# Doctrine Deprecations
A small (side-effect free by default) layer on top of
`trigger_error(E_USER_DEPRECATED)` or PSR-3 logging.
- no side-effects by default, making it a perfect fit for libraries that don't know how the error handler works they operate under
- options to avoid having to rely on error handlers global state by using PSR-3 logging
- deduplicate deprecation messages to avoid excessive triggering and reduce overhead
We recommend to collect Deprecations using a PSR logger instead of relying on
the global error handler.
## Usage from consumer perspective:
Enable Doctrine deprecations to be sent to a PSR3 logger:
```php
\Doctrine\Deprecations\Deprecation::enableWithPsrLogger($logger);
```
Enable Doctrine deprecations to be sent as `@trigger_error($message, E_USER_DEPRECATED)`
messages.
```php
\Doctrine\Deprecations\Deprecation::enableWithTriggerError();
```
If you only want to enable deprecation tracking, without logging or calling `trigger_error` then call:
```php
\Doctrine\Deprecations\Deprecation::enableTrackingDeprecations();
```
Tracking is enabled with all three modes and provides access to all triggered
deprecations and their individual count:
```php
$deprecations = \Doctrine\Deprecations\Deprecation::getTriggeredDeprecations();
foreach ($deprecations as $identifier => $count) {
echo $identifier . " was triggered " . $count . " times\n";
}
```
### Suppressing Specific Deprecations
Disable triggering about specific deprecations:
```php
\Doctrine\Deprecations\Deprecation::ignoreDeprecations("https://link/to/deprecations-description-identifier");
```
Disable all deprecations from a package
```php
\Doctrine\Deprecations\Deprecation::ignorePackage("doctrine/orm");
```
### Other Operations
When used within PHPUnit or other tools that could collect multiple instances of the same deprecations
the deduplication can be disabled:
```php
\Doctrine\Deprecations\Deprecation::withoutDeduplication();
```
Disable deprecation tracking again:
```php
\Doctrine\Deprecations\Deprecation::disable();
```
## Usage from a library/producer perspective:
When you want to unconditionally trigger a deprecation even when called
from the library itself then the `trigger` method is the way to go:
```php
\Doctrine\Deprecations\Deprecation::trigger(
"doctrine/orm",
"https://link/to/deprecations-description",
"message"
);
```
If variable arguments are provided at the end, they are used with `sprintf` on
the message.
```php
\Doctrine\Deprecations\Deprecation::trigger(
"doctrine/orm",
"https://github.com/doctrine/orm/issue/1234",
"message %s %d",
"foo",
1234
);
```
When you want to trigger a deprecation only when it is called by a function
outside of the current package, but not trigger when the package itself is the cause,
then use:
```php
\Doctrine\Deprecations\Deprecation::triggerIfCalledFromOutside(
"doctrine/orm",
"https://link/to/deprecations-description",
"message"
);
```
Based on the issue link each deprecation message is only triggered once per
request.
A limited stacktrace is included in the deprecation message to find the
offending location.
Note: A producer/library should never call `Deprecation::enableWith` methods
and leave the decision how to handle deprecations to application and
frameworks.
## Usage in PHPUnit tests
There is a `VerifyDeprecations` trait that you can use to make assertions on
the occurrence of deprecations within a test.
```php
use Doctrine\Deprecations\PHPUnit\VerifyDeprecations;
class MyTest extends TestCase
{
use VerifyDeprecations;
public function testSomethingDeprecation()
{
$this->expectDeprecationWithIdentifier('https://github.com/doctrine/orm/issue/1234');
triggerTheCodeWithDeprecation();
}
public function testSomethingDeprecationFixed()
{
$this->expectNoDeprecationWithIdentifier('https://github.com/doctrine/orm/issue/1234');
triggerTheCodeWithoutDeprecation();
}
}
```
## What is a deprecation identifier?
An identifier for deprecations is just a link to any resource, most often a
Github Issue or Pull Request explaining the deprecation and potentially its
alternative.