用栏杆输入条形码，而无需单击输入字段

Question

I'm curious right now if it's possible to have a usb barcode scanner connected to a pc and if you just scan something it should just check the database for the product.

more details:

We got a CRM written in rails now if you click on a input field you can simple scan and everything is just fine but is it possible to let the people do whatever they want but if they scan it should automatically check the database for the product? even if they don't click into a input field?

scanner: http://www.conrad.at/medias/global/ce/9000_9999/9100/9140/9144/914408_LB_00_FB.EPS_1000.jpg

tl;dr

usb barcode scanner -> scanning and query database without clicking into input fields

edit:

Alright now i have copied some code from a site, it bassically captures the barcode and prints it out. Now I'd like to hide the form but still get the input printed is this possible somehow?

http://www.deadosaurus.com/demos/barcode.html

There is a form but i just want a keylogger like tool which checks for any input without input fields.

Thanks guys!

    var pressed = false; 
    var chars = []; 
    $(window).keypress(function(e) {
        if (e.which >= 48 && e.which <= 57) {
            chars.push(String.fromCharCode(e.which));
        }
        console.log(e.which + ":" + chars.join("|"));
        if (pressed == false) {
            setTimeout(function(){
                if (chars.length >= 10) {
                    var barcode = chars.join("");
                    console.log("Barcode Scanned: " + barcode);
                    // assign value to some input (or do whatever you want)
                    $("#barcode").val(barcode);
                }
                chars = [];
                pressed = false;
            },500);
        }
        pressed = true;
    });
});
$("#barcode").keypress(function(e){
    if ( e.which === 13 ) {
        console.log("Prevent form submit.");
        e.preventDefault();
    }
});

Answer 1

This is possible, I've done it once for a warehouse application. But it might depend on the type of barcode scanner you use.

Most barcode scanners will return the scanned code terminated by a newline character . If you focus the input field after the page has loaded, the user can scan a product and the form will be submitted automatically.

So it's as simple as:

<form action="..." method="post">
  <input type="text" name="barcode" autofocus />
</form>

Answer 2

This theoretically, is possible.

Most barcode scanners can be programmed, by scanning programming barcodes from the manual.

In our application, every barcode scanner gets programmed to have a prefix followed by the scanned data, and then suffix, which as @zwippie pointed out is usually carriage return (enter key) character.

[prefix] + [data] + [suffix]

So you could watch for the prefix, capture the data, and submit on the carriage return.