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By defining another interface method, we'll explore another feature of abstract classes. When a class is defined as abstract, it does not need to define all methods. Instead it passes that requirement to the next NON-abstract class.
Currently, the collection
class is abstract and
0:01
it implements the CollectionInterface.
0:05
All methods from the interface are being
implemented in the collection class.
0:07
Let's add one more method
to that interface.
0:12
We'll call this public function getTitle.
0:15
Now let's preview our site again.
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We get another error like we've
seen before because we have not
0:25
implemented our required method.
0:28
But let's take a closer
look at that error.
0:30
First, notice that the error is on the
post class, not on the collection class.
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The next part of the error explains why.
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The abstract method must
either be implemented or
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the class itself may be declared abstract.
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Because the collection class is abstract.
0:50
And therefore cannot be instantiated,
0:52
it is not required to implement
all the required methods itself.
0:55
Instead, this requirement is
passed to any non-abstract class,
1:00
extending the collection class.
1:05
Let's add this method to the post class.
1:07
Public function getTitle.
1:20
First, if this count is equal to 1,
1:27
This means that we're
on a single post page.
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If we're on a single post page,
we want to return the current title.
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If we make it past this return,
we'll simply return Latest Posts.
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Let's clean up our pages.
1:59
In header.php, in our views folder,
We used the title twice.
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Let's replace those with this new
method instead, content getTitle.
2:08
Now we can remove the title
from the index page.
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Since we don't need to set the title,
we can make this a single if statement.
2:43
So, if our content is not set or
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the content count is not equal to 1, or,
2:55
The content current status
does not equal published.
3:06
Then we will select all posts.
3:15
Once again,
3:17
let's preview the site to make sure
everything is still functioning properly.
3:18
Looks good.
3:27
We're ready to add
a second content type for
3:28
pages by extending a second
child of the collection class.
3:31
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