Question

I am trying to do something like this:

JavaScript:

function readMultipleFiles(evt) {
    //Retrieve all the files from the FileList object
    var files = evt.target.files;
    window.array = []
    if (files) {
        for (var i = 0, f; f = files[i]; i++) {
            var r = new FileReader();
            r.onload = (function (f) {
                return function (e) {
                    var contents = e.target.result;
                    window.array.push(contents);
                };
            })(f);
            r.readAsText(f);
        }
        alert(window.array);
    } else {
        alert("Failed to load files");
    }
}
document.getElementById('fileinput').addEventListener('change', readMultipleFiles, false);​

HTML:

<input type="file" id="fileinput" multiple />

So that I can read local files locally.
However, instead I want to store the file contents in an array of this format:

[file1Contents, file2Contents, file3Contents... etc]

How would I go about this? I tried setting a global variable (e.g. window.fileContents) and updating inside the on.load, but that did not work

Thanks

Answer 1

I’m not exactly sure what you’re looking to do, but I’ll give it a swing. I see that you’re already reading the file as text.. could you not just shove that into the array there? I’ve modified your code below:

var masterFileArray = [];  // where I will store the contents

function readMultipleFiles(evt) {
    //Retrieve all the files from the FileList object
    var files = evt.target.files;
    window.array = []
    if (files) {
        for (var i = 0, f; f = files[i]; i++) {
            var r = new FileReader();
            r.onload = (function (f) {
                return function (e) {
                    var contents = e.target.result;
                    window.array.push(contents);
                    masterFileArray.append({name:f.name, contents: contents}); // storing as object
                };
            })(f);
            r.readAsText(f);
        }
        console.log(masterFileArray);
    } else {
        alert("Failed to load files");
    }
}
document.getElementById('fileinput').addEventListener('change', readMultipleFiles, false);