css url function OR operator - css

Hi I want to know if I can use OR operator in CSS url function.
Example:
Is this possible ?
happy.moods {
background-image: url( 'pathA/img.png' || 'pathB/img.png' );
}

As some other users pointed out in the comments, there is no way to do what you speak of. While we can set things like min-width and max-width to achieve some half-baked logic, CSS and HTML really does not have a concept of logic at all. Even with psuedo-class selectors, the logic for displaying changes in a webpage is not a property of the code you have written but a property of the web browser.
This is why you can literally write any thing (regardless of whether it is proper code or not) into an HTML or CSS file and it won't cause the program to "break" because there is nothing to "compile".
However, this is where some concepts of Javascript come into play. I'm going to assume that you want a dynamic background image, if so, just go ahead and search that on SO or on Google, there are multiple pages out there to help you out.
Hope this helps!

Related

Change Events Calendar widget hyperlink colour with custom CSS in WordPress

Have found great help with R on SO--now for something completely different.
I am working in WordPress 5.8.3.
I am building a website using the Blank Canvas theme, a child-theme of Seedlet--Not sure whether that is all relevant. I am a novice with WP and all things web development. I have installed the Events Calendar plugin and have it all configured with some test events and dates so no issues there. I am customizing the theme colours using the Additional CSS prompt from the WordPress dashboard interface.
I haven't gotten permission to publish the site, so unfortunately I can't offer a live demo. I will try to be explicit.
I have found helpful resources with instructions on how to use this utility for menus, for general custom CSS, and some useful information for changing properties of footers with CSS. Now I am trying to modify hyperlink colours within the Events calendar widget. I have approached this problem the same way as all the others but this one has stumped me. I elaborate:
From this image, you can see the Events Calendar hyperlink text is yellow. I opened the inspector and determined that this object is called .tribe-events-widget .tribe-events-widget-events-list__view-more-link. I thought the following code should change the colour
.tribe-events-widget .tribe-events-widget-events-list__view-more-link {
color:#000;
}
It does not. This code makes no visible change. However, when I also change the background-color like this:
.tribe-events-widget .tribe-events-widget-events-list__view-more-link {
background-color:black;
color:#000;
}
The result is:
This led me to believe that there is no colour option for this element---HOWEVER, the inspector shows that this element has the 'color' property:
And I'm stumped. I'm not even sure when or how this color-link-accent got defined. This check-mark toggle is not a permanent solution and besides, I would very much like to understand what is going on here.
Any advice would be greatly appreciated.
It's a bit difficult to be certain of the problem as we don't have the context, however I was surprised that you saw just this:
.tribe-events-widget .tribe-events-widget-events-list__view-more-link
and didn't find an anchor (a) element within it.
I would have expected that you'd have to do:
.tribe-events-widget .tribe-events-widget-events-list__view-more-link a {
color:#000;
}
as it is quite likely the anchor element will have its own special styling which will override your setting because of the increase specificity.
If that doesn't work then use your browser dev tools inspect facility to find out more about the context of that a element - you may need to give even more hints to the browser on pinning it down.
Well, this would have helped me, so I will post the solution to my question for posterity. I learned from this question and thread about overriding cascading commands. I still don't understand where the command producing the yellow text in the first place was, but I managed to override it by appending !important in my CSS. The full CSS to turn the text from yellow to black is:
.tribe-events-widget .tribe-events-widget-events-list__view-more-link {
color:black !important;
}
Reading on, this does not necessarily mean that I was specific enough about the context although I find it hard to tell in this case. This reference has some other useful info as to when it is appropriate to use !important. It seems this is not the optimal solution.
Hope somebody else can benefit from my toiling...

How do I know which CSS is overriding my background image?

I want a background image on my page (background.png), but some rogue CSS is thwarting me.
I can see that my style.css from line 39 is being overwritten. I would think this is being done by something like style.css. I search and do not find anything but my original desired specification in that file. I can not find out what css is doing the overriding.
I have searched all the css files I can think of for the specified image (bg_p2_28.jpg). I have searched all the css files for background, nothing seems to come up. It is not being specified in the main HTML
I am barely struggling through as a reasonably competent programmer that has not used HTML since the mid 1990's. I am just trying to modify a template I bought.
What techniques can I use, or how do I interpret what I have here shown here to figure out what CSS override is ultimately being pushed into the page?
EDIT:
Adding the !important; works. It feels very dirty for some reason. I do not know why. I have tried following the javascript in, but the debugger is confusing to the uninitiated. Is the Important! a terrible thing to do, or reasonable? I think it would be useful to understand where these are being set in the java code, but when I search the code, I think the values are stored in variable, so can only be caught at run time.
That's coming from the inline style="" attribute.
If you don't see it in the HTML source, it's probably being set by Javascript.
You can right-click the element in the inspector and click Break on Attribute Modifications to find out where.
You could try background: url(src) !important;, not the perfect solution, but i think it will work for you in this case.
The grey element.style means that it's a style attribute directly on the element itself. Any style on an element will override styles from style sheets unless the sytlesheet style is marked with !important

Selecting objects within a class

So, this is a question that's been nagging at me for a long time. I've been digging much more into CSS these days. I'm trying to stay away from jQuery for this project as it's in Drupal and I'm trying to stay away from custom code.
So, we have a class the system applies to BODY called "not-logged-in" when the user isn't logged in. Now this should work well for us (as I understand CSS), as we're only allowing admins to "log in". We are having collisions when we have someone editing a node -- all our custom classes are loaded in both cases and some of the editing controls are looking funky because of it.
So the BODY style is something like this:
<body class="html not-front not-logged-in no-sidebars page-node page-node- page-node-1 node-type-page footer-columns" >
... [much body content here--other divs, other classes, elements with IDs] ...
<div class='mycustomclass'>Should be bigger if logged in</div>
</body>
So, when I try to add a CSS selector and style, like this:
.not-logged-in .mycustomclass {
font-size: 20px;
}
It seems to ignore .mycustomclass. I've run into this before and chalked it up to my poor CSS-fu. And there was always jQuery, so I really didn't have to care. I'd really appreciate it if someone could clear this long-time mystery up for me.
Your syntax is fine, no problems there.
I imagine one of two problems:
The class is not actually being loaded, either on the body, or on your mycustomclass element. Check both in the rendered source (i.e. in the browser), not just your own code. As it's Drupal, it could be caching so your changes are not being loaded. Clear the Drupal cache.
Specificity. Perhaps there is another class on the element, or perhaps there's a global rule. Either way, something could be overriding your CSS on that element.
To solve both, use Firebug and the Web Developer Toolbar in Firefox. Both are essential for doing CSS.
Be sure that Drupal is adding the css script tags in the <head> of your HTML. You should have them follow after your stylesheet references. That's it, the drupal css (the one that is adding the not-logged-in class to the <body>) must execute before your css.

What's so bad about in-line CSS?

When I see website starter code and examples, the CSS is always in a separate file, named something like "main.css", "default.css", or "Site.css". However, when I'm coding up a page, I'm often tempted to throw the CSS in-line with a DOM element, such as by setting "float: right" on an image. I get the feeling that this is "bad coding", since it's so rarely done in examples.
I understand that if the style will be applied to multiple objects, it's wise to follow "Don't Repeat Yourself" (DRY) and assign it to a CSS class to be referenced by each element. However, if I won't be repeating the CSS on another element, why not in-line the CSS as I write the HTML?
The question: Is using in-line CSS considered bad, even if it will only be used on that element? If so, why?
Example (is this bad?):
<img src="myimage.gif" style="float:right" />
Having to change 100 lines of code when you want to make the site look different. That may not apply in your example, but if you're using inline css for things like
<div style ="font-size:larger; text-align:center; font-weight:bold">
on each page to denote a page header, it would be a lot easier to maintain as
<div class="pageheader">
if the pageheader is defined in a single stylesheet so that if you want to change how a page header looks across the entire site, you change the css in one place.
However, I'll be a heretic and say that in your example, I see no problem. You're targeting the behavior of a single image, which probably has to look right on a single page, so putting the actual css in a stylesheet would probably be overkill.
The advantage for having a different css file are
Easy to maintain your html page
Change to the Look and feel will be easy and you can have support for many themes on your pages.
Your css file will be cached on the browser side. So you will contribute a little on internet traffic by not loading some kbs of data every time a the page is refreshed or user navigates your site.
The html5 approach to fast css prototyping
or: <style> tags are no longer just for the head any more!
Hacking CSS
Let's say you're debugging, and want to modify your page-css, make a certain section only look better. Instead of creating your styles inline the quick and dirty and un-maintainable way, you can do what I do these days and take a staged approach.
No inline style attribute
Never create your css inline, by which I mean: <element style='color:red'> or even <img style='float:right'> It's very convenient, but doesn't reflect actual selector specificity in a real css file later, and if you keep it, you'll regret the maintenance load later.
Prototype with <style> instead
Where you would have used inline css, instead use in-page <style> elements. Try that out! It works fine in all browsers, so is great for testing, yet allows you to gracefully move such css out to your global css files whenever you want/need to! ( *just be aware that the selectors will only have page-level specificity, instead of site-level specificity, so be wary of being too general) Just as clean as in your css files:
<style>
.avatar-image{
float:right
}
.faq .warning{
color:crimson;
}
p{
border-left:thin medium blue;
// this general of a selector would be very bad, though.
// so be aware of what'll happen to general selectors if they go
// global
}
</style>
Refactoring other people's inline css
Sometimes you're not even the problem, and you're dealing with someone else's inline css, and you have to refactor it. This is another great use for the <style> in page, so that you can directly strip the inline css and immediate place it right on the page in classes or ids or selectors while you're refactoring. If you are careful enough with your selectors as you go, you can then move the final result to the global css file at the end with just a copy & paste.
It's a little hard to transfer every bit of css immediately to the global css file, but with in-page <style> elements, we now have alternatives.
In addition to other answers.... Internationalization.
Depending of the language of the content - you often need to adapt the styling of an element.
One obvious example would be right-to-left languages.
Let's say you used your code:
<img src="myimage.gif" style="float:right" />
Now say you want your website to support rtl languages - you would need:
<img src="myimage.gif" style="float:left" />
So now, if you want to support both languages, there's no way to assign a value to float using inline styling.
With CSS this is easily taken care of with the lang attribute
So you could do something like this:
img {
float:right;
}
html[lang="he"] img { /* Hebrew. or.. lang="ar" for Arabic etc */
float:left;
}
Demo
Inline CSS will always, always win in precedence over any linked-stylesheet CSS. This can cause enormous headache for you if and when you go and write a proper cascading stylesheet, and your properties aren't applying correctly.
It also hurts your application semantically: CSS is about separating presentation from markup. When you tangle the two together, things get much more difficult to understand and maintain. It's a similar principle as separating database code from your controller code on the server side of things.
Finally, imagine that you have 20 of those image tags. What happens when you decide that they should be floated left?
This only applies to handwritten code. If you generate code, I think that it's okay to use inline styles here and then, especially in cases where elements and controls need special treatment.
DRY is a good concept for handwritten code, but in machine-generated code, I opt for "Law of Demeter": "What belongs together, must stay together". It's easier to manipulate code that generates Style tags than to edit a global style a second time in a different and "remote" CSS file.
The answer to your question: it depends...
Using inline CSS is much harder to maintain.
For every property you want to change, using inline CSS requires you to look for the corresponding HTML code, instead of just looking inside clearly-defined and hopefully well-structured CSS files.
The whole point of CSS is to separate content from its presentation. So in your example you are mixing content with presentation and this may be "considered harmful".
In addition to the other answers, another concern is that it violates the recommended Content Security Policy from MDN, https://infosec.mozilla.org/guidelines/web_security#content-security-policy
The justification they use is that inline javascript is harmful, XSS, etc., but it doesn't justify why inline styles should also be disabled. Maybe someone can comment as to why, but until then, I'll just rely on appeal-to-authority and claim: it's a security best practice to avoid inline styles.
Code how you like to code, but if you are passing it on to someone else it is best to use what everyone else does. There are reasons for CSS, then there are reasons for inline. I use both, because it is just easier for me. Using CSS is wonderful when you have a lot of the same repetition. However, when you have a bunch of different elements with different properties then that becomes a problem. One instance for me is when I am positioning elements on a page. Each element as a different top and left property. If I put that all in a CSS that would really annoy the mess out of me going between the html and css page. So CSS is great when you want everything to have the same font, color, hover effect, etc. But when everything has a different position adding a CSS instance for each element can really be a pain. That is just my opinion though. CSS really has great relevance in larger applications when your having to dig through code. Use Mozilla web developer plugin and it will help you find the elements IDs and Classes.
I think that even if you want to have a certain style for one element, you have to consider the possibility that you may want to apply the same style on the same element on different pages.
One day somebody may ask to change or add more stylistic changes to the same element on every page. If you had the styles defined in an external CSS file, you would only have to make changes there, and it would be reflected in the same element in all of the pages, thus saving you a headache. :-)
Even if you only use the style once as in this example you've still mixed CONTENT and DESIGN. Lookup "Separation of concerns".
Using inline styles violates the Separation of Concerns principle, as you are effectively mixing markup and style in the same source file. It also, in most cases, violates the DRY (Don't Repeat Yourself) principle since they are only applicable to a single element, whereas a class can be applied to several of them (and even be extended through the magic of CSS rules!).
Furthermore, judicious use of classes is beneficial if your site contains scripting. For example, several popular JavaScript libs such as JQuery depend heavily on classes as selectors.
Finally, using classes adds additional clarity to your DOM, since you effectively have descriptors telling you what kind of element a given node in it is. For example:
<div class="header-row">It's a row!</div>
Is a lot more expressive than:
<div style="height: 80px; width: 100%;">It's...something?</div>
Inline CSS is good for machine-generated code, and can be fine when most visitors only browse one page on a site, but one thing it can't do is handle media queries to allow different looks for screens of different sizes. For that, you need to include the CSS either in an external style sheet or in an internal style tag.
In-page css is the in-thing at the moment because Google rates it as giving a better user experience than css loaded from a separate file. A possible solution is to put the css in a text file, load it on the fly with php, and output it into the document head. In the <head> section include this:
<head> ...
<?php
$codestring = file_get_contents("styles/style1.txt");
echo "<style>" . $codestring . "</style>";
?>
... </head>
Put the required css in styles/style1.txt and it'll get spat out in the <head> section of your document. This way, you'll have in-page css with the benefit of using a style template, style1.txt, which can be shared by any and all pages, allowing site-wide style changes to be made via only that one file. Furthermore, this method doesn't require the browser to request separate css files from the server (thus minimising retrieval / rendering time), since everything is delivered at once by php.
Having implemented this, individual one-time-only styles can be manually coded where needed.
According to the AMP HTML Specification it is necessary to put CSS in your HTML file (vs an external stylesheet) for performance purposes. This does not mean inline CSS but they do specify no external stylesheets.
An incomplete list of optimizations such a serving system might do is:
Replace image references with images sized to the viewer’s viewport.
Inline images that are visible above the fold.
Inline CSS variables.
Preload extended components.
Minify HTML and CSS.
Personally, I think the hatred of inline css is just ridiculous. Hardcore cult behaviour, people just sheepishly repeat "Separation of concerns!". Yes, there are times where if there is a repeating element and you will need repeated styling to use a class targeted from a CSS file, but most of the time it improves speed of development and CLARITY OF CODE to put the style inline, it's great if I can look at the code and see that there is a custom margin height, it helps me picture the HTML document as a whole, instead of some named class that gives me little insight into which styles will be applied.
So I will be the contrarian here and say that inline css is great and that people who scream at you for using it are just following what they have been told without actually giving it any original unbiased consideration.
Even though I totally agree with all the answers given above that writing CSS in a separate file is always better from code reusability, maintainability, better separation of concerns there are many scenarios where people prefer inline CSS in their production code -
The external CSS file causes one extra HTTP call to browser and thus additional latency. Instead if the CSS is inserted inline then browser can start parsing it right away. Especially over SSL HTTP calls are more costly and adds up additional latency to the page. There are many tools available that helps to generate static HTML pages (or page snippet) by inserting external CSS files as inline code. These tools are used at the Build and Release phase where the production binary is generated. This way we get all the advantages of external CSS and also the page becomes faster.
In addition to other answers, you cant target the pseudo-classes or pseudo-elements in inline CSS
We have created a template-driven artifact generator that provides an include file capability for any kind of text artifact -- HTML, XML, computer languages, unstructured text, DSV, etc. (E.g., it's great for handling common Web or manual page headers and footers without scripting.)
Once you have that and use it to provide "style" tags inside your "head" tag, the "separation of concerns" argument goes away, to be replaced by "we have to regenerate after every change to the template" and "we have to debug the template from what it generates". Those gripes have been around since the first computer language to get a preprocessor (or someone started using M4).
On balance, we think the meta-izing capability of either a CSS file or "style" tags is cleaner and less error-prone than element-level styling. But it does require some professional judgment, so newbies and scatterbrains don't bother.

How to animate mouse cursor with custom image when loading page?

I'm trying to change cursor mouse on my website with custom images.
Here is my actual CSS:
<style type="text/css">
<!--
body {
cursor:url(images/default.cur),auto;
}
a:hover {
cursor: url(images/hover.cur),auto;
}
a:active {
cursor: url(images/wait.ani),auto;
}
-->
</style>
Firefox 3.5.6 does change the default cursor with my .cur file but the problem is that .ani cursor doesn't work with Firefox (and even .gif). It does work on IE.
The cursor files I'm using can be found here.
The other problem is that I'm just changing a:active image to animate my cursor but it disappear fast.
I would like to change cursor when we click to go to some page and the cursor to become "normal" once this page is loaded.
What I'm looking to is a way to change cursor when somebody clicks on some internal links of my website.
I wouldn't have to change all my links to do this, but it doesn't seem to work.
I thought about some window.onload JavaScript but I didn't achieve to write it and there might be better ways.
Thanks for your CSS or JavaScript suggestions.
Please don't give design feedback when asked for programming solutions. It is not the role of developers to pass back design critique. It may not be his decision, it may not work but he wants to try it and we should help. If you've been in an environment where programmers pass critical judgement on every design decision you'll realize its very destructive for the whole team. Designers and team members will value you a lot higher if you refrain from commenting on whether or not you agree with what they want to do unless asked. I hope if you think about it you will understand why its important.
Don't. How would you like it if you went to your friend's myspace page and your cursor suddenly turned into a big purple dragon and you had no idea where it was actually pointing.
It's jarring to the user, therefore irritation. If you want to let them know something is working in the background use an animated gif displayed over the page, not as the cursor.
If you have too, you may be able to set it with javascript on all your the elements on the page. I don't think it cascades. If it does, just set it on body and be done with it.
if using ASP, it simplifies things a bit to use resolve url... ie
cursor:url('\<\%\=ResolveUrl("~/img/magnify.cur")\%\>');
Evidently I'm inclined to agree with the other statements, as familiarity is key in any good design, customizing an environment to such a degree that the user feels either unfamiliar with it or under the impression that somehow their system is altered,is a bad bad bad design and reflects poorly on the designer as well. I'm not saying be dull in design, but be a tad reserved.
I might not like MetroUI (rather Metro Web Design) much, but I love it's root,the design concept of "Bauhaus".
"There is beauty in simplicity."

Resources