- Autoload (自动加载)
-
Installed versions (已安装版本)
- Knowing whether package X (or virtual package) is present (了解是否存在包 X(或虚拟包))
- Knowing whether package X is installed in version Y (明确程序包 X 是否安装在 Y 版中)
- Knowing the version of package X (了解包 X 的版本)
- Knowing a package's own installed version (了解一个包自己的已安装版本)
- Knowing the path in which a package is installed 了解安装包的路径
- Knowing which packages of a given type are installed 了解安装了给定类型的哪些包
- Platform check (平台检查)
- Autoloader path in binaries 二进制文件中的自动加载器路径
- Binary (bin-dir) path in binaries
Runtime Composer utilities(运行时 Composer 实用工具)#
While Composer is mostly used around your project to install its dependencies, there are a few things which are made available to you at runtime.
If you need to rely on some of these in a specific version, you can require
the composer-runtime-api
package.
Autoload(自动加载)#
The autoloader is the most used one, and is already covered in our basic usage guide. It is available in all Composer versions.
Installed versions(已安装版本)#
composer-runtime-api 2.0 introduced a new Composer\InstalledVersions
class which offers
a few static methods to inspect which versions are currently installed. This is
automatically available to your code as long as you include the Composer autoloader.
The main use cases for this class are the following:
Knowing whether package X (or virtual package) is present(了解是否存在包 X(或虚拟包))#
\Composer\InstalledVersions::isInstalled('vendor/package'); // returns bool
\Composer\InstalledVersions::isInstalled('psr/log-implementation'); // returns bool
As of Composer 2.1, you may also check if something was installed via require-dev or not by passing false as second argument:
\Composer\InstalledVersions::isInstalled('vendor/package'); // returns true assuming this package is installed
\Composer\InstalledVersions::isInstalled('vendor/package', false); // returns true if vendor/package is in require, false if in require-dev
Note that this can not be used to check whether platform packages are installed.
Knowing whether package X is installed in version Y(明确程序包 X 是否安装在 Y 版中)#
Note: To use this, your package must require
"composer/semver": "^3.0"
.
use Composer\Semver\VersionParser;
\Composer\InstalledVersions::satisfies(new VersionParser, 'vendor/package', '2.0.*');
\Composer\InstalledVersions::satisfies(new VersionParser, 'psr/log-implementation', '^1.0');
This will return true if e.g. vendor/package is installed in a version matching
2.0.*
, but also if the given package name is replaced or provided by some other
package.
Knowing the version of package X(了解包 X 的版本)#
Note: This will return
null
if the package name you ask for is not itself installed but merely provided or replaced by another package. We therefore recommend using satisfies() in library code at least. In application code you have a bit more control and it is less important.
// returns a normalized version (e.g. 1.2.3.0) if vendor/package is installed,
// or null if it is provided/replaced,
// or throws OutOfBoundsException if the package is not installed at all
\Composer\InstalledVersions::getVersion('vendor/package');
// returns the original version (e.g. v1.2.3) if vendor/package is installed,
// or null if it is provided/replaced,
// or throws OutOfBoundsException if the package is not installed at all
\Composer\InstalledVersions::getPrettyVersion('vendor/package');
// returns the package dist or source reference (e.g. a git commit hash) if vendor/package is installed,
// or null if it is provided/replaced,
// or throws OutOfBoundsException if the package is not installed at all
\Composer\InstalledVersions::getReference('vendor/package');
Knowing a package's own installed version(了解一个包自己的已安装版本)#
If you are only interested in getting a package's own version, e.g. in the source of acme/foo you want to know which version acme/foo is currently running to display that to the user, then it is acceptable to use getVersion/getPrettyVersion/getReference.
The warning in the section above does not apply in this case as you are sure the package is present and not being replaced if your code is running.
It is nonetheless a good idea to make sure you handle the null
return value as gracefully as
possible for safety.
A few other methods are available for more complex usages, please refer to the source/docblocks of the class itself.
Knowing the path in which a package is installed了解安装包的路径#
The getInstallPath
method to retrieve a package's absolute install path.
Note: The path, while absolute, may contain
../
or symlinks. It is not guaranteed to be equivalent to arealpath()
so you should run a realpath on it if that matters to you.
// returns an absolute path to the package installation location if vendor/package is installed,
// or null if it is provided/replaced, or the package is a metapackage
// or throws OutOfBoundsException if the package is not installed at all
\Composer\InstalledVersions::getInstallPath('vendor/package');
Available as of Composer 2.1 (i.e.
composer-runtime-api ^2.1
)
Knowing which packages of a given type are installed了解安装了给定类型的哪些包#
The getInstalledPackagesByType
method accepts a package type (e.g. foo-plugin) and lists
the packages of that type which are installed. You can then use the methods above to retrieve
more information about each package if needed.
This method should alleviate the need for custom installers placing plugins in a specific path instead of leaving them in the vendor dir. You can then find plugins to initialize at runtime via InstalledVersions, including their paths via getInstallPath if needed.
\Composer\InstalledVersions::getInstalledPackagesByType('foo-plugin');
Available as of Composer 2.1 (i.e.
composer-runtime-api ^2.1
)
Platform check(平台检查)#
composer-runtime-api 2.0 introduced a new vendor/composer/platform_check.php
file, which
is included automatically when you include the Composer autoloader.
It verifies that platform requirements (i.e. php and php extensions) are fulfilled by the PHP process currently running. If the requirements are not met, the script prints a warning with the missing requirements and exits with code 104.
To avoid an unexpected white page of death with some obscure PHP extension warning in
production, you can run composer check-platform-reqs
as part of your
deployment/build and if that returns a non-0 code you should abort.
The default value is php-only
which only checks the PHP version.
If you for some reason do not want to use this safety check, and would rather
risk runtime errors when your code executes, you can disable this by setting the
platform-check
config option to false
.
If you want the check to include verifying the presence of PHP extensions,
set the config option to true
. ext-*
requirements will then be verified
but for performance reasons Composer only checks the extension is present,
not its exact version.
lib-*
requirements are never supported/checked by the platform check feature.
Autoloader path in binaries二进制文件中的自动加载器路径#
composer-runtime-api 2.2 introduced a new $_composer_autoload_path
global
variable set when running binaries installed with Composer. Read more
about this on the vendor binaries docs.
This is set by the binary proxy and as such is not made available to projects
by Composer's vendor/autoload.php
, which would be useless as it would point back
to itself.
Binary (bin-dir) path in binaries#
composer-runtime-api 2.2.2 introduced a new $_composer_bin_dir
global
variable set when running binaries installed with Composer. Read more
about this on the vendor binaries docs.
This is set by the binary proxy and as such is not made available to projects
by Composer's vendor/autoload.php
.