angularJs - Custom validation rules for form - angularjs

I'm working on a form where I'd like to have some custom validation rules like:
field 2 has to be larger than field 1
field 3 is required if field 2 is not negative
...
HTML
<table>
<tr><th>Category</th><th> > </th> ≤ <th></tr>
<tr><td>Green</td>
<td><input type="number" id="field1" ng-model="green.low"/></td>
<td><input type="number" id="field2" ng-model="green.high"/></td></tr>
</table>
JS
I check the validation this way:
function verifyForm(form, scope) {
if (form.$error.required) {
scope.addAlert("danger", "[![base.error.msg.required_fields]]");
return false;
}
if (!form.$valid) {
scope.addAlert("danger", "[![base.error.msg.invalid_form]]");
return false;
}
return true;
};
So when the submit button is clicked, I just have to do this:
if (!verifyForm($scope.formName, $scope))
return;
How can I add those custom validation rules? Or, if I have to write them myself in javascript, how can I "invalidate" certain elements?

I think the right Angular approach to this kind of problem is creating directives that perform custom validation.
It's not very intuitive, and you'll probably have to spend a few minutes learning the basic idea, but when it works, it's actually one of the great powers of Angular.
Here's how a validator for 'greater-than-other-input' might look like:
angular.module('myApp', []).directive('gtOther', function() {
return {
restrict: 'A',
require: 'ngModel',
link: function(scope, elm, attrs, ctrl) {
ctrl.$validators.gtOther = function(modelValue, viewValue) {
var other = scope.$eval(attrs['gtOther']);
var thisValue = parseInt(viewValue);
return thisValue > other;
};
}
};
});
Here's a working plunkr

for field2 valid use:
<input type="number" max={{field1}}>
for field3 use:
<input type="number" ng-required="field2>0">

Related

compare two input field values in a table using angular

I am a beginner in angularjs and I am trying to make a dynamic table but with custom validations. for instance, I have 2 input fields namely totalSalary and pension paid. The pension paid entered should not be greater than the totalSalary. I am trying to build a custom directive for the pension paid field but how to get the value of the totalSalary field to do the comparison?
Thanks to help.
Ashley
Updated:
This is the table I have made so far as per the next link. Dynamic table made so far
Below are two fields I need to compare.
<td><input type="text" class="form-control" ng-model="employee.details.salary" fcsa-number required/></td>
<td><input type="text" class="form-control" ng-model="employee.details.pension" fcsa-number not-greater-than-yearly-sal required/></td>
The directive so far I have worked on is as per below. I got the value of pension1 but now how to get the value of salary. On leaving the input for pension1, if the amount is greater than the salary, it should prompt the user and clear the value.
angular.module('app').directive("notGreaterThanYearlySal", function () {
return {
restrict: "A",
require: "?ngModel",
link: function (scope, element, attributes, ngModel) {
element.bind('blur', function(event){
alert(element.val());
});
}
};
});
One way you achieve with custom directives
for example here i match email :
<p>Email:<input type="email" name="email1" ng-model="emailReg">
Repeat Email:<input type="email" name="email2" ng-model="emailReg2" ng-match="emailReg"></p>
<span data-ng-show="myForm.emailReg2.$error.match">Emails have to match!</span>
Without using custom Directives :
<button ng-click="add()></button>
<span ng-show="IsMatch">Emails have to match!</span>
$scope.add = function() {
if ($scope.emailReg != $scope.emailReg2) {
$scope.IsMatch=true;
return false;
}
$scope.IsMatch=false;
}
I think this is a really neat way of doing this. You could set something like ng-max to the second input and set it's value as the other inputs ng-model. Then according to this you could show a error message.
<form name="numberForm">
First input:
<input type="number" name="number1" ng-model="number1">
Second input:
<input type="number" name="number2" ng-model="number2" ng-max="number1">
<span ng-show="numberForm.number2.$error.max">This field should not be larger than the other</span>
</form>
Here's a JSFiddle: https://jsfiddle.net/thepio/dpgfuy06/
No need for directive!
Make the following changes in your code:-
Use ng-repeat to iterate over your array of elements in the employee details like this:-
<div ng-repeat ="details in employee.details">
</div>
where all your elements should be put in the employee.details array
Accordingly change your ng-model to "details.pension" and "details.salary"
Make a div below your input fields and specify the condition you want in ng-show
and display an error message for the same.
For instance, in your case it would look like:-
<div ng-show="details.pension > details.salary">Pension cannot be greater than salary!
</div>
This should do the validations there and then itself.
Using custom directive:
.directive("compareTo", function () {
return {
require: "ngModel",
scope: {
otherModelValue: "=compareTo"
},
link: function (scope, element, attributes, ngModel) {
ngModel.$validators.compareTo = function (modelValue) {
return modelValue == scope.otherModelValue;
};
scope.$watch("otherModelValue", function () {
ngModel.$validate();
});
}
};
})

Is there a better way to validate this angular form?

I have a working solution for validating each field on keyup in a form in angularjs. I feel it can be better though. Are there any more clever ways?
The HTML:
<input type="text" placeholder="First Name" ng-keyup="validateFirstName($event) "ng-model="user.firstName"/>
<i ng-class="firstNameValidation" class="icon placeholder-icon padding"></i>
<input type="text" placeholder="Last Name"/>
<i ng-class="lastNameValidation" class="icon placeholder-icon padding"></i>
<input type="email" placeholder="Email"/>
<i ng-class="emailValidation" class="icon placeholder-icon padding"></i>
And in the controller i have:
$scope.user = {}
$scope.firstNameValidation = "ion-arrow-left-a text-danger"
$scope.lastNameValidation = "ion-arrow-left-a text-danger"
$scope.emailValidation = "ion-arrow-left-a text-danger"
$scope.validateFirstName = ($event) ->
if $scope.user.firstName.trim().length > 2
$scope.firstNameValidation = "ion-checkmark-circled text-success"
else
$scope.firstNameValidation = "ion-arrow-left-a text-danger"
...
And so on, a function for each field of the input validation. I feel like there is too much redundancy.
Any ideas?
The AngularJS team provide you with a small set of predefined
validators that you can use out of the box and I recommend you to take
a look at their documentation at
https://docs.angularjs.org/api/ng/directive/input
There's a great article over at year of moo with a more in-depth
view and explanation on how this is done in 1.3
The fun part
Here's a simple and dirty plunkr to show you the 1.2.x way i action
Given the following template
<form name="myForm">
<!-- Notice my custom validator named max-length -->
<input type="text" name="firstName" ng-model="firstName"
max-length="20"
ng-class="myForm.firstName.$error.maxLength ? 'ion-arrow-left-a text-danger' : 'ion-checkmark-circled text-success'"
/>
</form>
here's how you do it in Angular 1.2.x
angular
.module('App')
.directive('maxLength', function() {
return {
require: 'ngModel',
link: function(scope, elem, attr, ngModel) {
var maxLength = parseInt(attr.maxLength);
//For DOM -> model validation
ngModel.$parsers.unshift(function(value) {
var validity = validate(value);
ngModel.$setValidity('maxLength', validity);
return validity ? value : undefined;
});
//For model -> DOM validation
ngModel.$formatters.unshift(function(value) {
var validity = validate(value);
ngModel.$setValidity('maxLength', validity);
return value;
});
function validate(value) {
return value.trim().length < maxLength;
}
}
};
});
and here's how it's done in Angular 1.3.x
angular
.module('App')
.directive('maxLength', function() {
return {
require: 'ngModel',
link: function(scope, elem, attr, ngModel) {
var maxLength = parseInt(attr.maxLength);
ngModel.$validators.maxLength(function(value) {
return validate(value, maxLength);
});
function validate(value, maxLength) {
return value.trim().length < maxLength;
}
}
};
});
To conclude
Now, what I've shown you is one way, and the way the angular team thinks of custom validation according to their documentation but, one size doesn't fit all and there are other ways to do this validation. One such way is to make use of 3rd party modules like the one Marcel-Stör mentioned in his answer.
Best of luck to you on your road to mastering custom validation in angularjs :)
It may be a matter of style or preference but I suggest you give valdr a try. I'm quite convinced it offers the features you're looking for - particularly if redundancy bothers you.

How can I extend AngularJS model flags on an Angular form?

AngularJS provides what they call 'model flags' on their forms. For example, you can have formName.$dirty, formName.$invalid, etc. What I want to know is how can I create my own custom flag for my AngularJS forms? A high level demonstration or link to an article would be a sufficient answer.
See here: how-to-add-custom-validation-to-an-angular-js-form.
In short, this is a custom valitation directive example:
app.directive('blacklist', function (){
return {
require: 'ngModel',
link: function(scope, elem, attr, ngModel) {
var blacklist = attr.blacklist.split(',');
// for DOM -> model validation
ngModel.$parsers.unshift(function(value) {
var valid = blacklist.indexOf(value) === -1;
ngModel.$setValidity('blacklist', valid);
return valid ? value : undefined;
});
//For model -> DOM validation
ngModel.$formatters.unshift(function(value) {
ngModel.$setValidity('blacklist', blacklist.indexOf(value) === -1);
return value;
});
}
};
});
And this it's an example of it's usage:
<form name="myForm" ng-submit="doSomething()">
<input type="text" name="fruitName" ng-model="data.fruitName" blacklist="coconuts,bananas,pears" required/>
<span ng-show="myForm.fruitName.$error.blacklist">
The phrase "{{data.fruitName}}" is blacklisted</span>
<span ng-show="myForm.fruitName.$error.required">required</span>
<button type="submit" ng-disabled="myForm.$invalid">Submit</button>
</form>
But, again, read the referenced question and accepted answer, it's by far more complete...

AngularJS prevent ngModel sync

I have a simple directive called po-datepicker, it displays a datepicker on the screen, but allows the user to type a date manually:
<input type="text" ng-model="model" po-datepicker required />
and this is the directive:
myApp.directive('poDatepicker', function () {
return {
require: ['?^ngModel'],
restrict: 'A',
link: function ($scope, elem, attrs, ctrl) {
var ngModel = ctrl[0];
var picker = elem.datepicker();
picker.on('changeDate', function(e) {
ngModel.$setViewValue(e.date);
...
});
elem.parent().find('button').on('click', function() {
picker.datepicker('show');
});
var changeFn = function(e) {
// Here I have some logic that calls $setViewValue();
};
picker.on('hide', changeFn);
elem.on('keyup blur', changeFn);
}
};
});
this works as expected, but when I try to type a value in the input, it updates the ngModel, changing the variable in the scope, how can I prevent ngModel from being changed in the input?
Here is a plunkr, try manually writing a value and you'll understand what I'm talking.
Actually, after some research, I found a solution for this problem.
What I found on forums and questions is that I needed to unbind the element's events, like this:
elem.unbind('input').unbind('keydown').unbind('change');
But that solution didn't work as expected.
The problem is that I'm currently using Angular 1.2.x, I found out that you need also to set some priority to the directive, such as:
return {
require: ['?^ngModel'],
priority: 1,
...
}
The priority: 1 is needed in this case, because of the priority of some internal Angular.js directives.
Here is an updated plunker with the right priority set up.
Just add 'disabled' to the input http://plnkr.co/edit/xFeAmSCtKdNSQR1zbAsd?p=preview
<input type="text" class="form-control" ng-model="test" po-datepicker required feedback disabled/>

How to add custom validation to an AngularJS form?

I have a form with input fields and validation setup by adding the required attributes and such. But for some fields I need to do some extra validation. How would I "tap in" to the validation that FormController controls?
Custom validation could be something like "if these 3 fields are filled in, then this field is required and needs to be formatted in a particular way".
There's a method in FormController.$setValidity but that doesn't look like a public API so I rather not use it. Creating a custom directive and using NgModelController looks like another option, but would basically require me to create a directive for each custom validation rule, which I do not want.
Actually, marking a field from the controller as invalid (while also keeping FormController in sync) might be the thing that I need in the simplest scenario to get the job done, but I don't know how to do that.
Edit: added information about ngMessages (>= 1.3.X) below.
Standard form validation messages (1.0.X and above)
Since this is one of the top results if you Google "Angular Form Validation", currently, I want to add another answer to this for anyone coming in from there.
There's a method in FormController.$setValidity but that doesn't look like a public API so I rather not use it.
It's "public", no worries. Use it. That's what it's for. If it weren't meant to be used, the Angular devs would have privatized it in a closure.
To do custom validation, if you don't want to use Angular-UI as the other answer suggested, you can simply roll your own validation directive.
app.directive('blacklist', function (){
return {
require: 'ngModel',
link: function(scope, elem, attr, ngModel) {
var blacklist = attr.blacklist.split(',');
//For DOM -> model validation
ngModel.$parsers.unshift(function(value) {
var valid = blacklist.indexOf(value) === -1;
ngModel.$setValidity('blacklist', valid);
return valid ? value : undefined;
});
//For model -> DOM validation
ngModel.$formatters.unshift(function(value) {
ngModel.$setValidity('blacklist', blacklist.indexOf(value) === -1);
return value;
});
}
};
});
And here's some example usage:
<form name="myForm" ng-submit="doSomething()">
<input type="text" name="fruitName" ng-model="data.fruitName" blacklist="coconuts,bananas,pears" required/>
<span ng-show="myForm.fruitName.$error.blacklist">
The phrase "{{data.fruitName}}" is blacklisted</span>
<span ng-show="myForm.fruitName.$error.required">required</span>
<button type="submit" ng-disabled="myForm.$invalid">Submit</button>
</form>
Note: in 1.2.X it's probably preferrable to substitute ng-if for ng-show above
Here is an obligatory plunker link
Also, I've written a few blog entries about just this subject that goes into a little more detail:
Angular Form Validation
Custom Validation Directives
Edit: using ngMessages in 1.3.X
You can now use the ngMessages module instead of ngShow to show your error messages. It will actually work with anything, it doesn't have to be an error message, but here's the basics:
Include <script src="angular-messages.js"></script>
Reference ngMessages in your module declaration:
var app = angular.module('myApp', ['ngMessages']);
Add the appropriate markup:
<form name="personForm">
<input type="email" name="email" ng-model="person.email" required/>
<div ng-messages="personForm.email.$error">
<div ng-message="required">required</div>
<div ng-message="email">invalid email</div>
</div>
</form>
In the above markup, ng-message="personForm.email.$error" basically specifies a context for the ng-message child directives. Then ng-message="required" and ng-message="email" specify properties on that context to watch. Most importantly, they also specify an order to check them in. The first one it finds in the list that is "truthy" wins, and it will show that message and none of the others.
And a plunker for the ngMessages example
Angular-UI's project includes a ui-validate directive, which will probably help you with this. It let's you specify a function to call to do the validation.
Have a look at the demo page: http://angular-ui.github.com/, search down to the Validate heading.
From the demo page:
<input ng-model="email" ui-validate='{blacklist : notBlackListed}'>
<span ng-show='form.email.$error.blacklist'>This e-mail is black-listed!</span>
then in your controller:
function ValidateCtrl($scope) {
$scope.blackList = ['bad#domain.example','verybad#domain.example'];
$scope.notBlackListed = function(value) {
return $scope.blackList.indexOf(value) === -1;
};
}
You can use ng-required for your validation scenario ("if these 3 fields are filled in, then this field is required":
<div ng-app>
<input type="text" ng-model="field1" placeholder="Field1">
<input type="text" ng-model="field2" placeholder="Field2">
<input type="text" ng-model="field3" placeholder="Field3">
<input type="text" ng-model="dependentField" placeholder="Custom validation"
ng-required="field1 && field2 && field3">
</div>
You can use Angular-Validator.
Example: using a function to validate a field
<input type = "text"
name = "firstName"
ng-model = "person.firstName"
validator = "myCustomValidationFunction(form.firstName)">
Then in your controller you would have something like
$scope.myCustomValidationFunction = function(firstName){
if ( firstName === "John") {
return true;
}
You can also do something like this:
<input type = "text"
name = "firstName"
ng-model = "person.firstName"
validator = "'!(field1 && field2 && field3)'"
invalid-message = "'This field is required'">
(where field1 field2, and field3 are scope variables. You might also want to check if the fields do not equal the empty string)
If the field does not pass the validator then the field will be marked as invalid and the user will not be able to submit the form.
For more use cases and examples see: https://github.com/turinggroup/angular-validator
Disclaimer: I am the author of Angular-Validator
I recently created a directive to allow for expression-based invalidation of angular form inputs. Any valid angular expression can be used, and it supports custom validation keys using object notation. Tested with angular v1.3.8
.directive('invalidIf', [function () {
return {
require: 'ngModel',
link: function (scope, elm, attrs, ctrl) {
var argsObject = scope.$eval(attrs.invalidIf);
if (!angular.isObject(argsObject)) {
argsObject = { invalidIf: attrs.invalidIf };
}
for (var validationKey in argsObject) {
scope.$watch(argsObject[validationKey], function (newVal) {
ctrl.$setValidity(validationKey, !newVal);
});
}
}
};
}]);
You can use it like this:
<input ng-model="foo" invalid-if="{fooIsGreaterThanBar: 'foo > bar',
fooEqualsSomeFuncResult: 'foo == someFuncResult()'}/>
Or by just passing in an expression (it will be given the default validationKey of "invalidIf")
<input ng-model="foo" invalid-if="foo > bar"/>
Here's a cool way to do custom wildcard expression validations in a form (from: Advanced form validation with AngularJS and filters):
<form novalidate="">
<input type="text" id="name" name="name" ng-model="newPerson.name"
ensure-expression="(persons | filter:{name: newPerson.name}:true).length !== 1">
<!-- or in your case:-->
<input type="text" id="fruitName" name="fruitName" ng-model="data.fruitName"
ensure-expression="(blacklist | filter:{fruitName: data.fruitName}:true).length !== 1">
</form>
app.directive('ensureExpression', ['$http', '$parse', function($http, $parse) {
return {
require: 'ngModel',
link: function(scope, ele, attrs, ngModelController) {
scope.$watch(attrs.ngModel, function(value) {
var booleanResult = $parse(attrs.ensureExpression)(scope);
ngModelController.$setValidity('expression', booleanResult);
});
}
};
}]);
jsFiddle demo (supports expression naming and multiple expressions)
It's similar to ui-validate, but you don't need a scope specific validation function (this works generically) and ofcourse you don't need ui.utils this way.
#synergetic I think #blesh suppose to put function validate as below
function validate(value) {
var valid = blacklist.indexOf(value) === -1;
ngModel.$setValidity('blacklist', valid);
return valid ? value : undefined;
}
ngModel.$formatters.unshift(validate);
ngModel.$parsers.unshift(validate);
Update:
Improved and simplified version of previous directive (one instead of two) with same functionality:
.directive('myTestExpression', ['$parse', function ($parse) {
return {
restrict: 'A',
require: 'ngModel',
link: function (scope, element, attrs, ctrl) {
var expr = attrs.myTestExpression;
var watches = attrs.myTestExpressionWatch;
ctrl.$validators.mytestexpression = function (modelValue, viewValue) {
return expr == undefined || (angular.isString(expr) && expr.length < 1) || $parse(expr)(scope, { $model: modelValue, $view: viewValue }) === true;
};
if (angular.isString(watches)) {
angular.forEach(watches.split(",").filter(function (n) { return !!n; }), function (n) {
scope.$watch(n, function () {
ctrl.$validate();
});
});
}
}
};
}])
Example usage:
<input ng-model="price1"
my-test-expression="$model > 0"
my-test-expression-watch="price2,someOtherWatchedPrice" />
<input ng-model="price2"
my-test-expression="$model > 10"
my-test-expression-watch="price1"
required />
Result: Mutually dependent test expressions where validators are executed on change of other's directive model and current model.
Test expression has local $model variable which you should use to compare it to other variables.
Previously:
I've made an attempt to improve #Plantface code by adding extra directive. This extra directive very useful if our expression needs to be executed when changes are made in more than one ngModel variables.
.directive('ensureExpression', ['$parse', function($parse) {
return {
restrict: 'A',
require: 'ngModel',
controller: function () { },
scope: true,
link: function (scope, element, attrs, ngModelCtrl) {
scope.validate = function () {
var booleanResult = $parse(attrs.ensureExpression)(scope);
ngModelCtrl.$setValidity('expression', booleanResult);
};
scope.$watch(attrs.ngModel, function(value) {
scope.validate();
});
}
};
}])
.directive('ensureWatch', ['$parse', function ($parse) {
return {
restrict: 'A',
require: 'ensureExpression',
link: function (scope, element, attrs, ctrl) {
angular.forEach(attrs.ensureWatch.split(",").filter(function (n) { return !!n; }), function (n) {
scope.$watch(n, function () {
scope.validate();
});
});
}
};
}])
Example how to use it to make cross validated fields:
<input name="price1"
ng-model="price1"
ensure-expression="price1 > price2"
ensure-watch="price2" />
<input name="price2"
ng-model="price2"
ensure-expression="price2 > price3"
ensure-watch="price3" />
<input name="price3"
ng-model="price3"
ensure-expression="price3 > price1 && price3 > price2"
ensure-watch="price1,price2" />
ensure-expression is executed to validate model when ng-model or any of ensure-watch variables is changed.
Custom Validations that call a Server
Use the ngModelController $asyncValidators API which handles asynchronous validation, such as making an $http request to the backend. Functions added to the object must return a promise that must be resolved when valid or rejected when invalid. In-progress async validations are stored by key in ngModelController.$pending. For more information, see AngularJS Developer Guide - Forms (Custom Validation).
ngModel.$asyncValidators.uniqueUsername = function(modelValue, viewValue) {
var value = modelValue || viewValue;
// Lookup user by username
return $http.get('/api/users/' + value).
then(function resolved() {
//username exists, this means validation fails
return $q.reject('exists');
}, function rejected() {
//username does not exist, therefore this validation passes
return true;
});
};
For more information, see
ngModelController $asyncValidators API
AngularJS Developer Guide - Forms (Custom Validation).
Using the $validators API
The accepted answer uses the $parsers and $formatters pipelines to add a custom synchronous validator. AngularJS 1.3+ added a $validators API so there is no need to put validators in the $parsers and $formatters pipelines:
app.directive('blacklist', function (){
return {
require: 'ngModel',
link: function(scope, elem, attr, ngModel) {
ngModel.$validators.blacklist = function(modelValue, viewValue) {
var blacklist = attr.blacklist.split(',');
var value = modelValue || viewValue;
var valid = blacklist.indexOf(value) === -1;
return valid;
});
}
};
});
For more information, see AngularJS ngModelController API Reference - $validators.
In AngularJS the best place to define Custom Validation is Cutsom directive.
AngularJS provide a ngMessages module.
ngMessages is a directive that is designed to show and hide messages
based on the state of a key/value object that it listens on. The
directive itself complements error message reporting with the ngModel
$error object (which stores a key/value state of validation errors).
For custom form validation One should use ngMessages Modules with custom directive.Here i have a simple validation which will check if number length is less then 6 display an error on screen
<form name="myform" novalidate>
<table>
<tr>
<td><input name='test' type='text' required ng-model='test' custom-validation></td>
<td ng-messages="myform.test.$error"><span ng-message="invalidshrt">Too Short</span></td>
</tr>
</table>
</form>
Here is how to create custom validation directive
angular.module('myApp',['ngMessages']);
angular.module('myApp',['ngMessages']).directive('customValidation',function(){
return{
restrict:'A',
require: 'ngModel',
link:function (scope, element, attr, ctrl) {// 4th argument contain model information
function validationError(value) // you can use any function and parameter name
{
if (value.length > 6) // if model length is greater then 6 it is valide state
{
ctrl.$setValidity('invalidshrt',true);
}
else
{
ctrl.$setValidity('invalidshrt',false) //if less then 6 is invalide
}
return value; //return to display error
}
ctrl.$parsers.push(validationError); //parsers change how view values will be saved in the model
}
};
});
$setValidity is inbuilt function to set model state to valid/invalid
I extended #Ben Lesh's answer with an ability to specify whether the validation is case sensitive or not (default)
use:
<input type="text" name="fruitName" ng-model="data.fruitName" blacklist="Coconuts,Bananas,Pears" caseSensitive="true" required/>
code:
angular.module('crm.directives', []).
directive('blacklist', [
function () {
return {
restrict: 'A',
require: 'ngModel',
scope: {
'blacklist': '=',
},
link: function ($scope, $elem, $attrs, modelCtrl) {
var check = function (value) {
if (!$attrs.casesensitive) {
value = (value && value.toUpperCase) ? value.toUpperCase() : value;
$scope.blacklist = _.map($scope.blacklist, function (item) {
return (item.toUpperCase) ? item.toUpperCase() : item
})
}
return !_.isArray($scope.blacklist) || $scope.blacklist.indexOf(value) === -1;
}
//For DOM -> model validation
modelCtrl.$parsers.unshift(function (value) {
var valid = check(value);
modelCtrl.$setValidity('blacklist', valid);
return value;
});
//For model -> DOM validation
modelCtrl.$formatters.unshift(function (value) {
modelCtrl.$setValidity('blacklist', check(value));
return value;
});
}
};
}
]);
Some great examples and libs presented in this thread, but they didn't quite have what I was looking for. My approach: angular-validity -- a promise based validation lib for asynchronous validation, with optional Bootstrap styling baked-in.
An angular-validity solution for the OP's use case might look something like this:
<input type="text" name="field4" ng-model="field4"
validity="eval"
validity-eval="!(field1 && field2 && field3 && !field4)"
validity-message-eval="This field is required">
Here's a Fiddle, if you want to take it for a spin. The lib is available on GitHub, has detailed documentation, and plenty of live demos.

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