I have class .hello in css:
<style>
.hello { color:#ccc }
</style>
How can use Jquery to check class .hello exist in style or not?
Of course, it need to check all style even in <link href='style.css' /> document.
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3stackoverflow.com/questions/983586/…Milind Anantwar– Milind Anantwar2016-01-11 07:51:46 +00:00Commented Jan 11, 2016 at 7:51
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I need jquery solution. If you have answer, please place it below.Hai Tien– Hai Tien2016-01-11 07:53:11 +00:00Commented Jan 11, 2016 at 7:53
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you can iterate over all stylesheets using document.styleSheets. check for rules and selector text in it.Milind Anantwar– Milind Anantwar2016-01-11 08:07:17 +00:00Commented Jan 11, 2016 at 8:07
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This might help stackoverflow.com/questions/983586/…4dgaurav– 4dgaurav2016-01-11 08:08:20 +00:00Commented Jan 11, 2016 at 8:08
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Mr. 4dgaurav, Please have a look on first comment.Sarower Jahan– Sarower Jahan2016-01-11 08:18:31 +00:00Commented Jan 11, 2016 at 8:18
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5 Answers
Following will check if certain styles are applied to the element (doesn't absolutely confirms that whether it came from stylesheet)
if ($('.hello').css('color') == '#CCC') {
// true
} else {
// false
}
2 Comments
Hai Tien
You might misunderstood my question. It is only checking a class exist in style document or not.
4dgaurav
@MinhAnh yeah, I get your point, this will check for styles that are applied to the element ".hello", so if you have applied any styles in stylesheet to the element it will be true. The thing here is to know before hand that a particular style/styles that are expected to the element and it is present or not, this will certainly give you the idea whether its in stylesheet or not.
See below code snippet, the function returns the found class or id from the stylesheet or from style tag we pass. And returns an empty string if not found.
<script type="text/javascript">
function getDefinedCss(s){
if(!document.styleSheets) return '';
if(typeof s== 'string') s= RegExp('\\b'+s+'\\b','i'); // IE
capitalizes html selectors
var A, S, DS= document.styleSheets, n= DS.length, SA= [];
while(n){
S= DS[--n];
A= (S.rules)? S.rules: S.cssRules;
for(var i= 0, L= A.length; i<L; i++){
tem= A[i].selectorText? [A[i].selectorText,
A[i].style.cssText]: [A[i]+''];
if(s.test(tem[0])) SA[SA.length]= tem;
}
}
return SA.join('\n\n');
}
console.log(getDefinedCss ('ui-helper-hidden'));
</script>
Let me know if it works for you.
Comments
First specify the external file you want to search an existing class then try to replace whitespaces to "" if string "gap" was found is greater than 0 then class "gap" is found.
(function($){
jQuery.get('assets/css/main.css', function(data) {
var str = data.replace('n','');
if(str.match(/gap/g).length>0) {
console.log('class was found!');
}else{
console.log('no class!');
}
});
}) (jQuery);
1 Comment
DBS
Welcome to StackOverflow, when you answer a post it's good to include some explanation as well as code. You appear to be removing every
n, then searching for the string gap? (Were you perhaps trying to remove newlines? \n and then search for the class name?)You can use getComputedStyle() for element to get the styles.
Color is obtained as rgba and is converted to hex with the logic here
$('.hello').each((i, el) => {
if (rgb2hex(getComputedStyle(el).color) == "#cccccc") {
console.log('#cccccc el => ', el);
}
});
function rgb2hex(rgb) {
rgb = rgb.match(/^rgb\((\d+),\s*(\d+),\s*(\d+)\)$/);
return "#" + hex(rgb[1]) + hex(rgb[2]) + hex(rgb[3]);
}
function hex(x) {
let hexDigits = new Array("0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f");
return isNaN(x) ? "00" : hexDigits[(x - x % 16) / 16] + hexDigits[x % 16];
}.hello {
color: #cccccc;
}<script src="https://code.jquery.com/jquery-3.4.1.min.js" integrity="sha256-CSXorXvZcTkaix6Yvo6HppcZGetbYMGWSFlBw8HfCJo=" crossorigin="anonymous"></script>
<div class="hello">
hello
</div>
<div class="hi">
hi
</div>
Comments
Simpler still..
if($('.<class name>').length <= 0)
{
// load style sheet
$('<link href="style sheet ULR" rel="stylesheet">').appendTo("head");
}