Is substring Matching css attr selector considered as a bad practise? - html

In order to avoid adding an extra is-icon class to each of my icon elements, such as this:
<style>
.is-icon { // Base styling of icon }
.icon-car { // specific car styling }
</style>
<span class="is-icon icon-car">car</span>
I am using this CSS to solve it:
<style>
span[class^="icon-"] { // base icon styling }
.icon-car { // specific car styling }
</style>
<span class="icon-car">car</span>
<span class="icon-cat">cat</span> ETC...
My question is: does span[class^="icon-"] css selector is expensive? and which one is a better practise? My understanding is Substring Matching css attr selector is not a bad practise at all, it's just more of a preference. Please help me understand this.

Related

SASS extend from root only

I recently encountered a.. "thing" in the land of SASS. And maybe you guys know a trick or something alike to "fix" it.
I've got this class .icon. It contains some basic styling for my icons (Used for an iconfont). These icons can then be placed in the markup whereever I want. For example in a button. But inside the button this icon needs some extra styling. So I do the following:
.icon {
// Basic styling
}
button {
.icon {
// Additional styling
}
}
It compiles to this css:
.icon {
// Basic styling
}
button .icon {
// Additional styling
}
Everything OK so far. But now I want to extend the .icon to an after-element inside of all my .foo elements like so:
.foo:after {
#extend .icon;
}
Now it compiles to this css:
.icon, .foo:after { // This is good, exactly what I want
// Basic styling
}
button .icon, button .foo:after { // But I don't need the second half of this line
// Basic Additional
}
Now the foo-element isn't just extending the "root" icon-class but also the icon-class under button and all its additional stylings. But I don't need that. I don't want that element to have that additional styling. It doesn't result in problems yet. But maybe that could happen later. So I was curious if it is possible to extend only the .icon from the root, omitting the nested .icon in the button, and possibly more nested icon-classes in other elements later on.
My first thought was to use an abstact class like %icon and extend from that, but the above mentioned icon-class, and the file that it is placed in, is generated by grunt-webfont. So I can't just change the icon-class styling 'cause its overwritten all the time.
What can I do? Is there some more to the extend function of SASS that I don't know of? Or is there a totally different way?
Thanks for any help.
SOLUTION:
Using all the awesome help and tips I found a way to avoid this problem:
Grunt-Webfont suggests to use the i-tag to display the icons. Font-Awesome does the same. So, I'm doing exactly that. And I usually don't use it for anything else.
This allows it to use the i-tag under the button for my extra styling, and not the .icon class. This way the .icon class is used only once in the generated file and then never again.
.icon {
// Basic styling
}
button {
i { // <= Previously '.icon'
// Additional styling
}
}
Have you tried doing something like this?
.icon {
//some styles from external (ie: grunt webfont)
color: red;
}
%icon {
#extend .icon;
}
button {
.ico {
#extend %icon;
//add some additional styles
}
}
.foo:after {
#extend %icon;
//add some more
}
You would then avoid generating the foo:after rule for the .icon inside the button.
EDIT2 - you'll need to create an additional class which you can use inside your styles, so there's only one .icon class defined (in your grunt-webfont generated css). Then just use the .ico class inside your styles and extend the %icon placeholder like shown above.
EDIT - have you considered solving this problem in your grunt-webfont generator?
From the documentation, it seems you can set the output to scss like so:
options: {
stylesheet: 'scss',
mixinPrefix: 'mixin-'
Then just use the mixin to define the styles of your desired classes?
I think this gets the result you're looking for? Albeit, slightly messily.
The method: make a placeholder style and extend that into .icon to begin with.
%icon-styles{
basic: styling;
}
.icon {
#extend %icon-styles;
}
.foo:after {
#extend %icon-styles;
}
button .icon {
#extend %icon-styles;
additional: styling;
}
It compiles into:
.icon, .foo:after, button .icon {
basic: styling;
}
button .icon {
additional: styling;
}
You can also use custom template with grunt-webfont. It’ll give you much more control on generated CSS.

CSS Dot Notation Naming Convention

I am getting started with learning CSS.
While looking through the tutorial on w3schools.
I realized some of the example start with
.awesome-text-box{}
Is there a different between
.awesome-text-box {} and awesome-text-box{}
without the dot?
What does the dot notation means here
p.one {
border-style: solid;
border-width: 5px;
}
p.two {
border-style: solid;
border-width: medium;
}
p referes to ?
A dot in css is for what is called a class.
They can be called almost anything, for example in your CSS you would create a class and add style for it (in this case, I'm making the background black);
.my-first-class {
background-color: #000;
...
}
and to apply this class to an HTML element, you would do the following
<body class="my-first-class">
...
</body>
this would mean the body of the page would become black.
Now, you can create classes for CSS style or you can reference HTML elements directly, for example (CSS again);
body {
background-color: #000;
}
would directly reference the <body> element on the page and do the same again.
The main difference between the two is that CSS classes are reusable. By comparison, referencing the HTML tag directly will affect all tags on the page (that are the same), for example (CSS again);
body {
background-color: #000;
}
.my-first-class {
background-color: #FFF;
}
and now for some HTML;
<body>
<p class="my-first-class">This is the first line</p>
<p class="my-first-class">This is the second line</p>
</body>
This would produce a black page, with 2 white boxes with text inside them (try it out!)
Now for your last part of the question about p.one {...} CSS.
This is a reference to a <p> tag that has class="one" added to it, <p class="one">...</p>
That CSS will only work on a <p> tag with the one class added (as above).
Extra for experts...
There is also one more selector type and it's called an ID (and I personally do not use these when doing CSS styling but some people like too and I don't know why...)
Much like a class, you can have an id on an HTML element; <p id="my-first-id"></p>
and to add CSS style to this, you would put (in the CSS);
#my-first-id {
...
}
and that would style all elements with that id added.
Hopefully that helped answer all the parts, ask again if you need an even better explanation :)
The dot denotes that the selector is a class. So it will select elements in your page as such:
.awesome-text-box {
}
<div class="awesome-text-box"></div>
Whereas without the dot denotes an element name. Such as:
div {
}
<div></div>
In the other example you gave, the dot notation is using chaining this is where you can select an element with numerous conditions. In your example:
p.one {
}
// Will find
<p class="one"></p>
// However it will not find
<div class="one"></div>
Whilst I am here I can give you a list of other common selectors too:
#awesome-text-box => <div id="awesome-text-box"></div> => ID
.btn.btn-style-1 => <span class="btn btn-style-1"></span> => Chaining classes
p > span => <p><span></span></p> => Child
p span => <p><a><span></span></a><span></span> => Descendant (anything below)
p + span => <p></p><span></span> => Sibling
A '.' refers to a class, while a '#' refers to a id.
When neither a '.' or a '#' are used, the CSS will apply the style to an HTML object.
So for p .one and p .two, the CSS will be applied to the '.one' and '.two' classes that exists within the 'p' object.
For a more detailed example;
<p class = "one">This text will have the CSS of "p .one"</p>
<p class = "two">This text will have the CSS of "p .two"</p>
. means a class. You can call that CSS class with HTML
example
<span class="awesome-text-box"> ABCD </span>
and P means <p> tag in HTML you can call
<p class="one"> ABCD </p>
Ref -
http://www.w3schools.com/css/css_selectors.asp
The dot notation is for class and without dot that would not work. The selector name like div, p don't need dot notation. And use hash (#) for the selector with id.
Ex-
<div id="foo">foo bar</div>
<div class="bar">foo bar</div>
#foo{} /* selects foo with id foo */
.bar{} /* selects foo with class bar */
div{} /* selects the div */
Here . is class selector. It means apply style to all elements which has class awesome-text-box ie,
<div class="awesome-text-box"></div>
while without dot it is tag name like you mention in second example p Here p is tag:
<p>Some text</p>
Similarly p.one apply the style to all p tags which has class one. ie,
<p class="one">Some text</p>

CSS selection HTML conditional css

Is there any way to select a CSS based on one particular 'id' used in the page.
For example.
HTML
<li id="button_preview" href="#inline_content2"></li>
<li id="button_suspend" href="#inline_content1"></li>
Here I need to select one style sheet for #inline_content1 and another stylesheet for #inline_content2. Is it possible to do?
Sure, ID selectors.
li#button_preview {color: red;}
You can't select a specific style-sheet based on the attribute-value, or id, of an element, but you can apply a particular style to an element based on its attribute value:
li[href='#inline_content1'] {
/* css */
}
li[href='#inline_content2'] {
/* css */
}
Or, to use the id:
#inline_content1 {
/* css */
}
You can create a css like this:
#button_preview {
}
http://www.w3schools.com/css/css_id_class.asp

edit css style of an element with a space in its class name

I'm creating a tumblr them and I have to write an external CSS file but I am having trouble editing the css style of the post elements.
This its structure:
<li class="post quote">
{other code}
</li>
The problem is that the class name has a space in it.
How would I create a CSS class to access this? And yes, I know I can just put a style attribute in the element tag but I was kind of hoping for another option.
The problem is that the class name has a space in it.
This is not possible in CSS. What you are doing is giving the element two classes.
You can address them such:
.post.quote { .... }
but in your case, it's probably better to use a valid separator like
post_quote
This element actually has two classes - it is marked with both the post class and the quote class. So, you can use the following selectors to access it:
// css
.post { ... } // elements with the post class
.quote { ... } // elements with the quote class
// jQuery
var postLis = $('.post');
var quoteLis = $('.quote');
You can also stack selectors to return all elements which meet all conditions in the selector, by including the different selectors together:
// css
.post.quote { ... } // elements with both the post and quote classes
// jQuery
var postAndQuoteLis = $('.post.quote');
This might work:
$('li').each(function() {
if($(this).attr('class').indexOf(" ")>-1) {
$(this).css('border','1px solid #ff0000')
}
}

Which attribute of a <div> tag should reference the CSS?

This is probably a case of trying to run before I can walk, however... I have the following code:
<div class="hidden" id="repair_complete">
// some code
</div>
I was under the impression that if my CSS file contained:
#hidden {
display: none;
}
... then the div content wouldn't display. However, it seems to only adopt this behaviour if the CSS file contains a reference to the div id:
#repair_complete {
display: none;
}
In a book I'm working through the opposite seems to be true - the style sheet refers to the class name, not the id.
Any ideas where I'm going wrong?!
Your CSS syntax is incorrect.
If you want to access this div, you can do it like this:
/* By class: */
.hidden {
display: none;
}
/* By ID: */
#repair_complete {
display: none;
}
Note that to access an element by class you use a dot before the class name. You use a hash before the ID.
The other answers have the technical stuff right: you need .hidden, not #hidden.
Now you have to decide whether you want to attach CSS to divs by class or id. I find classes are better in the long run, unless you are really certain that there will ever really and truly be one of the thing you are making.
Also, don't forget that you can attach more than one class to an element:
<div class="red fat shallow">blah blah</div>
Then you can style this element with any of these selectors:
.red {...}
.fat {...}
.shallow {...}
.red.fat {...} /* Applies only to things that are both red and fat */
.red.fat.shallow {...} /* Very specific */
/* etc. */
A "." before the name will refer to classes, and a "#" will refer to ids:
.hidden
{
display: none;
}
You need:
.hidden{
display:none;
}
period is a class specifier, pound sign is for id's.
To use class name use the dot.
i.e.
.hidden refers to the class name
#repair_complete refers to the id.
To refer to an element's ID you use the # selector, to refer to it's class name you use the . selector.
So in your example you would use
#repair_complete {
display:none;
}
or
.hidden {
display:none;
}