正则表达式提取电子邮件地址

Question

I want to be able to extract an email address embedded in tags eg <email> test@demo.com </email> where the src is as <email>test@demo.com</email>

My expression I use is as follows: (?<=email&gt;).*(?=&lt;)/i) . This works well. However, if the email is a hyperlink ie &lt;email&gt;**<a href="mailto:test@demo.com" target="_blank"**>test@demo.com</a> &lt;/email&gt; then i can no longer extract the extact email address. i get the following: <a href="mailto:test@demo.com">test@demo.com</a> instead of test@demo.com . I have tried (?<=a href="mailto:).*(?="target="_blank")/i) but nothing is returned. Any ideas on how to extract the email when the hyperlink is there?

Answer 1

Web dev 101: don't parse HTML with regex, use DOM manipulations instead.

This below logs all the emails, whether they are inside plain email tags or a inside email tags or any nesting of tags.

 console.log( Array.from(document.getElementsByTagName('email')) .map(elt => elt.textContent) .map(email => email.trim()) ) 

 <email>john@doe.com</email> <email><a href="mailto:john@doe.com">john@doe.com</a></email> <email><b><a href="mailto:john@doe.com">john@doe.com</a></b></email> <email><span><b><a href="mailto:john@doe.com">john@doe.com</a></b></span></email> <email>"o'brian"@irish.com</email> 

The .trim() is useful in case there is whitespace in the HTML which can show up around the email.

Answer 2

You can parse each line of Dom and match email regex with tag content, like below snippet :

<script>
function getEmailsFromText (text)
{
    return text.match(/([a-zA-Z0-9._-]+@[a-zA-Z0-9._-]+\.[a-zA-Z0-9._-]+)/gi);
}
var items = document.getElementsByTagName("*");
    for (var i = 0; i < items.length; i++) {
        var text = items.item(i).textContent;
        var emailIds = getEmailsFromText(text);
        if(emailIds){
        console.log("Emails ID's : "+emailIds);
        }
    }
</script>

To test, open your javascript console tab and paste the above code which inside script tag and you can see all email id's of current html page.