admin管理员组

文章数量:1352069

I have implemented input validation in my HTML form. However, it does not prompt the user in case of any errors and still proceeds to send its data to the test server.

Below is my code:

<html>
<head>
    <style>
        input {margin: 10px 5px 10px 5px;}
        select {margin: 10px 5px 10px 5px;}
    </style>
    <script language="JavaScript">
    function validate(form1)
    { if (form1.name.value == "" || form1.surname.value == "" || form1.email.value == "" || form1.dob.value == "")
        { alert("One of the field is empty.")
            form1.firstname.focus()
            form1.firstname.select()
            form1.lastname.focus()
            form1.lastname.select()
            form1.email.focus()
            form1.email.select()
            form1.dob.focus()
            form1.dob.select()

            return false
        }
    return true}
    </script>

</head>
<body>
    <form method="GET" action="/cgi-bin/reply.pl"
    onSubmit="return validate(this)">
        First Name<input type="text" name="firstname"><br>
        Last Name<input type="text" name="lastname"><br>
        Email Address<input type="email" name="email"><br>
        Date of Birth<input type="date" name="dob"><br>
        Favourite Sport
        <select name="sports"><br>
        <option value="athletics">Athletics</option><br>
        <option value="basketball">Basketball</option><br>
        <option value="cricket">Cricket</option><br>
        <option value="football">Football</option><br>
        <option value="hockey">Hockey</option><br>
        <option value="swimming">Swimming</option><br>
        <option value="tennis">Tennis</option><br>
        </select><br>
        <input type="Submit"> <input type="reset">
    </form>

</body>

</html>

I have implemented input validation in my HTML form. However, it does not prompt the user in case of any errors and still proceeds to send its data to the test server.

Below is my code:

<html>
<head>
    <style>
        input {margin: 10px 5px 10px 5px;}
        select {margin: 10px 5px 10px 5px;}
    </style>
    <script language="JavaScript">
    function validate(form1)
    { if (form1.name.value == "" || form1.surname.value == "" || form1.email.value == "" || form1.dob.value == "")
        { alert("One of the field is empty.")
            form1.firstname.focus()
            form1.firstname.select()
            form1.lastname.focus()
            form1.lastname.select()
            form1.email.focus()
            form1.email.select()
            form1.dob.focus()
            form1.dob.select()

            return false
        }
    return true}
    </script>

</head>
<body>
    <form method="GET" action="http://www.test/cgi-bin/reply.pl"
    onSubmit="return validate(this)">
        First Name<input type="text" name="firstname"><br>
        Last Name<input type="text" name="lastname"><br>
        Email Address<input type="email" name="email"><br>
        Date of Birth<input type="date" name="dob"><br>
        Favourite Sport
        <select name="sports"><br>
        <option value="athletics">Athletics</option><br>
        <option value="basketball">Basketball</option><br>
        <option value="cricket">Cricket</option><br>
        <option value="football">Football</option><br>
        <option value="hockey">Hockey</option><br>
        <option value="swimming">Swimming</option><br>
        <option value="tennis">Tennis</option><br>
        </select><br>
        <input type="Submit"> <input type="reset">
    </form>

</body>

</html>
  • javascript
  • html
  • css
  • forms
  • validation
Share Improve this question edited Jun 8, 2016 at 17:11 stark 2,2562 gold badges24 silver badges35 bronze badges asked Jun 8, 2016 at 16:11 gymcodegymcode 4,63315 gold badges78 silver badges140 bronze badges 1
  • What's is form1.name ? – Akshey Bhat Commented Jun 8, 2016 at 16:16
Add a ment  | 

2 Answers 2

Reset to default 11

The problem is that when you use onsubmit, your code won't call your function until submission. One way to deal with a user submitting a form with a required input blank is using the required element: 

<form>
First Name<input type="text" name="firstname" required><br>
<input type="Submit"> <input type="reset">
</form>

https://jsfiddle/d43rLno5/

onSubmit happens when you submit the form as far as I understand so to make it fire before you need to use onclick and onkeyup for enter key to include the key event

Trigger a button click with JavaScript on the Enter key in a text box

Form 'onsubmit' not getting called

Otherwise you need to stop the default event from happening if you don't want the form action to be called right away

You can stop the default event with 

if (event.preventDefault) {
    event.preventDefault(); 
} else { 
    event.returnValue = false; 
}

Then you can use jquery .post method to send an Ajax query to your script

本文标签： javascriptHTML Form Check Empty FieldsStack Overflow

版权声明：本文标题：javascript - HTML Form Check Empty Fields - Stack Overflow 内容由网友自发贡献，该文观点仅代表作者本人， 转载请联系作者并注明出处：http://www.betaflare.com/web/1743639499a2514469.html， 本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌抄袭侵权/违法违规的内容，一经查实，本站将立刻删除。