AngularJS - Invoking function from a dynamically created element - angularjs

I'm developing a query builder in angularJS. I'm customizing angular-query-builder .
The Code structure is (only the code relevant to the context is shown )
base.html
<query-builder group="filter.group"></query-builder>
querybuilder.html
<select ng-options="t.name as t.name for t in fields" ng-model="rule.field" execute-change="setValidation()" class="form-control input-sm"><option value="">--Select Filter--</option></select>
<select style="margin-left: 5px" ng-options="c.name as c.name for c in conditions" ng-model="rule.condition" class="form-control input-sm"></select>
<input type="text" ng-model="rule.data" class="form-control input-sm condition-inp" />
controller.js
$scope.setValidation = function () {
console.log('Triggred')
}
directive.js
.directive('queryBuilder', ['$compile', function ($compile) {
return {
restrict: 'E',
scope: {
group: '='
},
templateUrl: 'querybuilder.html',
compile: function (element, attrs) {
var content, directive;
content = element.contents().remove();
return function (scope, element, attrs) {
element.on('change', function (e) {
scope.$apply(attrs.executeChange);
});
}
}
}
}]);
What I want is When selecting an item in the first drop down mentioned in querybuilder.html I need to add validation to the corresponding input box.
ie, if the item selected is date, then the input box must be date picker and if it is phone number, then the input box should be integer.
I'm trying to do that using the setValidation function in controller.js But that function is not getting triggered.

I'm hoping that this is used with a parent of a form as $setValidity is called on a named form input myFrom.nameOfInput.$setValidity.
If so you can pass the form to the directive or pass the validitor function as a parameter to the directive like scope right now takes only group let it take parentValidator as well and have that be a function in the parent controller that sets the validity.

Related

Dynamic add attributes on component in Angular pre compile

I have component that is used multiple times, 58 times to be exakt. The only thing that differs between them is unique attributes to add validations. What I want to do is to add a array of attributes to my template before is compiled. Is this possible to achieve when working with a Angular component?
component.js
(function () {
'use strict';
angular
.module('upaApp')
.component('component', {
bindings: {
inputAttributes: '#',
},
controller: controller,
restrict: 'E',
templateUrl: 'app/component/component.html'
});
function controller() {
var $ctrl = this;
}
})();
component.html
<input {{ $ctrl.inputAttributes }}
class="form-control"
type="text" />
When I use the component <component input-attributes="directive1, directive2"></component> it doesn't render out my string and even if it did I would not be sure that it would work. So is there a way to dynamically be able to set the attributes in AngularJS?
Is this angular 1 or 2?
Ill assume the former.
I dont know of a way to place a string as an attribute. What you could do as a workaround is conditionally insert attributes with the ng-attr- attribute. This will insert the attribute if the variable is not undefined.
maybe something like this:
$scope.ctrl.inputAttributes = {
directive1:undefined, //this one wont show
directive2:"this one will show"// as directive2="this one will show"
}
then in your markup:
<input ng-attr-directive1="ctrl.inputAttributes.directive1"
ng-attr-directive2="ctrl.inputAttributes.directive2"
class="form-control"
type="text" />
https://www.thinkingmedia.ca/2015/03/conditionally-add-a-html-element-attribute-value-in-angularjs/
EDIT: it may not be clean, but you could create a directive that compiles html.
app.directive('dynamicAttributes', function ($compile) {
return {
restrict: 'E',
scope: {
attributes: '#'
},
link: function (scope, elem, attrs) {
var h = '<input '+scope.attributes + ' class="form-control" type="text" />';
elem.replaceWith($compile(h)(scope));
}
}
});
then in your DOM
<dynamic-attributes attributes="1 2 3"></dynamic-attributes>
fiddle: http://jsfiddle.net/brhardwick/nx16zdrL/1/
There was actually a very simple solution on my problem. You could use ng-model to send the value to the component. And when I placed my directives on the component it validates accordingly since it can access the value from ng-model.

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();
});
}
};
})

In AngularJS, how to force the re-validation of a field in a form when another value in the same form is changed?

I have a form with few fields, however a select and an input field are coupled: the validation on the input depends on which value the user chooses in the select field.
I'll try to clarify with an example. Let's say that the select contains names of planets:
<select id="planet" class="form-control" name="planet" ng-model="planet" ng-options="c.val as c.label for c in planets"></select>
in the input I apply custom validation via a custom directive named "input-validation":
<input id="city" input-validation iv-allow-if="planet==='earth'" class="form-control" name="city" ng-model="city" required>
where this is the directive:
.directive('inputValidation', [function() {
return {
require: 'ngModel',
restrict: 'A',
scope: {
ivAllowIf: '='
},
link: function(scope, elm, attrs, ctrl) {
ctrl.$parsers.unshift(function(viewValue) {
//input is allowed if the attribute is not present or the expression evaluates to true
var inputAllowed = attrs.ivAllowIf === undefined || scope.$parent.$eval(attrs.ivAllowIf);
if (inputAllowed) {
ctrl.$setValidity('iv', true);
return viewValue;
} else {
ctrl.$setValidity('iv', false);
return undefined;
}
});
}
};
}])
The full example can be examined in Plnkr: http://plnkr.co/edit/t2xMPy1ehVFA5KNEDfrf?p=preview
Whenever the select is modified, I need the input to be verified again. This is not happening in my code. What am I doing wrong?
I have done the same thing for validation of start-date on change of end-date. In the directive of start-date add watch for change of end-date and then call ngModel.$validate() in case end-date new value is defined.
scope.$watch(function () {
return $parse(attrs.endDate)(scope);
}, function () {
ngModel.$validate();
});
The important part to take is call to ngModel.$validate() inside the directive.
Note
you should use $validators for custom validations above to work. read here, $parsers is the old way - from angularjs 1.3 use $validators
FIXED PLUNKER LINK

Pass form to directive

I want to encapsulate my form fields in a directive so I can simply do this:
<div ng-form='myForm'>
<my-input name='Email' type='email' label='Email Address' placeholder="Enter email" ng-model='model.email' required='false'></my-input>
</div>
How do I access the myForm in my directive so I can do validation checks, e.g. myForm.Email.$valid?
To access the FormController in a directive:
require: '^form',
Then it will be available as the 4th argument to your link function:
link: function(scope, element, attrs, formCtrl) {
console.log(formCtrl);
}
fiddle
You may only need access to the NgModelController though:
require: 'ngModel',
link: function(scope, element, attrs, ngModelCtrl) {
console.log(ngModelCtrl);
}
fiddle
If you need access to both:
require: ['^form','ngModel'],
link: function(scope, element, attrs, ctrls) {
console.log(ctrls);
}
fiddle
Here a complete example (styled using Bootstrap 3.1)
It contains a form with several inputs (name, email, age, and country).
Name, email and age are directives. Country is a "regular" input.
For each input is displayed an help message when the user does not enter a correct value.
The form contains a save button which is disabled if the form contains at least one error.
<!-- index.html -->
<body ng-controller="AppCtrl">
<script>
var app = angular.module('app', []);
app.controller('AppCtrl', function($scope) {
$scope.person = {};
});
</script>
<script src="inputName.js"></script>
<script src="InputNameCtrl.js"></script>
<!-- ... -->
<form name="myForm" class="form-horizontal" novalidate>
<div class="form-group">
<input-name ng-model='person.name' required></input-name>
</div>
<!-- ... -->
<div class="form-group">
<div class="col-sm-offset-2 col-sm-4">
<button class="btn btn-primary" ng-disabled="myForm.$invalid">
<span class="glyphicon glyphicon-cloud-upload"></span> Save
</button>
</div>
</div>
</form>
Person: <pre>{{person | json}}</pre>
Form $error: <pre>{{myForm.$error | json}}</pre>
<p>Is the form valid?: {{myForm.$valid}}</p>
<p>Is name valid?: {{myForm.name.$valid}}</p>
</body>
// inputName.js
app.directive('inputName', function() {
return {
restrict: 'E',
templateUrl: 'input-name.html',
replace: false,
controller: 'InputNameCtrl',
require: ['^form', 'ngModel'],
// See Isolating the Scope of a Directive http://docs.angularjs.org/guide/directive#isolating-the-scope-of-a-directive
scope: {},
link: function(scope, element, attrs, ctrls) {
scope.form = ctrls[0];
var ngModel = ctrls[1];
if (attrs.required !== undefined) {
// If attribute required exists
// ng-required takes a boolean
scope.required = true;
}
scope.$watch('name', function() {
ngModel.$setViewValue(scope.name);
});
}
};
});
// inputNameCtrl
app.controller('InputNameCtrl', ['$scope', function($scope) {
}]);
Edit 2: I'll leave my answer, as it might be helpful for other reasons, but the other answer from Mark Rajcok is what I originally wanted to do, but failed to get to work. Apparently the parent controller here would be form, not ngForm.
You can pass it in using an attribute on your directive, although that will get rather verbose.
Example
Here's a working, simplified jsFiddle.
Code
HTML:
<div ng-form="myForm">
<my-input form="myForm"></my-input>
</div>
Essential parts of the directive:
app.directive('myInput', function() {
return {
scope: {
form: '='
},
link: function(scope, element, attrs) {
console.log(scope.form);
}
};
});
What's happening
We've asked Angular to bind the scope value named in the form attribute to our isolated scope, by using an '='.
Doing it this way decouples the actual form from the input directive.
Note: I tried using require: "^ngForm", but the ngForm directive does not define a controller, and cannot be used in that manner (which is too bad).
All that being said, I think this is a very verbose and messy way to handle this. You might be better off adding a new directive to the form element, and use require to access that item. I'll see if I can put something together.
Edit: Using a parent directive
OK, here's the best I could figure out using a parent directive, I'll explain more in a second:
Working jsFiddle using parent directive
HTML:
<div ng-app="myApp">
<div ng-form="theForm">
<my-form form="theForm">
<my-input></my-input>
</my-form>
</div>
</div>
JS (partial):
app.directive('myForm', function() {
return {
restrict: 'E',
scope: {
form: '='
},
controller: ['$scope', function($scope) {
this.getForm = function() {
return $scope.form;
}
}]
}
});
app.directive('myInput', function() {
return {
require: '^myForm',
link: function(scope, element, attrs, myForm) {
console.log(myForm.getForm());
}
};
});
This stores the form in the parent directive scope (myForm), and allows child directives to access it by requiring the parent form (require: '^myForm'), and accessing the directive's controller in the linking function (myForm.getForm()).
Benefits:
You only need to identify the form in one place
You can use your parent controller to house common code
Negatives:
You need an extra node
You need to put the form name in twice
What I'd prefer
I was trying to get it to work using an attribute on the form element. If this worked, you'd only have to add the directive to the same element as ngForm.
However, I was getting some weird behavior with the scope, where the myFormName variable would be visible within $scope, but would be undefined when I tried to access it. That one has me confused.
Starting with AngularJS 1.5.0, there is much cleaner solution for this (as opposed to using the link function directly). If you want to access a form's FormController in your subcomponent's directive controller, you can simply slap the require attribute on the directive, like so:
return {
restrict : 'EA',
require : {
form : '^'
},
controller : MyDirectiveController,
controllerAs : 'vm',
bindToController : true,
...
};
Next, you'll be able to access it in your template or directive controller like you would any other scope variable, e.g.:
function MyDirectiveController() {
var vm = this;
console.log('Is the form valid? - %s', vm.form.$valid);
}
Note that for this to work, you also need to have the bindToController: true attribute set on your directive. See the documentation for $compile and this question for more information.
Relevant parts from the documentation:
require
Require another directive and inject its controller as the fourth argument to the linking function. The require property can be a string, an array or an object:
If the require property is an object and bindToController is truthy, then the required controllers are bound to the controller using the keys of the require property. If the name of the required controller is the same as the local name (the key), the name can be omitted. For example, {parentDir: '^parentDir'} is equivalent to {parentDir: '^'}.
Made your 'What I'd prefer' fiddle work!
For some reason you could see the "$scope.ngForm" string in a console.log, but logging it directly didn't work, resulting in undefined.
However, you can get it if you pass attributes to the controller function.
app.directive('myForm', function() {
return {
restrict: 'A',
controller: ['$scope','$element','$attrs', function($scope,$element,$attrs) {
this.getForm = function() {
return $scope[$attrs['ngForm']];
}
}]
}
});
http://jsfiddle.net/vZ6MD/20/

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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