CODEWITHSUNDEEP
php
Jason
Jason

Reputation: 4772

Should "use" statement generally reference a [fully qualified] class or a namespace?

There are lots of articles that describe how to use namespaces in PHP-5.3+ I am particularly interested in the conventions in the use statement.

What most articles dot not point out, is that use can reference a namespace or a class. So to reference my class in PSR-0 location Foobar/Helper/Helper.php I can either do this:

use \Foobar\Helper; // This is a namespace
class Whatever {
    ...
    Helper\Helper::MyHelperMethod();

or this:

use \Foobar\Helper\Helper; // This is a class
class Whatever {
    ...
    Helper::MyHelperMethod();

No packages I have seen document which they are using on each use statement, and that can often lead to guesswork.

So, is it bad practice to use one approach or the other? Or perhaps to mix the concepts? Or is it perhaps just one of those things people rarely document?

Or maybe I am just misunderstanding the whole issue?

Upvotes: 3

Views: 722

Answers (2)

Oswald
Oswald

Reputation: 31665

If you have a namespace \Foobar\Helper, then

use \Foobar\Helper;

allows you to access all classes from the \Foobar\Helper namespace with Helper as a namespace qualifier. The line

use \Foobar\Helper\Helper;

gives you more control over what classes you want to access without the namespace qualifier. On the other hand, it is quite tedious to keep the use declarations in sync with the code during development. On the third hand, it servers as a documentation about what dependencies exist in the file.

To distinguish whether a use statement refers to a namespace or a class, an IDE such as Eclipse PDT helps.

Upvotes: 3

deceze
deceze

Reputation: 522210

The point of use is to reduce repeatedly typing the same fully qualified class name. It allows you to produce shorter, more readable code. It depends on your situation which is the most readable way to write your code. If you just need one class from a namespace, you can alias it directly. If you need a lot of classes from one namespace, it may make the most sense to alias only up to the namespace. If several classes from separate namespaces are similarly named, it can make code clearer if you only alias up to the namespace. It's entirely up to you and the situation.

Upvotes: 2

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