javascript MDLテキストフィールドから間違ったパスワードエラーメッセージを表示するには

Question

ログインページを作成しようとしていますが、パスワードが間違っているとmdl-textfield__errorにメッセージが表示されません。次のように私のhtmlコードは次のとおりです。

<div class="mdl-layout mdl-js-layout mdl-color--grey-100"> 
<main class="mdl-layout__content"> 
    <div class="mdl-grid"> 
     <div class="mdl-layout-spacer"></div> 
     <div class="mdl-card mdl-cell mdl-cell--4-col mdl-cell--4-col-tablet mdl-shadow--6dp"> 
      <div class="mdl-card__title mdl-color--primary mdl-color-text--white"> 
       <h2 class="mdl-card__title-text">Title</h2> 
      </div> 
      <div class="mdl-card__supporting-text"> 
       <form action="#"> 
        <div class="mdl-textfield mdl-js-textfield"> 
         <input class="mdl-textfield__input" type="email" id="username" /> 
         <label class="mdl-textfield__label" for="username">Email</label> 
        </div> 
        <div class="mdl-textfield mdl-js-textfield"> 
         <input class="mdl-textfield__input" type="password" id="userpass" /> 
         <label class="mdl-textfield__label" for="userpass">Şifre</label> 
         <span class="mdl-textfield__error">Şifre yanlış. Tekrar deneyin.</span> 
        </div> 
       </form> 
      </div> 
      <div class="mdl-card__actions mdl-card--border"> 
       <button id="sign-in" class="mdl-button mdl-button--colored mdl-js-button mdl-js-ripple-effect">Giriş Yap</button> 
      </div> 
     </div> 
     <div class="mdl-layout-spacer"></div> 
    </div> 
</main> 

Answer 1

親.mdl-textfield要素にis-invalidとis-dirtyクラスを追加します。

<link href="https://code.getmdl.io/1.3.0/material.indigo-pink.min.css" rel="stylesheet"/> 
 
<div class="mdl-layout mdl-js-layout mdl-color--grey-100"> 
 
<main class="mdl-layout__content"> 
 
    <div class="mdl-grid"> 
 
    <div class="mdl-layout-spacer"></div> 
 
    <div class="mdl-card mdl-cell mdl-cell--4-col mdl-cell--4-col-tablet mdl-shadow--6dp"> 
 
     <div class="mdl-card__title mdl-color--primary mdl-color-text--white"> 
 
     <h2 class="mdl-card__title-text">OLUF 17 Giriş</h2> 
 
     </div> 
 
     <div class="mdl-card__supporting-text"> 
 
     <form action="#"> 
 
      <div class="mdl-textfield mdl-js-textfield"> 
 
      <input class="mdl-textfield__input" type="email" id="username" /> 
 
      <label class="mdl-textfield__label" for="username">Email</label> 
 
      </div> 
 
      <div class="mdl-textfield mdl-js-textfield is-dirty is-invalid"> 
 
      <input class="mdl-textfield__input" type="password" id="userpass" /> 
 
      <label class="mdl-textfield__label" for="userpass">Şifre</label> 
 
      <span class="mdl-textfield__error">Şifre yanlış. Tekrar deneyin.</span> 
 
      </div> 
 
     </form> 
 
     </div> 
 
     <div class="mdl-card__actions mdl-card--border"> 
 
     <button id="sign-in" class="mdl-button mdl-button--colored mdl-js-button mdl-js-ripple-effect">Giriş Yap</button> 
 
     </div> 
 
    </div> 
 
    <div class="mdl-layout-spacer"></div> 
 
    </div> 
 
</main>