Angular.js - ngModel value is undefined when ng-pattern is set in directive

问题

something similar may have been answered (ng-pattern + ng-change) but all responses were unable to fix this issue.

I have two imbricated directives for creating a form input, a parent directive to control name, label, validator etc. and a child directive to set pattern and input type specific stuff.

However, when setting a pattern, the value on my model is set to undefined when ng-pattern return false.

Directives:

<input-wrapper ng-model="vm.customer.phone" name="phone" label="Phone number">
    <input-text type="tel"></input-text>
</input-wrapper>

Generated HTML:

<label for="phone">Phone number:</label>
<input type="text" name="phone" 
  ng-model="value"
  ng-model-options="{ updateOn: \'blur\' }"
  ng-change="onChange()"
  ng-pattern="/^[\+]?[(]?[0-9]{3}[)]?[-\s\.]?[0-9]{3}[-\s\.]?[0-9]{4,6}$/">

JS:

angular.module('components', [])
    .directive('inputWrapper', function() {
    return {
        restrict: 'E',
        require: 'ngModel',
        scope: true,
        link: function (scope, element, attrs, ngModel) {
          scope.name = attrs.name;
          scope.label = attrs.label;

          scope.onChange = function () {
            ngModel.$setViewValue(scope.value);
          };

          ngModel.$render = function () {
            scope.value = ngModel.$modelValue;
          };
        }
    }
    })
  .directive('inputText', function() {
    return {
        restrict: 'E',
        template: '<label for="{{name}}">{{label}}:</label><input type="text" name="{{name}}" ng-model="value" ng-model-options="{ updateOn: \'blur\' }" ng-change="onChange()" ng-pattern="pattern">',
        link: function (scope, element, attrs) {

          if (attrs.type === 'tel') {
            scope.pattern = /^[\+]?[(]?[0-9]{3}[)]?[-\s\.]?[0-9]{3}[-\s\.]?[0-9]{4,6}$/;
          }
        }
    }
    });

angular.module('app',['components'])
        .controller('ctrl',function($scope){
          var vm = this;

          vm.customer = {
            phone: '010203040506'
          };
        });

What am I doing wrong ?

Codepen for use case: https://codepen.io/Yosky/pen/yVrmvw

回答1:

By default in angular if a validator fail, undefined value assigned to ng-model, You can change this setting as follow :

 <div ng-model-options="{ allowInvalid: true}">

read here for detail docs

回答2:

I had some requirements that meant that I really really didn't want ng-model to write out undefined to the scope when validation was invalid, and I didn't want the invalid value either, so allowInvalid didn't help. In stead I just wanted ng-model do not write anything, but I couldn't find any option for this.

So I couldn't see any way forward except for doing some monkey patching of the ng-model controller.

So first I required ngModel in the component I was building require: { model: 'ngModel' } and then I did this in the $onInit hook:

const writeModelToScope = this.model.$$writeModelToScope;
const _this = this;
this.model.$$writeModelToScope = function() {
    const allowInvalid = _this.model.$options.getOption('allowInvalid');
    if (!allowInvalid && _this.model.$invalid) {
        return;
    }
    writeModelToScope.bind(this)();
};

I also didn't want to take in a new model value while the value was invalid and the component had focus, so I did:

const setModelValue = this.model.$$setModelValue;
this.model.$$setModelValue = function(modelValue) {
    _this.lastModelValue = modelValue;
    if (_this.model.$invalid) {
        return;
    }
    if (_this.hasFocus) {
        return;
    }
    setModelValue.bind(this)(modelValue);
};

element.on('focus', () => {
    this.hasFocus = true;
});

element.on('blur', (event) => {
    this.hasFocus = false;
    const allowInvalid = this.model.$options.getOption('allowInvalid');
    if (!allowInvalid && this.model.$invalid) {
        this.value = this.lastModelValue;
    }
    event.preventDefault();
});

Feel free to judge me, just know that I already feel dirty.

来源：https://stackoverflow.com/questions/41301290/angular-js-ngmodel-value-is-undefined-when-ng-pattern-is-set-in-directive