使用javascript正则表达式，从网页获取元标记数据

Question

I wanna get meta tags data using javascript(jquery) and regex.

Here are some meta tags.

<meta name="description" content="Amazon.com : Google Chromecast HDMI Streaming Media Player : Streaming Media Clients : Electronics" />
<meta name="title" content="Amazon.com : Google Chromecast HDMI Streaming Media Player : Streaming Media Clients : Electronics" />

I can get content from those forms using below function.

function getProductInfo(attr) {
    var m = $("meta[name="+attr+"]");
    var content = m.attr("content");
    return content; 
}
if(!title) var title = getProductInfo('title');

However sometimes there are different form of meta tags like

<meta property="title" content="....">
<meta property="og:title" content="....">
<meta name="title" description="....">

That's why I'm considering using regex. but I have no idea. please give me a tip. thanks.

Answer 1

$('meta').each(function() {
        console.log($(this).attr('content'));
    });

No need for regex, for unsorted tags.

function getProductInfo(attr) {
            $('meta').each(function(index,tag) {
                if($(tag)[0].attributes[0].textContent == attr) { 
                        console.log($(tag)[0].attributes[0].textContent, $(tag)[0].attributes[1].textContent);
                     }
            });
        }
        getProductInfo('title');

This will get you anything , that has title in name/property.

Answer 2

Here's how you do it by not using RegEx

No libraries, pure vanilla JS:

var meta = document.querySelectorAll('meta');
for(var i=0;i<meta.length;i++){
   var content = meta[i].getAttribute('content'); /* here's the content */
}

http://jsfiddle.net/JA9Yq/

jQuery:

$('meta').each(function(index,tag){
    var content = tag.getAttribute('content');
});

http://jsfiddle.net/duL6E/

Answer 3

Its also possible using RegEx:

<meta[^>]+content="([^")]*)"

Result:

$matches Array:
(
    [0] => Array
    (
        [0] => <meta name="description" content="Amazon.com : Google Chromecast HDMI Streaming Media Player : Streaming Media Clients : Electronics"
        [1] => <meta name="title" content="Amazon.com : Google Chromecast HDMI Streaming Media Player : Streaming Media Clients : Electronics"
    )

    [1] => Array
    (
        [0] => Amazon.com : Google Chromecast HDMI Streaming Media Player : Streaming Media Clients : Electronics
        [1] => Amazon.com : Google Chromecast HDMI Streaming Media Player : Streaming Media Clients : Electronics
    )
)

Answer 4

may be this..

var desc = $('meta[name=description]').attr("content");
var title= $('meta[name=title]').attr("content");

var desc = $('meta[property=description]').attr("content");
var title= $("meta[property='og:title]").attr("content");

note: Apparently it doesn't like the colon. I was able to fix it by using double and single quotes like this:

Answer 5

This should work on all meta tags I think...

    /\<meta.*?\>/

Here's a link to regexr, which is a good tool to try things out

http://gskinner.com/RegExr

But it's better to use @subZero advice and not use regex if you don't have to... I think.