Is there anyway i can access the style property for the particular div? For example, I have a code like below
<div class="testing" style="background-color:#ff00ff;">
This is my test Paragraph
</div>
I want to apply some other background color for this division. But i don't want to modify the class "testing", because it is being used in some other places also. Is there anyway using CSS only to access the style property and apply my new color?
I think attribute selectors may be what you are looking for:
div.testing[style="background-color:#ff00ff;"] {
background-color: new_color !important;
}
You can create another class and overwrite necessary property:
.testing-active {
background-color: red;
}
and use it like this:
<div class="testing testing-active"></div>
You need to make a style that has higher priority than the style. You could use the !important attribute to do that:
<div class="testing" style="background-color:#ff00ff;background-color:red !important;">
Big important caveat: whatever it is you're trying to do doesn't sound like a good idea, because the code will be very difficult to maintain. What is the underlying problem that you are trying to solve?
You can access the elements with this certain style like this:
.testing[style="background-color:#ff00ff;"] {
/* put your attributes here*/
}
but you cannot change the background-color attribute since this one has a higher priority in the html.
see this:
.testing[style="background-color:#ff00ff;"] {
background-color: #00f; /* not possible */
margin: 30px; /* possible */
}
what you can do is add a new attribute to your html like this:
<div class="testing" changecss="true">
This is my test Paragraph
</div>
and add this css:
.testing[changecss="true"] {
background-color: #00f;
}
See the JsFiddle as well.
"Think it is a dynamic code. How can i add new class without using javascript? "
The Answers is You cannot add a new class using CSS dynamically/ runtime. The only way to do it is by using javascript/jquery:-
HTML:
<div id="mydiv" class="testing" style="background-color:#ff00ff;">
This is my test Paragraph
</div>
JQUERY:
$('#mydiv').css('background','#ColorCode');
This way your class also wont change( since its being used in other places) and you can change the background also.
Can i ask why you are trying to achieve this using CSS?
Related
I need help on how to make CSS styles final so that they could not be overwritten by Javascript.
Problem: Sometimes, because of the img tag in the JavaScript code, everything, (all styles of all of the images) gets overwritten.
Here is my code:
<img src='logoImg' style='width:45px; height:30px;' >
Please tell me ways to do this in JavaScript or in CSS itself.
Desired output: I need the Logo Image to have final styling. So it is not affected by JavaScript through the DOM (document object model).
You can try adding !important keyword to your CSS properties to prevent them from getting changed.
Example
const test = document.getElementById("test");
// The color won't change to orange
// due to !important keyword in the CSS code
test.style.backgroundColor = "orange";
#test {
width: 50px;
height: 50px;
background: green !important;
}
<div id="test"></div>
Ideally though it would be better to work around this using a different solution like using a more specific method of selecting an HTML element and changing it's properties.
If you have some kind of a style applied by selecting a tag, you can override it by using a class or an id when it comes to CSS. If you're searching for elements in JavaScript code, you can look for them by a class name or an id value instead.
An alternative solution in your case would be to re-write/modify the JavaScript code that targets your img tags and either skip images that have a specific class like let's say logo, or make a custom class for all your standard images that do not include your logo element and look them up in your JavaScript code using document.getElementsByClassName method.
If you want to prevent JS to overwrite the style of an image, you need to style it in CSS and add important; to raise it specificty weight. !important has a higher specificty weight then inline-style and as such JS style (JS add the style as inline-style) wont apply.
function resize() {
document.querySelector("img").style.height = "200px";
document.querySelector("img").style.width = "200px";
}
img.test {
width: 45px !important;
height: 30px !important;
}
<img src='https://via.placeholder.com/200x200.jpg' class="test">
<button onclick="resize()">Test</button>
I want to set background color on flexbox and tried as follow.
Class definition on app:
<App id="app" class="weight-protocol"></App>
on FlexBox:
<FlexBox
height="20%"
width="100%"
alignItems="Start"
class="calendar-header-bg"
justifyContent="Center">
in the css file:
.weight-protocol .calendar-header-bg {
background-color: #007DB2;
}
The custom background color is not going to apply at all as you can see:
Look at the code inspector, the custom css class stays at the beginning calendar-header-bg instead at last.
Did you try without .weight-protocol ?
.calendar-header-bg {
background-color: #007DB2;
}
If not work you can use !important tag:
.calendar-header-bg {
background-color: #007DB2 !important;
}
You can also try use only background tag instead background-color:
.calendar-header-bg {
background: #007DB2 !important;
}
I hope this helps...
Good Luck!
Shouldn't FlexBox have some css to do what you are trying to achieve? use inspector and watch for the div that cointains the flexbox.
Can you be more specific?
I'm guessing the problem is specificity also known as importance of selectors. This means that the selector you're using (class nested in class) has little weight overall, and it very likely overwritten by a different, heavier selector from within the library you're using. For instance the library might be targeting a class within a class within an id or something similar.
My advice is to see the applied styles within the dev tools, see what's overwriting your styles and then decide if you'll make your selector stronger( by making it more specific) or just add !important after your background-color declaration.
Is there any problem creating a CSS class like this:
[test] { font: 13px; }
and use it in an HTML attribute as this:
<div test></div>
Would the performance in some browsers be affected by using this method?, I've tested it with Mozilla Firefox and Google Chrome and they seem to work with no problems.
Your custom attributes are not valid HTML. You must use data-* attributes if you want to put custom data on your elements. This makes what you are doing bad practice.
In addition, there are CSS classes already that should meet your needs, unless there is more to your question than you have described.
While there is no problem in applying styles this way, and sure it does work in the browsers, you have to understand that this is not a standard way of applying styles.
Since you have also asked from a 'practice' perspective, then, yes, this surely is not the right practice. The idea is: HTML is used to define the elements to be shown within the browser window, CSS is used to apply any styling that needs to be applied on these elements and JavaScript is used to perform any 'action' on it. So, from a practice perspective, this surely is bad practice!
On another note, why the reluctance to create a class and apply it on the div? After all, this class can be reused as and when required. If you need it only once, then why not create an id selector?
HTML:
<div class="rightApproach">The right way of applying styles</div>
CSS:
.rightApproach { color:Red; }
See this fiddle where you can see your approach as well as the correct way of applying styles, be it class selector or id selector.
http://jsfiddle.net/JkRPt/
It's better to use classes. This way will not work in older browsers and it's not professional.
However it doesn't have any performance issues.
HTML:
<div class="test">
CSS:
.test { font:13px; }
its good to use classes. Example:
<div class="module accordion expand"></div>
/* All these match that */
.module { }
.accordion { }
.expand { }
I'm dealing with a real hash of a site, so this is why I'm asking about this absurd question.
I've looked everywhere to find some sort of way to make a class override another class in the HTML class tag to no avail.
I can either do this, try to untie a ton of spaghetti (which I probably won't be allowed to do anyways), or something anyone else can recommend (would be greatly appreciated).
Is this possible?
class="myClass !important"
If not, is there some sort of equivalent?
Please help! Many thanks in advance!
No, that's not possible. You're going to have to iron out the CSS Specificity by yourself I'm afraid.
If you have the ability to change the HTML templates, you can always go in and add a <div id="override"> or something like that to the outer most wrapper of the page to use as the "master" rule in your CSS classes. Then, in the CSS, you can just add that ID before any of the existing classes or ones that you need to modify.
For instance, if you have the following and want to override the .some-class:
<div class="some-class">Bleh.</div>
And the corresponding CSS:
.some-class { color: red; }
You can wrap the whole thing with:
<div id="override">
<div class="some-class">Bleh.</div>
</div>
And add the #override (or whatever you want to name it) before the .some-class and this rule will take precedence over the other:
#override .some-class { color: green; } /* This will override the red color form the other rule */
.some-class { color: red; }
You can't use !important for entire selectors. You need to find the specific rules you want to override, and use !important on each.
You can add more than one class to a selector as follows:
class="myClass myClass2"
Above is what the class attribute would look like on your HTML element.
As far as the CSS goes, define the classes as follows:
.myClass {
color: black;
font-size: 14px;
}
The above is just a sample of some properties you may have.
Defining "myClass2" after "myClass" in your stylesheet will allow the properties from "myClass2" to overrided the matching ones in "myClass":
//This goes below myClass
.myClass2 {
font-size: 16px;
}
As long as "myClass2" is after "myClass", your font will take the size property of '16px;' The value of "myClass" will be overwritten by that of "myClass2". If "myClass2" comes before "myClass", you can use !important to ensure that style is taken over the one defined later:
//This goes above myClass
.myClass2 {
font-size: 16px !important;
}
Hope this helps.
CSS classes are just a group of styles so you can use class instead of inline style tag.
The !important keyword helps you to override a specific style and not working on classes.
So, for example:
Lets say that we have a css rule on every div somewhere in our CSS file
div{border:solid 1px #ff0000;}
And later on we have this rule:
div{background:#000000;}
Every div in our page will be with border and a background if we want to override the div css rules we need to do something like this:
div{background:none !important;border:none !important;/*...ADD YOUR CSS...*/}
you can create a css reset class to reset all the settings that you want and than add your css
Note, this is different than the older question How can I apply CSS on all buttons which are present in that page? because this is an already existing style. So given that a style, which we'll call "standard_label_style" already exists in an included CSS file, what can I do to say that all the labels on this page should have that style short of adding:
class="standard_label_style"
to each and every one? And yes, I know I could apply the styles ex-post-facto with a snippet of jQuery or JavaScript code. I'm just trying to learn how I'm supposed to do it with CSS.
Follow Up
I've gotten several comments that say just use syntax like this .standard_label_style, label... Unfortunately that does nothing like what I want. That would allow me to apply additional rules to the standard_label_style class, as well as rules to labels within this page, but would not allow me to apply that style to all the labels on this page. To see an example of this, here is a stylesheet and html to demonstrate. The label without a class will still not appear in red but that's what I'm hoping to have happen. I want to apply an existing class to all those labels on the page, not just the one with the class and without adding new styling on this page, the existing style should be the only style.
included.css:
.standard_label_style { color: red; }
test.html:
<html>
<head>
<link rel="stylesheet" type="text/css" href="included.css">
<style>
.standard_label_style, label { }
</style>
</head>
<body>
<label class="standard_label_style">Test Label</label><br/>
<label>Unclassed Test Label</label>
</body>
</html>
CSS doesn't really work like that.
You can apply a style to all labels directly:
label {
color: Lime;
}
or apply a class to all labels
.labelClass {
color: Lime;
}
<label class="labelClass"></label>
You can also have multiple selectors, so you could ammend your current style to be
.labelClass, label {
color: Lime;
}
What you can't do in standard CSS is something like
label {
.labelClass;
}
The good news is that there are a bunch of server side libraries which make CSS suck less and let you do exactly this kind of thing, see for example dotLess if you're using .NET which provides nested rules and a basic inheratance model.
To apply a style to every label on the page, use this CSS:
label {
/* styles... */
}
If you have an existing style (e.g. "standard_label_style") in the CSS already, you can apply that to every label:
.standard_label_style, label {
/* styles... */
}
This will affect every label through the site, so use with caution!
In your css file, can't you just put
.standard_label_style, label
{
//styles
}
.standard_label_style, label {
/* stuff */
}
I'm not sure you can... one possible workaround (feels a bit hackish though) is to attach the style to your body tag, then change the css to be this:
body.standard_label_style label{
//Your styles here
}
One of the most underused CSS tricks of all time: Give your bodies an id or class!
HTML:
<body id="standard_label_style">
<label>Hey!</label>
</body>
CSS:
#standard_label_style label{
the styles
}
will take the styles, while
HTML:
<body id="custom_label_style">
<label>Custom!</label>
</body>
Will not.
You are dealing here with CSS precedence. Declarations which are "more vague" (body tag, classes) are applied before declarations which are "less vague" (specific elements, inline CSS).
Thus your answer depends on how the stylesheet is defining label styles. If for example it says label {...}, then that's fairly specific, and your best bet is to use a more specific CSS style, see:
http://www.vanseodesign.com/css/css-specificity-inheritance-cascaade/ (good tutorial?)
CSS precedence
The level of "specificity" you need to override, as I said, depend on how specific your other stylesheet was. According to the link, "CSS embedded in the html always come after external stylesheets regardless of the order in the html".
There is also a chance that if you yourself define label {your custom css} that should work, if you import your stylesheet afterwards. It is what I would try first to see if it works. Have you tried this? What was the result?
Note that if you want to completely override the other stylesheet, you will need to also reset any CSS you are not using by settings its values to inherit or as appropriate.