Javascript / DOM, parsing Key/Value string

Question

I send a string from a server to the Firefox Browser in the format below:

"KEY:a1 VAL:123.45"

And this string can contain many such records.

Here is the code I have written:

    var e;
    var reply = request.responseText;
    var txt = "", tab, key = "", val = "";
    var x = reply.getElementsByTagName("KEY:");
    for(i = 0; i < x.length; i++)
    {
        txt = x[i].childNodes[0].nodeValue; // "KEY:%c%c VAL:%.2F"
        tab = txt.split(":");
        key = "table_" + tab[1].substring(0,1);
        val = tab[2];
        e = document.getElementById(key);
        e.innerHTML = val;
        e.style.display = "block";
    }

val displays "KEY:a1 VAL:123.45" instead of the expected "123.45" (and of course the key variable is also wrong, not matching a table cell, just picking the first one in the table).

I don't even know how to display the key and val values (document.write() and alert() do nothing and I don't see how to trace this code in Firefox).

Any idea, tip, correction, or code example is welcome but please don't recommend using any library, I want to do it with little code.

EDIT: from the two comments, I understand that there are two distinct ways to proceed: either using DOM objects and HTML tags, or using 'strings'. I would prefer to keep using the format above, so please guide me to a 'string' solution. Thanks!

reply is not a DOM element, it's a string. Strings don't have a a method getElementsByTagName and that string does not even contain HTML. — Felix Kling
– Felix Kling, Commented Mar 9, 2012 at 17:47
Thanks for the information. Can you elaborate how should I do it then? (either creating 'objects' and using HTML tags, or parsing a 'string' - the latter having my favor) — Gil
– Gil, Commented Mar 9, 2012 at 17:53

Felix Kling · Accepted Answer · 2012-03-09 18:03:38Z

2

You can use a simple regular expression to extract the information from the string:

var value = "KEY:a1 VAL:123.45",
    pattern = /KEY:(\S+) VAL:(.+)$/g;

var result = pattern.exec(value);
// result[1] == 'a1'
// result[2] == '123.45'

In your case, you'd use request.responseText instead of value.

answered Mar 9, 2012 at 18:03

Felix Kling

820k181 gold badges1.1k silver badges1.2k bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Felix Kling Over a year ago

Don't forget to accept the answer that helped you the most ;)

Collectives™ on Stack Overflow

Javascript / DOM, parsing Key/Value string

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related