Javascript: Read Text File using AJAX

Question

Can't get AJAX to work! I have a marquee on a website, got it working! But I want it to find the text of the marquee in a text file, and I want it to read the text in the text file (which is one line) and assign it to the variable called content, which is a global variable in the script tag.

When I run the website (local IIS), the marquee text is: "undefined" (without the quotes).

Why isn't it assigning the text to the variable content?

    var content

    function loadXMLDoc()
    {   
        var textfile;
        if (window.XMLHttpRequest)
        { 
            textfile = new XMLHttpRequest(); 
        }
        textfile.onreadystatechange = function ()
        {   
            if (textfile.readyState == 4 && textfile.status == 200)
            { 
                content = textfile.responseText; 
            }
        }
        textfile.open("GET", "C:\Users\Fares\Dropbox\Sync\College\Computing\DeltaOne\MarqueeText.txt", true);
        textfile.send();
    }

EDIT: A million thanks to @kuncajs, as he pointed out I forgot to call the function! :) Fixed! Thanks to everyone else!

Thanks @BLSully for the formatting – Fares K. A. Mar 21 '13 at 12:34 — Fares K. A., Mar 21 '13 at 12:34

kuncajs · Accepted Answer · 2013-03-21T12:41:40.227

2

Do not use local paths like: C:\Users\Fares\Dropbox\Sync\College\Computing\DeltaOne\MarqueeText.txt

Place it in the www directory of your IIS and state the path like: localhost/text.txt

The server can have restricted access to your filesystem and also you should try relative paths like text.txt or absolute paths /text.txt so the paths work even when you deploy it in the production environment.

EDIT: So if this did not help then make sure that you really call the loadXMLDoc() function. Also check that everything you do is after the AJAX ends! I mean you do the assignment in the if - when AJAX is done but you should also initialize your marquee !AFTER! the text is loaded. If you do it before it will be undefined

edited Mar 21 '13 at 12:41

answered Mar 21 '13 at 12:26

kuncajs

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Hiya! Thanks @kuncajs! Just did as you told me, still got "undefined" in the marquee box unfortunately. I tried also removing "localhost/" and keeping just the text file name. The text file is in the root folder of the www. – Fares K. A. Mar 21 '13 at 12:29
OK, it works for me: I have got `textfile.open("GET", "text.txt", true);` the files text.txt is in the same directory as my html file with JS. Are you sure you are really calling `loadXMLDoc()` somewhere in your code - i mean executing the function? – kuncajs Mar 21 '13 at 12:37
Ah! You're right @kuncajs I forgot to call the function! It's working now, thanks a million!!! – Fares K. A. Mar 21 '13 at 12:40

score 0 · Answer 2 · answered Mar 21 '13 at 12:38

Try using a relative or absolute path first.

If that doesn't work check that when using your browser you can access the file (let's say your website is on mysite.com/index.html, try opening mysite.com/text.txt)

If you can't access it using your browser then you will have to configure your server to allow this file to be read, never tried IIS so I can't help you there.

Also since you are asking your XHR to be asynchronous it might take a little time before the variable is populated (depending on your/your server's speed)

Javascript: Read Text File using AJAX

2 Answers2

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