadHandler(event);

I also faced similar problem and was able to achieve it without use of addeventlistener. I had used onloadend, so below is what I did.
My ts file had below code:-
let reader = new FileReader();
reader.onloadend = function() {
let dataUrl = reader.result;
// Some working here
};
reader.readAsDataURL(blob);
My spec file (test) case code :-
let mockFileReader = {
result:'',
readAsDataURL:(blobInput)=> {
console.log('readAsDataURL');
},
onloadend:()=> {
console.log('onloadend');
}
};
spyOn<any>(window, 'FileReader').and.returnValue(mockFileReader);
spyOn<any>(mockFileReader, 'readAsDataURL').and.callFake((blobInput)=> {
// debug your running application and assign to "encodedString" whatever
//value comes actually after using readAsDataURL for e.g.
//"data:*/*;base64,XoteIKsldk......"
mockFileReader.result = encodedString;
mockFileReader.onloadend();
});
This way you have mocked the FileReader object and returned a fake call to your own "readAsDataURL". And thus now when your actual code calls "reasAsDataURL" your fake function is called in which you are assigning an encoded string in "result" and calling "onloadend" function which you had already assigned a functionality in your code (.ts) file. And hence it gets called with expected result.
Hope it helps.

I think the best way is to use the real FileReader (don't mock it), and pass in a real File or Blob. This improves your test coverage and makes your tests less brittle.
If your tests don't run in IE, you can use the File constructor, e.g.
const fakeFile = new File(["some contents"], "file.txt", {type: "text/plain"});
If you need to be compatible with IE, you can construct a Blob and make it look like a file:
const fakeFile = new Blob(["some contents"]);
fakeFile.name = "file.txt";
fakeFile.type = "text/plain";
The FileReader can read either of these objects so there is no need to mock it.

i found easiest for myself to do next.
mock blob file
run reader.onload while in test environment.
as result - i do not mock Filereader
// CONTROLLER
$scope.handleFile = function (e) {
var f = e[0];
$scope.myFile = {
name: "",
size: "",
base64: ""
};
var reader = new FileReader();
reader.onload = function (e) {
try {
var buffer = e.target.result;
$scope.myFile = {
name: f.name,
size: f.size,
base64: XLSX.arrayBufferToBase64(buffer)
};
$scope.$apply();
} catch (error) {
$scope.error = "ERROR!";
$scope.$apply();
}
};
reader.readAsArrayBuffer(f);
//run in test env
if ( typeof jasmine == 'object') {reader.onload(e)}
}
//JASMINE TEST
it('handleFile 0', function () {
var fileContentsEncodedInHex = ["\x45\x6e\x63\x6f\x64\x65\x49\x6e\x48\x65\x78\x42\x65\x63\x61\x75\x73\x65\x42\x69\x6e\x61\x72\x79\x46\x69\x6c\x65\x73\x43\x6f\x6e\x74\x61\x69\x6e\x55\x6e\x70\x72\x69\x6e\x74\x61\x62\x6c\x65\x43\x68\x61\x72\x61\x63\x74\x65\x72\x73"];
var blob = new Blob(fileContentsEncodedInHex);
blob.type = 'application/zip';
blob.name = 'name';
blob.size = 11111;
var e = {0: blob, target: {result: {}}};
$scope.handleFile(e);
expect($scope.error ).toEqual("");
});

I struggled to figure out how to test onloadend when it gets called from readAsDataURL.
Here is a dump of what I ended up with.
Production code:
loadFileDataIntoChargeback(tempFileList) {
var fileNamesAndData = [];
for (var i = 0, f; f = tempFileList[i]; i++) {
let theFile = tempFileList[i];
var reader = new FileReader();
reader.onloadend = ((theFile) => {
return (fileData) => {
var insertionIndex = this.chargeback.fileList.length;
this.chargeback.fileList.push({ FileName: theFile.name, Data: fileData.target.result, FileType: theFile.type });
this.loadFilePreviews(theFile, insertionIndex);
}
})(f);
reader.readAsDataURL(f);
}
this.fileInputPath = "";
}
Test code:
describe('when the files are loaded into the chargeback', () => {
it('loads file previews', () => {
let mockFileReader = {
target: { result: '' },
readAsDataURL: (blobInput) => {},
onloadend: () => {}
};
spyOn(chargeback, "loadFilePreviews");
spyOn(window, 'FileReader').and.returnValue(mockFileReader);
spyOn(mockFileReader, 'readAsDataURL').and.callFake((blobInput) => {
mockFileReader.onloadend({ target: { result: "data:image/jpeg;base64,/9j/4QAYRXh" } });
});
var readFileList = chargeback.getArrayFromFileInput([getImageFile1()]);
chargeback.loadFileDataIntoChargeback(readFileList);
expect(chargeback.loadFilePreviews).toHaveBeenCalled();
});
});