Angularjs Form/Field validation using JavaScript function without directives - javascript

Is there a way to validate a field in angular without using a directive?
For example: I want to make following validation on an input field.
If field is empty we should show "Field must contain a value" message.
if field contains alpha Numeric characters we should show "Field can contain only digits".
An EVEN number - message to the user "Value must be an even number".
I want to make following validation in a call to JavaScript function.
I googled around and saw that there is a way to use ng-valid and $error , however I was not managed to make it work.
Code below is according to one of the answers I got:
<div ng-app>
<form name='theForm' novalidate>
<input type='text' name='theText' ng-model='theText' ng-pattern='/^[0-9]+$/'/>
<span ng-show='theForm.theText.$error.pattern'>Field can contain only digits</span>
<span ng-show='theText.length<1'>Field must contain a value</span>
<span ng-show='theText%2!=0&&document.getElementsByName("theText").value!=""&&!theForm.theText.$error.pattern&&!theForm.theText.$pristine'>Value must be an even number</span>
<br/><input type='submit' value='Submit' />
</form>
I want to take what inside the last [span] and put inside a JavaScript function in order to make it more generic and eventually change only JS and not the HTML when conditions are changing
Can someone please advise? a working example would be great.

I'm surprised no one has mentioned ui-validate
$scope.isOdd = function($value){
return $value % 2;
}
...
<form name="myform">
<input ng-model="myVal" name="value" required
ng-pattern="/^[0-9]*$/" ui-validate=" 'isOdd($value)' "></input>
<pre>{{myform.value.$error|json}}</pre>
</form>
Doesn't get any simpler than that, and it's PROPER AngularJS validation (not silly watches)
Here's a working demo

Take a look at the angularjs form documentation - http://docs.angularjs.org/guide/forms . In general, it is based on the HTML5 attributes like required, min, max, etc.
To get, for example, your first requirement done - "an empty field should show "Field must contain a value" message, yo uwould do something like that:
<input type="text" ng-model="user.name" name="uName" required /><br />
<div ng-show="form.uName.$invalid">
<span ng-show="form.uName.$error.required">Field must contain a value.</span>
</div>
For digits only field you can use the pattern attribute with a matching regular expression (example: http://www.wufoo.com/html5/attributes/10-pattern.html).
For even number validation, I'm not sure - I think you'd have to go with custom validation for that (meaning you'd have to create a directive) or use the pattern attribute somehow.
Last but not least - remember to add novalidate to the <form> tag. Otherwise the browser will try to validate your fields as well and you don't want that:
<form ... novalidate>
...
</form>

I know the question is old and I know you didn't want a directive but you may consider using a directive if it's "Angular" way... Well here is my Angular-Validation. I made a project on Github and I think that it just rocks compare to whatever is/was available...I based myself on the excellent Laravel PHP Framework and made it available under Angular... It is so crazy simple, you need 2 lines 1 line of code, 1 line for the input, 1 line for error display, that's it... never more and never less!!! Enough said, let's give some examples:
<!-- example 1 -->
<label for="input1">Email</label>
<input type="text" validation="email|min_len:3|max_len:25|required" ng-model="form1.input1" name="input1" />
<!-- example 2 -->
<label for="input2">Alphanumeric + Exact(3) + required</label>
<input type="text" validation="alpha|exact_len:3|required" ng-model="form1.input2" name="input2" />
So I can define whatever amount of validation rules (already 25+ type of validators) which I want in a simple directive validation="min_len:2|max_len:10|required|integer" and the error message will always display in the next <span> Don't you guys like it already? 1 line of code for your input, 1 line of code for the error display, you can't be simpler than that...oh and I even support your custom Regex if you want to add. Another bonus, I also support whichever trigger event you want, most common are probably onblur and onkeyup. Oh and I also support multiple localization languages via JSON external files. I really added all the imaginable features I wanted into 1 crazy simple directive.
No more clustered Form with 10 lines of code for 1 input (sorry but always found that a little extreme) when the only thing you need is 2 lines, no more, even for an input with 5 validators on it. And no worries about the form not becoming invalid, I took care of that as well, it's all handled the good "Angular" way.
Take a look at my Github project Angular-Validation... I'm sure you'll love it =)
UPDATE
Another candy bonus! To make an even more smoother user experience, I added validation on timer. The concept is simple, don't bother the user while he's typing but do validate if he makes a pause or change input (onBlur)... Love it!!!
You can even customize the timer as per your liking, I've decided to default it to 1 second within the directive but if you want to customize you can call as for example typing-limit="5000" to make a 5 sec. timeout. Full example:
<input type="text" ng-model="form1.input1" typing-limit="5000" validation="integer|required" name="input1" />
<span class="validation text-danger"></span>
UPDATE #2
Also added input match confirmation validation (ex.: password confirmation), here is a sample code
<!-- input match confirmation, as for example: password confirmation -->
<label for="input4">Password</label>
<input type="password" name="input4" ng-model="form1.input4" validation="alpha|min_len:4|required" />
<label for="input4c">Password Confirmation</label>
<input type="password" name="input4c" ng-model="form1.input4c" validation="match:form1.input4,Password|required" />
UPDATE #3
Refactored the directive so that the requirement of having a <span> to display the error is unnecessary, the directive now handles it by itself, see the code change reflected on top.
DEMO
Added a live demo on Plunker

Well you can try to create a func
<span ng-show='isEven(theText)'>Value must be an even number</span>
$scope.isEven=function(data) {
if(data) {
return data%2===0
}
return true;
}
The method can either be defined on the current controller scope or on $rootScope.
Not a very angular way, as directives would be better but i think it would work.

Related

Angular form validation with external data binding

I have an Angular 4 form, but with the data tracked in an injected service (for reasons outside the scope of this question).
Each input looks something like...
<input name="..." [ngModel]='getVal(...)' (ngModelChange)='setVal(...)'>
...because there's extra functionality in those getters/setters.
That's working great, but I would also like to use the built-in validation. If I give my form a template reference variable...
<form id="..." #myForm="ngForm">
and look at the value of myForm, it's not tracking any of those inputs. I get that, I mean, I'm specifically telling it to track them elsewhere.
But how can I take advantage of the built in HTML5 validation? i.e. required and pattern
You can use validation like this in your html. This is template based validation as per your requirement.
Submit button will not be active till all the fields are validated.
<form (ngSubmit)="submitFunc()">
<input name="name" [ngModel]='getVal(...)' (ngModelChange)='setVal(...)'
required pattern=""> //required pattern here
<button [disabled]="!myForm.form.valid" type="submit">Submit Form </button>
</form>
You have to add required in your input field and specify pattern with a regular exression.

AngularJS: ngMessage weird behavior with input with type "email"

I follow Moving from ngModel.$parsers /ng-if to ngModel.$validators /ngMessages article from Todd Motto's blog and I want to migrate from ng-if to ng-messages. But ng-messages directive behaves very weird when I try to display to user two different messages for <input type="email">: first, when user leave field empty (then required error occurs) and second, when format is wrong (then email error occurs) - it displays both required and mail messages, but my old code displays only one message - about required error - and that is I think welcomed behavior. Here is simplified code:
<form name="ngMessageMailForm">
<input type="email" required="" name="email" ng-model="ctrl.ngMessageMail" />
<div ng-messages="ngMessageMailForm.email.$error" ng-if="ngMessageMailForm.email.$touched">
<span ng-message="email">
E-mail has not proper format<br />
</span>
<span ng-message="required">
E-mail is required<br />
</span>
</div>
</form>
Comparison between old and new code you can find in this Plunker: Ng-if vs ng-messages at plnkr.co, to reproduce weird behavior of ng-message click inside and then outside of mail inputs. You will see one message in case of ng-if form, and two messages in case of ng-message form.
Did I miss something while migrating from ng-if to ng-messages? Thank you in advance for any help.
Everything is fine but you miss to add angular-messages library to your project...
Add its files to your project and inject ngMessages to your angularjs module then you are good to go...
here is update plunker

AngularJS validation, binding, etc. not working when using jQuery plugins (eg. autoNumeric)

I have an angular form which was using angular's built-in validation successfully. Take the following markup for example:
<form name="numberForm" novalidate>
<input type="text" required />
<button type="submit">Submit</button>
</form>
When the browser loads, the input field renders like this (unnecessary attributes removed):
<input class="ng-pristine ng-invalid ng-invalid-required" />
If I were to enter a value in the input field, the markup turns into:
<input class="ng-dirty ng-valid ng-valid-required" />
All of this was working great. Then I implemented two jQuery plugins to implement some masking/input formatting for the form: autoNumeric and jQuery.maskedinput. Now, nothing I do will change the original ng-pristine ng-invalid... classes on the input. It also doesn't seem to allow the binding of models to be successful either.
Any ideas?
I tried creating a http://jsfiddle.net/ma44H/3/, but can't seem to figure out how to get it to work.
JQuery and Angular do not cooperate well
Chocolate and Peanut Butter taste great together, but AngularJS and JQuery are a painful mix. We've all tried (with varying success) to accomplish this.
The problem is that JQuery DOM manipulation works outside of AngularJS Digest Cycle. The lesson is usually that using pure Angular is better.
Alternative #1: Angular UI
Try Angular-UI. Set of tools every Angular Developer could use.
Whatever Mask you want to implement can be done with their ui-mask directive:
Want a Date Mask?
<input type="text" ng-model="date" ui-mask="99/99/9999" />
Currency Mask?
<input type="text" ng-model="currency" ui-mask="$99999999.99" />
Phone Mask?
<input type="text" ng-model="phone" ui-mask="1 (999) 999-9999" />
:
See Fiddle
:
Alternative #2: Filters
Angular has built-in filters:
Currency:
$filter('currency')(amount, symbol)
Date:
$filter('date')(date, format)
Insist on using JQuery? Try the jQuery Passthrough directive from the angular-ui toolset. I haven't made use of this directive but it's an intriguing option:
To call something like $.fn.tooltip() simply do ui-jq="tooltip". Note
that the name of the function must be identical. This also works for
normal jQuery commands such as $.fn.slideUp().
To pass parameters use the ui-options attribute. The value will be
evaluated in the $scope context and passed to the function. If
defaults are set, the passed options will extend them. If a string is
passed, the default options will be ignored.
Use the directive name jq for namespacing inside uiJqConfig. Then
sub-namespace options for each function by the name of that function
(exactly as it is passed to ui-jq) so that you don't have to pass
options every time you call the directive.

Javascript - concatenate field value to onclick button link?

I have an issue I need to fix on an existing app that I didn't initially write. Here is a snippet of code that doesn't do what it is intended to do. What it is supposed to do is take the value of the field and upon clicking "Search", append that to the redirection to pass in the querystring to the destination page:
<form name="frm_someform">
<input type="text" name="f_date" id="f_date"/>
<input type="button" value="Search" onclick="parent.location='runreport.asp?date=' + document.frm_someform.elements['f_date'].value); + '"/>
</form>
Now, as you javascript folks can plainly see, the concatenation doesn't work. I've searched high and low for how to properly concatenate, but something isn't translating correctly (in my head). Note that if I take out the concatenation, the redirection works fine, so there is something with that causing the issue. Yes, of course in the example above, I could simply make the form submit the proper value with a real 'submit' button, but I have whittled the code down here for simplicity - it is much more complex than the example I have above.
(*Note, I successfully tested concatenation through other javascript functions, but the possibility exists that the purely inline code must be different)
Thanks in advance,
Beems
Please, try this:
<form name="frm_someform">
<input type="text" name="f_date" id="f_date"/>
<input type="button" value="Search" onclick="parent.location='runreport.asp?date='+ document.getElementById('f_date').value"/>
</form>

Long form validation in JavaScript / jQuery

I have a long long long form. It has about 200 fields. Now, about 50 fields need to be validated through JavaScript / jQuery. How can I easily validate them without a huge amount of code. I want to avoid doing this:
field1 = document.getElementById("field1").value;
if (field1 == '') {
alert ("Please enter a value for Field1");
return false
}
Is there an easier way? Thanks a lot.
Use the jquery Form validation plugin and assign the correct classes to the fields.
It's as simple as class="required" in most cases!
If you just want to check if the field is empty or not you could do something like this using jQuery:
HTML:
<form>
<input class="validate" type="text" />
<input type="text" />
<input class="validate" type="text" />
<input type="text" />
<input class="validate" type="text" />
</form>
SCRIPT:
$('.validate').each(function() { //this will get every input marked with class "validate"
if ($(this).val() == '')
return false;
});
Using JQuery validate plugin can be much help. You can control the way plugin works from your HTML code and even not write any javascript! If you need more complex validatio, you can extend it by adding specific validation functions. It allows you to localize the application as well.
This page gives a good example on how to use the plugin: http://jquery.bassistance.de/validate/demo/milk/ (click the "Show script used on this page" link).
Here is a rudimentary fiddle, that you can use to validate your form, Just add a span after each of the fields that you need to validate.
http://jsfiddle.net/refhat/h2S6G/35/
I thought about this too, but the plugin can be a bit difficult to
use. Do you know if it allows to display an alert box when an error is
found, instead of the actual displaying on the page? That's a bit too
much for this form. Thanks a lot
Here's a validator I wrote that uses a pop-up style alert box for error messages. Is that the sort of thing you are after?
http://validator.codeplex.com/
Do you want default error messages like for required validator? Regarding jquery validate plugin was it the syntax it offers to place validation information in the method call you found difficult since for a large form having validation information located separately from the text boxes makes it harder to go through and verify all fields have the right validators and messages?

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