- Course Overview 1:49
- Attribute Selectors 8:44
- Styling Form Buttons and Links with Attribute Selectors 3:34
- Attribute Selectors Challenge 3 objectives
- DRY CSS 10:51
- Child, Adjacent, and General Sibling Combinators 9:03
- Combinators Challenge 2 objectives
- Attribute Selectors and Combinators Review 5 questions
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Child, Adjacent, and General Sibling Combinators
9:03Combinators give us the flexibility of targeting any siblings of an element. We can use the greater-than sign (>), plus sign (+), or tilde symbol (~) to make our selectors more specific.
Combinators explain the relationship
between elements in a selector.
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So every time we target two or more
elements with one selector.
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We'll need to use a combinator, and would
actually used combinators back in
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CSS basics when we wrote descendant
selectors,
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because the white space between the two
selectors is also considered a combinator.
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Besides being able to target descendant
elements,
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combinators also give us the flexibility
of targeting any siblings of an element.
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We can use the greater than sign, the plus
sign, or
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a tilde symbol to make our selectors more
specific.
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Let's take a look at these.
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First up, in a CSS selector,
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the greater than sign is referred to as a
child combinator.
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And selectors that use child combinators
are called child selectors,
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because they target elements that are
direct children of other elements.
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Now, direct children are those elements
that are directly nested
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inside a parent element.
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So, for example, when we take a look at
our HTML file, we can see that the form,
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the hr and img elements are direct
children of the container div here.
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But, the h1, the label element and
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the input fields are all direct children
of the form element.
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They're not direct children of this
container div.
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So, knowing this, let's go back to our
style sheet, and the first thing I'm
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gonna do is copy one of these comments and
scroll all the way down to the bottom,
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and then, I'm going to create a new
comment that says Combinators.
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So first, let's create a direct child
selector,
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that targets anchor elements that are
direct children of a form.
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So first, we're going to target the form
element, and then we're going
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to follow that with a greater than sign
and then an a or anchor element.
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Then we're going to give this anchor
elements a font size value of .7em.
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Right.
So
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let's save our style sheet, and let's
scroll down to our second form.
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Notice how when we refresh the browser the
direct child selector we just wrote.
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Targets this link, because it is in fact a
direct child of the form element.
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But you may ask, well, it's the only link
in the form.
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Well, let's see what happens when we add
this link as
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a descendant of another child element.
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So I'm gonna go ahead and copy.
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The last link here.
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And then I'll just paste it inside any of
the labels.
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So for example I'm going to paste it
inside the password label.
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All right?
So, when we save our index file and
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take a look at it again.
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Notice how it doesn't target that
particular link inside the password label,
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since this link is no longer a direct
child of the form element,
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it's now a direct child of the label
element.
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So as we can see, this is a very specific
selector.
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So now I'll just go back and undo.
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The nested anchor element and the password
label.
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And refresh.
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So another combinator we can use in a
selector is a plus sign.
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The plus sign combinator is called an
adjacent sibling combinator.
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And selectors that use them are called
adjacent sibling selectors,
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because they target an elements next
sibling on the page.
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So the one that immediately follows the
element.
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For example, the two input element here in
the first form are sibling elements so
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let's go ahead and take a look at these in
the browser.
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So notice how currently,
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when the two buttons are in line they're a
little too close together.
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Now what if we could somehow apply a left
margin.
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To any button that's next to another
button.
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So that way the first button remains flush
with the contact,
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while the second button, gets a little bit
of separation with the left margin.
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Well, with the adjacent sibling selector,
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we can specifically target button elements
that immediately follow a button element.
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without having to add extra classes in our
mark.
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So let's go back to our style sheet, and
right above in the media query we wrote
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earlier, let's create a new selector that
targets the class button.
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Then with the plus sign combinator.
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Will target its immediate sibling with the
same class.
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So right after that we'll type .button.
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And in this new rule let's add a margin
left property.
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And let's set the value to 20 pixels.
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So let's save our style sheet and bring up
the browser.
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And when we refresh the page,
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notice how the second reset button gets a
left margin.
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While the first button is still aligned
with the content.
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It's left aligned.
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So now, any time we see two or more
sibling elements with that class button,
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we'll see some separation between them
with that left margin.
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So for example, let's go ahead and copy
these two.
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And just paste them below.
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And if we save and take a look at it
again,.
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We see the separation between each button
while that first button remains aligned to
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the left with the content.
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So, now we'll be back and undo those two
buttons and just keep the submit and
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reset ones moving forward.
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Finally, the third combinator we can use
is the tilde symbol.
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Now, the tilde symbol is called a general
sibling combinator.
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Because it targets siblings, but this time
it not only targets an immediate sibling,
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it actually targets every specified
sibling that follows.
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Now, this general sibling comminator isn't
as commonly used as the child and
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sibling selectors we just wrote.
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But to quickly demonstrate how it works,
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let's create one of these general sibling
selectors.
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So, we'll go back to our style sheet, and
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right beneath the child selector let's
create a general sibling selector that
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targets every sibling label element that
follows an h1.
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So, we'll do that by first selecting the
h1 element.
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And then, we'll follow that with the tilde
symbol and the label element type.
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So, again, with this selector, we're
telling the browser to
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target all sibling label elements that
follow an h1.
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So now, let's write a few CSS properties,
so
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we can see which labels this selector will
target.
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So first, let's add a background property,
and
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let's set the color to tomato, my favorite
color, hah.
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And then we'll set the color to white, and
let's give it a little bit of padding.
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Let's say five pixels.
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All right, so let's save our style sheet.
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And refresh the page.
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And as we can see, because there's an h1
in the contact form here,
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now every sibling that follows the h1
takes on those styles we just wrote.
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And if we were to keep adding labels to
this first form, they'd also turn red.
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And also notice that only the labels in
the top contact form take on those styles,
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not the ones in the login form, since
there isn't an H1 element in this form.
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Just up top in the contact form.
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So, as we've learned, combinators help us
create styles for
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specific child elements, and sibling
elements.
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But, keep in mind that we're only able to
target siblings that follow an element,
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not ones that precede an element.
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You'll learn a couple more uses for
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these in the next code challenge, so be
sure not to skip it.
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So let's quickly review some of what we've
learned so far about CSS selectors.
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First, attribute selectors give us a lot
of flexibility for selecting elements,
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because we're able to target an element by
any of its HTML attributes.
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For example, a link's target attribute, or
an input element's type attribute.
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remember the dry concept "Don't Repeat
Yourself."
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So if we have CSS that is repeated several
times throughout our style sheet,
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it is a good idea to refractor the CSS so
that each property and
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value pair is defined once.
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This makes our stop sheets more
maintainable.
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Besides using descendant selectors to
target descendants of an element.
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We can define more specific child and
sibling selectors, with combinators.
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Remember.
[SOUND] The greater than sign
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targets a direct child of an element.
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[SOUND] The plus sign combinator targets
immediate siblings.
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[SOUND] While the tilde symbol targets all
the specified siblings that
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follow an element.
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When used carefully, combinators let us
target more elements without having to
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write extra classes or IDs in our markup.
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Up next, we'll kick things up a notch when
we learn about structural pseudoclasses,
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new powerful attribute selectors, and
more.
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Now, if you thought these selectors were
pretty neat,
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wait until you see what's next.
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