我需要的信息在一个元标签中。当属性=“视频”时,我如何访问元标签的“内容”数据?
HTML:
<meta property="video" content="http://video.com/video33353.mp4" />
我需要的信息在一个元标签中。当属性=“视频”时,我如何访问元标签的“内容”数据?
HTML:
<meta property="video" content="http://video.com/video33353.mp4" />
当前回答
<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>
Demo
其他回答
你可以用这个:
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'));
使用元根,然后获取和设置它的任何属性:
let meta = document.getElementsByTagName('meta')
console.log(meta.video.content)
> "http://video.com/video33353.mp4"
meta.video.content = "https://www.example.com/newlink"
在Jquery中,你可以实现这一点:
$("meta[property='video']");
在JavaScript中,你可以通过以下方法实现:
document.getElementsByTagName('meta').item(property='video');
下面是一个函数,它将返回任何元标记的内容并记住结果,避免不必要的DOM查询。
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 */
下面是一个扩展版本,它也可以查询打开的图形标签,并使用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"
供参考,根据https://developer.mozilla.org/en-US/docs/Web/HTML/Element/meta全局属性是有效的,这意味着id属性可以与getElementById一起使用。