Importing a file in Javascript using Ubuntu

how do I import a file in Javascript on Ubuntu? Here is my current code:

TextFile.js

var file = null;
function createFile()
{
    file = new StreamReader();
    file.open("~//home//chris//LcdDisplayFile//qml//file.txt");
}

function readLine()
{
    var str = file.readLine();
    return str;
}

For some reason it cannot find the file. I am new to both jscript and ubuntu. Error:

file:///home/chris/LcdDisplayFile/qml/TextFile.js:10: TypeError: Result of expression 'fi开发者_Python百科le' [null] is not an object.

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~ already points to /home/chris/. Also, why did you use a double //?^[1] These slashes have no special meaning inside a string.

^[1]Windows directories are separated by a backslash (\), which have a special meaning in JavaScript strings (escape character), hence \\. Normal slashes do not have to be escaped, and can be safely written as / (One exception: Regular expressions)

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Don't know anything about QML, I assume it supports IO and provides it own class for reading streams and that you are using it correctly. Either way your file path is invalid... shouldn't it just be:

var path = '~/LcdDisplayFile/qml/file.txt'

or

var path = '/home/chris/LcdDisplayFile/qml/file.txt'

Also keep in mine Linux file paths are case-sensitive.

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Unless you are using a non-standard server-side extension of JavaScript such as NodeJS ( http://nodejs.org/docs/v0.5.9/api/fs.html#fs.open ), file I/O is not part of the standard set of objects. JavaScript in the browser does not support file I/O.

At any rate, the main problem here is, what and where is the StreamReader object. If the given JavaScript environment provides it, then the object should not be a null.

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Here's some documentation regarding using javascript with QML. I hope this helps:

http://qt-project.org/doc/qt-5.0/qtqml/qtqml-javascript-imports.html