本地.txt文件上的XMLHttpRequest（）在除Firefox以外的所有浏览器中返回空的responseText

Question

For some reason my XMLHttpRequest().responseText is empty when trying to pull from a file contained in the same subdirectory.

I'm not checking for XMLHttpRequest().status == 200 , because from what I have been able to discover during my searches, status will always be 0 if the requested file is local - an issue I had encountered minutes before when I was checking for XMLHttpRequest().readyState == 4 && XMLHttpRequest().status == 200 . This is due to not going through a webserver.

The file (data.txt) contains plain text, but the responseText is always returned empty, and I cannot figure out why. Any help will be greatly appreciated!

UPDATE: Seems it works in Firefox, but not Chrome (with which I was using to test), or IE. These browser aren't putting data into responseText, so does anyone know why, or better, how to rectify it?

function loadData()
{
    var request = new XMLHttpRequest();
    request.open("GET", "data.txt", true);
    request.onreadystatechange = function()
    {
        if (request.readyState == 4)
            useData(request.responseText);
    }
    request.send(null);
}

Answer 1

This is by design to prevent javascript exploits shared as for example attachments in mail files (as something along the lines of domains doesn't exist for desktop application and there is just a single filesystem). For development you can disable this security feature in chrome by using the --disable-web-security flag, but in general you just have to accept that that's impossible.