StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

PO
text
Body
copied!<p>This is mostly a summary of (my perspective of) <a href="http://chat.stackoverflow.com/rooms/6954/discussion-between-zerkms-and-deceze">the chat that ensued between me and @zerkms</a>:</p> <p>The point of contention is actually this:</p> <pre><code>public function doSomething($id) { $user = User::getByPhone($this->pdo, $id); // do something with user return $someData; } </code></pre> <p>This makes it hard to test <code>doSomething</code> since it hardcodes the <code>User</code> class, which may or may not have a lot of dependencies. But this is in fact the same as instantiating the object using a non-static method:</p> <pre><code>public function doSomething($id) { $user = new User; $user->initializeFromDb($this->pdo, $id); // do something with user return $someData; } </code></pre> <p>We're not using a static method, but it's still unmockable. Actually, it got worse.<br> The answer is to use a factory:</p> <pre><code>public function doSomething($id) { $user = $this->UserFactory->byPhone($id); // do something with user return $someData; } </code></pre> <p>Now the factory can be dependency injected and mocked and the <code>User</code> class is no longer hardcoded. You may or may not think this overkill, but it certainly improves mockability.</p> <p>That does not change the fact though that this factory may very well instantiate the actual user object using a static method:</p> <pre><code>public function byPhone($id) { return User::getByPhone($this->db, $id); } </code></pre> <p>There's no difference between using a static method or a regular constructor here.</p> <pre><code>$user = new User($db, $id); $user = User::getByPhone($db, $id); </code></pre> <p>Both expressions return an instance of <code>User</code> and both "hardcode" the <code>User</code> class. Which simply needs to happen at some point anyway.</p> <p>For my use case, a <code>static</code> constructor method makes the most sense for the object. And as was demonstrated, <code>static</code> methods are not the problem. Where to <em>call</em> them is the point of contention, not that they exist at all. And I have yet to see a convincing argument for not using static constructors, since they can be wrapped in a factory, which alleviates any problem with mockability, the same as it does for regular object instantiation.</p>

Querying!

Guidance

An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload