.net core Razor 보기의 Tag Helper

Tag Helper

Form Tag Helper

<form asp-controller="Demo" asp-action="Register" method="post">

form>

<form method="post" action="/Demo/Register">

  <input name="__RequestVerificationToken" type="hidden" value="" />
 form>

이름 지정 라우팅 사용

<form asp-route="register" method="post">
    
form>

<form asp-controller="Account" asp-action="Login"
  method="post" class="form-horizontal" role="form">
  
form>

Input Tag Helper

역할:

public class RegisterViewModel
{
    [Required]
    [EmailAddress]
    [Display(Name = "Email Address")]
    public string Email { get; set; }

    [Required]
    [DataType(DataType.Password)]
    public string Password { get; set; }
}

@model RegisterViewModel

<form asp-controller="Demo" asp-action="RegisterInput" method="post">
    Email:  <input asp-for="Email" /> <br />
    Password: <input asp-for="Password" /><br />
    <button type="submit">Registerbutton>
form>

<form method="post" action="/Demo/RegisterInput">
    Email:
    <input type="email" data-val="true"
           data-val-email="The Email Address field is not a valid e-mail address."
           data-val-required="The Email Address field is required."
           id="Email" name="Email" value="" /> <br>
    Password:
    <input type="password" data-val="true"
           data-val-required="The Password field is required."
           id="Password" name="Password" /><br>
    <button type="submit">Registerbutton>
  <input name="__RequestVerificationToken" type="hidden" value="" />
form>

하위 속성 찾기

// A
public class AddressViewModel
 {
     public string AddressLine { get; set; }
 }
// B     A
 public class RegisterAddressViewModel
 {
     public string Email { get; set; }

     [DataType(DataType.Password)]
     public string Password { get; set; }

     public AddressViewModel Address { get; set; }
 }

@model RegisterAddressViewModel

<form asp-controller="Demo" asp-action="RegisterAddress" method="post">
    Email:  <input asp-for="Email" /> <br />
    Password: <input asp-for="Password" /><br />
    Address: <input asp-for="Address.AddressLine" /><br />
    <button type="submit">Registerbutton>
form>

Tag Helper 검증

<span asp-validation-for="Email"></span>

<span class="field-validation-valid"
  data-valmsg-for="Email"
  data-valmsg-replace="true">
</span>

Select Tag Helper

public class CountryViewModel
{
    public string Country { get; set; }

    public List Countries { get; } = new List
    {
        new SelectListItem { Value = "MX", Text = "Mexico" },
         new SelectListItem { Value = "CA", Text = "Canada" },
         new SelectListItem { Value = "US", Text = "USA"  },
    };
}

public IActionResult Index()
{
    var model = new CountryViewModel();
    model.Country = "CA";
    return View(model);
}

@model CountryViewModel

<form asp-controller="Home" asp-action="Index" method="post">
    <select asp-for="Country" asp-items="Model.Countries">select> 
    <br /><button type="submit">Registerbutton>
form>

method="post" action="/">
  "Country" name="Country">
    <option value="MX">Mexicooption>
    <option selected="selected" value="CA">Canadaoption>
    <option value="US">USAoption>
  
    
type="submit">Register
  "__RequestVerificationToken" type="hidden" value="" />

옵션 그룹

public class CountryViewModelGroup
 {
     public CountryViewModelGroup()
     {
        var AmericaGroup = new SelectListGroup { Name = "America" };
        var EuropeGroup = new SelectListGroup { Name = "Europe" };
        public string Country { get; set; }

        public List Countries { get; } = new List
         {            
             new SelectListItem
             {
                 Value = "CAN",
                 Text = "Canada",
                 Group = AmericaGroup
             },
             new SelectListItem
             {
                 Value = "US",
                 Text = "USA",
                 Group = AmericaGroup
             },
             new SelectListItem
             {
                 Value = "FR",
                 Text = "France",
                 Group = EuropeGroup
             },
             new SelectListItem
             {
                 Value = "ES",
                 Text = "Spain",
                 Group = EuropeGroup
             },            
       };
     }
 }

public enum CountryEnum
{
    Mexico,
    [Display(Name = "United States of America")]
    USA,
    Canada,
    France,
    Germany,
    Spain
}

public class CountryEnumViewModel
 {
     public CountryEnum EnumCountry { get; set; }
 }

@model CountryEnumViewModel

<form asp-controller="Home" asp-action="IndexEnum" method="post">
    <select asp-for="EnumCountry" 
            asp-items="Html.GetEnumSelectList()"> >
    select> 
    <br /><button type="submit">Registerbutton>
form>

method="post" action="/Home/IndexEnum">
      val="true" data-val-required="The EnumCountry field is required."
              id="EnumCountry" name="EnumCountry">
          <option value="0">Mexicooption>
          <option value="1">United States of Americaoption>
          <option value="2">Canadaoption>
          <option value="3">Franceoption>
          <option value="4">Germanyoption>
          <option selected="selected" value="5">Spainoption>
      
      
type="submit">Register
      "__RequestVerificationToken" type="hidden" value="" />
 

<email>Supportemail>

//[HtmlTargetElement(Attributes = "email")]
public class EmailTagHelper : TagHelper
{
    private const string EmailDomain = "contoso.com";

    public override void Process(TagHelperContext context, TagHelperOutput output)
    {
        output.TagName = "a";    // Replaces  with tag

        var address = MailTo + "@" + EmailDomain;
        output.Attributes.SetAttribute("href", "mailto:" + address);
        output.Content.SetContent(address);
    }
}

//  Process
public override async Task ProcessAsync(TagHelperContext context, TagHelperOutput output)
{
    output.TagName = "a";                                 // Replaces  with tag
    var content = await output.GetChildContentAsync();
    var target = content.GetContent() + "@" + EmailDomain;
    output.Attributes.SetAttribute("href", "mailto:" + target);
    output.Content.SetContent(target);
}