Regular Expression to select part in HTML - javascript

I have requirement to extract meta property from scrolled HTML source code. After scrolling HTML code contains as follows
Example:
<meta property="og:site_name" content="asasasas">
<meta property="og:title" content="asajhskajhsaksp;" />
<meta property="og:image" content="images.cxs.com/2014/09/modit1.gif?w=209" />
Here I want to get the content of only where meta property="og:image" ie result should be only
images.cxs.com/2014/09/modit1.gif?w=209

was it so difficult to use jquery
$('meta[property="og:image"]').attr('content')

As #Biffen said, don't use regex to parse html.
If you have the said string in a variable you can use querySelector() like
var html = '<meta property="og:site_name" content="asasasas" /><meta property="og:title" content="asajhskajhsaksp;" /><meta property="og:image" content="images.cxs.com/2014/09/modit1.gif?w=209" />';
var el = document.createElement('div');
el.innerHTML = html;
var meta = el.querySelector('meta[property="og:image"]');
console.log(meta.content);
document.getElementById('result').innerHTML = meta.content;
<div id="result"></div>
If it is part of the current page then
var meta = document.querySelector('meta[property="og:image"]');
console.log(meta.content);
document.getElementById('result').innerHTML = meta.content;
<meta property="og:site_name" content="asasasas"/>
<meta property="og:title" content="asajhskajhsaksp;" />
<meta property="og:image" content="images.cxs.com/2014/09/modit1.gif?w=209" />
<div id="result"></div>

You can use the approach suggested by Arun, however there may be user agents that don't support the Selectors API or don't support the required features (e.g. IE8). In that case, you can use getElementsByTagName and a plain old for loop.
var node, nodes = document.getElementsByTagName('meta');
for (var i=0, iLen=nodes.length; i<iLen; i++) {
node = nodes[i];
if (node.getAttribute('property') == 'og:image') {
// do something with content
console.log(node.content);
}
}
the above will work in any browser in use and doesn't require any external library.

Related

React not getting different images for same URL

I am making a users page with arbitrary data and noticed that since the image URL is the same (https://source.unsplash.com/random) the image is the same. How can I prevent this?
That is because, your browser caches your url and assumes you are hitting the same url so it populates previous result. Add a random query to the url like source.unsplash.com/random?v={random_number_here} will solve your problem
This has nothing to do with react.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<div id="images-wrapper"></div>
<script>
const wrapper = document.getElementById('images-wrapper');
var html = '';
// for(var i =0; i< 10; i++){ // same images
// html += '<img src="https://source.unsplash.com/random">';
// }
for(var i =0; i< 10; i++){ // different images
html += '<img src="https://source.unsplash.com/random?v='+(i+1)+'">';
}
wrapper.innerHTML = html;
</script>
</body>
</html>

document.creatElement can't show utf8 chars

I create label elem with document.crteateElement and I set text value to elem with .innerHTML but on page browser don't show utf-8 characters correct I see only '?' in black rectangle.
This my hrml charset:
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-9">
<META HTTP-EQUIV="Content-language" CONTENT="tr">
I use this function for convert :
GetChar(char) {
return unescape(decodeURIComponent(char))
}
and this is my value
const target= '${this.GetChar('İ')}stikamet'
then here is I set value to label elem
var elem = document.createElement('label)
elem.innerHTML = target
What is the corrent way show this characters on browser ?
Try this instead of your current meta-tags
<meta charset="UTF-8">
EDIT:
The following HTML displays your example-char fine for me:
<html>
<meta charset="UTF-8">
<body>
<label>İ</label>
</body>
</html>

Fnd links containing particular string in href and remove href between slashes with javascript only

I have a use case, where i have to select all <a>, containing string in url like "/web/local" and remove "/web/local" from all href of all these links.
Note: i can't use jQuery. I can use either pure js or YUI.
Thanks in advance.
See comments inline:
let phrase = "/web/local";
// Get all the links that contain the desired phrase into an Array
let links = Array.prototype.slice.call(document.querySelectorAll("a[href*='" + phrase +"']"));
// Loop over results
links.forEach(function(link){
// Remove the phrase from the href
link.href = link.href.replace(phrase, "");
});
// Just for testing:
console.log(document.querySelectorAll("a"));
Some Link
Some Link
Some Link
Some Link
Some Link
In order to get /set correctly the href attribute you need to use getAttribute/setAttribute:
document.querySelectorAll('a[href*="/web/local"').forEach(function(ele) {
ele.setAttribute('href',
ele.getAttribute('href').replace('/web/local', ''));
console.log(ele.outerHTML);
});
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
Link 1
Link 2
<script>
var string = '/web/locale/';
var links = document.getElementsByTagName('a');
for (var i = 0; i < links.length; i++) {
var link = links[i].getAttribute('href');
link = link.replace(string, '');
links[i].setAttribute('href', link);
}
</script>
</body>
</html>

How to store the value of an attribute inside a variable using html, javascript?

I have a line <meta property="product:price:amount" content="3.05"/>
in a large html file.
I need to store the value of content inside a variable, so that I may access it globally.
How can I do that?
Just catch it with querySelector to get it's content attribute.
const content = document.querySelector('meta').content;
console.log(content);
<meta property="product:price:amount" content="3.05"/>
In case of multiple meta tags:
const elems = document.querySelectorAll('meta');
let content = Array.from(elems).find(v => v.content).content;
console.log(content);
<meta property="product:price:amount"/>
<meta property="product:price:amount"/>
<meta property="product:price:amount" content="3.05"/>
To very specifically get the meta tag you are after (event if there are multiple meta tags):
var variable = document.querySelectorAll('meta[property="product:price:amount"]')[0].content;
If there is only one item then simply
document.getElementsByTagName("meta")[0].content
For a single meta tag:
var myGlobal = document.querySelector('meta[content]').getAttribute('content');
document.body.textContent = myGlobal;
<meta property="product:price:amount" content="3.05"/>
If you have a lot of tags:
var contentArray = [];
document.querySelectorAll('meta[content]').forEach(function(meta){
contentArray.push(meta.getAttribute('content'));
});
document.body.textContent = contentArray.join(' - ');
<meta property="product:price:amount" content="3.05"/>
<meta property="product:quality:amount" content="9.25"/>
<meta property="product:id:amount" content="1.0"/>
If you want to be more specific about the tag you can change the selector:
...querySelector('meta[property="product:price:amount"][content]')...
Read more about selectors https://developer.mozilla.org/en-US/docs/Learn/CSS/Introduction_to_CSS/Selectors

Handling meta data with Javascript

I am trying to read meta data from an html page using JavaScript. I created an array of all the meta tags and I am trying to read the property field, but I cant seem to get it to work. Here is the console:
>meta[6]
<meta property=​"og:​image" content=​"http:​/​/​www. example.com/img/1.png">​
>meta[6].property
undefined
>meta[6].content
"http:​/​/​www. example.com/img/1.png"
How am I able to access the content but not the property field and how can I get the property?
To answer the question:
"How am I able to access the content
but not the property field"
content is a standard attribute of the HTML meta element, so browsers will create an equivalent DOM property for the related DOM meta element.
property is not a standard attribute for the HTML meta element, so some browsers will not create a similar property (e.g. Firefox), while other browsers (e.g. IE) will. Therefore getAttribute should be used for any non-standard attribute value, but direct DOM property access should be used for the values of standard attributes.
As a general rule, you should not use non-standard attributes on HTML elements, then you can always access values using DOM properties (which is the most appropriate method for HTML DOM elements).
Note that the HTML5 meta element is the same as the HTML 4.01 element linked to above, however the HTML 4 spec is probably the better one to use on the general web for the time being. HTML5-specific code should really only be used when targetting the HTML5 features of a particular browser.
Here is a complete working example..
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">
<head>
<title>Cross-Window HTML</title>
<meta property="og:title" content="Share Title" />
<meta property="og:description" content="Share Page Description" />
<meta property="og:image" content="Path to Share Image" />
<link rel="canonical" href="http://127.0.0.1/newWindowWrite.html" />
<script type="text/javascript">
function GetMetaValue(meta_name) {
var my_arr = document.getElementsByTagName("meta");
for (var counter = 0; counter < my_arr.length; counter++) {
console.log(my_arr[counter].getAttribute('property'));
if (my_arr[counter].getAttribute('property') == meta_name) {
return my_arr[counter].content;
}
}
return "N/A";
}
function newHTML() {
HTMLstring = '<html>\n';
HTMLstring += '<head>\n';
HTMLstring += '<title>Google +1</title>\n';
HTMLstring += '<meta property="og:title" content="' + GetMetaValue('og:title') + '"/>\n';
HTMLstring += '<meta property="og:description" content="' + GetMetaValue('og:description') + '"/>\n';
HTMLstring += '<meta property="og:image" content="' + GetMetaValue('og:image') + '"/>\n';
HTMLstring += '<link rel="canonical" href="' + location.href + '"/>\n';
HTMLstring += '</head>\n';
HTMLstring += '<body>\n';
HTMLstring += '<div id="shareContent">\n';
HTMLstring += '</div>\n';
HTMLstring += '</body>\n';
HTMLstring += '</html>';
console.log(HTMLstring);
newwindow = window.open();
newdocument = newwindow.document;
newdocument.write(HTMLstring);
newdocument.close();
}
</script>
</head>
<body>
<div onclick="newHTML();">Spawn Sharing Window</div>
</body>
</html>
you want the getAttribute function:
>meta[6].getAttribute('property');
"og:image"

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