I have started using BEM methodology while writing my CSS and there have been few occasions where I have struggled to find out the best way to do a particular thing.
I would like to take up a simple example of a panel here.
Lets say I am writing a panel component CSS using BEM style. So my CSS might look as follows:
.panel {}
.panel__titlebar {}
.panel__content { display: none; }
A panel can be either chromeless or with chrome. So I define another modifier class for the panel:
.panel--with-chrome {
border: 4px solid black;
border-radius: 4px;
}
Now lets say, the panel can be in a fullscreen/maximized state also in which the chrome and titlebar disappear. Instead of defining modifiers for both panel and titlebar, it would be be wise to define the modifier just on parent (say panel--fullscreen) and rest elements shall change accordingly. So now my CSS becomes:
.panel--fullscreen {
/* something has to be done here */
}
.panel--fullscreen .panel__titlebar { display: none; }
To remove the chrome in fullscreen mode, I can either:
toggle the panel--with-chrome class in JS along with the panel--fullscreen class
overwrite the chrome CSS inside the panel--fullscreen class.
First isn't good because ideally I would like to simply toggle just one class (.panel--fullscreen) in JS to toggle fullscreen mode.
And second one is bad because I'll have to overwrite previous CSS which is a bad practice.
So whats the best way to go about it? Appreciate your comments.
Thanks
The answer depends on many things.
First, how much logic and appearance have "panel--with-chrome" and "panel--fullscreen" modifiers. And also on what kind this logic is.
If "panel--with-chrome" brings a lot of CSS properties and special JS functionality, I would toggle it in JavaScript when applying "panel--fullscreen".
It also depends on a JavaScript framework you use. In "i-bem.js" which we use at Yandex it's easy to react to appending a modifier:
A square changes size modifier when after a click
Reacting on applying a modifier
But if the framework you use doesn't allow to express such a reaction handy, this answer won't work that great for you.
In the other case, when "panel--with-chrome" has not very much properties and doesn't bring any JavaScript logic to a page, I would redefine those CSS properties in "panel--fullscreen" class.
To sum up, there is no universal solution and strict rules to follow. You should decide yourself what will be useful in your case. The decision should depend on many things:
if you expect your project to be maintained in the future, which solution will be easier to support?
capabilities of the JavaScript framework you use
performance stuff
Not in this particular case, but sometimes we measure speed of rendering for variants we are choosing from.
opinion of the other guys, if you work in team
file structure of your project
We, here at Yandex, store CSS and JavaScript for a block in the same block folder. So, it is not a problem to share logic between CSS and JavaScript since they all are in one place.
But if you keep your JavaScript files separately, this can influence on how comfortable it is to support shared logic.
And so on...
I’d go with the first option; you are toggling state after all, so you need to add/remove/toggle classes accordingly. It’s better than undoing a load of stuff in CSS IMO.
Related
I've just started my first project which is building an admin panel. My task is to create HTML and CSS - sort of a base of design to process further to the back-end developers.
I was asked to keep CSS simple and classes as descriptive as possible ( could be long ) and to use Bootstrap.
To avoid creating unnecessary classes which could be used once or twice I decided to go with :nth-child since I thought giving new class to each column is too much. Additionally I created few base classes that might be used for adding 0px padding and margin.
Unfortunately, as I was writing more and more code I've noticed that some CSS code looks like this:
.print-history-advanced-search > [class*='col-']:nth-child(5) > .form-group > .form-horizontal > .form-group > [class*='col-']:first-child
And it is not a single line.
Additionally, I've noticed that sometimes that when I am making a new class and it has lots of parent elements, I cannot write the CSS selector by its own, but I need to state the parents of the this particular element and put the class at the end, which does not make sense.
Is there any solution I could use to avoid creating classes that are simply used in one or two divs, but also make the CSS code less chaotic and avoid very long names? Or maybe I should just give up on children and nesting and work with just classes?
Thank you for your help!
Have a nice day!
If you want to write good CSS, then I'd suggest the BEM model is a good route to go down.
The essentials are;
No element/selector heirachy
No use of elements in selectors
Class based styles only
BEM stands for Block, Element, Modifier - which is how your class names are formed. Borrowing an example from their site;
.form { }
.form--theme-xmas { }
.form--simple { }
.form__input { }
.form__submit { }
.form__submit--disabled { }
<form class="form form--theme-xmas form--simple">
<input class="form__input" type="text" />
<input
class="form__submit form__submit--disabled"
type="submit" />
</form>
You can see there's a form Block, and then a form__input and form__submit Element, and then a form__submit--disabled Modifier.
Depending on your needs I would recommend using css preprocessors like SASS,LESS.
You’ll find that as a website grows, you’ll develop a pretty long, scrolling list of various elements and CSS rules. Some of the rules might overlap or override each other eventually (in that case, usually the more specific rule will win).
You can end up with a lot more code than you expected, especially considering the different variations of a rule you need for different browsers and screen sizes.
There are many ways to refactor your CSS code to make it easier to navigate and use. Some of the easiest methods are the most effective and have the most mileage. Here are some of the quickest ones:
Keep your spacing uniform: Maintain the same spacing between rules
and within declarations throughout your file so that it’s easier to
read.
Use semantic or “familiar” class/id names: Instead of using a class
name like “bottom_menu”, try using the semantic tag “footer”. Or
when you have an image in your “contact” section, make sure you’re
using a class on your image like “contact_image”
Keep it DRY (Don’t Repeat Yourself): Ideally you want to repeat as
little of your code as possible. Do you find the declaration
“background-color: #000″ repeated throughout your CSS file? Consider
typing it once and instead, using multiple selectors on the one
declaration.
Put your tidiness to the test with these tools: Run your CSS through
CSS Lint or W3C—these will help to parse your CSS file correctly,
and highlight problem areas. Your web browser’s developer tools are
also extremely useful for pinpointing specific elements on your
website and using the area as a sandbox to experiment with different
styles and positioning.
Have a look here for more info
I've just started learning GWT so my question might be noobish. Tried to find a 'standard' solution but couldn't find it.
I'm developing an AddressWidget. It is implemented as a Composite widget which consist of atomic widgets (Labels, TextBoxes, ListBoxes...) defined in AddressWidget.ui.xml. These tiny building blocks should get their CSS from the common-widgets.css. The AddressWidget itself should get the default styles from address-widget.css.
As this widget will be used on different pages, they should be able to override the styles applied in order to customize the appearance. I.e. the OrderPage should apply its own from the order-page-address-widget.css, the ContactDetailsPage – from the contact-details-address-widget.css
How do I implement that?
My advice - drop this idea. It will be hell to develop and maintain, and I mean it. You will constantly try to figure out which CSS file has to be updated, and then you will have to test every update in multiple places, because an update in one file can mess up with CSS from another file.
Many GWT developers prefer to use CssResource approach to CSS. I've never heard any designer favoring this solution, though.
After years of working with GWT on both the code and design sides, I strongly prefer to use a single CSS file for the entire application. CSS was built for inheritance, and this is what a single file achieves. You can define basic style, like:
input {
height: 24px;
}
If you need to change these styles in specific widgets or parts of the application, you can set, for example, "contacts" class on the contacts page/widget, and then add this to your CSS file:
.contacts input {
background: grey;
}
The advatantages of this approach:
easier to enforce consistent look throughout the application
easier to maintain your CSS, because there is one file to update, and there are no conflicts with CSS defined anywhere else
it is an approach that most designers understand and know how to use
it is the easiest solution if you want to create multiple skins or themes for your application
it is easy to make your CSS adjust to different screen sizes, or define special styles for printing.
On my page I have few blocks (div) that have the same style regarding background and border (menu panel, info panel, footer panel, ...).
Now I would like to write that style only once and not repeat it for every panel. Yet I don't see any comfortable way of doing that.
One approach I investigated was to introduce a dedicated class (for example panelClass) that would capture the common panel styles. Then in (X)HTML I would just add that class to every element that is supposed to be a panel.
But this doesn't feel right. After all I would be "revealing implementation" in the (X)HTML. I'm no longer able to transparently change things easily because that requires modification of the (X)HTML.
Not to mention that it introduces issues with order of the classes (and thus order in which CSS attributes will be overwritten if needed).
EDIT: (an extended explanation for kolin's answer)
By “revealing implementation” I meant that the (X)HTML (“the content”) is much more strongly connected to the CSS (“the presentation”) than I would like them to be. Maybe I’m pursuing an unreachable ideal (maybe even an unreal or a dummy one!) but I’m trying to keep “the content” separate from “the presentation”.
Thus having a class menu isn’t bad because it describes “contents” not “presentation”. While using instead (what I understood from the cited articles and few others on that site) classes like menu box bordered left_column is bad because it mixes presentation with contents. Once you start adding such classes you might very well add that CSS directly to style attribute. It sure would be much more work and an unmaintainable result but conceptually (when regarding contents-presentation separation) it wouldn’t make a difference.
Now I do realize that in real life for real pages (rich and nice) it is virtually impossible to keep contents entirely separate from presentation. But still you may (should?) at least try to.
Also just look at the “But” in the end of the article The single responsibility principle applied to CSS. In my opinion the island class he used is already presentational because it does not describe contents. It describes how to show it. And that is immediately obvious once you see how widely he used (or might have used) that class on elements having nothing in common as regarding contents.
END EDIT
Another approach was to use selectors grouping. So I would have something like:
#menu, #info, #footer {
background: /* ... */
border: /* ... */
}
This avoids the need to modify (X)HTML. But still causes order issues. And also makes it hard to group styles logically. Especially if they are distributed among many files.
I think that what I really would like to have is to be able to name a group of attributes and just import them somehow in selectors. Something like #include in C++ for example. Is there any way to achieve this? I doubt it but maybe...
If not then is there any other method?
Using classes to define styles is the correct way to do it.
One approach I investigated was to introduce a dedicated class (for example panelClass) that would capture the common panel styles. Then in (X)HTML I would just add that class to every element that is supposed to be a panel.
For me this is exactly the way I would do it.
But this doesn't feel right. After all I would be "revealing implementation" in the (X)HTML.
is there a security problem with revealing implementation?
A few selected posts from Harry Roberts :
http://csswizardry.com/2012/04/my-html-css-coding-style/
http://csswizardry.com/2012/04/the-single-responsibility-principle-applied-to-css/
http://csswizardry.com/2012/05/keep-your-css-selectors-short
I find his style of using CSS eye opening, and it may help you
update
Following on from your update, I agree with you that you should try and seperate structure from presentation, although there will be times where we can't quite manage it. Whether it is fully possible or not, i don't know.
I partially disagree about the island class, the padding property to me kind of hovers over the border of structural and presentational. structural because it alters the layout of whatever element it is applied to, presentational because the padding alters how it looks on the page.
in an ideal world you should never need a class attribute that encompasses menu box bordered left_column, because you would write a couple of classes that seperate out the structure and presentation.
thinking about your case I might create a panel class
.panel{
margin:10px 0;
padding: 10px;
display:block
}
and a panel-display class
.panel-display{
background-color:#1111e4
}
.panel-display > a{
color:#fff
}
in this way I could just play with the presentation without affecting the structure of the site.
(n.b. I'm not sure if this helps you in anyway!, it just seems logical to me)
A client asks for an admin table and one column will have different cell colors based on some rules.
My problem is : what is the best css practice for this.
we know inline is bad from the start
we could do some css classes for each color and give them a good name but this will just clutter then main css file with classes that will probably never be used again.
So what would be a good approach for this simple problem ?
So what would be a good approach for this simple problem ?
You have essentially already outlined your two options. It's your choice.
I would always go with classes, and never with inline CSS. If you're worried about cluttering, you could add some order using comments:
/** Table highlight styles **/
table.data td.highlight { background-color: #CCCCCC }
table.data td.total { background-color: #ABCDEF }
You could theoretically put these into a separate CSS file, but the number of style sheets should be kept as low as possible. To do this right, you could use a CSS preprocessor as suggested by #Ian.... but that is an entirely different and new can of worms.
Personally, I would recommend using something like dotless(DotNet) or less (Ruby).
Here you can define a colour like #MyMainColour and then have div.SomeBackground { background: #MyMainColour; }
These tools will allow you to "compile" your CSS compress and turn out customer specific themes.
You might consider:
Keep a separate css file for specific adjustments. This might be a good compromise between keeping a main style file uncluttered, but still be able to target specific GUIs with adjustments.
Let a GUI have an id. This way you can let GUI specific adjustments only affect that GUI with styles given in context.
This might be a basic CSS question: I have a site designed with well-defined CSS themes. I'm adding some controls (from jquery), but they have the style of their designers, not my site's. What is the easiest way (least amount of work) to make the inserted controls use the site's css rather than the styles of the control? Is there an easy way to map one set of classes/ids onto another? Or am I missing something basic about css?
I'm assuming you're using jQuery UI? If so, they have a ThemeRoller.
You can try to "map" things by defining your own widgets and the external ones at the same time as much as possible:
div.my_widget,
div.external_widget
{ border: 1px blue solid; }
How successful that can be depends heavily on your site's and the controls' structure.
As a general rule, rather change your own stylesheets to work with the control, instead of changing the control to work with your stylesheet. That way, you can easily integrate new versions of the control.
Most common way is to inspect the DOM structure of the controls you are adding, and see if you can use the classes applied to style it the way you want, typically be overriding the CSS selectors in place for the control, or by writing CSS for the control DOM structure from scratch.