I have written a quantity selector function to display on a page. The page can open some modals, which need to have another quantity selector within each.
I am calling the function within the main page, and also within the modal (to enable the functionality once the modal is displayed.)
When I adjust the quantity in the modal, close the modal, and adjust the quantity on the main page, the quantity increments/decrements double (or 3 times if I was to call the function 3 times.)
Is there a way to "reset" each of these event listeners/functions, to only adjust for their respective elements?
I've looked into "removeEventListener" but haven't had any joy in implementing this within my code.
Example of my work so far here (you can see what I mean if you click the buttons.)
https://codepen.io/777333/pen/zYoKYRN
const quantitySelector = () => {
const qtyGroups = document.querySelectorAll('.qty-group');
if(qtyGroups) {
qtyGroups.forEach((qtyGroup) => {
const qtyDecrease = qtyGroup.querySelector('[data-quantity-decrease]');
const qtyIncrease = qtyGroup.querySelector('[data-quantity-increase]');
const qtyInput = qtyGroup.querySelector('[data-quantity-input]');
const disableEnableDecrease = () => {
if(qtyInput.value == 1) {
qtyDecrease.disabled = true;
} else {
qtyDecrease.disabled = false;
}
};
qtyDecrease.addEventListener('click', (event) => {
event.preventDefault();
if(qtyInput.value > 1) {
qtyInput.value--;
}
disableEnableDecrease();
});
qtyIncrease.addEventListener('click', (event) => {
event.preventDefault();
qtyInput.value++;
disableEnableDecrease();
});
qtyInput.addEventListener('keyup', () => {
disableEnableDecrease();
});
});
}
};
quantitySelector(); // called within main page
quantitySelector(); // called within modal
The issue at hand is that each time you're calling the function, a new event handler is added on top of the previous ones. The best way to avoid this is through Event Delegation where you add a global event handler only once.
// A global event handler
document.addEventListener(
"click",
function (event) {
// Find the qty-group if clicked on it
const qtyGroup = event.target.closest(".qty-group");
// Stop if the click was elsewhere
if (qtyGroup) {
// Get your elements
const qtyDecrease = qtyGroup.querySelector("[data-quantity-decrease]");
const qtyIncrease = qtyGroup.querySelector("[data-quantity-increase]");
const qtyInput = qtyGroup.querySelector("[data-quantity-input]");
const disableEnableDecrease = () => {
if (qtyInput.value == 1) {
qtyDecrease.disabled = true;
} else {
qtyDecrease.disabled = false;
}
};
// Match your elements against what was clicked on.
if (event.target == qtyDecrease) {
event.preventDefault();
if (qtyInput.value > 1) {
qtyInput.value--;
}
disableEnableDecrease();
}
if (event.target == qtyIncrease) {
event.preventDefault();
qtyInput.value++;
disableEnableDecrease();
}
}
},
false
);
Instead of listening to individual elements, you can capture all the clicks on the document, and then finding those that click on elements of interest. You can make a second event handler for the keyup event.
You can save the value of qtyInput on mousedown event and then in the increment you add or subtract one from the saved value instead of the current value of the input.
const quantitySelector = () => {
const qtyGroups = document.querySelectorAll('.qty-group');
if(qtyGroups) {
qtyGroups.forEach((qtyGroup) => {
const qtyDecrease = qtyGroup.querySelector('[data-quantity-decrease]');
const qtyIncrease = qtyGroup.querySelector('[data-quantity-increase]');
const qtyInput = qtyGroup.querySelector('[data-quantity-input]');
const disableEnableDecrease = () => {
if(qtyInput.value == 1) {
qtyDecrease.disabled = true;
} else {
qtyDecrease.disabled = false;
}
};
let savedValue = null;
const saveState = (evebt) => savedValue = Number(qtyInput.value);
qtyDecrease.addEventListener('mousedown', saveState)
qtyIncrease.addEventListener('mousedown', saveState)
qtyDecrease.addEventListener('click', (event) => {
event.preventDefault();
event.stopPropagation();
if(qtyInput.value > 1) {
qtyInput.value = savedValue - 1;
}
disableEnableDecrease();
});
qtyIncrease.addEventListener('click', (event) => {
event.preventDefault();
event.stopPropagation();
qtyInput.value = savedValue + 1;
disableEnableDecrease();
});
qtyInput.addEventListener('keyup', () => {
disableEnableDecrease();
event.stopPropagation();
});
});
}
};
quantitySelector();
quantitySelector();
There is a method called removeEventListener (MDN) but I suggest you to reshape your code such that you do not add event listener if they are already present.
Put all of your addEventListener just when you create your elements, or in a "document ready" callback if they are instantiated by HTML code. Then, when you open your modal, just update your values.
UPDATING YOUR CODE
// hide/show modal function
function toggleModal() {
let modal = document.getElementById('modal');
modal.style.display = modal.style.display == 'none' ? 'block' : 'none';
}
// your document ready function
function onReady() {
const qtyGroups = document.querySelectorAll('.qty-group');
if(qtyGroups) {
qtyGroups.forEach((qtyGroup) => {
const qtyDecrease = qtyGroup.querySelector('[data-quantity-decrease]');
const qtyIncrease = qtyGroup.querySelector('[data-quantity-increase]');
const qtyInput = qtyGroup.querySelector('[data-quantity-input]');
const disableEnableDecrease = () => {
if(qtyInput.value == 1) {
qtyDecrease.disabled = true;
} else {
qtyDecrease.disabled = false;
}
};
qtyDecrease.addEventListener('click', (event) => {
event.preventDefault();
if(qtyInput.value > 1) {
qtyInput.value--;
}
disableEnableDecrease();
});
qtyIncrease.addEventListener('click', (event) => {
event.preventDefault();
qtyInput.value++;
disableEnableDecrease();
});
qtyInput.addEventListener('keyup', () => {
disableEnableDecrease();
});
});
}
// attach hide/show modal handler
const toggle = document.getElementById('modal_toggle');
toggle.addEventListener('click', toggleModal);
}
onReady();
<div class="qty-group">
<button data-quantity-decrease disabled>-</button>
<input data-quantity-input value="1">
<button data-quantity-increase>+</button>
</div>
<div class="qty-group" id="modal" style="display: none;">
<button data-quantity-decrease disabled>-</button>
<input data-quantity-input value="1">
<button data-quantity-increase>+</button>
</div>
<button id="modal_toggle">Toggle Modal</button>
REFACTORING
It is better in such cases to reason as Components. Components ensure code encapsulation, maintainability, reusage, single responsability and many other usefull principles:
// hide/show modal function
function toggleModal() {
// get the modal
let modal = document.getElementById('modal');
// hide the modal
modal.style.display = modal.style.display == 'none' ? 'block' : 'none';
// reset the input of the modal
modalInputReference.reset();
}
function createQuantityInput(target, initialQuantity=1, min=1, max=10, step=1) {
let quantity = 0;
// assign and check if should be disable, also bind to input value
let assign = (q) => {
quantity = Math.max(Math.min(q, max), min);
decrease.disabled = quantity <= min;
increase.disabled = quantity >= max;
input.value = quantity;
};
// CREATION
// This part is not mandatory, you can also get the elements from
// the target (document.querySelector('button.decrease') or similar)
// and then attach the listener.
// Creation is better: ensure encapsulation and single responsability
// create decrease button
let decrease = document.createElement('button');
decrease.addEventListener('click', () => { assign(quantity - step); });
decrease.innerText = '-';
// create increase button
let increase = document.createElement('button');
increase.addEventListener('click', () => { assign(quantity + step); });
increase.innerText = '+'
// create input field
let input = document.createElement('input');
input.value = quantity
input.addEventListener('change', () => { assign(parseFloat(input.value)); });
// resetting the quantity
assign(initialQuantity);
// appending the new component to its parent
target.appendChild(decrease);
target.appendChild(input);
target.appendChild(increase);
// return a reference to manipulate this component
return {
get quantity() { return quantity; },
set quantity(q) { assign(q); },
assign,
reset: () => assign(initialQuantity)
};
}
// this will be your modal reference
let modalInputReference;
function onReady() {
// inject all qty-group with a "quantityInput" component
document.querySelectorAll('.qty-group').forEach(elem => {
let input = createQuantityInput(elem);
if (elem.id == 'modal') {
// if it is the modal I save it for later use
// this is just an hack for now,
// a full code should split this part into a "modal" component maybe
modalInputReference = input;
}
});
// emualte the modal
let toggle = document.getElementById('modal_toggle')
toggle.addEventListener('click', toggleModal)
}
// this function should be wrapped by a
// $(document).ready(onReady) or any other
// function that ensure that all the DOM is successfully loaded
// and the code is not executed before the browser has generated
// all the elements present in the HTML
onReady();
<div class="qty-group"></div>
<div class="qty-group" id="modal" style="display: none;"></div>
<button id="modal_toggle">Toggle Modal</button>
It is shorter (without comments) and also more maintenable. Don't trust who says it is overengineered, it is just kind of time to learn to reason this way, then is much easier and faster. It is just a time investment to waste less time in the future. Try figure out why React or Angular(JS) have climbed the charts of the best frameworks so fast.
I use google MATERIAL COMPONENTS FOR THE WEB and have problems with the "Dialogs".
Check my codepen: Dialog
What do I have to do to have multiple dialogs per page?
JS:
// Find all the dialogs on the page
const dialogEls = Array.from(document.querySelectorAll('.mdc-dialog'));
dialogEls.forEach((ele) => {
const dialog = new mdc.dialog.MDCDialog(ele);
dialog.listen('MDCDialog:accept', function() {
console.log('accepted');
})
dialog.listen('MDCDialog:cancel', function() {
console.log('canceled');
})
// From here I do not know how to continue....
// Here the selector '#dialog-login' should still be dynamic
document.querySelector('#dialog-login').addEventListener('click', function (evt) {
event.preventDefault(evt);
dialog.lastFocusedTarget = evt.target;
// This shows all dialogs, which is wrong.
dialog.show();
})
});
I have updated answer from #Jodo.
I suggest for dynamic approach using data attribute on dialog tags with value of opening button.
// Find all the dialogs on the page
const dialogEls = Array.from(document.querySelectorAll('.mdc-dialog'));
dialogEls.forEach((ele) => {
const dialog = new mdc.dialog.MDCDialog(ele);
dialog.listen('MDCDialog:accept', function() {
console.log('accepted');
})
dialog.listen('MDCDialog:cancel', function() {
console.log('canceled');
})
document.querySelector('#' + ele.dataset.dialog).addEventListener('click', function (evt) {
dialog.show();
});
});
https://codepen.io/woytam/pen/abvdZBQ?editors=1010
Simply add data-dialog attribute to each dialog with value of your button/link. JavaScript function then will use ele.dataset.dialog in foreach.
The Dialog opens twice because you create two event listeners for #dialog-login.
One of them opens the Login Dialog the other one opens the Delivery Dialog.
Since you have two different distinct Dialogs, I would suggest a more static way and declare both dialogs independently:
const dialogLoginEle = document.getElementById('mdc-dialog-login');
const dialogLogin = new mdc.dialog.MDCDialog(dialogLoginEle);
dialogLogin.listen('MDCDialog:accept', function() {
console.log('accepted login');
});
dialogLogin.listen('MDCDialog:cancel', function() {
console.log('canceled login');
});
const dialogDeliveryEle = document.getElementById('mdc-dialog-delivery-condition');
const dialogDelivery = new mdc.dialog.MDCDialog(dialogDeliveryEle);
dialogDelivery.listen('MDCDialog:accept', function() {
console.log('accepted delivery');
});
dialogDelivery.listen('MDCDialog:cancel', function() {
console.log('canceled delivery');
});
document.querySelector('#dialog-login').addEventListener('click', function (evt) {
dialogLogin.show();
});
document.querySelector('#dialog-delivery').addEventListener('click', function (evt) {
dialogDelivery.show();
});
https://codepen.io/j-o-d-o/pen/XZqNYy?editors=1010
Here a "dynamic" approach as requested, but IMHO this is not very readable and error prone.
// Find all the dialogs on the page
const dialogEls = Array.from(document.querySelectorAll('.mdc-dialog'));
// First one is the Login, Second one is the Delivery
var dialogArr = [];
dialogEls.forEach((ele) => {
const dialog = new mdc.dialog.MDCDialog(ele);
dialog.listen('MDCDialog:accept', function() {
console.log('accepted');
})
dialog.listen('MDCDialog:cancel', function() {
console.log('canceled');
})
dialogArr.push(dialog);
});
document.querySelector('#dialog-login').addEventListener('click', function (evt) {
dialogArr[0].show();
});
document.querySelector('#dialog-delivery').addEventListener('click', function (evt) {
dialogArr[1].show();
});
https://codepen.io/j-o-d-o/pen/jZxmxa?editors=1010
I am trying to bind the value=".."-attribute from an <input>-field to a JsViews observable, so that changes made from a JS datepicker will get detected by the JsView framework.
Example
On initial rendering, the data-linked observedDate parameter is displayed in the <input>-field:
<input class="flatpickr-calendar" type="text" data-link="observedDate">
Then, selecting a new date using the flatpickr javascript tool, the new date will be stored in the value=".."-field:
<input class="flatpickr-calendar" type="text" data-link="observedDate" value="2017-05-09">
The problem
There is now a divergence between the date handled by observedDate and the value-attribute:
JsViews does not detect the change in the value-attribute.
Does anyone have some suggestion as of how to handle this situation? Thanks.
You need an event onChange update value observedDate.
For example, you can do so:
$(".flatpickr").flatpickr({
onChange: function(selectedDates, dateStr, instance) {
$.observable($.view(this.input).data).setProperty("observedDate", dateStr);
},
});
full code.
Update
Or you can create custom tag:
$.views.tags({
flatpickr: {
template: "<input/>",
onUpdate: false,
dataBoundOnly: true,
flatpickr: null,
isChange: false,
changeEvent: function (selectedDates, dateStr, instance) {
this.isChange = true;
this.update(dateStr);
this.isChange = false;
},
onDispose: function () {
if (this.flatpickr) {
this.flatpickr.destroy();
}
},
onAfterLink: function (tagCtx, linkCtx) {
var tag = this;
var props = tagCtx.props;
var options = {
defaultDate: tagCtx.args[0]
};
if (tag._.unlinked) {
if (!tag.linkedElem) {
tag.linkedElem = tag._.inline ? tag.contents("*").first() : $(linkCtx.elem);
}
$.each(props, function (key, prop) {
var option;
if (key.charAt(0) === "_") {
key = key.slice(1);
options[key] = prop;
}
});
options.onChange = $.proxy(tag.changeEvent, tag);
this.flatpickr = tag.linkedElem.flatpickr(options);
} else {
if (!this.isChange) {
this.flatpickr.setDate(options.defaultDate)
}
}
}
}
});
And use:
{^{flatpickr observedDate /}}
full code
Support flatpickr options:
{^{flatpickr observedDate _inline=true _maxDate='2018-05-01' _minDate='2017-05-01'/}}
full code
We can use file.onchange if we gonna set an event callback for file reading using javascript, but how to set event for when user cancel the upload (close the browse panel)?
There is no API for the file input modal. Besides, if the user closes the browser your code won't be running anymore, will it?
Of course there is the window.onunload method which allows you to detect the example you give.
Per the comments, the best thing I can come up with that would be helpful is that if nothing is selected, file.value.length will be 0.
That’s a great solution:
const createUpload = () => {
let lock = false
return new Promise((resolve, reject) => {
const el = document.createElement('input');
el.id = +new Date();
el.style.display = 'none';
el.setAttribute('type', 'file');
document.body.appendChild(el)
el.addEventListener('change', () => {
lock = true;
const file = el.files[0];
resolve(file)
document.body.removeChild(document.getElementById(el.id));
}, { once: true })
window.addEventListener('focus', () => { // file blur
setTimeout(() => {
if (!lock && document.getElementById(el.id)) {
reject(new Error('onblur'))
document.body.removeChild(document.getElementById(el.id))
}
}, 300)
}, { once: true })
el.click() // open file select box
})
}
Ussage:
// $label.classList.add('loading');
createUpload()
.then(function (file) {
// Sent file
// $label.classList.remove('loading');
})
.catch(function (err) {
// Your Cancel Event
// $label.classList.remove('loading');
});
It is very simple with jQuery :
$("#fileInputId").change(function () {
//implement your code here
});
How I can programmatically detect when text input filled by typing on keyboard and when it filled automatically by bar-code scanner?
I wrote this answer, because my Barcode Scanner Motorola LS1203 generated keypress event, so I can't use Utkanos's solution.
My solution is:
var BarcodeScanerEvents = function() {
this.initialize.apply(this, arguments);
};
BarcodeScanerEvents.prototype = {
initialize: function() {
$(document).on({
keyup: $.proxy(this._keyup, this)
});
},
_timeoutHandler: 0,
_inputString: '',
_keyup: function (e) {
if (this._timeoutHandler) {
clearTimeout(this._timeoutHandler);
this._inputString += String.fromCharCode(e.which);
}
this._timeoutHandler = setTimeout($.proxy(function () {
if (this._inputString.length <= 3) {
this._inputString = '';
return;
}
$(document).trigger('onbarcodescaned', this._inputString);
this._inputString = '';
}, this), 20);
}
};
Adapted the super useful Vitall answer above to utilize an IIFE instead of prototyping, in case anyone just seeing this now is into that.
This also uses the 'keypress' event instead of keyup, which allowed me to reliably use KeyboardEvent.key, since KeyboardEvent.which is deprecated now. I found this to work for barcode scanning as well as magnetic-strip card swipes.
In my experience, handling card swipes with keyup caused me to do extra work handling 'Shift' keycodes e.g. a Shift code would be followed by the code representing '/', with the intended character being '?'. Using 'keypress' solved this as well.
(function($) {
var _timeoutHandler = 0,
_inputString = '',
_onKeypress = function(e) {
if (_timeoutHandler) {
clearTimeout(_timeoutHandler);
}
_inputString += e.key;
_timeoutHandler = setTimeout(function () {
if (_inputString.length <= 3) {
_inputString = '';
return;
}
$(e.target).trigger('altdeviceinput', _inputString);
_inputString = '';
}, 20);
};
$(document).on({
keypress: _onKeypress
});
})($);
Well a barcode won't fire any key events so you could do something like:
$('#my_field').on({
keypress: function() { typed_into = true; },
change: function() {
if (typed_into) {
alert('type');
typed_into = false; //reset type listener
} else {
alert('not type');
}
}
});
Depending on when you want to evaluate this, you may want to do this check not on change but on submit, or whatever.
you can try following example, using jQuery plugin https://plugins.jquery.com/scannerdetection/
Its highly configurable, time based scanner detector. It can be used as solution for prefix/postfix based, time based barcode scanner.
Tutorial for usage and best practices, as well discussed about various Barcode Scanner Models and how to deal with it. http://a.kabachnik.info/jquery-scannerdetection-tutorial.html
$(window).ready(function(){
//$("#bCode").scannerDetection();
console.log('all is well');
$(window).scannerDetection();
$(window).bind('scannerDetectionComplete',function(e,data){
console.log('complete '+data.string);
$("#bCode").val(data.string);
})
.bind('scannerDetectionError',function(e,data){
console.log('detection error '+data.string);
})
.bind('scannerDetectionReceive',function(e,data){
console.log('Recieve');
console.log(data.evt.which);
})
//$(window).scannerDetection('success');
<input id='bCode'type='text' value='barcode appears here'/>
For ES6 2019 version of Vitall answer.
const events = mitt()
class BarcodeScaner {
initialize = () => {
document.addEventListener('keypress', this.keyup)
if (this.timeoutHandler) {
clearTimeout(this.timeoutHandler)
}
this.timeoutHandler = setTimeout(() => {
this.inputString = ''
}, 10)
}
close = () => {
document.removeEventListener('keypress', this.keyup)
}
timeoutHandler = 0
inputString = ''
keyup = (e) => {
if (this.timeoutHandler) {
clearTimeout(this.timeoutHandler)
this.inputString += String.fromCharCode(e.keyCode)
}
this.timeoutHandler = setTimeout(() => {
if (this.inputString.length <= 3) {
this.inputString = ''
return
}
events.emit('onbarcodescaned', this.inputString)
this.inputString = ''
}, 10)
}
}
Can be used with react hooks like so:
const ScanComponent = (props) => {
const [scanned, setScanned] = useState('')
useEffect(() => {
const barcode = new BarcodeScaner()
barcode.initialize()
return () => {
barcode.close()
}
}, [])
useEffect(() => {
const scanHandler = code => {
console.log(code)
setScanned(code)
}
events.on('onbarcodescaned', scanHandler)
return () => {
events.off('onbarcodescaned', scanHandler)
}
}, [/* here put dependencies for your scanHandler ;) */])
return <div>{scanned}</div>
}
I use mitt from npm for events, but you can use whatever you prefer ;)
Tested on Zebra DS4208
The solution from Vitall only works fine if you already hit at least one key. If you don't the first character will be ignored (if(this._timeoutHandler) returns false and the char will not be appended).
If you want to begin scanning immediately you can use the following code:
var BarcodeScanerEvents = function() {
this.initialize.apply(this, arguments);
};
BarcodeScanerEvents.prototype = {
initialize : function() {
$(document).on({
keyup : $.proxy(this._keyup, this)
});
},
_timeoutHandler : 0,
_inputString : '',
_keyup : function(e) {
if (this._timeoutHandler) {
clearTimeout(this._timeoutHandler);
}
this._inputString += String.fromCharCode(e.which);
this._timeoutHandler = setTimeout($.proxy(function() {
if (this._inputString.length <= 3) {
this._inputString = '';
return;
}
$(document).trigger('onbarcodescaned', this._inputString);
this._inputString = '';
}, this), 20);
}
};
If you can set a prefix to your barcode scanner I suggests this (I changed a bit the Vitall code):
var BarcodeScanner = function(options) {
this.initialize.call(this, options);
};
BarcodeScanner.prototype = {
initialize: function(options) {
$.extend(this._options,options);
if(this._options.debug) console.log("BarcodeScanner: Initializing");
$(this._options.eventObj).on({
keydown: $.proxy(this._keydown, this),
});
},
destroy: function() {
$(this._options.eventObj).off("keyup",null,this._keyup);
$(this._options.eventObj).off("keydown",null,this._keydown);
},
fire: function(str){
if(this._options.debug) console.log("BarcodeScanner: Firing barcode event with string: "+str);
$(this._options.fireObj).trigger('barcode',[str]);
},
isReading: function(){
return this._isReading;
},
checkEvent: function(e){
return this._isReading || (this._options.isShiftPrefix?e.shiftKey:!e.shiftKey) && e.which==this._options.prefixCode;
},
_options: {timeout: 600, prefixCode: 36, suffixCode: 13, minCode: 32, maxCode: 126, isShiftPrefix: false, debug: false, eventObj: document, fireObj: document},
_isReading: false,
_timeoutHandler: false,
_inputString: '',
_keydown: function (e) {
if(this._input.call(this,e))
return false;
},
_input: function (e) {
if(this._isReading){
if(e.which==this._options.suffixCode){
//read end
if(this._options.debug) console.log("BarcodeScanner: Read END");
if (this._timeoutHandler)
clearTimeout(this._timeoutHandler);
this._isReading=false;
this.fire.call(this,this._inputString);
this._inputString='';
}else{
//char reading
if(this._options.debug) console.log("BarcodeScanner: Char reading "+(e.which));
if(e.which>=this._options.minCode && e.which<=this._options.maxCode)
this._inputString += String.fromCharCode(e.which);
}
return true;
}else{
if((this._options.isShiftPrefix?e.shiftKey:!e.shiftKey) && e.which==this._options.prefixCode){
//start reading
if(this._options.debug) console.log("BarcodeScanner: Start reading");
this._isReading=true;
this._timeoutHandler = setTimeout($.proxy(function () {
//read timeout
if(this._options.debug) console.log("BarcodeScanner: Read timeout");
this._inputString='';
this._isReading=false;
this._timeoutHandler=false;
}, this), this._options.timeout);
return true;
}
}
return false;
}
};
If you need you customize timeout, suffix, prefix, min/max ascii code readed:
new BarcodeScanner({timeout: 600, prefixKeyCode: 36, suffixKeyCode: 13, minKeyCode: 32, maxKeyCode: 126});
I also added the isShiftPrefix option to use for example the $ char as prefix with these options: new BarcodeScanner({prefixKeyCode: 52, isShiftPrefix: true});
This is a fiddle: https://jsfiddle.net/xmt76ca5/
You can use a "onkeyup" event on that input box. If the event has triggered then you can called it "Input from Keyboard".
$(window).ready(function(){
//$("#bCode").scannerDetection();
console.log('all is well');
$(window).scannerDetection();
$(window).bind('scannerDetectionComplete',function(e,data){
console.log('complete '+data.string);
$("#bCode").val(data.string);
})
.bind('scannerDetectionError',function(e,data){
console.log('detection error '+data.string);
})
.bind('scannerDetectionReceive',function(e,data){
console.log('Recieve');
console.log(data.evt.which);
})
//$(window).scannerDetection('success');
<input id='bCode'type='text' value='barcode appears here'/>
Hi I have and alternative solution for evaluate a result of the bar code scanner without use of jQuery, first you need and input text that have a focus the moment that the barcode scanner is works
<input id="input_resultado" type="text" />
The code in JavaScript is:
var elmInputScan = document.getElementById('input_resultado');
elmInputScan.addEventListener('keypress', function (e){
clearInterval( timer_response );
timer_response = setTimeout( "onInputChange()", 10);
});
When the barcode scanner input the text call serveral times to the keypress event, but only I interested to the final result, for this reason I use the timer. That's all, you can process the value into the onInputChange function.
function onInputChange() {
console.log( document.getElementById('input_resultado').value );
}
document.addEventListener("keypress", function (e) {
if (e.target.tagName !== "INPUT") {
// it's your scanner
}
});
None of the solutions worked for me because I don't want to focus on an input. I want the result page(item details page) to keep listening for the scanner to scan next item. My scanner fires the keypress event so this worked like a charm for me.
var inputTemp = '';
var inputTempInterval = setInterval(function() {
// change 5 as minimum length of the scan code
if (inputTemp.length >= 5) {
var detected = inputTemp;
inputTemp = '';
clearInterval(inputTempInterval); // stop listening if you don't need anymore
onScannerTrigger(detected);
} else {
inputTemp = '';
}
}, 100);
$(window).keypress(function(e){
inputTemp += String.fromCharCode(e.which);
});
function onScannerTrigger(scannedCode) {
console.log(scannedCode);
// do your stuff
}
I have published a lightweight JS package which doesn't rely on jQuery or input fields. It simple looks at the timing of the keyPress-events to determine wether it was a barcode scanner or regular input.
https://www.npmjs.com/package/#itexperts/barcode-scanner
import {BarcodeScanner} from "#itexperts/barcode-scanner";
let options = {
timeOut: 130,
characterCount: 13
}
let barcodeScanner = new BarcodeScanner(options);
barcodeScanner.addEventListener('scan', function(e){
let barcode = e.detail;
console.log(barcode);
});
I highly recommend this js plugin https://github.com/axenox/onscan.js
It's easy to use and has tones of options to meet your need.
<script src="path-to-onScan.js"></script>
<script>
// Initialize with options
onScan.attachTo(document, {
suffixKeyCodes: [13], // enter-key expected at the end of a scan
reactToPaste: true, // Compatibility to built-in scanners in paste-mode (as opposed to keyboard-mode)
onScan: function(sCode, iQty) { // Alternative to document.addEventListener('scan')
console.log('Scanned: ' + iQty + 'x ' + sCode);
},
onKeyDetect: function(iKeyCode){ // output all potentially relevant key events - great for debugging!
console.log('Pressed: ' + iKeyCode);
}
});
</script>