防止用空输入提交表单？ [英] prevent form submit with empty input?

问题描述

可能存在重复：

如何防止提交HTML表单的输入字段值，如果它为空

 <？php 
 
 include'../core/init.php ; 
 if（isset（$ _ POST ['nt']）&& isset（$ _ POST ['ntb']））{
 mysql_query（INSERT INTO`post`（`myid`，`` （''。$ _ SESSION ['id']。'，'.mysql_real_escape_string（$ _ POST ['nt']）。'））; 
} 
？> 
 
< iframe style =display：nonename =submissiontargetid =submissiontarget>< / iframe> 
< form method =posttarget =submittargetaction =../ajax/post.phpname =form> 
< input type =textboxname =ntclass =postwallid =ntplaceholder =贴在墙上rows =7wrap =physicalcols =40 onfocus =if（this.value =='贴在墙上'）this.value =''; onblur =if（this.value ==''）this.value ='贴在墙上'; /> 
< input type =submitstyle =display：none; name ='ntb'id ='ntb'class =Buttonchatvalue =发布/> 
< / form> 
  

我希望能够做到这一点，所以如果文本框是空白的，它说'他们是错误发布在你的墙上，请重试'。

解决方案

  if（isset（$ _POST ['nt']）&& isset（$ _ POST ['ntb']））{
 ... 
} else {
 echo请再试一次。; 
} 
  

在副本中捕获空输入提交是一个额外的功能，但你不会在服务器端执行。

Possible Duplicate:
How to prevent submitting the HTML form’s input field value if it empty

<?php

include '../core/init.php';
if(isset($_POST['nt']) && isset($_POST['ntb'])){
mysql_query("INSERT INTO `post` (`myid`, `text`) VALUES ('".$_SESSION['id']."', '".mysql_real_escape_string($_POST['nt'])."')");
}
?>

<iframe style="display:none" name="submissiontarget" id="submissiontarget"></iframe>
<form method="post" target="submissiontarget" action = "../ajax/post.php" name="form">
<input type="textbox" name="nt" class="postwall" id="nt"  placeholder="Post on your wall" rows="7" wrap="physical" cols="40" onfocus="if(this.value=='Post On Your Wall')this.value='';" onblur="if(this.value=='')this.value='Post On Your Wall';" />
<input type="submit" style="display:none;" name='ntb' id='ntb'  class="Buttonchat"     value="Post" />
</form>

I want to be able to do it so if the textbox is blank it says, 'Their was an error posting on your wall, please try again'.

解决方案

if(isset($_POST['nt']) && isset($_POST['ntb'])) {
    …
} else {
    echo "There was an error posting on your wall, please try again.";
}

The catching of empty input submits on clientside, as demonstrated in the duplicate, might be an additional feature, but you won't get around doing it serverside.

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