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Validation tih a ni

HTML5 form validation hmangin i hmangtute hnenah feedback hlu tak, actionable tak pe la, browser default behavior emaw custom style leh JavaScript hmangin pe rawh.

Tunah hian client-side custom validation style leh tooltips te hi assistive technology hmanga inhmang an nih loh avangin hman theih a ni lo tih kan hria. Solution kan thawh lai hian server-side option emaw default browser validation method emaw hmang turin kan rawt ang.

A hnathawh dan

Bootstrap hmanga form validation hnathawh dan chu hetiang hi a ni:

  • HTML form validation hi CSS-a pseudo-classes pahnih hmangin hman a ni a, :invalidleh :valid. <input>, <select>, leh <textarea>element- ah te a hman theih .
  • Bootstrap hian :invalidand :validstyles chu parent .was-validatedclass-ah a scope a, a tlangpuiin <form>. Chutiang a nih loh chuan value nei lo field mamawh apiang chu page load-ah a dik lo angin a lang. Chutiang chuan engtikah nge activate tur tih i thlang thei ang (a tlangpuiin form thehluh tum hnuah).
  • Form hmel reset tur chuan (entir nan, AJAX hmanga dynamic form submission a nih chuan), submission hnua again .was-validatedatang chuan class chu paih chhuak rawh.<form>
  • Fallback angin, .is-invalidleh server-side validation.is-valid atan pseudo-classes aiah class hman theih a ni . Nu leh pa class an mamawh lo ..was-validated
  • CSS hnathawh danah harsatna a awm avangin (tunah chuan) <label>DOM-a form control hmaa lo awm a chu custom JavaScript puihna tel lovin style kan hmang thei lo.
  • Tunlai browser zawng zawng hian constraint validation API , form controls validate nana JavaScript method hrang hrang an support a.
  • Feedback message-ah hian browser default (browser tin tan a danglam, CSS hmanga style theih loh) emaw, HTML leh CSS dang nena kan custom feedback style emaw a hmang thei bawk.
  • setCustomValidityJavaScript hmangin custom validity message i pe thei bawk.

Chu chu ngaihtuah chungin, kan custom form validation styles, optional server-side classes, leh browser defaults te tana a hnuaia demos te hi ngaihtuah la.

Custom style hrang hrang a awm bawk

Custom Bootstrap form validation message atan chuan novalidateboolean attribute chu i <form>. Hei hian browser default feedback tooltips te chu a titawp a, mahse JavaScript-a form validation API te chu a la lut thei tho. A hnuaia form hi thehluh tum ang che; kan JavaScript chuan submit button chu a intercept ang a, feedback a relay ang che. Submit i tum hian i form controls-a :invalidand styles hman dan i hmu ang.:valid

Custom feedback style-ah chuan feedback inhrilh tawnna tha zawk neih theih nan custom color, border, focus style leh background icon te a hmang thin. Background icons for <select>s hi .form-select, nen chauh a awm a, .form-control.

Looks good!
Looks good!
@ a ni.
Please choose a username.
Please provide a valid city.
Please select a valid state.
Please provide a valid zip.
You must agree before submitting.
<form class="row g-3 needs-validation" novalidate>
  <div class="col-md-4">
    <label for="validationCustom01" class="form-label">First name</label>
    <input type="text" class="form-control" id="validationCustom01" value="Mark" required>
    <div class="valid-feedback">
      Looks good!
    </div>
  </div>
  <div class="col-md-4">
    <label for="validationCustom02" class="form-label">Last name</label>
    <input type="text" class="form-control" id="validationCustom02" value="Otto" required>
    <div class="valid-feedback">
      Looks good!
    </div>
  </div>
  <div class="col-md-4">
    <label for="validationCustomUsername" class="form-label">Username</label>
    <div class="input-group has-validation">
      <span class="input-group-text" id="inputGroupPrepend">@</span>
      <input type="text" class="form-control" id="validationCustomUsername" aria-describedby="inputGroupPrepend" required>
      <div class="invalid-feedback">
        Please choose a username.
      </div>
    </div>
  </div>
  <div class="col-md-6">
    <label for="validationCustom03" class="form-label">City</label>
    <input type="text" class="form-control" id="validationCustom03" required>
    <div class="invalid-feedback">
      Please provide a valid city.
    </div>
  </div>
  <div class="col-md-3">
    <label for="validationCustom04" class="form-label">State</label>
    <select class="form-select" id="validationCustom04" required>
      <option selected disabled value="">Choose...</option>
      <option>...</option>
    </select>
    <div class="invalid-feedback">
      Please select a valid state.
    </div>
  </div>
  <div class="col-md-3">
    <label for="validationCustom05" class="form-label">Zip</label>
    <input type="text" class="form-control" id="validationCustom05" required>
    <div class="invalid-feedback">
      Please provide a valid zip.
    </div>
  </div>
  <div class="col-12">
    <div class="form-check">
      <input class="form-check-input" type="checkbox" value="" id="invalidCheck" required>
      <label class="form-check-label" for="invalidCheck">
        Agree to terms and conditions
      </label>
      <div class="invalid-feedback">
        You must agree before submitting.
      </div>
    </div>
  </div>
  <div class="col-12">
    <button class="btn btn-primary" type="submit">Submit form</button>
  </div>
</form>
// Example starter JavaScript for disabling form submissions if there are invalid fields
(function () {
  'use strict'

  // Fetch all the forms we want to apply custom Bootstrap validation styles to
  var forms = document.querySelectorAll('.needs-validation')

  // Loop over them and prevent submission
  Array.prototype.slice.call(forms)
    .forEach(function (form) {
      form.addEventListener('submit', function (event) {
        if (!form.checkValidity()) {
          event.preventDefault()
          event.stopPropagation()
        }

        form.classList.add('was-validated')
      }, false)
    })
})()

Browser a default a ni

Custom validation feedback message emaw, form behavior thlak danglam tur JavaScript ziah emaw duh lo em ni? All good, browser defaults te pawh i hmang thei bawk. A hnuaia form hi submit tum ang che. I browser leh OS a zirin feedback style danglam deuh deuh i hmu ang.

Heng feedback style te hi CSS hmanga style theih a nih loh laiin, JavaScript hmangin feedback text chu i siam danglam thei tho.

@ a ni.
<form class="row g-3">
  <div class="col-md-4">
    <label for="validationDefault01" class="form-label">First name</label>
    <input type="text" class="form-control" id="validationDefault01" value="Mark" required>
  </div>
  <div class="col-md-4">
    <label for="validationDefault02" class="form-label">Last name</label>
    <input type="text" class="form-control" id="validationDefault02" value="Otto" required>
  </div>
  <div class="col-md-4">
    <label for="validationDefaultUsername" class="form-label">Username</label>
    <div class="input-group">
      <span class="input-group-text" id="inputGroupPrepend2">@</span>
      <input type="text" class="form-control" id="validationDefaultUsername"  aria-describedby="inputGroupPrepend2" required>
    </div>
  </div>
  <div class="col-md-6">
    <label for="validationDefault03" class="form-label">City</label>
    <input type="text" class="form-control" id="validationDefault03" required>
  </div>
  <div class="col-md-3">
    <label for="validationDefault04" class="form-label">State</label>
    <select class="form-select" id="validationDefault04" required>
      <option selected disabled value="">Choose...</option>
      <option>...</option>
    </select>
  </div>
  <div class="col-md-3">
    <label for="validationDefault05" class="form-label">Zip</label>
    <input type="text" class="form-control" id="validationDefault05" required>
  </div>
  <div class="col-12">
    <div class="form-check">
      <input class="form-check-input" type="checkbox" value="" id="invalidCheck2" required>
      <label class="form-check-label" for="invalidCheck2">
        Agree to terms and conditions
      </label>
    </div>
  </div>
  <div class="col-12">
    <button class="btn btn-primary" type="submit">Submit form</button>
  </div>
</form>

Server lam a ni

Client-side validation hman kan rawt a, mahse server-side validation i mamawh a nih chuan form field dik lo leh dik lo chu leh hmangin i tarlang thei .is-invalidang .is-valid. .invalid-feedbackHeng class te nen hian a support bawk tih hre reng ang che .

Field dik lo tan chuan feedback/error message dik lo chu form field nena inzawm a nih leh nih loh enfiah rawh aria-describedby(he attribute hian pakhat aia tam idreference a phal tih hre reng ang che, field chuan form text dang a kawhhmuh tawh a nih chuan).

Border radii -a harsatna awmte siam\hat nan input group -ah chuan .has-validationclass dang a ngai a ni.

A tha hle mai!
A tha hle mai!
@ a ni.
Khawngaihin username pakhat thlang rawh.
Khawpui dik tak min pe dawn nia.
Khawngaihin state dik tak thlang rawh.
Zip dik tak pe turin kan ngen a che u.
Submit hmain i remti tur a ni.
<form class="row g-3">
  <div class="col-md-4">
    <label for="validationServer01" class="form-label">First name</label>
    <input type="text" class="form-control is-valid" id="validationServer01" value="Mark" required>
    <div class="valid-feedback">
      Looks good!
    </div>
  </div>
  <div class="col-md-4">
    <label for="validationServer02" class="form-label">Last name</label>
    <input type="text" class="form-control is-valid" id="validationServer02" value="Otto" required>
    <div class="valid-feedback">
      Looks good!
    </div>
  </div>
  <div class="col-md-4">
    <label for="validationServerUsername" class="form-label">Username</label>
    <div class="input-group has-validation">
      <span class="input-group-text" id="inputGroupPrepend3">@</span>
      <input type="text" class="form-control is-invalid" id="validationServerUsername" aria-describedby="inputGroupPrepend3 validationServerUsernameFeedback" required>
      <div id="validationServerUsernameFeedback" class="invalid-feedback">
        Please choose a username.
      </div>
    </div>
  </div>
  <div class="col-md-6">
    <label for="validationServer03" class="form-label">City</label>
    <input type="text" class="form-control is-invalid" id="validationServer03" aria-describedby="validationServer03Feedback" required>
    <div id="validationServer03Feedback" class="invalid-feedback">
      Please provide a valid city.
    </div>
  </div>
  <div class="col-md-3">
    <label for="validationServer04" class="form-label">State</label>
    <select class="form-select is-invalid" id="validationServer04" aria-describedby="validationServer04Feedback" required>
      <option selected disabled value="">Choose...</option>
      <option>...</option>
    </select>
    <div id="validationServer04Feedback" class="invalid-feedback">
      Please select a valid state.
    </div>
  </div>
  <div class="col-md-3">
    <label for="validationServer05" class="form-label">Zip</label>
    <input type="text" class="form-control is-invalid" id="validationServer05" aria-describedby="validationServer05Feedback" required>
    <div id="validationServer05Feedback" class="invalid-feedback">
      Please provide a valid zip.
    </div>
  </div>
  <div class="col-12">
    <div class="form-check">
      <input class="form-check-input is-invalid" type="checkbox" value="" id="invalidCheck3" aria-describedby="invalidCheck3Feedback" required>
      <label class="form-check-label" for="invalidCheck3">
        Agree to terms and conditions
      </label>
      <div id="invalidCheck3Feedback" class="invalid-feedback">
        You must agree before submitting.
      </div>
    </div>
  </div>
  <div class="col-12">
    <button class="btn btn-primary" type="submit">Submit form</button>
  </div>
</form>

Element thlawptu te

A hnuaia form control leh component hrang hrangte tan hian validation style a awm a:

  • <input>s leh <textarea>s with ( input group- .form-controla pakhat thleng telh ) ..form-control
  • <select>s nen.form-select
  • .form-checks
Textarea ah hian message ziak la.
Entirna feedback text dik lo
Entirna tam zawk feedback text dik lo
Entirna dik lo select feedback
Entirnan form file feedback dik lo
<form class="was-validated">
  <div class="mb-3">
    <label for="validationTextarea" class="form-label">Textarea</label>
    <textarea class="form-control is-invalid" id="validationTextarea" placeholder="Required example textarea" required></textarea>
    <div class="invalid-feedback">
      Please enter a message in the textarea.
    </div>
  </div>

  <div class="form-check mb-3">
    <input type="checkbox" class="form-check-input" id="validationFormCheck1" required>
    <label class="form-check-label" for="validationFormCheck1">Check this checkbox</label>
    <div class="invalid-feedback">Example invalid feedback text</div>
  </div>

  <div class="form-check">
    <input type="radio" class="form-check-input" id="validationFormCheck2" name="radio-stacked" required>
    <label class="form-check-label" for="validationFormCheck2">Toggle this radio</label>
  </div>
  <div class="form-check mb-3">
    <input type="radio" class="form-check-input" id="validationFormCheck3" name="radio-stacked" required>
    <label class="form-check-label" for="validationFormCheck3">Or toggle this other radio</label>
    <div class="invalid-feedback">More example invalid feedback text</div>
  </div>

  <div class="mb-3">
    <select class="form-select" required aria-label="select example">
      <option value="">Open this select menu</option>
      <option value="1">One</option>
      <option value="2">Two</option>
      <option value="3">Three</option>
    </select>
    <div class="invalid-feedback">Example invalid select feedback</div>
  </div>

  <div class="mb-3">
    <input type="file" class="form-control" aria-label="file example" required>
    <div class="invalid-feedback">Example invalid form file feedback</div>
  </div>

  <div class="mb-3">
    <button class="btn btn-primary" type="submit" disabled>Submit form</button>
  </div>
</form>

Hmanraw hman dan tur

I form layout-in a phal chuan, styled tooltip-a validation feedback lantir turin class-te .{valid|invalid}-feedbackchu class-te nen i swap thei ang. Tooltip positioning atan .{valid|invalid}-tooltipnu leh pa nei ngei ngei tur a ni. position: relativeA hnuaia entirnan hian kan column class te hian hei hi an nei tawh a, mahse i project hian setup dang a mamawh mai thei.

Looks good!
Looks good!
@ a ni.
Please choose a unique and valid username.
Please provide a valid city.
Please select a valid state.
Please provide a valid zip.
<form class="row g-3 needs-validation" novalidate>
  <div class="col-md-4 position-relative">
    <label for="validationTooltip01" class="form-label">First name</label>
    <input type="text" class="form-control" id="validationTooltip01" value="Mark" required>
    <div class="valid-tooltip">
      Looks good!
    </div>
  </div>
  <div class="col-md-4 position-relative">
    <label for="validationTooltip02" class="form-label">Last name</label>
    <input type="text" class="form-control" id="validationTooltip02" value="Otto" required>
    <div class="valid-tooltip">
      Looks good!
    </div>
  </div>
  <div class="col-md-4 position-relative">
    <label for="validationTooltipUsername" class="form-label">Username</label>
    <div class="input-group has-validation">
      <span class="input-group-text" id="validationTooltipUsernamePrepend">@</span>
      <input type="text" class="form-control" id="validationTooltipUsername" aria-describedby="validationTooltipUsernamePrepend" required>
      <div class="invalid-tooltip">
        Please choose a unique and valid username.
      </div>
    </div>
  </div>
  <div class="col-md-6 position-relative">
    <label for="validationTooltip03" class="form-label">City</label>
    <input type="text" class="form-control" id="validationTooltip03" required>
    <div class="invalid-tooltip">
      Please provide a valid city.
    </div>
  </div>
  <div class="col-md-3 position-relative">
    <label for="validationTooltip04" class="form-label">State</label>
    <select class="form-select" id="validationTooltip04" required>
      <option selected disabled value="">Choose...</option>
      <option>...</option>
    </select>
    <div class="invalid-tooltip">
      Please select a valid state.
    </div>
  </div>
  <div class="col-md-3 position-relative">
    <label for="validationTooltip05" class="form-label">Zip</label>
    <input type="text" class="form-control" id="validationTooltip05" required>
    <div class="invalid-tooltip">
      Please provide a valid zip.
    </div>
  </div>
  <div class="col-12">
    <button class="btn btn-primary" type="submit">Submit form</button>
  </div>
</form>

Sass a ni

Variables te pawh a awm

$form-feedback-margin-top:          $form-text-margin-top;
$form-feedback-font-size:           $form-text-font-size;
$form-feedback-font-style:          $form-text-font-style;
$form-feedback-valid-color:         $success;
$form-feedback-invalid-color:       $danger;

$form-feedback-icon-valid-color:    $form-feedback-valid-color;
$form-feedback-icon-valid:          url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 8 8'><path fill='#{$form-feedback-icon-valid-color}' d='M2.3 6.73L.6 4.53c-.4-1.04.46-1.4 1.1-.8l1.1 1.4 3.4-3.8c.6-.63 1.6-.27 1.2.7l-4 4.6c-.43.5-.8.4-1.1.1z'/></svg>");
$form-feedback-icon-invalid-color:  $form-feedback-invalid-color;
$form-feedback-icon-invalid:        url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 12 12' width='12' height='12' fill='none' stroke='#{$form-feedback-icon-invalid-color}'><circle cx='6' cy='6' r='4.5'/><path stroke-linejoin='round' d='M5.8 3.6h.4L6 6.5z'/><circle cx='6' cy='8.2' r='.6' fill='#{$form-feedback-icon-invalid-color}' stroke='none'/></svg>");

Mixins te a awm

Mixin pahnih kan inzawm khawm a, kan loop hmangin kan form validation feedback styles te kan siam chhuak a.

@mixin form-validation-state-selector($state) {
  @if ($state == "valid" or $state == "invalid") {
    .was-validated #{if(&, "&", "")}:#{$state},
    #{if(&, "&", "")}.is-#{$state} {
      @content;
    }
  } @else {
    #{if(&, "&", "")}.is-#{$state} {
      @content;
    }
  }
}

@mixin form-validation-state(
  $state,
  $color,
  $icon,
  $tooltip-color: color-contrast($color),
  $tooltip-bg-color: rgba($color, $form-feedback-tooltip-opacity),
  $focus-box-shadow: 0 0 $input-btn-focus-blur $input-focus-width rgba($color, $input-btn-focus-color-opacity)
) {
  .#{$state}-feedback {
    display: none;
    width: 100%;
    margin-top: $form-feedback-margin-top;
    @include font-size($form-feedback-font-size);
    font-style: $form-feedback-font-style;
    color: $color;
  }

  .#{$state}-tooltip {
    position: absolute;
    top: 100%;
    z-index: 5;
    display: none;
    max-width: 100%; // Contain to parent when possible
    padding: $form-feedback-tooltip-padding-y $form-feedback-tooltip-padding-x;
    margin-top: .1rem;
    @include font-size($form-feedback-tooltip-font-size);
    line-height: $form-feedback-tooltip-line-height;
    color: $tooltip-color;
    background-color: $tooltip-bg-color;
    @include border-radius($form-feedback-tooltip-border-radius);
  }

  @include form-validation-state-selector($state) {
    ~ .#{$state}-feedback,
    ~ .#{$state}-tooltip {
      display: block;
    }
  }

  .form-control {
    @include form-validation-state-selector($state) {
      border-color: $color;

      @if $enable-validation-icons {
        padding-right: $input-height-inner;
        background-image: escape-svg($icon);
        background-repeat: no-repeat;
        background-position: right $input-height-inner-quarter center;
        background-size: $input-height-inner-half $input-height-inner-half;
      }

      &:focus {
        border-color: $color;
        box-shadow: $focus-box-shadow;
      }
    }
  }

  // stylelint-disable-next-line selector-no-qualifying-type
  textarea.form-control {
    @include form-validation-state-selector($state) {
      @if $enable-validation-icons {
        padding-right: $input-height-inner;
        background-position: top $input-height-inner-quarter right $input-height-inner-quarter;
      }
    }
  }

  .form-select {
    @include form-validation-state-selector($state) {
      border-color: $color;

      @if $enable-validation-icons {
        &:not([multiple]):not([size]),
        &:not([multiple])[size="1"] {
          padding-right: $form-select-feedback-icon-padding-end;
          background-image: escape-svg($form-select-indicator), escape-svg($icon);
          background-position: $form-select-bg-position, $form-select-feedback-icon-position;
          background-size: $form-select-bg-size, $form-select-feedback-icon-size;
        }
      }

      &:focus {
        border-color: $color;
        box-shadow: $focus-box-shadow;
      }
    }
  }

  .form-check-input {
    @include form-validation-state-selector($state) {
      border-color: $color;

      &:checked {
        background-color: $color;
      }

      &:focus {
        box-shadow: $focus-box-shadow;
      }

      ~ .form-check-label {
        color: $color;
      }
    }
  }
  .form-check-inline .form-check-input {
    ~ .#{$state}-feedback {
      margin-left: .5em;
    }
  }

  .input-group .form-control,
  .input-group .form-select {
    @include form-validation-state-selector($state) {
      @if $state == "valid" {
        z-index: 1;
      } @else if $state == "invalid" {
        z-index: 2;
      }
      &:focus {
        z-index: 3;
      }
    }
  }
}

Map a ni

Hei hi validation Sass map atanga lak chhuah _variables.scssa ni. Hei hi override emaw extend emaw la, state hrang hrang emaw additional emaw siam rawh.

$form-validation-states: (
  "valid": (
    "color": $form-feedback-valid-color,
    "icon": $form-feedback-icon-valid
  ),
  "invalid": (
    "color": $form-feedback-invalid-color,
    "icon": $form-feedback-icon-invalid
  )
);

Maps of $form-validation-stateshian tooltips leh focus styles override theihna tur optional parameter pathum a nei thei.

Suih

$form-validation-statesKan validation style siam nan map value chunga iterate nan hman thin . A chunga Sass map-a siam danglamna awm apiang chu he loop hmang hian i compile CSS-ah a lang ang.

@each $state, $data in $form-validation-states {
  @include form-validation-state($state, $data...);
}

Customizing a ni

Validation state te chu Sass hmangin $form-validation-statesmap nen customize theih a ni. Kan _variables.scssfile-a awm, he Sass map hi default valid/ invalidvalidation states kan siam dan a ni. State tinte color, icon, tooltip color, leh focus shadow te siam dan tur nested map a awm bawk. State dang browser-in a support loh laiin, custom style hmangtute chuan awlsam takin form feedback complex zawk an dah belh thei a ni.

Mixin pawh siam danglam lovin value customize kan rawt lo tih$form-validation-statesform-validation-state hre reng ang che .