How do I get the information from a meta tag with JavaScript?
JavascriptHtmlGreasemonkeyMeta TagsJavascript Problem Overview
The information I need is in a meta tag. How can I access the "content" data of the meta tag when property="video"?
HTML:
<meta property="video" content="http://video.com/video33353.mp4" />
Javascript Solutions
Solution 1 - Javascript
The other answers should probably do the trick, but this one is simpler and does not require jQuery:
document.head.querySelector("[property~=video][content]").content;
The original question used an RDFa tag with a property="" attribute. For the normal HTML <meta name="" …> tags you could use something like:
document.querySelector('meta[name="description"]').content
Solution 2 - Javascript
You can use this:
function getMeta(metaName) {
const metas = document.getElementsByTagName('meta');
for (let i = 0; i < metas.length; i++) {
if (metas[i].getAttribute('name') === metaName) {
return metas[i].getAttribute('content');
}
}
return '';
}
console.log(getMeta('video'));
Solution 3 - Javascript
One liner here
document.querySelector("meta[property='og:image']").getAttribute("content");
Solution 4 - Javascript
There is an easier way:
document.getElementsByName('name of metatag')[0].getAttribute('content')
Solution 5 - Javascript
function getMetaContentByName(name,content){
var content = (content==null)?'content':content;
return document.querySelector("meta[name='"+name+"']").getAttribute(content);
}
Used in this way:
getMetaContentByName("video");
The example on this page:
getMetaContentByName("twitter:domain");
Solution 6 - Javascript
If you use JQuery, you can use:
$("meta[property='video']").attr('content');
Solution 7 - Javascript
In Jquery you can achieve this with:
$("meta[property='video']");
In JavaScript you can achieve this with:
document.getElementsByTagName('meta').item(property='video');
Solution 8 - Javascript
document.querySelector('meta[name=NAME_OF_THE_FIELD]').content
this way you can get the content of the meta.
Solution 9 - Javascript
Way - [ 1 ]
function getMetaContent(property, name){
return document.head.querySelector("["+property+"="+name+"]").content;
}
console.log(getMetaContent('name', 'csrf-token'));
You may get error: Uncaught TypeError: Cannot read property 'getAttribute' of null
Way - [ 2 ]
function getMetaContent(name){
return document.getElementsByTagName('meta')[name].getAttribute("content");
}
console.log(getMetaContent('csrf-token'));
You may get error: Uncaught TypeError: Cannot read property 'getAttribute' of null
Way - [ 3 ]
function getMetaContent(name){
name = document.getElementsByTagName('meta')[name];
if(name != undefined){
name = name.getAttribute("content");
if(name != undefined){
return name;
}
}
return null;
}
console.log(getMetaContent('csrf-token'));
Instead getting error, you get null, that is good.
Solution 10 - Javascript
Simple one, right?
document.head.querySelector("meta[property=video]").content
Solution 11 - Javascript
This code works for me
<meta name="text" property="text" content="This is text" />
<meta name="video" property="text" content="http://video.com/video33353.mp4" />
JS
var x = document.getElementsByTagName("META");
var txt = "";
var i;
for (i = 0; i < x.length; i++) {
if (x[i].name=="video")
{
alert(x[i].content);
}
}
Example fiddle: http://jsfiddle.net/muthupandiant/ogfLwdwt/
Solution 12 - Javascript
function getDescription() {
var info = document.getElementsByTagName('meta');
return [].filter.call(info, function (val) {
if(val.name === 'description') return val;
})[0].content;
}
update version:
function getDesc() {
var desc = document.head.querySelector('meta[name=description]');
return desc ? desc.content : undefined;
}
Solution 13 - Javascript
My variant of the function:
const getMetaValue = (name) => {
const element = document.querySelector(`meta[name="${name}"]`)
return element?.getAttribute('content')
}
Solution 14 - Javascript
copy all meta values to a cache-object:
/* <meta name="video" content="some-video"> */
const meta = Array.from(document.querySelectorAll('meta[name]')).reduce((acc, meta) => (
Object.assign(acc, { [meta.name]: meta.content })), {});
console.log(meta.video);
Solution 15 - Javascript
Here's a function that will return the content of any meta tag and will memoize the result, avoiding unnecessary querying of the DOM.
var getMetaContent = (function(){
var metas = {};
var metaGetter = function(metaName){
var theMetaContent, wasDOMQueried = true;;
if (metas[metaName]) {
theMetaContent = metas[metaName];
wasDOMQueried = false;
}
else {
Array.prototype.forEach.call(document.getElementsByTagName("meta"), function(el) {
if (el.name === metaName) theMetaContent = el.content;
metas[metaName] = theMetaContent;
});
}
console.log("Q:wasDOMQueried? A:" + wasDOMQueried);
return theMetaContent;
}
return metaGetter;
})();
getMetaContent("description"); /* getMetaContent console.logs the content of the description metatag. If invoked a second time it confirms that the DOM was only queried once */
And here's an extended version that also queries for open graph tags, and uses Array#some:
var getMetaContent = (function(){
var metas = {};
var metaGetter = function(metaName){
wasDOMQueried = true;
if (metas[metaName]) {
wasDOMQueried = false;
}
else {
Array.prototype.some.call(document.getElementsByTagName("meta"), function(el) {
if(el.name === metaName){
metas[metaName] = el.content;
return true;
}
if(el.getAttribute("property") === metaName){
metas[metaName] = el.content;
return true;
}
else{
metas[metaName] = "meta tag not found";
}
});
}
console.info("Q:wasDOMQueried? A:" + wasDOMQueried);
console.info(metas);
return metas[metaName];
}
return metaGetter;
})();
getMetaContent("video"); // "http://video.com/video33353.mp4"
Solution 16 - Javascript
If you are interessted in a more far-reaching solution to get all meta tags you could use this piece of code
function getAllMetas() {
var metas = document.getElementsByTagName('meta');
var summary = [];
Array.from(metas)
.forEach((meta) => {
var tempsum = {};
var attributes = meta.getAttributeNames();
attributes.forEach(function(attribute) {
tempsum[attribute] = meta.getAttribute(attribute);
});
summary.push(tempsum);
});
return summary;
}
// usage
console.log(getAllMetas());
Solution 17 - Javascript
The simple way preferred
We can use direct one line to get meta description or keyword or any meta tag in head section as this code:
document.head.getElementsByTagName('meta')['description'].getAttribute('content');
Just change ['description'] to keywords or element of meta name rang
This is an example: using document.head to get meta names values
Solution 18 - Javascript
I personally prefer to just get them in one object hash, then I can access them anywhere. This could easily be set to an injectable variable and then everything could have it and it only grabbed once.
By wrapping the function this can also be done as a one liner.
var meta = (function () {
var m = document.querySelectorAll("meta"), r = {};
for (var i = 0; i < m.length; i += 1) {
r[m[i].getAttribute("name")] = m[i].getAttribute("content")
}
return r;
})();
Solution 19 - Javascript
FYI according to https://developer.mozilla.org/en-US/docs/Web/HTML/Element/meta global attributes are valid which means the id attribute can be used with getElementById.
Solution 20 - Javascript
Using meta root and then getting and setting any of its properties:
let meta = document.getElementsByTagName('meta')
console.log(meta.video.content)
> "http://video.com/video33353.mp4"
meta.video.content = "https://www.example.com/newlink"
Solution 21 - Javascript
<html>
<head>
<meta property="video" content="http://video.com/video33353.mp4" />
<meta name="video" content="http://video.com/video33353.mp4" />
</head>
<body>
<script>
var meta = document.getElementsByTagName("meta");
size = meta.length;
for(var i=0; i<size; i++) {
if (meta[i].getAttribute("property") === "video") {
alert(meta[i].getAttribute("content"));
}
}
meta = document.getElementsByTagName("meta")["video"].getAttribute("content");
alert(meta);
</script>
</body>
</html>
Solution 22 - Javascript
document.head.querySelector('meta[property=video]').content;
Solution 23 - Javascript
if the meta tag is:
<meta name="url" content="www.google.com" />
JQuery will be:
const url = $('meta[name="url"]').attr('content'); // url = 'www.google.com'
JavaScript will be: (It will return whole HTML)
const metaHtml = document.getElementsByTagName('meta').url // metaHtml = '<meta name="url" content="www.google.com" />'