我想知道当我同时使用onblur处理程序和onsubmit处理程序时如何验证表单。我试过这样做，直接进入提交页面而不显示错误信息。
因为我还有单选按钮和复选框，如果用户没有单击单选按钮并从验证中排除复选框，如何验证这些。
谢谢
function IsNotBlank(tf, tfHelp) {
var value = tf.value;
if (value == " ") {
tf.className = "invalid ";
tfHelp.innerHTML = "This field can 't be blank.";
return false;
} else {
tf.className = "valid";
tfHelp.innerHTML = "";
return true;
}
}
function CheckLetters(tf, tfHelp) {
//check empty field from previous function.
var NotEmpty = IsNotBlank(tf, tfHelp);
if (NotEmpty == false) {
return false;
}
//assign field value
var value = tf.value;
//check if there is numbers.
var regex = new RegExp(/^[A-Za-z]{5,18}$/);
var testResult = regex.test(value);
if (testResult == false) {
tf.className = "invalid";
tfHelp.innerHTML = "Use letters only and lengths must be between 5 and 18 characters.";
return false;
} else {
tf.className = "valid";
tfHelp.innerHTML = "";
return true;
}
}
function CheckPhNumber(tf, tfHelp) {
//check empty field
var NotEmpty = IsNotBlank(tf, tfHelp);
if (NotEmpty == false)
return false;
var value = tf.value;
//validate phone number.
var regex = /^\d{8,10}$/;
var testResult = regex.test(value);
//logic
if (testResult == false) {
tf.className = "invalid";
tfHelp.innerHTML = "Please enter a valid phone number.";
return false;
} else {
tf.ClassName = "valid";
tfHelp.innerHTML = "";
return true;
}
}
function CheckEmail(tf, tfHelp) {
//check empty field
NotEmpty = IsNotBlank(tf, tfHelp);
if (NotEmpty == false) {
return false;
}
var value = tf.value;
//validate email address
var regex = /^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/;
var testResult = regex.test(value);
//logic
if (testResult == false) {
tf.className = "invalid";
tfHelp.innerHTML = "Please enter a valid email address.";
return false;
} else {
tf.className = "valid";
tfHelp.innerHTML = "";
return true;
}
}
function CheckPostCode(tf, tfHelp) {
//check empty field
var NotEmpty = IsNotBlank(tf, tfHelp);
if (NotEmpty == false)
return false;
var value = tf.value;
//validate postcode.
var regex = /^\d{4}$/;
var testResult = regex.test(value);
//logic
if (testResult == false) {
tf.className = "invalid";
tfHelp.innerHTML = "Please enter a 4 digit post code.";
return false;
} else {
tf.ClassName = "valid";
tfHelp.innerHTML = "";
return false;
}
}
function ValidateForm(form) {
var formCheck = true;
for (var i = 0; i < form.elements.length; i++) {
var e = form.elements[i];
//alert(form.elements[i]);
if (e.onblur) {
// alert(e.onblur());
formCheck = e.onblur() && formCheck;
}
}
return formCheck;
}
function ResetForm(form) {
//select input elements and change color back to default
var arrayInputs = document.getElementsByTagName("input");
for (var i = 0; i < arrayInputs.length; i++) {
arrayInputs[i].className = "valid";
}
//clear text on span elements
var arraySpans = document.getElementsByTagName('span ');
for (var i = 0; i < arraySpans.length; i++) {
arraySpans[i].innerHTML = "";
}
}<form action="submit.html" onreset="ResetForm()" onsubmit="ValidateForm(this);">
<div>
<label for="fname" class="label">First Name:</label>
<input class="valid" type="text" id="txtFname" onblur="return CheckLetters(this, txtFnameHelp);" />
<span id="txtFnameHelp"></span>
</div>
<div class="one">
<label for="lname" class="label">Last Name:</label>
<input class="valid" name="lname" id="txtLname" type="text" onblur="return CheckLetters(this, txtLnameHelp);" />
<span id="txtLnameHelp"></span>
</div>
<div class="one">
<label class="label" for="phone">Phone Number:</label>
<input class="one" id="txtPhone" type="text" onblur="CheckPhNumber(this, txtPhoneHelp);"><br>
<span id="txtPhoneHelp"></span>
</div>
<div class="one">
<label for="email" class="label">Email Address:</label>
<input class="valid" id="txtEmail" type="text" onblur="CheckEmail(this, txtEmailHelp)">
<span id="txtEmailHelp"></span><br>
</div>
<div class="one">
<label class="label">Post Code:</label>
<input id="txtPostcode" type="text" onblur="CheckPostCode(this, txtPostCodeHelp);"> <br>
<span id="txtPostCodeHelp"></span>
</div>
<br>
<div>
<label>Prefered Contact Method</label><br>
</div>
<div class="one">
</--<input type="radio" name="contact" value="email">Email
</-- <input type="radio" name="contact" value="phone">Phone
</div>
<br>
<div class="one">
<label>Your Message:</label><br />
<textarea id="txtMessage" rows="8" cols="40" onblur="IsNotBlank(this, txtMessageHelp)">Your Message</textarea>
<span id="txtMessageHelp"></span>
<br><br>
</div>
</--<input class="one" type="checkbox" name="newsletter" value="subscribe">I would like to subscribe to the newsletter <br>
<div>
<input class="one" type="submit" value="Send">
<input class="one " type="Reset " value="Clear">
<br><br>
</div>
</form>
请注意，这些类型的JavaScript代码只能出于某种原因使用Microsoft Visual Studio进行调试，并且无法使用旧版文本编辑器。
答案 0 :(得分：0)
您可以使用以下概念执行这两项操作，并使用window.addEventListener('DOMContentLoaded'function(e) {})检查验证
var error_user_name = false;
function checkpw(ele, e){
var user_name = document.forms["joinform"]["user_name"].value;
if (user_name == null || user_name == "") {
text = "UserName : Required";
document.getElementById("errormsg4").innerHTML = text;
error_user_name = false;
} else {
document.getElementById("errormsg4").innerHTML = "";
error_user_name = true;
}
}
function submitall(ele, e) {
checkpw();
if(error_user_name == false) {
e.preventDefault();
} else {
console.log('form submitted');
}
}
window.addEventListener('DOMContentLoaded', function(e) { document.getElementById('user_name').addEventListener('blur', function(e) {
checkpw(this, e);
setTimeout(function() {
if (document.activeElement.id == 'join') {
document.activeElement.click();
}
}, 10);
}, false);
document.getElementById('joinform').addEventListener('submit', function(e) {
submitall(this, e);
}, false);
});<form id="joinform" method="post" name="joinform" action="#hello">
<h2>Join</h2>
<input type="text" name="user_name" id="user_name" placeholder="User_Name"/>
<div class ="errormsg" id ="errormsg4"></div><br>
<input type="submit" name="join" id="join" value="Submit" ><br><br>
</form>