Scan barcode into a specific textbox

Question

I am working on bar-code scanners. The bar-code scanner that I am using is a plug-n-play type and scans the code automatically wherever you place the cursor. But what i want is that whether i can scan it to a specific text-box on a web page everytime my scanner reads a code

For eg, if my form looks like this

<input type="text" name="txtItem" id="txtItem" class="m-wrap w-120" tabindex="6">

<input type="text" name="itemId" id="itemId" class="m-wrap w-120" tabindex="6">

<input type="text" name="itemName" id="itemName" class="m-wrap w-120" tabindex="6">

<input type="text" name="itemQty" id="itemQty" class="m-wrap w-120" tabindex="6">

so everytime i scan a code it should always appear in the txtitem text-box no matter where my current focus is.

Can anybody guide me or help me find a solution here??

Answer 1

Some Barcode Scanners act just like another input device. The form cannot tell the difference between information being entered by a keyboard vs. a scanner unless you use a timer to monitor how quickly it is entered.

Some scanners "paste" the values in to the focused control - others send each individual key stroke.

The following JSFiddle is able to detect when input occurs when characters are sent individually on a single control:

http://jsfiddle.net/PhilM/Bf89R/3/

You could adapt this to make it a delegate for the whole form and remove the input from the control it was input into and put it into the correct form.

The test html for the fiddle is this:

<form>
    <input id="scanInput" />
    <button id="reset">Reset</button>
</form>
<br/>
<div>
    <h2>Event Information</h2>
    Start: <span id="startTime"></span> 
    <br/>First Key: <span id="firstKey"></span> 
    <br/>Last Ley: <span id="lastKey"></span> 
    <br/>End: <span id="endTime"></span> 
    <br/>Elapsed: <span id="totalTime"></span>
</div>
<div>
    <h2>Results</h2>
    <div id="resultsList"></div>
</div>

The Javascript for the sample fiddle is:

/*
    This code will determine when a code has been either entered manually or
    entered using a scanner.
    It assumes that a code has finished being entered when one of the following
    events occurs:
        • The enter key (keycode 13) is input
        • The input has a minumum length of text and loses focus
        • Input stops after being entered very fast (assumed to be a scanner)
*/

var inputStart, inputStop, firstKey, lastKey, timing, userFinishedEntering;
var minChars = 3;

// handle a key value being entered by either keyboard or scanner
$("#scanInput").keypress(function (e) {
    // restart the timer
    if (timing) {
        clearTimeout(timing);
    }

    // handle the key event
    if (e.which == 13) {
        // Enter key was entered

        // don't submit the form
        e.preventDefault();

        // has the user finished entering manually?
        if ($("#scanInput").val().length >= minChars){
            userFinishedEntering = true; // incase the user pressed the enter key
            inputComplete();
        }
    }
    else {
        // some other key value was entered

        // could be the last character
        inputStop = performance.now();
        lastKey = e.which;

        // don't assume it's finished just yet
        userFinishedEntering = false;

        // is this the first character?
        if (!inputStart) {
            firstKey = e.which;
            inputStart = inputStop;

            // watch for a loss of focus
            $("body").on("blur", "#scanInput", inputBlur);
        }

        // start the timer again
        timing = setTimeout(inputTimeoutHandler, 500);
    }
});

// Assume that a loss of focus means the value has finished being entered
function inputBlur(){
    clearTimeout(timing);
    if ($("#scanInput").val().length >= minChars){
        userFinishedEntering = true;
        inputComplete();
    }
};


// reset the page
$("#reset").click(function (e) {
    e.preventDefault();
    resetValues();
});

function resetValues() {
    // clear the variables
    inputStart = null;
    inputStop = null;
    firstKey = null;
    lastKey = null;
    // clear the results
    inputComplete();
}

// Assume that it is from the scanner if it was entered really fast
function isScannerInput() {
    return (((inputStop - inputStart) / $("#scanInput").val().length) < 15);
}

// Determine if the user is just typing slowly
function isUserFinishedEntering(){
    return !isScannerInput() && userFinishedEntering;
}

function inputTimeoutHandler(){
    // stop listening for a timer event
    clearTimeout(timing);
    // if the value is being entered manually and hasn't finished being entered
    if (!isUserFinishedEntering() || $("#scanInput").val().length < 3) {
        // keep waiting for input
        return;
    }
    else{
        reportValues();
    }
}

// here we decide what to do now that we know a value has been completely entered
function inputComplete(){
    // stop listening for the input to lose focus
    $("body").off("blur", "#scanInput", inputBlur);
    // report the results
    reportValues();
}

function reportValues() {
    // update the metrics
    $("#startTime").text(inputStart == null ? "" : inputStart);
    $("#firstKey").text(firstKey == null ? "" : firstKey);
    $("#endTime").text(inputStop == null ? "" : inputStop);
    $("#lastKey").text(lastKey == null ? "" : lastKey);
    $("#totalTime").text(inputStart == null ? "" : (inputStop - inputStart) + " milliseconds");
    if (!inputStart) {
        // clear the results
        $("#resultsList").html("");
        $("#scanInput").focus().select();
    } else {
        // prepend another result item
        var inputMethod = isScannerInput() ? "Scanner" : "Keyboard";
        $("#resultsList").prepend("<div class='resultItem " + inputMethod + "'>" +
            "<span>Value: " + $("#scanInput").val() + "<br/>" +
            "<span>ms/char: " + ((inputStop - inputStart) / $("#scanInput").val().length) + "</span></br>" +
            "<span>InputMethod: <strong>" + inputMethod + "</strong></span></br>" +
            "</span></div></br>");
        $("#scanInput").focus().select();
        inputStart = null;
    }
}

$("#scanInput").focus();

The code above does not support copy/paste, but in our situation this is unlikely to happen anyway.