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Now that you know how to grab specific items, the next step is to be able to sort those items to make it easier to check for a specific item.
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Steps Used for Sorting the Items
Step 1: Create an Associative Array for Sorting
Instead of $output being a simple indexed array, we will change this to an associative array with the key being the ID and the value being the item Title.
$sort = $item["title"];
$output[$id] = $sort;
Step 2: Sort the Array by Value and Return Only the Keys
asort($output);
return array_keys($output);
Step 3: Trim "The ", "A ", "An " from the beginning of the title
$sort = ltrim($sort,"The ");
$sort = ltrim($sort,"A ");
$sort = ltrim($sort,"An ");
Step 4: Sort the Full Catalog
To do this we will need to remove the early return from the function which was bypassing the sort. Instead, we will combine the two category conditionals. Either $category should be null (in this case we use every item) OR $category should match the item category.
if ($category == null OR strtolower($category) == strtolower($item["category"])) {
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In the last video, you learned how to grab
only the items in a certain category.
0:00
With our current data,
that's only four items on a category page.
0:04
So it doesn't really make much
difference how it's sorted.
0:07
That's easy enough to see everything, but
when we look full catalog of 12 items,
0:11
we can start to see how we could easily
miss a particular item when our catalog
0:16
expands.
0:20
It would be much easier to find things
if we could sort this by title.
0:22
So, let's get into our function and
make some modifications.
0:26
Go back into function.php and
go into the array category function.
0:30
After we check if this
item matches our category.
0:37
We want to create a variable to use for
sorting.
0:41
We can choose any element to sort with,
but
0:44
title would seem to be the most useful.
0:46
So we set sort =
0:49
item "title".
0:53
Now instead of just adding
the key to the array,
0:58
we also want to assign the value to sort.
1:00
We change this line to be output id
1:04
= sort.
1:09
Before we return our output array,
we need to do two things.
1:14
One, sort the array using
a built-in function
1:18
called asort, asort($output);
1:24
Since we changed our array to
include more than just the keys,
1:30
we want to return only the keys,
like we did on null.
1:34
So again, we use array_keys.
1:38
Let's go back to our browser and
see what this looks like on our page.
1:47
We go into books,
our book items are now sorted by title.
1:51
Great, but you'll notice, The Clean Coder
is at the end because it starts with a T.
1:55
Typically, when items are alphabetized,
the preposition a, and,
2:03
and the,
are ignored at the beginning of the title.
2:07
Let's set up our code to work that way.
2:10
We want to remove, or trim, any the, a,
or and from the beginning of our sort.
2:13
To do this,
2:20
we'll use another built in function,
ltrim, meaning trim from the left.
2:20
After setting the variable for
sort, let's add the following line.
2:28
Sort equals ltrim,
2:31
sort, T-H-E space.
2:35
Make sure you include
the space after T-H-E or
2:41
it will trim T-H-E off anything and
not just the word the.
2:45
This means that theme would become me,
and that's not what we want to happen.
2:49
Let's copy this line twice.
2:55
And change the to a and
2:59
an respectively.
3:03
Now, when we refresh our page in the
browser, our books are sorted by title.
3:07
And The Clean Coder is right next to Clean
Code because the sort is ignoring The at
3:12
the beginning of the title.
3:17
Our Movies page and our Music page
are also sorting alphabetically.
3:18
The only page that's not sorting
alphabetically yet is our full catalog.
3:24
Let's go back into our function and
fix that.
3:29
Back in our function,
3:33
we have it returning just an array of
all the keys, if our category is null.
3:34
Let's combine our if statements.
3:39
Let's move this first if down to this if.
3:41
Then we'll combine it with an or.
3:50
Now our function will sort the items
that match our category, or
3:55
sort all the items if we
pass a null category.
3:59
Before we go, let's change our h1 tag to
include the link to the full catalog.
4:04
We only wanna do this if
we're on a category page.
4:09
So we'll start by adding a conditional.
4:12
Up here with our page title.
4:16
We'll first start with if
4:17
section is not equal null.
4:22
Going to do something.
4:31
Pay special attention to the exclamation
point which is our negation or
4:34
not operator.
4:39
It can be confusing when you
start working with negatives, but
4:40
it can also make things a lot easier.
4:43
One value not true versus
multiple values that are true.
4:45
If our section variable is null
then we're on our full catalog.
4:50
And we don't need to show that link.
4:54
But we are checking to see if our
section variable is not null.
4:56
So we can print an extra line
that links to our full catalog.
5:00
We're going to use
5:07
a special character
5:12
to separate our title.
5:17
& gt;,
5:25
this is a greater than sign but it keeps
it from being confused with our HTML.
5:28
Whether our section variable is null or
not, we still want to keep our page title.
5:34
Now when we preview our page,
we can click through our categories and
5:38
back to our full catalog.
5:43
Our Catalog page is ready to go.
5:45
And you've learned a lot about utilizing
arrays and the built-in array functions.
5:47
There are several other functions
associated with sorting and arrays.
5:51
Including reverse order and sorting
the array keys instead of the values.
5:55
Go back into the array functions in
the PHP docs and give some of them a try.
6:00
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