[jquery] How do I block or restrict special characters from input fields with jquery?

Restrict specials characters on keypress. Here's a test page for key codes: http://www.asquare.net/javascript/tests/KeyCode.html

var specialChars = [62,33,36,64,35,37,94,38,42,40,41];

some_element.bind("keypress", function(event) {
// prevent if in array
   if($.inArray(event.which,specialChars) != -1) {
       event.preventDefault();
   }
});

In Angular, I needed a proper currency format in my textfield. My solution:

var angularApp = angular.module('Application', []);

...

// new angular directive
angularApp.directive('onlyNum', function() {
    return function( scope, element, attrs) {

        var specialChars = [62,33,36,64,35,37,94,38,42,40,41];

        // prevent these special characters
        element.bind("keypress", function(event) {
            if($.inArray(event.which,specialChars) != -1) {
                prevent( scope, event, attrs)
             }
        });

        var allowableKeys = [8,9,37,39,46,48,49,50,51,52,53,54,55,56
            ,57,96,97,98,99,100,101,102,103,104,105,110,190];

        element.bind("keydown", function(event) {
            if($.inArray(event.which,allowableKeys) == -1) {
                prevent( scope, event, attrs)
            }
        });
    };
})

// scope.$apply makes angular aware of your changes
function prevent( scope, event, attrs) {
    scope.$apply(function(){
        scope.$eval(attrs.onlyNum);
        event.preventDefault();
    });
    event.preventDefault();
}

In the html add the directive

<input only-num type="text" maxlength="10" id="amount" placeholder="$XXXX.XX"
   autocomplete="off" ng-model="vm.amount" ng-change="vm.updateRequest()">

and in the corresponding angular controller I only allow there to be only 1 period, convert text to number and add number rounding on 'blur'

...

this.updateRequest = function() {
    amount = $scope.amount;
    if (amount != undefined) {
        document.getElementById('spcf').onkeypress = function (e) {
        // only allow one period in currency
        if (e.keyCode === 46 && this.value.split('.').length === 2) {
            return false;
        }
    }
    // Remove "." When Last Character and round the number on blur
    $("#amount").on("blur", function() {
      if (this.value.charAt(this.value.length-1) == ".") {
          this.value.replace(".","");
          $("#amount").val(this.value);
      }
      var num = parseFloat(this.value);
      // check for 'NaN' if its safe continue
      if (!isNaN(num)) {
        var num = (Math.round(parseFloat(this.value) * 100) / 100).toFixed(2);
        $("#amount").val(num);
      }
    });
    this.data.amountRequested = Math.round(parseFloat(amount) * 100) / 100;
}

...

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