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Sass maps provide a flexible way to keep track of data by associating a name with a particular value.
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Sass maps provide a flexible
way to keep track of data
0:00
by associating a name
with a particular value.
0:03
For example, the name of a a social
network with its brand color.
0:06
Let's say you're displaying a list
of links to all your company's
0:09
social networks.
0:12
Next to each link is
an icon font of the logo.
0:13
And it needs to be the brand color of
that social network like Facebook and
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Twitter blue, Dribbble pink,
YouTube red and so on.
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Manually creating a selector and
rule for each social network and
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defining the brand specific color
value would be pretty tedious, right?
0:26
Well, we can instead use maps to
make the process faster and easier.
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Inside a map, you store data in what
are called the key value pairs.
0:35
The key is like a variable
name that belongs to the map
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like the name of the social network.
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And a key gets assigned
a value like it's brand color.
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You can access any value in a map
based on the key name you assign it.
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So, let's look at how maps make it
easy to collect key values pairs into
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name groups using our
sites break point values.
0:56
The break extra small, small, medium and
0:59
large variables together represent
a group of break point values.
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So instead of declaring
separate variables for
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each break point value, we can store them
within a map and access them dynamically.
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You define a Sass map using the dollar
sign immediately followed by the name of
1:14
the map like a variable.
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So in the variables partial let's
create a map named breakpoints.
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We'll follow the name with a colon,
a set of parentheses and then a semicolon.
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Inside the parenthesis
you match keys to values.
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A key can be of any data type
like a string or number and
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each key needs to be unique.
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So let's create a key for
the extra small break point by typing
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the string xs then a colon and
a value 575 pixels.
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Each key value pair must
be comma separated.
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So now let's create the key value
pairs for the remaining breakpoints.
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I'll simply copy the small through large
variables above Paste them inside the map,
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and change the variables to
the keys small, medium, and large.
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Replacing the semicolons with commas
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Now the comma after the last
key value pair is optional.
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But developers commonly include the comma
to make it easier to add, remove or
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reorder key value pairs inside a map.
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You may also define keys
without quotes like xs and sm.
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These are 100% valid key definitions.
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But if the keys are strings like ours,
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it's a best practice to
wrap them in quotes.
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So now we've declared a global variable
of breakpoints which is a map.
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Consisting of named break point values.
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Sass provides several
functions to manipulate maps.
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Most of the time you'll use the map get
function to retrieve values from a map.
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So over in the mixins partial,
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let's return the value of
the extra small break point.
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By replacing the first break-xs variable,
with map-get.
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Followed by a set of print.
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So map get accepts two arguments.
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The name of a map, and the key for
the value you want to return.
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For instance, to get the value
of the extra small breakpoint
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stored inside the breakpoints map
passed map-get the arguments,
3:45
breakpoints and
the string access for extra small.
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So here, map-get looks up the value
3:54
of the xs key inside the map.
3:59
And returns 575 pixels so
over in the output CSS, if you take a look
4:04
at the extra small media query, you'll
see @media-width, 575 pixels, great.
4:09
Now, using map get over and
4:15
over again to get the values of all
break points is not only repetitive, but
4:17
also adds more code to the mixin,
making it harder to read and maintain.
4:21
Our mixin is already
repetitive the way it is.
4:25
Notice how it's repeating
else if break equals and
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the min with feature for
the small to large break points.
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Well our break points Sass map
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can make the media query mixin even
less repetitive and easier to manage.
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So inside the media query mixin.
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Let's declare a local variable that stores
a value associated with a given key and
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a break points map.
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We'll name the variable value and
set it to the map get function.
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Then pass it the arguments,
breakpoints and break.
5:01
So the mixin needs to output a media
query using the max-width media feature
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if the argument passed for
break is the extra small breakpoint key.
5:15
So in other words, if value is
smaller than the small breakpoint.
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Now I just used the word if, so
5:26
that's a good sign and
if statement will come in handy here.
5:28
Right below value let's declare
another local variable,
5:32
that will store the value of
the small key in our breakpoints map.
5:36
We'll name it sm for small and
set it to the map get function,
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passing it the arguments,
breakpoints, and the string small.
5:47
So now I'll delete all but
the if condition, and one of the else,
5:59
if conditions inside the mixin.
6:04
Select and delete the last two else, ifs.
6:07
Then change the if statement
if value is less than small.
6:11
Then set the max width value here
in the media query expression
6:20
to the value variable.
6:24
So this will output the max width
media query set to a value,
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return from the map if it's
less than the value of small.
6:31
Otherwise, if the value is
the small breakpoint or
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larger, the mixin should output
a min width media query.
6:40
So right below, we'll use the else
directive to output the media query,
6:45
using the value returned
from the breakpoints map.
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So I'll set the min width value
here to the value variable.
6:54
We'll give the save and
test it in the browser.
7:04
Now, since we've named our break
point keys xs, sm, medium and large,
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the responsive layout should still look
and work the same as before, and it does.
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So using Sass maps made our
media query mixin leaner,
7:21
smarter and easier to maintain.
7:25
Now we can remove the breakpoint variables
7:28
from our variables partial since all
breakpoints are now stored in a map.
7:31
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