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minor #4372 Tweaks after proofreading the 2.6 OptionsResolver stuff (…

…weaverryan, WouterJ)

This PR was merged into the master branch.

Discussion
----------

Tweaks after proofreading the 2.6 OptionsResolver stuff

Hi guys!

This is a proofread after merging #4159. There were enough changes there that the easiest way to handle things was to merge, re-read entirely, then open a PR with small tweaks. But largely, I am very happy with how the document turned out :).

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | 2.6+
| Fixed tickets | --

Thanks!

Commits
-------

b49731b Linking to the 2.6 headline thanks to a suggestion from @xabbuh
a1badc5 Renaming a method at the suggestion of my friend Bernhard
f179ec7 A few more tweaks from comments
59fd436 Also did a quick proofread
d190831 Tweaks after proofreading the 2.6 OptionsResolver stuff
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weaverryan committed Oct 28, 2014
2 parents 90bc241 + b49731b commit 22b9b27859939e3b35fd733436df6f15216c0adc
Showing with 60 additions and 38 deletions.
  1. +60 −38 components/options_resolver.rst
@@ -5,7 +5,9 @@
The OptionsResolver Component
=============================
The OptionsResolver component is `array_replace()` on steroids.
The OptionsResolver component is :phpfunction:`array_replace` on steroids.
It allows you to create an options system with required options, defaults,
validation (type, value), normalization and more.
Installation
------------
@@ -20,8 +22,8 @@ Notes on Previous Versions
.. versionadded:: 2.6
This documentation was written for Symfony 2.6 and later. If you use an older
version, please read the corresponding documentation using the version
drop-down on the upper right.
version, please `read the Symfony 2.5 documentation`_. For a list of changes,
see the `CHANGELOG`_.
Usage
-----
@@ -48,29 +50,35 @@ check which options are set::
public function sendMail($from, $to)
{
$mail = ...;
$mail->setHost(isset($this->options['host'])
? $this->options['host']
: 'smtp.example.org');
$mail->setUsername(isset($this->options['username'])
? $this->options['username']
: 'user');
$mail->setPassword(isset($this->options['password'])
? $this->options['password']
: 'pa$$word');
$mail->setPort(isset($this->options['port'])
? $this->options['port']
: 25);
// ...
}
}
This boilerplate is hard to read and repetitive. Also, the default values of the
options are buried in the business logic of your code. We can use
options are buried in the business logic of your code. Use the
:phpfunction:`array_replace` to fix that::
class Mailer
{
// ...
public function __construct(array $options = array())
{
$this->options = array_replace(array(
@@ -83,27 +91,27 @@ options are buried in the business logic of your code. We can use
}
Now all four options are guaranteed to be set. But what happens if the user of
the ``Mailer`` class does a mistake?
the ``Mailer`` class makes a mistake?
.. code-block:: php
$mailer = new Mailer(array(
'usernme' => 'johndoe',
));
No error will be shown. In the best case, the bug will be appear during testing.
The developer will possibly spend a lot of time looking for the problem. In the
worst case, however, the bug won't even appear and will be deployed to the live
system.
No error will be shown. In the best case, the bug will appear during testing,
but the developer will spend time looking for the problem. In the worst case,
the bug might not appear until it's deployed to the live system.
Let's use the :class:`Symfony\\Component\\OptionsResolver\\OptionsResolver`
class to fix this problem::
Fortunately, the :class:`Symfony\\Component\\OptionsResolver\\OptionsResolver`
class helps you to fix this problem::
use Symfony\Component\OptionsResolver\Options;
class Mailer
{
// ...
public function __construct(array $options = array())
{
$resolver = new OptionsResolver();
@@ -136,6 +144,7 @@ code::
class Mailer
{
// ...
public function sendMail($from, $to)
{
$mail = ...;
@@ -153,6 +162,7 @@ It's a good practice to split the option configuration into a separate method::
class Mailer
{
// ...
public function __construct(array $options = array())
{
$resolver = new OptionsResolver();
@@ -164,10 +174,10 @@ It's a good practice to split the option configuration into a separate method::
protected function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults(array(
'host' => 'smtp.example.org',
'username' => 'user',
'password' => 'pa$$word',
'port' => 25,
'host' => 'smtp.example.org',
'username' => 'user',
'password' => 'pa$$word',
'port' => 25,
'encryption' => null,
));
}
@@ -196,12 +206,13 @@ Required Options
If an option must be set by the caller, pass that option to
:method:`Symfony\\Component\\OptionsResolver\\OptionsResolver::setRequired`.
For example, let's make the ``host`` option required::
For example, to make the ``host`` option required, you can do::
// ...
class Mailer
{
// ...
protected function configureOptions(OptionsResolver $resolver)
{
// ...
@@ -210,8 +221,8 @@ For example, let's make the ``host`` option required::
}
.. versionadded:: 2.6
Before Symfony 2.6, `setRequired()` accepted only arrays. Since then, single
option names can be passed as well.
As of Symfony 2.6, ``setRequired()`` accepts both an array of options or a
single option. Prior to 2.6, you could only pass arrays.
If you omit a required option, a
:class:`Symfony\\Component\\OptionsResolver\\Exception\\MissingOptionsException`
@@ -229,6 +240,7 @@ one required option::
class Mailer
{
// ...
protected function configureOptions(OptionsResolver $resolver)
{
// ...
@@ -268,14 +280,15 @@ retrieve the names of all required options::
If you want to check whether a required option is still missing from the default
options, you can use :method:`Symfony\\Component\\OptionsResolver\\OptionsResolver::isMissing`.
The difference to :method:`Symfony\\Component\\OptionsResolver\\OptionsResolver::isRequired`
is that this method will return false for required options that have already
The difference between this and :method:`Symfony\\Component\\OptionsResolver\\OptionsResolver::isRequired`
is that this method will return false if a required option has already
been set::
// ...
class Mailer
{
// ...
protected function configureOptions(OptionsResolver $resolver)
{
// ...
@@ -320,6 +333,7 @@ correctly. To validate the types of the options, call
class Mailer
{
// ...
protected function configureOptions(OptionsResolver $resolver)
{
// ...
@@ -329,8 +343,8 @@ correctly. To validate the types of the options, call
}
For each option, you can define either just one type or an array of acceptable
types. You can pass any type for which an ``is_<type>()`` method is defined.
Additionally, you may pass fully qualified class or interface names.
types. You can pass any type for which an ``is_<type>()`` function is defined
in PHP. Additionally, you may pass fully qualified class or interface names.
If you pass an invalid option now, an
:class:`Symfony\\Component\\OptionsResolver\\Exception\\InvalidOptionsException`
@@ -348,9 +362,7 @@ to add additional allowed types without erasing the ones already set.
.. versionadded:: 2.6
Before Symfony 2.6, `setAllowedTypes()` and `addAllowedTypes()` expected
the values to be given as an array mapping option names to allowed types:
.. code-block:: php
the values to be given as an array mapping option names to allowed types::
$resolver->setAllowedTypes(array('port' => array('null', 'int')));
@@ -360,13 +372,14 @@ Value Validation
Some options can only take one of a fixed list of predefined values. For
example, suppose the ``Mailer`` class has a ``transport`` option which can be
one of ``sendmail``, ``mail`` and ``smtp``. Use the method
:method:`Symfony\\Component\\OptionsResolver\\OptionsResolver::setAllowedValues` to verify
that the passed option contains one of these values::
:method:`Symfony\\Component\\OptionsResolver\\OptionsResolver::setAllowedValues`
to verify that the passed option contains one of these values::
// ...
class Mailer
{
// ...
protected function configureOptions(OptionsResolver $resolver)
{
// ...
@@ -420,9 +433,11 @@ option. You can configure a normalizer by calling
class Mailer
{
// ...
protected function configureOptions(OptionsResolver $resolver)
{
// ...
$resolver->setNormalizer('host', function ($options, $value) {
if ('http://' !== substr($value, 0, 7)) {
$value = 'http://'.$value;
@@ -467,12 +482,12 @@ Default Values that Depend on another Option
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Suppose you want to set the default value of the ``port`` option based on the
encryption chosen by the user of the ``Mailer`` class. More precisely, we want
encryption chosen by the user of the ``Mailer`` class. More precisely, you want
to set the port to ``465`` if SSL is used and to ``25`` otherwise.
You can implement this feature by passing a closure as default value of the
``port`` option. The closure receives the options as argument. Based on these
options, you can return the desired default value::
You can implement this feature by passing a closure as the default value of
the ``port`` option. The closure receives the options as argument. Based on
these options, you can return the desired default value::
use Symfony\Component\OptionsResolver\Options;
@@ -498,7 +513,7 @@ options, you can return the desired default value::
.. caution::
The argument of the callable must be type hinted as ``Options``. Otherwise,
the callable is considered as the default value of the option.
the callable itself is considered as the default value of the option.
.. note::
@@ -546,8 +561,10 @@ Options without Default Values
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In some cases, it is useful to define an option without setting a default value.
Mostly, you will need this when you want to know whether an option was passed
or not. If you set a default value for that option, this is not possible::
This is useful if you need to know whether or not the user *actually* set
an option or not. For example, if you set the default value for an option,
it's not possible to know whether the user passed this value or if it simply
comes from the default::
// ...
class Mailer
@@ -584,6 +601,7 @@ be included in the resolved options if it was actually passed to
class Mailer
{
// ...
protected function configureOptions(OptionsResolver $resolver)
{
// ...
@@ -637,6 +655,8 @@ let you find out which options are defined::
// ...
class GoogleMailer extends Mailer
{
// ...
protected function configureOptions(OptionsResolver $resolver)
{
parent::configureOptions($resolver);
@@ -671,10 +691,10 @@ can change your code to do the configuration only once per class::
public function __construct(array $options = array())
{
// Are we a Mailer, a GoogleMailer, ... ?
// What type of Mailer is this, a Mailer, a GoogleMailer, ... ?
$class = get_class($this);
// Did we call configureOptions() before for this class?
// Was configureOptions() executed before for this class?
if (!isset(self::$resolversByClass[$class])) {
self::$resolversByClass[$class] = new OptionsResolver();
$this->configureOptions(self::$resolversByClass[$class]);
@@ -693,14 +713,14 @@ Now the :class:`Symfony\\Component\\OptionsResolver\\OptionsResolver` instance
will be created once per class and reused from that on. Be aware that this may
lead to memory leaks in long-running applications, if the default options contain
references to objects or object graphs. If that's the case for you, implement a
method ``clearDefaultOptions()`` and call it periodically::
method ``clearOptionsConfig()`` and call it periodically::
// ...
class Mailer
{
private static $resolversByClass = array();
public static function clearDefaultOptions()
public static function clearOptionsConfig()
{
self::$resolversByClass = array();
}
@@ -713,3 +733,5 @@ options in your code.
.. _Packagist: https://packagist.org/packages/symfony/options-resolver
.. _Form component: http://symfony.com/doc/current/components/form/introduction.html
.. _CHANGELOG: https://github.com/symfony/symfony/blob/master/src/Symfony/Component/OptionsResolver/CHANGELOG.md#260
.. _`read the Symfony 2.5 documentation`: http://symfony.com/doc/2.5/components/options_resolver.html

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