- Creating Powerful Mixins 4:30
- Smarter Mixins with null and Keyword Arguments 8:17
- Advanced Mixins Challenge 4 objectives
- Add Conditional Logic to Your Stylesheets 8:11
- Storing Values in Maps 7:37
- Write Loops with @for 6:24
- Loop Through Lists with @each 4:25
- Loop Through Data in a Map with @each 6:18
- Maps and Loops Review 5 questions
- Handling Errors with @error and @warn 3:51
- Debugging Sass with Sourcemaps 3:08
- Debugging Review 5 questions
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Storing Values in Maps
7:37Sass maps provide a flexible way to keep track of data by associating a name with a particular value.
Sass maps provide a flexible
way to keep track of data
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by associating a name
with a particular value.
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For example, the name of a a social
network with its brand color.
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Let's say you're displaying a list
of links to all your company's
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social networks.
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Next to each link is
an icon font of the logo.
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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?
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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.
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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.
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The break extra small, small, medium and
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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
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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,
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breakpoints and
the string access for extra small.
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So here, map-get looks up the value
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of the xs key inside the map.
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And returns 575 pixels so
over in the output CSS, if you take a look
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at the extra small media query, you'll
see @media-width, 575 pixels, great.
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Now, using map get over and
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over again to get the values of all
break points is not only repetitive, but
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also adds more code to the mixin,
making it harder to read and maintain.
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Our mixin is already
repetitive the way it is.
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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.
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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.
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So in other words, if value is
smaller than the small breakpoint.
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Now I just used the word if, so
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that's a good sign and
if statement will come in handy here.
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Right below value let's declare
another local variable,
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that will store the value of
the small key in our breakpoints map.
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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.
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So now I'll delete all but
the if condition, and one of the else,
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if conditions inside the mixin.
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Select and delete the last two else, ifs.
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Then change the if statement
if value is less than small.
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Then set the max width value here
in the media query expression
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to the value variable.
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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.
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Otherwise, if the value is
the small breakpoint or
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larger, the mixin should output
a min width media query.
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So right below, we'll use the else
directive to output the media query,
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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.
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We'll give the save and
test it in the browser.
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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,
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smarter and easier to maintain.
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Now we can remove the breakpoint variables
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from our variables partial since all
breakpoints are now stored in a map.
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