Merge pull request #402 from garoevans/php-doc

Add a PHPDoc post
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Phil Sturgeon
2014-07-02 12:24:13 +01:00

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_posts/15-01-01-PHPDoc.md Normal file
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---
anchor: phpdoc
---
# PHPDoc {#phpdoc}
PHPDoc is an informal standard for commenting PHP code. There are a *lot* of different [tags](http://www.phpdoc.org/docs/latest/references/phpdoc/tags/index.html) available. The full list of tags and examples can be found at the [PHPDoc manual](http://www.phpdoc.org/docs/latest/index.html).
Below is an example of how you might document a class with a few methods;
{% highlight php %}
<?php
/**
* @author A Name <a.name@example.com>
* @link http://www.phpdoc.org/docs/latest/index.html
* @package helper
*/
class DateTimeHelper
{
/**
* @param mixed $anything Anything that we can convert to a \DateTime object
*
* @return \DateTime
* @throws \InvalidArgumentException
*/
public function dateTimeFromAnything($anything)
{
$type = gettype($anything);
switch ($type) {
// Some code that tries to return a \DateTime object
}
throw new \InvalidArgumentException(
"Failed Converting param of type '{$type}' to DateTime object"
);
}
/**
* @param mixed $date Anything that we can convert to a \DateTime object
*
* @return void
*/
public function printISO8601Date($date)
{
echo $this->dateTimeFromAnything($date)->format('c');
}
/**
* @param mixed $date Anything that we can convert to a \DateTime object
*/
public function printRFC2822Date($date)
{
echo $this->dateTimeFromAnything($date)->format('r');
}
}
{% endhighlight %}
The documentation for the class as a whole firstly has the [@author](http://www.phpdoc.org/docs/latest/references/phpdoc/tags/author.html) tag, this tag is used to document the author of the code and can be repeated for documenting several authors. Secondly is the [@link](http://www.phpdoc.org/docs/latest/references/phpdoc/tags/link.html) tag, used to link to a website indicating a relationship between the website and the code. Thirdly it has the [@pacakge](http://www.phpdoc.org/docs/latest/references/phpdoc/tags/package.html) tag, used to categorize the code.
Inside the class, the first method has an [@param](http://www.phpdoc.org/docs/latest/references/phpdoc/tags/param.html) tag documenting the type, name and description of the parameter being passed to the method. Additionally it has the [@return](http://www.phpdoc.org/docs/latest/references/phpdoc/tags/return.html) and [@throws](http://www.phpdoc.org/docs/latest/references/phpdoc/tags/throws.html) tags for documenting the return type, and any exceptions that could be throw respectively.
The second and third methods are very similar and have a single [@param](http://www.phpdoc.org/docs/latest/references/phpdoc/tags/param.html) tag as did the first method. The import difference between the second and third method is doc block is the inclusion/exclusion of the [@return](http://www.phpdoc.org/docs/latest/references/phpdoc/tags/return.html) tag. `@return void` explicitly informs us that there is no return, historically omitting the `@return void` statement also results in the same (no return) action.