如何将输入字段设置为只读或输入字段

Question

如果有可用数据，我正在输入项目，该字段应为只读 必填项目。

  <input type="text" name="login_password" 
  id="login_password" 
 placeholder="Desgination" value="<?php echo 
   $row["designation"] ?>" Readonly required>

Answer 1

您可以尝试一下，如果字段中有一些值，它将回显readonly，否则将是空白字段，required

<input type="text" name="login_password"   id="login_password"  placeholder="Desgination" value="<?php echo  $row["designation"]; ?>"  <?php if(trim($row["designation"]) !="") echo "Readonly"; else echo "required"; ?> >

Answer 2

我的2美分！如果没有在html代码中，那是个坏习惯，恕我直言

$readonly = isset($row["designation"]) ? 'required' : '';

<input type="text" name="login_password" id="login_password" placeholder="Desgination" value="<?php echo $row["designation"] ?>" <?php echo $readonly; ?> required>

Answer 3

尝试

<?php 
    if(!empty($row["designation"])){
       $condition = "readonly";
    else
      $condition = "required"; 
?>
<input type="text" name="login_password" id="login_password" placeholder="Desgination" value="<?php echo 
$row["designation"] ?>" <?php echo $condition; ?>>