Currently, I am facing a problem on a mobile device. I have an input field where only some keys are allowed to be pressed: e.g. only the numbers 0–9. It works fantastic on a web browser. But when I open it in my Android mobile device it fails.

I have used keyup and keypress. keyup is working but I want to know which key fired the event from the mobile keyboard. How would I get that?

Currently, I am facing a problem on a mobile device. I have an input field where only some keys are allowed to be pressed: e.g. only the numbers 0–9. It works fantastic on a web browser. But when I open it in my Android mobile device it fails.

I have used keyup and keypress. keyup is working but I want to know which key fired the event from the mobile keyboard. How would I get that?

• javascript
• android
• jquery
• mobile
• keyevent

• you can use event.keyCode or event.key to get key info. Try this: document.onkeyup = function(e){ console.log(e); } – Dipen Shah Commented Aug 13, 2015 at 4:42
• Possible duplicate of stackoverflow./questions/302122/… – Kushal Commented Aug 13, 2015 at 4:43
• problem is that some keycode in mobile will having same keycode that are for numeric so it will allows that keys also.I have faced same problem and i e around answer that i have give here – Juned Lanja Commented Aug 13, 2015 at 5:08
• 1 @Jugnu when i already tried this type of code. First thing when you write keyCode or charCode it will gives on only 229 0 result. So how would you know which key press currently. – Arya Commented Aug 13, 2015 at 5:20
• 1 @Kushal yes all the browsers gave the keycode on keypress but not on android mobile chrome browser. It will give only in desktops. – Arya Commented Aug 13, 2015 at 6:51

2 Answers 2

I'm using a array that has maping to all keyboard keys with keycode at given index and then on element's keydown i'm checking whether its allowed key or not, because in mobile some keyboard key will have the same code as numeric key's keycode so it will allow that keys.

So i'm using following to prevent that situation.

//keyboard maping array   
var keyboardMap = ["", "", "", "CANCEL", "", "", "HELP", "", "BACK_SPACE", "TAB", "", "", "CLEAR", "ENTER", "RETURN", "", "SHIFT", "CONTROL", "ALT", "PAUSE", "CAPS_LOCK", "KANA", "EISU", "JUNJA", "FINAL", "HANJA", "", "ESCAPE", "CONVERT", "NONCONVERT", "ACCEPT", "MODECHANGE", "SPACE", "PAGE_UP", "PAGE_DOWN", "END", "HOME", "LEFT", "UP", "RIGHT", "DOWN", "SELECT", "PRINT", "EXECUTE", "PRINTSCREEN", "INSERT", "DELETE", "", "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "COLON", "SEMICOLON", "LESS_THAN", "EQUALS", "GREATER_THAN", "QUESTION_MARK", "AT", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "WIN", "", "CONTEXT_MENU", "", "SLEEP", "NUMPAD0", "NUMPAD1", "NUMPAD2", "NUMPAD3", "NUMPAD4", "NUMPAD5", "NUMPAD6", "NUMPAD7", "NUMPAD8", "NUMPAD9", "MULTIPLY", "ADD", "SEPARATOR", "SUBTRACT", "DECIMAL", "DIVIDE", "F1", "F2", "F3", "F4", "F5", "F6", "F7", "F8", "F9", "F10", "F11", "F12", "F13", "F14", "F15", "F16", "F17", "F18", "F19", "F20", "F21", "F22", "F23", "F24", "", "", "", "", "", "", "", "", "NUM_LOCK", "SCROLL_LOCK", "WIN_OEM_FJ_JISHO", "WIN_OEM_FJ_MASSHOU", "WIN_OEM_FJ_TOUROKU", "WIN_OEM_FJ_LOYA", "WIN_OEM_FJ_ROYA", "", "", "", "", "", "", "", "", "", "CIRCUMFLEX", "EXCLAMATION", "DOUBLE_QUOTE", "HASH", "DOLLAR", "PERCENT", "AMPERSAND", "UNDERSCORE", "OPEN_PAREN", "CLOSE_PAREN", "ASTERISK", "PLUS", "PIPE", "HYPHEN_MINUS", "OPEN_CURLY_BRACKET", "CLOSE_CURLY_BRACKET", "TILDE", "", "", "", "", "VOLUME_MUTE", "VOLUME_DOWN", "VOLUME_UP", "", "", "", "", "COMMA", "", "PERIOD", "SLASH", "BACK_QUOTE", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "OPEN_BRACKET", "BACK_SLASH", "CLOSE_BRACKET", "QUOTE", "", "META", "ALTGR", "", "WIN_ICO_HELP", "WIN_ICO_00", "", "WIN_ICO_CLEAR", "", "", "WIN_OEM_RESET", "WIN_OEM_JUMP", "WIN_OEM_PA1", "WIN_OEM_PA2", "WIN_OEM_PA3", "WIN_OEM_WSCTRL", "WIN_OEM_CUSEL", "WIN_OEM_ATTN", "WIN_OEM_FINISH", "WIN_OEM_COPY", "WIN_OEM_AUTO", "WIN_OEM_ENLW", "WIN_OEM_BACKTAB", "ATTN", "CRSEL", "EXSEL", "EREOF", "PLAY", "ZOOM", "", "PA1", "WIN_OEM_CLEAR", ""];
//Allowed keys as per your requirement          
var allowedKey = ["0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "NUMPAD0", "NUMPAD1", "NUMPAD2", "NUMPAD3", "NUMPAD4", "NUMPAD5", "NUMPAD6", "NUMPAD7", "NUMPAD8", "NUMPAD9", "DELETE", "BACK_SPACE", "DECIMAL", "LEFT", "RIGHT", "TAB", "SUBTRACT", "PERIOD"];

//bind keydown to your element
element.on("keydown", function (e) {
        var key = e.charCode || e.keyCode || 0;
        var keyValue = keyboardMap[key];
        if ($.inArray(keyValue, allowedKey) !== -1){
              return true;
        }
        else{
              return  false;
        }
}

It's working for me hope so it will work for you also.

var input_field = document.getElementById('chatBot-input');
input_field.addEventListener('textInput', function (ev) {
  var char = ev.data; // In our example = "a"
  var keyCode = char.charCodeAt(0); // a = 97
  console.log(keyCode)
});

This will definitely works.