Symfony LTS : how to upgrade from 2. 8 到 3.4？

Question

Symfony 2.8 是 2.x 的最后一个版本分支和之前的 LTS。

Symfony 3.4 是 3.x 的最后一个版本分支和当前的 LTS。

从 2.8 升级 Symfony 需要哪些步骤至 3.4并切换到最后一个 LTS？

Answer 1

准备升级

检查 composer.json 中列出的所有依赖项和包已经发布了一个与 Symfony 3.4 兼容的版本，你可以通过在 Packagist 上搜索每个包来做到这一点，例如 EasyAdmin与 Symfony 3 兼容，因为 requires 中的依赖项不限于 Symfony 2(我们会看到类似 symfony/*: ~2.3 的东西)。如果其中一个依赖项与 Symfony 3 不兼容，则您必须找到替换包或修补这些库。

Composer .json

为了从 Symfony 升级您的应用程序 2.8到 Symfony 3.4您必须通过更改 composer.json 文件来更新您的依赖项:

( […] 表示代码不变)

旧 ( 2.8 ) 版本:

{
    […]
    "autoload-dev": {
        "files": [ "vendor/symfony/symfony/src/Symfony/Component/VarDumper/Resources/functions/dump.php" ]
     },
    "require": {
        "php": ">=5.3.9",
        "doctrine/doctrine-bundle": "~1.4",
        "doctrine/orm": "^2.4.8",
        "incenteev/composer-parameter-handler": "~2.0",
        "sensio/distribution-bundle": "~4.0",
        "sensio/framework-extra-bundle": "^3.0.2",
        "symfony/monolog-bundle": "^3.0.2",
        "symfony/swiftmailer-bundle": "~2.3,>=2.3.10",
        "symfony/symfony": "2.8.*",
        "twig/twig": "^1.0||^2.0"
    },
    "require-dev": {
        "sensio/generator-bundle": "~3.0",
        "symfony/phpunit-bridge": "~2.7"
    },
    "config": {
        "bin-dir": "bin",
        "platform": {
            "php": "5.6"
        },
        "sort-packages": true
    },
    "extra": {
        "symfony-app-dir": "app",
        "symfony-web-dir": "web",
        "symfony-assets-install": "relative",
        […]
        "branch-alias": {
            "dev-master": "2.8-dev"
        }
    }
}

新 ( 3.4 ) 版本:

{
    […]
    "autoload-dev": {
        "psr-4": { "Tests\\": "tests/" },
        "files": [ "vendor/symfony/symfony/src/Symfony/Component/VarDumper/Resources/functions/dump.php" ]
     },
    "require": {
        "php": ">=5.5.9",
        "doctrine/doctrine-bundle": "^1.6",
        "doctrine/orm": "^2.5",
        "incenteev/composer-parameter-handler": "^2.0",
        "sensio/distribution-bundle": "^5.0.19",
        "sensio/framework-extra-bundle": "^5.0.0",
        "symfony/monolog-bundle": "^3.1.0",
        "symfony/polyfill-apcu": "^1.0",
        "symfony/swiftmailer-bundle": "^2.6.4",
        "symfony/symfony": "3.4.*",
        "twig/twig": "^1.0||^2.0"
    },
    "require-dev": {
        "sensio/generator-bundle": "^3.0",
        "symfony/phpunit-bridge": "^3.0"
    },
    "config": {
        "platform": {
            "php": "5.6"
        },
        "sort-packages": true
    },

    "extra": {
        "symfony-app-dir": "app",
        "symfony-bin-dir": "bin",
        "symfony-var-dir": "var",
        "symfony-web-dir": "web",
        "symfony-tests-dir": "tests",
        "symfony-assets-install": "relative",
        […]
        "branch-alias": {
            "dev-master": "3.4-dev"
        }
    }
}

概括

autoload-dev.psr-4已添加(必须使用测试目录的路径更改)

Symfony 和依赖项已更新

symfony/polyfill-apcu是一个新的依赖

extra已更新以使用新的目录结构:var用于临时文件等

config.bin-dir已被删除

更多升级详情: → 3.0 , → 3.1 , → 3.2 , → 3.3 , → 3.4

应用程序/AppKernel.php

添加 getRootDir并更新 registerContainerConfiguration职能:

public function getRootDir()
{
    return __DIR__;
}

public function registerContainerConfiguration(LoaderInterface $loader)
{
    $loader->load($this->getRootDir().'/config/config_'.$this->getEnvironment().'.yml');
}

缓存和日志

如果你想把 cache和 logs在 var/ ，您必须更新您的 app/AppKernel.php通过添加以下几行文件:

public function getCacheDir()
{
    return dirname(__DIR__).'/var/cache/'.$this->getEnvironment();
}
public function getLogDir()
{
    return dirname(__DIR__).'/var/logs';
}

然后创建 var/目录并放置一个空文件 .gitkeep
并将这些更改应用于您的 .gitignore文件:

/var/cache/*
/var/logs/*
!var/cache/.gitkeep
!var/logs/.gitkeep

另见: What is the new Symfony 3 directory structure?

最后的步骤

更新 composer.json 文件后，您必须更新依赖项:

composer update

然后你可能需要刷新缓存:

php app/console cache:clear --env=dev

注意:我使用以下命令来获取 composer.json 文件:

# create Symfony "2.8.*" project in the "2.8" directory
composer create-project symfony/framework-standard-edition "2.8" "2.8.*" --no-interaction -v
# create Symfony "3.4.*" project in the "3.4" directory
composer create-project symfony/framework-standard-edition "3.4" "3.4.*" --no-interaction -v
# compare the Symfony 2.8 and 3.4 composer.json files
diff -u 2.8/composer.json 3.4/composer.json

差异可在 GitHub 获得也。

奖金: enable autowiring of services .