Phone Number Validation MVC

Question

I am trying to use a regular expression to validate a phone number and return an error when an invalid number or phone number is submitted.

MVC Code:

<ol class="row">
    <li class="cell" style="width: 20%;">Phone Number:</li>
    <li class="cell last" style="width: 60%;">
        @Html.TextBoxFor(model => model.PhoneNumber, new { @class = "textbox" }) 
        @Html.ValidationMessageFor(model => model.PhoneNumber)
    </li>
</ol>

C# Code:

[DataType(DataType.PhoneNumber)]
[Display(Name = "Phone Number")]
[Required(ErrorMessage = "Phone Number Required!")]
[RegularExpression(@"^\(?([0-9]{3})\)?[-. ]?([0-9]{3})[-. ]?([0-9]{4})$",
                   ErrorMessage = "Entered phone format is not valid.")]
public string PhoneNumber { get; set; }

However, the input box will not show a message to the user indicating that the phone number which was submitted is not valid.

Enneahedron

so what's the problem coming, I mean where you need help? – Lanky

The input box will not show a message to the user indicating that the phone number which was submitted is not valid. – Enneahedron

What's the criteria for valid phone number? – Lanky

10 Digits and standard US phone number. – Enneahedron

#9776731 – Lanky

you don't have a @ValidationFor() on the page. – Putto

possible duplicate of A comprehensive regex for phone number validation – Niels

So add the @Validation in my view? – Enneahedron

Your regular expression has 4 spaces in it, those would cause your regex to fail. – Pandolfi

Answer 1

Model

[Required(ErrorMessage = "You must provide a phone number")]
[Display(Name = "Home Phone")]
[DataType(DataType.PhoneNumber)]
[RegularExpression(@"^\(?([0-9]{3})\)?[-. ]?([0-9]{3})[-. ]?([0-9]{4})$", ErrorMessage = "Not a valid phone number")]
public string PhoneNumber { get; set; }

View:

@Html.LabelFor(model => model.PhoneNumber)
@Html.EditorFor(model => model.PhoneNumber)
@Html.ValidationMessageFor(model => model.PhoneNumber)

Accordion

What about DisplayFor? Can it take a string like 8005551212 and convert it to [phone]? – Kliber

Is this DataAnnotation alone is not enough ? [DataType(DataType.PhoneNumber)]. If we need regex for validation then why do we need the DataType.PhoneNumber. What's it purpose ? – Nowell

well obviously because not every country has the same format of phone numbers – Accordion

If you have to supply the Regular Expression that does the phone number validation, then what's the purpose of the [DataType(DataType.PhoneNumber)] attribute? – Girard

Answer 2

Try for simple regular expression for Mobile No

[Required (ErrorMessage="Required")]
[RegularExpression(@"^(\d{10})$", ErrorMessage = "Wrong mobile")]
public string Mobile { get; set; }

Superfamily

Answer 3

You don't have a validator on the page. Add something like this to show the validation message.

@Html.ValidationMessageFor(model => model.PhoneNumber, "", new { @class = "text-danger" })

Putto

Answer 4

Along with the above answers Try this for min and max length:

In Model

[StringLength(13, MinimumLength=10)]
public string MobileNo { get; set; }

In view

 <div class="col-md-8">
           @Html.TextBoxFor(m => m.MobileNo, new { @class = "form-control" , type="phone"})
           @Html.ValidationMessageFor(m => m.MobileNo,"Invalid Number")
           @Html.CheckBoxFor(m => m.IsAgreeTerms, new {@checked="checked",style="display:none" })
  </div>

Attorn

Answer 5

Try this:

[DataType(DataType.PhoneNumber, ErrorMessage = "Provided phone number not valid")]

Superfamily

This alone is not working. I have to add regular expression check as well. – Nowell

Answer 6

Or you can use JQuery - just add your input field to the class "phone" and put this in your script section:

$(".phone").keyup(function () {
        $(this).val($(this).val().replace(/^(\d{3})(\d{3})(\d)+$/, "($1)$2-$3"));

There is no error message but you can see that the phone number is not correctly formatted until you have entered all ten digits.

Damara

Answer 7

[DataType(DataType.PhoneNumber)] does not come with any validation logic out of the box.

According to the docs:

When you apply the DataTypeAttribute attribute to a data field you must do the following:

• Issue validation errors as appropriate.

The [Phone] Attribute inherits from [DataType] and was introduced in .NET Framework 4.5+ and is in .NET Core which does provide it's own flavor of validation logic. So you can use like this:

[Phone()]
public string PhoneNumber { get; set; }

However, the out-of-the-box validation for Phone numbers is pretty permissive, so you might find yourself wanting to inherit from DataType and implement your own IsValid method or, as others have suggested here, use a regular expression & RegexValidator to constrain input.

Note: Use caution with Regex against unconstrained input per the best practices as .NET has made the pivot away from regular expressions in their own internal validation logic for phone numbers

Chart

Answer 8

The phone number data annotation attribute is for the data type, which is not related to the data display format. It's just a misunderstanding. Phone number means you can accept numbers and symbols used for phone numbers for this locale, but is not checking the format, length, range, or else. For display string format use the javascript to have a more dynamic user interaction, or a plugin for MVC mask, or just use a display format string properly.

If you are new to MVC programming put this code at the very end of your view file (.cshtml) and see the magic:

<script src="https://code.jquery.com/jquery-3.5.1.min.js" integrity="sha256-9/aliU8dGd2tb6OSsuzixeV4y/faTqgFtohetphbbj0=" crossorigin="anonymous"></script>
<script type="text/javascript">
    $(document).ready(function () {
        $("#the_id_of_your_field_control").keyup(function () {
            $(this).val($(this).val().replace(/^(\d{2})(\d{5})(\d{4})+$/, "($1) $2-$3"));
        });
    });
</script>

This format is currently used for mobile phones in Brazil. Adapt for your standard.

This will add the parenthesis and spaces to your field, which will increase the string length of your input data. If you want to save just the numbers you will have to trim out the non-numbers from the string before saving.

Reinforce

If you have more than one phone field in the same view you can change the #the_id_of_your_field_control for a class name like ".the_phone_class_name" like @Thomas-Fonseca used above to spread the solution over all fields with that class. – Reinforce