BEM component / object separation - html

We're using BEM extensively but are running into several ways of structuring and naming components and wanted opinions on best practice. We're using the notion of 'objects' for reusable components (e.g. .box, .media, .btn) and 'components' for designed UI components that tend to be a combination of objects.
As an example of the issue, consider this from a wireframe:
The idea being than an image is overlayed with the number of other images available for this particular item.
There are at least two ways of tackling this layout and we're trying to work out the best option.
Option 1
Apply the layout in markup/CSS rather than as a component. All of the styles below could then be re-used between projects; none are project-specific.
HTML:
<div class="relatively-positioned">
<img src="..." alt="" />
<div class="box box--rounded absolutely-positioned offset--10-10">12</div>
</div>
CSS:
.box {
padding: 5px;
}
.box--rounded {
border-radius: 5px;
}
.relatively-positioned { position: relative; }
.absolute-positioned { position: absolute; }
.offset--10-10 { top: 10px; left: 10px; }
Option 2
Implement this as a component made up of an image and a box for the count.
HTML:
<div class="image-preview">
<img class="image-preview__img" ... />
<div class="image-preview__count box box--rounded">12</div>
</div>
CSS:
The same CSS would apply for box / box--rounded and would be generic for re-use between projects. The component would be defined for this project only:
.image-preview {
position: relative;
}
.image-preview__count {
position: absolute;
top: 10px;
left: 10px;
}
Thoughts, opinions and other ideas all greatly received!

Second option is better because you end up with semantic blocks instead of inline-css-like approach in the first one.
You should think of your interface in terms of what it does and not in terms of what it looks like. Otherwise it's much harder to update design or actually do any change.

The best choice depends of your design. Repeating visual patterns can be implemented as reusable blocks, and semantic should be used for all specific cases.
Your second option is a mix of a semantic pattern (image-preview) and a visual pattern (box), probably good with your design.
If the pattern of an offset 10-10 is reused in many blocks, it can be implemented as a visual pattern block. But in the first choice, the classes relatively-positioned and absolutely-positioned are a bad idea. This is a confusion between visual patterns and CSS techniques.
An example of visual pattern implementation for the offset:
HTML:
<div class="image-preview offset-container">
<img class="image-preview__img" ... />
<div class="image-preview__count box box--rounded offset-container__offset">12</div>
</div>
CSS:
.offset-container {
position: relative;
}
.offset-container__offset {
position: absolute;
top: 10px;
left: 10px;
}

Related

CSS - How to fix border-bottom won't appear?

I'm following a tutorial on youtube to create a replica of LinkedIn with CSS + ReactJS. I've been following the tutorial exactly (using it as more of a learning opportunity than anything) yet sometimes when the tutorial adds certain code, it doesn't appear on my environment when I try to add it. I found a work around for one case, but when I try to add a border-bottom to css it just won't show up.
CSS:
.header{
position: sticky;
top: 0;
display: flex;
justify-content: space-evenly;
border-bottom: thin solid lightgray; /*this is a vscode shortcut*/
padding-top: 10px;
padding-bottom: 10px;
width: 100%;
z-index: 999;
}
JS:
function Header() {
return (
<div className ='Header'>
<div className="header__left">
<img src="https://www.flaticon.com/svg/static/icons/svg/174/174857.svg" alt=""/>
<div className="header__search">
<SearchIcon/>
<input type="text"/>
</div>
<div className="header__right">
<HeaderOption Icon= {HomeIcon} title="Home"/>
<HeaderOption Icon={SupervisorAccountIcon} title="My Network"/>
</div>
</div>
</div>
);
}
*HeaderOption is an imported JS function I created. It isn't conflicting with the CSS I believe because I have removed it and the border still won't appear.
Thank you in advance.
CSS is case insensitive.
But in HTML the class and ID are case sensitive
change
<div className ='Header'>
to
<div className ='header'>
First off, you might wanna check your classNames' spelling for case-sensitivity.
If that's not the issue, your divs are probably collapsing with each other, so it renders the pixels through approximation. This is usually the case if you try zooming in your page and the missing border magically appears.
I suggest setting a height for your header where the borders don't collapse with the other divs' borders. Also, I prefer setting a fixed measurement unit rather like px,rem,%, etc. rathen than using thin.

Background With Changing Elements HTML

Sorry if the title makes no sense, I didn't know how to call this issue, lol.
So... I have this android app which shows a parking lot, with the parking layout as the background and some cars showing "inside" each parking when needed. This is easy to build using different layouts for each parking and changing the image sources from empty to a car, etc.
The thing is... I need to replicate this on a web page, And I have no idea how could I build a background and change images on top of it. I suppose I could make a bunch of divs for each parking, changing the img sources when needed and use the parking lot layout as the background for the whole thing, however I don't know if this would be the best practice, and the whole idea doesn't really sound responsive to me.
Any ideas?
I don't expect/need it to change in real time like you can do with Android, but I do need to replicate the idea of changing images programatically on top of a background.
Thanks!
The only real way to overlay images with CSS is by having a relatively displayed container with it's inner image elements absolutely positioned.
Using this idea, it'd be possible to absolutely position the car images on top of your image parking spots.
That being said, why don't you create a more abstract representation of this parking lot?
.flex-container {
display: flex;
justify-content: center;
background-color: DodgerBlue;
}
.flex-container > div {
width: 100px;
margin: 10px;
text-align: center;
line-height: 75px;
font-size: 30px;
}
.available {
background-color: green;
}
.unavailable {
background-color: red;
}
<!DOCTYPE html>
<html>
<body>
<h1>Parking spot availability</h1>
<p>Green indicates an available spot. Red indicates an unavailable spot.</p>
<div class="flex-container">
<div class="available">1</div>
<div class="unavailable">2</div>
<div class="available">3</div>
</div>
</body>
</html>
For something like this, I would recommend using jQuery. Register event handlers for each of your images and adjust the src property accordingly. I have provided an example below for review:
$('.car').on('click', function () {
$(this).prop('src', 'https://placeholdit.co//i/300x150?text=A%20Completely%20New%20Image!&bg=111111');
});
.playground {
background-color: #ccc;
width: 500px;
height: 500px;
}
.car {
margin: 15px;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="playground">
<img src="https://placeholdit.co//i/200x150?text=The%20Original%20Image" class="car" />
</div>

How to place an html element outside of a newly generated one

Is it possible to place an Html element outside of a newly generated one?
Well, I have an IONIC2 app that generates a new element <scroll-content>, the issue is that this element has some CSS properties that affects the child elements.
So, what I would like to do it either to place that my div element outside of that <scroll-content> or even better to disable the CSS properties of <scroll-content> on the div
Here is the code, so I can make things clearer:
HTML
<ion-content id="contentPadding">
<div class="header">
</div>
</ion-content>
When Ionic renders the above code, the browser generate something like this:
HTML
<ion-content id="contentPadding">
<scroll-content>
<div class="header">
</div>
<scroll-content>
</ion-content>
CSS:
.top{
background:black;
}
//generated
scroll-content{
position: absolute;
top: 0;
right: 0;
bottom: 0;
left: 0;
z-index: 1;
display: block;
overflow-x: hidden;
overflow-y: scroll;
-webkit-overflow-scrolling: touch;
will-change: scroll-position;
}
I guess, it's clearly shown that a new element called <scroll-content> is being created and <div class="header"> inherits all the css properties of <scroll-content> which I would like to avoid in my case.
Your header (child) is inheriting its parent's (scroll-content) CSS styling. You need to clear any unwanted inherited rules by explicitly changing the inherited styles. For example, if you want to reset the css-display, write
.header {
display: initial;
}
Hopefully in the future we can avoid this with the all:initial trick - however, it currently isn't supported enough.

Change image size within a division

I have a division placed on the bottom of the page. I put an image into this division, but I don't know how to modify the image. The problem may be, that the inline style for <img> is setting modification rules for all images. I have an inline style sheet that has this code and HTML code for <div>.
My CSS code looks like this:
<style type="text/css">
img {
image-align: center;
padding: 10px;
height: 200px;
width: 140px;
}
div {
position: absolute;
right: 10px;
}
</style>
And my HTML code is like that:
<div align="center" >
<img src="images/music_banner.jpg" >
</div>
you can do this:
div img{
}
or give the div a name and do this
#div img{
}
or you give the img an id as below
<div>
<img id="mg"/>
</div>
Use id as #mg in CSS code.
or you can do as define class name in img tag.
<div>
<img class="mg"/>
</div>
Use class as .mg in CSS Code.
You might try learning a little bit more about CSS selectors: these are the rules that tell the browser which element you'd like to apply the following rules to.
I would recommend Code Academy for an easy to follow course. You can skip down to the CSS section if you are already comfortable with HTML.
Note: if you google CSS, you'll get "w3schools" as the first results. That website is generally derided on Stack Overflow. I don't know if it's really that bad, but I tend to skip it just because everyone else has a bad opinion of it. Your call if you find it helpful of course.
I should note that I like to use the W3C (World Wide Web Consortium) website for reference, as they're the ones trying to make everything standard. It is a pretty technical read, though.
Create a div element in your HTML code:
<div class="parent">
<img src="image">
</div>
Than add this to your CSS code:
.parent {
width: 42px; /* I took the width from your post and placed it in css */
height: 42px;
}
/* This will style any <img> element in .parent div */
.parent img {
height: 100%;
width: 100%;
}

Invert/change logo on scroll

An article over on askthecssguy.com shows how to change/invert an image on scroll using fixed backgrounds: http://askthecssguy.com/articles/mike-asks-the-css-guy-about-a-scrolling-trick-with-background-images/
My goal takes this concept further by having the image float over other elements (in this case images).
You can see the result here: http://playground.iamkeir.com/invert-logo/v2/
However, my implementation uses superfluous elements and, so, I was wondering if anyone had any ideas/suggestions of another way to achieve this?
Javascript is certainly an option but I worry it would not be lean/elegant. Someone also suggested using Canvas.
Any ideas welcomed! Thank you.
You can avoid extra markup by using :after CSS pseudo element. Thus, your final markup will look like:
<ul>
<li class="light">
<img src="http://farm3.static.flickr.com/2802/4253151258_7d12da9e1c_z.jpg" />
</li>
<li class="dark">
<img src="http://farm1.static.flickr.com/31/66005536_d1c5afca29_z.jpg?zz=1" />
</li>
<li class="light">
<img src="http://farm4.static.flickr.com/3574/3646151231_0c68f4f974_z.jpg" />
</li>
<li class="dark">
<img src="http://farm4.static.flickr.com/3432/3310214210_813d13c899_z.jpg" />
</li>
</ul>
And the altered CSS will be:
.dark:after,
.light:after,
.dark .after,
.light .after {
position: absolute;
display: block;
content: '';
top: 0; left: 0;
height: 100%;
width: 76px;
background: transparent url(logo-white.png) no-repeat fixed 0 0;
z-index: 5;
}
.dark:after,
.dark .after {
background-image: url(logo-black.png);
}
Notice that there is .after class there. This is to make it work in IE<8, which, sadly, requires to use an expression:
.dark,
.light {
behavior: expression( !this.before ? this.before = this.innerHTML = '<div class="after"></div>' + this.innerHTML : '' );
}
While using expressions is generally discouraged, this one shouldn't affect the performance too much, since it is fully evaluated only once, and when the element is created, the condition returns false.
There is one pitfall, though. If IE8 works in IE8/IE8 mode, the pseudo-elements will be under the images, unless you set negative z-index for the latter, which isn't always acceptable.
You can look at working example here.
what you're trying to do is totally possible using the current code you just need to use absolute positioning to move the content around. For example using the test page http://askthecssguy.com/examples/fixedBackgroundImages/example01.html you can modify the .header class and make it like this.
.header {
background: url("images/cuckoo_color.jpg") no-repeat fixed 20px 20px #DBDED1;
left: -151px;
padding: 40px 40px 40px 300px;
position: absolute;
}
Doing this will make the text float over the images. Going a step further instead of using a background image you could insert a transparent PNG into it's own DIV and float it over any position on the page and keep it's position fixed. You can checkout http://www.w3schools.com/css/css_positioning.asp for some examples.
Hope that helps!
Virgil