Angular 表单验证中的奇怪行为

Question

I am using an Angular directive to validate a form through a regex. A minimal representation of the code and HTML is given below.

The issue: The weird behavior is the following: the form signals an error with inputs of even length but not with inputs of odd length. Example keystrokes:

a --> valid

aa --> invalid

aaa --> valid

aaaa --> invalid

This happens both when typing and deleting letters. However, if I past aaaa or any string of even length it shows no error. I doubt it might be due to Angular digest loop, but I cannot figure out the issue.

Any clues on what I might want to look at?

Code

This is my directive:

var valid_input_regex = /^[\w]+$/g;

directives.directive('pn', function() {
return {
    require: 'ngModel',
    link: function(scope, elm, attrs, ctrl) {
        ctrl.$validators.pn = function(modelValue, viewValue) {
            if (!valid_input_regex.test(modelValue)) {
                return false;
            }
            return true;
        };
    }
};
});

And in the HTML

<input type="text" class="form-control" name="name" ng-model="name" pn>
<span ng-show="(form.name.$error.pn && !form.name.$pristine)">Please use plain text or numbers.</span>

Answer 1

get rid of the 'g' at the end of your regex

var valid_input_regex = /^[\w]+$/;

Should work then