如何在不提交form的情况下使用浏览器自带的html5的错误提示消息

具体的示例代码可以参考我 testcase 项目中 http://localhost:9000/form-user-interface.html 中 doCustomValidate 中的写法。

说透了就是： 如果想触发浏览器自带的html5错误消息提示，就必须触发form的提交事件，

To check whether a certain field is valid, use:

$('#myField')[0].checkValidity() // returns true/false

To check if the form is valid, use:

$('#myForm')[0].checkValidity() // returns true/false

If you want to display the native error messages that some browsers have (such as Chrome), unfortunately the only way to do that is by submitting the form, like this:

var $myForm = $('#myForm')
if (!$myForm[0].checkValidity()) {
  // If the form is invalid, submit it. The form won't actually submit;
  // this will just cause the browser to display the native HTML5 error messages.
  $myForm.submit()
}