silverstripe-framework/docs/en/03_Upgrading/index.md

title: Upgrading introduction: Upgrade your project SilverStripe 4 and keep it up to date with the latest fixes, security patches and new features.

Upgrading to SilverStripe 4

SilverStripe applications should be kept up to date with the latest security releases. Usually an update or upgrade to your SilverStripe installation means overwriting files, flushing the cache and updating your database schema.

See our [upgrade notes and changelogs](/changelogs/4.0.0) for 4.0.0 specific information, bugfixes and API changes.

Understanding and planning your upgrade

How easy will it be to update my project? It's a fair question, and sometimes a difficult one to answer.

• SilverStripe follows semantic versioning (see our release process for details).
  • "Major" releases introduces API change that may break your application.
  • "Minor" releases (x.y) introduces API changes in a backward compatible way and can mark some API as deprecated.
  • "Patch" releases (x.y.z) fix bugs without introducing any API changes.
• If you've made custom branches of SilverStripe core, or any thirdparty module, it's going to be harder to upgrade.
• The more custom features you have, the harder it will be to upgrade. You will have to re-test all of those features, and adapt to API changes in core.
• Customizations of a well defined type - such as custom page types or custom blog widgets - are going to be easier to upgrade than customisations that modify deep system internals like rewriting SQL queries.

Overview of changes

If you've already had a look over the changelog, you will see that there are some fundamental changes that need to be implemented to upgrade from 3.x. Here's a couple of the most important ones to consider.

• PHP 5.6 is now the minimum required version and up to PHP 7.2.x is supported.
• SilverStripe is now even more modular which allows you to remove functionality your project might not need.
• Common functionality sets can now be installed via SilverStripe recipes.
• SilverStripe modules can now be installed in the vendor folder along with your regular PHP packages.
• The SilverStripe codebase is now completely namespaced.
• SilverStripe 4 makes usage of PHP traits making it easy to apply common patterns to your classes.
• Publicly facing files can now be served from a public webroot for added security.
• The concept of ChangeSet has been added to versioning along with version ownership.
• GraphQL is now the favourite way of creating web services with SilverStripe.
• Asset management has been completely redone with a brand new react-based UI and the introduction of versioned files.
• Parts of the CMS UI are now build in react and entwine is in the process of being faded out.
• SilverStripe 4 now supports PSR-4 auto-loading for modules and for your main project.

Learn more about major API changes introduced by SilverStripe 4

Using recipes instead of requiring individual modules

The SilverStripe CMS and SilverStripe Framework are becoming more modular. Many of the secondary features contained in SilverStripe CMS 3 and SilverStripe Framework 3 have been moved to separate modules.

SilverStripe 4 introduces the concept of recipes. Recipes are a combination of modules to achieve a common pattern.

Read the Switching to recipes section of this guide for more information about how recipes work.

Automating your upgrades using the SilverStripe Upgrader tool

We've developed an upgrader tool which you can use to help with the upgrade process to SilverStripe 4. The upgrader is unlikely to completely upgrade your project to SilverStripe 4, however it can take care of the most tedious part of the upgrade.

It can also be use to upgrade your existing SilverStripe 4 to a newer minor release.

Each step in this upgrade guide explains how to use

Learn how to install the upgrader tool

Step 0 - Pre-requisites and background work

Before you begin the upgrade process, make sure you meat these pre-requisites

Back up your files and database

• Set up your project in your development environment.
• Backup your database content.
• Backup your webroot files.

Never update a website on the live server. Get it working on a development copy first!

Install composer

SilverStripe 4 requires the use of composer for dependency management.

Learn how to use composer with SilverStripe

We recommend using recipe-cms in your composer.json file to help you keep up to date and run composer update.

{
    "require": {
        "silverstripe/recipe-cms": "^4"
    }
}

This will also add extra dependencies, such as the admin, asset-admin, reports, errorpage and siteconfig modules.

If you want more granular control over what gets installed, reading through the README documentation in the recipe plugin repository and also checking the composer.json files in recipe-core and recipe-cms.

For a description on how to handle issues with pre-existing composer installs or upgrading other modules, please read through the Composer dependency update section

Install the upgrader tool (optional)

Using the upgrader is not mandatory, but it can speed up the upgrade process. To install the upgrader globally run this command.

composer global require silverstripe/upgrader

Add your global composer bin directory to your path. On *nix system, this directory is normally located at $HOME/.composer/vendor/bin. On Windows system, this directory is normally located at C:\Users\<COMPUTER NAME>\AppData\Roaming\Composer\vendor\bin. You can find the exact location by running this command:

composer global config bin-dir

On *nix system, the following command will add your global composer bin directory to your path if bash is your default shell environment:

echo 'export PATH=$PATH:~/.composer/vendor/bin/' >> ~/.bash_profile

Each command in the upgrader has somewhat different arguments. However, most of them accept these two options:

• --write which tells the upgrader to apply changes to your code base
• -d which can be use to explicitly specify the root of your project — if not specified the current working directory is assume to be the root of the project.

You can run upgrade-code help to get more information about the upgrader or upgrade-code help command-name to information about a specific command.

Sample upgrader commands in this guide assume your working directory is the root of your SilverStripe project. You'll need to use the `-d` flag if that's not the case.

Running all the upgrader commands in this guide in on line

The upgrader comes with an all command. This command will attempt to run all the upgrader commands in the same order as this guide. This is unlikely to work on your first try, but can be a good way to get started without going through this entire guide.

upgrade-code all --recipe-core-constraint=1.1 --namespace="App\\Web" --psr4

• --recipe-core-constraint defined your target version of silverstripe/recipe-core.
• --namespace allows you to specify what will be the main namespace of your project.
• --psr4 allows you to specify that your project structure respect the PSR-4 standard and to use sub-namespaces.
• --skip-add-namespace allows you to skip the add-namespace command.
• --skip-reorganise allows you to skip the reorganise command.
• --skip-webroot allows you to skip the webroot command.

Branching your project

Setting a dedicated branch in your source control system to track your upgrade work can help you manage your upgrade. If you're upgrading a big project, you should consider creating individual branches for each step.

Step 1 - Upgrade your dependencies

The first step is to update your dependencies' constraints in your composer.json file to require the latest version of the SilverStripe modules.

Automatically upgrade dependencies with the recompose upgrader command

If you've installed the upgrader, you can use the recompose command to help you upgrade your dependencies. This command will try to:

• upgrade your PHP constraint
• upgrade core SilverStripe modules to their version 4 equivalent
• switch to recipes where possible
• find SilverStripe 4 compatible versions of third party modules.

Take for example the following SilverStripe 3 composer.json file.

{
    "name": "app/cms-website",
    "description": "The Example website project.",
    "license": "BSD-3",
    "require": {
        "php": ">=5.3.3",
        "silverstripe/cms": "3.6.5@stable",
        "silverstripe/framework": "3.6.5@stable",
        "silverstripe/reports": "3.6.5@stable",
        "silverstripe/siteconfig": "3.6.5@stable",
        "dnadesign/silverstripe-elemental": "^1.8.0"
    }
}

You can upgrade the composer.json file with this command:

upgrade-code recompose --recipe-core-constraint=4.1 --write

The --recipe-core-constraint flag can be use to target a specific version of silverstripe/recipe-core. If this flag is omitted, the project will be upgraded to the latest stable version. You can use the --strict option if you want to use more conservative version constraints. Omit the --write flag to preview your changes.

Your upgraded composer.json file will look like this.

{
    "name": "app/cms-website",
    "description": "The Example website project.",
    "license": "BSD-3",
    "require": {
        "dnadesign/silverstripe-elemental": "^2.1",
        "php": ">=5.6",
        "silverstripe/recipe-cms": "^4.1"
    }
}

If the recompose command can't find a SilverStripe 4 compatible version for one of your module, it will keep this dependency in your composer.json file with its existing constraint.

Manually upgrading your dependencies

The instruction in this section assumed you'll be editing your composer.json file in a text editor.

Switching to recipes

Where possible, we recommend you use recipes.

If your SilverStripe 3 project requires the silverstripe/cms module, replace that dependency with silverstripe/recipe-cms. The version constraint for silverstripe/recipe-cms must match your targeted version of SilverStripe:

• ~4.0.0 to upgrade to SilverStripe 4.0
• ~4.1.0 to upgrade to SilverStripe 4.1
• ~4.2.0 to upgrade to SilverStripe 4.2
• and so on.

If your SilverStripe 3 project requires the silverstripe/framework module without silverstripe/cms, replace silverstripe/framework with silverstripe/recipe-core. The version constraint for silverstripe/recipe-core must match your targeted version of SilverStripe:

• ~4.0.0 to upgrade to SilverStripe 4.0
• ~4.1.0 to upgrade to SilverStripe 4.1
• ~4.2.0 to upgrade to SilverStripe 4.2
• and so on.

The following modules are implicitly required by silverstripe/recipe-core. They can be removed from your composer.json dependencies if you are using silverstripe/recipe-core or silverstripe/recipe-cms.

• sivlerstripe/framework
• silverstripe/config
• silverstripe/assets

The following modules are implicitly required by silverstripe/recipe-cms. They can be removed from your composer.json dependencies if you are using silverstripe/recipe-cms.

• silverstripe/admin
• silverstripe/asset-admin
• silverstripe/campaign-admin
• silverstripe/cms
• silverstripe/errorpage
• silverstripe/reports
• silverstripe/graphql
• silverstripe/siteconfig
• silverstripe/versioned
• silverstripe/recipe-core

Take for example the following SilverStripe 3 composer.json.

{
    "name": "app/cms-website",
    "require": {
        "silverstripe/cms": "3.6.5@stable",
        "silverstripe/framework": "3.6.5@stable",
        "silverstripe/reports": "3.6.5@stable",
        "silverstripe/siteconfig": "3.6.5@stable"
    }
}

After switching to SilverStripe 4 recipes, the composer.json file should look like this.

{
    "name": "app/cms-website",
    "require": {
        "silverstripe/recipe-cms": "~4.1.0"
    }
}

Explicitly defining your dependencies

If you would rather explicitly define your dependencies, you can do so. Update the silverstripe/framework constraint and silverstripe/cms constraint to match your targeted minor version of SilverStripe 4. If you use silverstripe/reports and silverstripe/siteconfig, update their constraints as well.

In most cases, you'll also want to require the same modules as the equivalent recipes. If you don't, your users will likely lose some features after the upgrade is completed.

Take for example the following SilverStripe 3 composer.json.

{
    "name": "app/cms-website",
    "require": {
        "silverstripe/cms": "3.6.5@stable",
        "silverstripe/framework": "3.6.5@stable",
        "silverstripe/reports": "3.6.5@stable",
        "silverstripe/siteconfig": "3.6.5@stable"
    }
}

After switching to SilverStripe 4 and explicitly defining your dependencies, the composer.json file should look like this.

{
    "name": "app/cms-website",
    "require": {
         "silverstripe/cms": "~4.1.0",
         "silverstripe/framework": "~4.1.0",
         "silverstripe/reports": "~4.1.0",
         "silverstripe/siteconfig": "~4.1.0",
         "silverstripe/admin": "~1.1.0",
         "silverstripe/asset-admin": "~1.1.0",
         "silverstripe/campaign-admin": "~1.1.0",
         "silverstripe/errorpage": "~1.1.0",
         "silverstripe/graphql": "~1.1.0",
         "silverstripe/versioned": "~1.1.0"
    }
}

Updating third party dependencies

If you project requires third party modules, you'll need to adjust their associated constraint. This will allow you to retrieve a SilverStripe 4 compatible version of the module.

Look up the module on Packagist to see if a SilverStripe 4 version is provided.

Take for example the following SilverStripe 3 composer.json.

{
    "name": "app/cms-website",
    "require": {
        "silverstripe/framework": "3.6.5@stable",
        "silverstripe/cms": "3.6.5@stable",
        "dnadesign/silverstripe-elemental": "^1.8.0"
    }
}

Looking at the Packagist entry for dnadesign/silverstripe-elemental, you can see that versions 2.0.0 and above of this module are compatible with SilverStripe 4. So you can update that constraint to ^2.0.0.

Alternatively, you can set a very permissive constraint and let composer find a SilverStripe 4 compatible version. After you're done updating your dependencies, make sure you adjust your constraints to be more specific.

Once you've updated your third-party modules constraints, try updating your dependencies by running composer update. If composer can't resolve all your dependencies it will throw an error.

Resolving conflicts

You'll likely have some conflicts to resolve, whether you've updated your dependencies with the upgrader or manually.

Running a composer update will tell you which modules are conflicted and suggested alternative combinations of modules that might work.

The most typical reason for a conflict is that the maintainer of a module hasn't released a version compatible with SilverStripe 4.

If the maintainer of the module is in the process of upgrading to SilverStripe 4, a development version of the module might be available. In some cases, it can be worthwhile to look up the repository of the module or to reach out to the maintainer.

If you're going to install development version of third party modules, you should consider adding the following entries to your `composer.json` file.

{
  // ...
  "minimum-stability": "dev",
  "prefer-stable": true,
  // ...
} 

To resolve a conflict you can either:

• remove the module from your project, if it is not essential
• integrate the affected module into your project's codebase
• fork the affected module and maintain it yourself.

To integrate a third party module in your project, remove it from your composer.json file and from your .gitignore file. Then track the module's codebase in your project source control. You'll need to upgrade the module's code to be compatible with SilverStripe 4.

If you're taking the time to upgrade a third party module, consider doing a pull request against the original project so other developers can benefit from your work or releasing your fork as a seperate module.

Learn about how to publish a SilverStripe module

Finalising your dependency upgrade

Once you've resolved all conflicts in your composer.json file, composer update will be able to run without errors.

This will install your new dependencies. You'll notice many of the folders in the root of your project will disappear. That's because SilverStripe 4 modules can be installed in the vendor folder like generic PHP packages.

If you've decided to use recipes, some generic files will be copied from the recipe into your project. The extra attribute in your composer.json file will be updated to keep track of those new files.

This is a good point to commit your changes to your source control system before moving on to the next step.

Step 2 - Update your environment configuration {#env}

The php configuration _ss_environment.php file has been replaced in favour of a non-executable .env file, which follows a syntax similar to a .ini file for key/value pair assignment. Your .env file may be placed in your project root, or one level above your project root.

Automatically convert _ss_environment.php to .env

If you have installed the upgrader tool, you can use the environment command to generate a valid .env file from your existing _ss_environment.php file.

upgrade-code environment --write

If your _ss_environment.php file contains unusual logic (conditional statements or loops), you will get a warning. upgrade-code will still try to convert the file, but you should double-check the output.

Omit the --write flag to do a dry-run.

Manually convert _ss_environment.php to .env

Create a .env file in the root of your project. Replace define statements from _ss_environment.php with KEY=VALUE pairs in .env.

Most SilverStripe 3 environment variables have been carried over to SilverStripe 4. See Environment Management docs for the full list of available variables. Your .env file can contain environment variables specific to your project as well.

The global array $_FILE_TO_URL_MAPPING has been removed and replaced with the SS_BASE_URL environment variable. SS_BASE_URL expects an absolute url with an optional protocol. The following are values would be valid entries for SS_BASE_URL:

• http://localhost/
• https://localhost/
• //localhost/

For example, take the following _ss_environment.php file.

<?php
// Environment
define('SS_ENVIRONMENT_TYPE', 'dev');
define('SS_DEFAULT_ADMIN_USERNAME', 'admin');
define('SS_DEFAULT_ADMIN_PASSWORD', 'password');
$_FILE_TO_URL_MAPPING[__DIR__] = 'http://localhost';

// Database
define('SS_DATABASE_CHOOSE_NAME', true);
define('SS_DATABASE_CLASS', 'MySQLDatabase');
define('SS_DATABASE_USERNAME', 'root');
define('SS_DATABASE_PASSWORD', '');
define('SS_DATABASE_SERVER', '127.0.0.1');

The equivalent .env file will look like this.

## Environment
SS_ENVIRONMENT_TYPE="dev"
SS_DEFAULT_ADMIN_USERNAME="admin"
SS_DEFAULT_ADMIN_PASSWORD="password"
SS_BASE_URL="http://localhost/"

## Database
SS_DATABASE_CHOOSE_NAME="true"
SS_DATABASE_CLASS="MySQLDatabase"
SS_DATABASE_USERNAME="root"
SS_DATABASE_PASSWORD=""
SS_DATABASE_SERVER="127.0.0.1"

Cleaning up mysite/_config.php after your environment configuration upgrade

You'll need to clean up your mysite/_config.php file after upgrading your environment file.

The global values $database and $databaseConfig have been deprecated. Your database configuration details should be stored in your .env file. If you want to keep your database configuration in _config.php, you can use the new DB::setConfig() api, however this is discouraged.

Requiring conf/ConfigureFromEnv.php is is no longer necessary. You should remove any references to it in _config.php.

The removal of the _ss_environment.php file means that conditional logic is no longer available in the environment variable set-up process. This encouraged bad practice and should be avoided. If you still require conditional logic early in the bootstrap, this is best placed in the _config.php files.

To access environment variables, use the SilverStripe\Core\Environment::getEnv() method. To define environment variables, use the SilverStripe\Core\Environment::setEnv() method.

Finalising your environment upgrade

It's inadvisable to track your .env file in your source control system as it might contain sensitive information.

You should ignore the .env file by adding an entry to your .gitignore file. You can create a sample environment configuration by duplicating your .env file as .env.sample, and removing sensitive information from it.

You can safely delete your legacy _ss_environement.php if you want.

This is a good point to commit your changes to your source control system before moving on to the next step.

Step 3 - Namespacing your project (optional)

Namespacing your code is an optional step. It is recommended and will help future-proof your code base.

To learn more about PHP namespace:

• Read the official Namespace PHP documentation
• Read the PSR-4: Autoloader standard.

Before you start namespacing your codebase

You need to choose a root namespace for your project. We recommend following the Vendor\Package pattern.

The Page and PageController classes must be defined in the global namespace (or without a namespace).

If you want your codebase to comply with the PSR-4 standard, make sure sub-directories of your code folder are using the UpperCamelCase naming convention. For example, mysite/code/page_types should be renamed to mysite/code/PageTypes.

Automatically namespacing your codebase with the upgrader

The add-namespace command of the upgrader tool provides a feature to namespace your codebase and to automatic update references to those classes.

composer global require silverstripe/upgrader
upgrade-code add-namespace "App\\Web" ./mysite/code --recursive --write

This task will do the following:

• Add the given namespace to all files in the code class, and subdirectories
• All references to classes in any namespaced files will be safely retained with additional use directives added as necessary
• A mysite/.upgrade.yml file be created/updated to record the new fully qualified name of each class.

.upgrade.yml will be used in later steps to update references to the old non-namespaced classes.

If you want to do a dry-run, omit the --write option to see a preview of all changed project files.

By default, the same namespace will be applied to all your classes regardless of which directory they are in. If you want to apply different namespaces to different folders to be compliant with PSR-4, combine the --recursive with the --psr4. Your folder structure has to be PSR4 compliant for this to work.

Manually namespacing your codebase

Go through each PHP file under mysite/code and add a namespace statement at the top, with the exception of the files for Page or PageController.

Take for example this SilverStripe 3 file located at mysite/code/Products/ExplosiveTennisBall.php.

<?php

class ExplosiveTennisBall extends DataObject
{
    // ...
}

Assuming your root namespace is App\Web, the equivalent namespaced file will look like this.

<?php
namespace App\Web\Products;

class ExplosiveTennisBall extends DataObject
{
    // ...
}

If you intend to use the upgrader to update references to your namespaced classes, you'll need to create a mysite/.upgrade.yml file.

mappings:
  ExplosiveTennisBall: App\Web\Products\ExplosiveTennisBall

If you intend to manually update references to your namespaced classes, you'll need to go through each of your file to add use statements.

For example, if mysite/code/ProductService.php is using the ExplosiveTennisBall class, you'll need to add a use statement at the top of the file just after it's own namespace definition.

<?php
namespace App\Web;

use App\Web\Products\ExplosiveTennisBall;

class ProductService
{
    // ...
}

Enable PSR-4 auto-loading in your composer.json file

If you have namespaced your project and followed the PSR-4 convention, you have the option to enable PSR-4 auto-loading in your composer.json file.

Enabling PSR-4 auto-loading is optional. It will provide better auto-loading of your classes in your development environment and will future proof your code.

For example, let's say you have defined the following namespaces for the following folders:

• App\Web for your main application logic contained in mysite/code
• App\SubModule for a secondary module contained in sub-module/code
• App\Web\Tests for your application test suite contained in mysite/tests.

Your autoload section in your composer.json file should look like this:

{
    // ...
    "autoload": {
        "psr-4": {
            "App\\Web\\": "mysite/code",
            "App\\SubModule\\": "sub-module/code"
        }
    },
    "autoload-dev": {
        "psr-4": {
            "App\\Web\\Tests\\": "mysite/tests"
        }
    },
    // ...
}

Read the Composer schema autoload documentation for more information about configuring auto-loading in your project.

Finalise your project namespacing

All your classes should now be fully namespaced.

Note that applying a namespace to your project will also affect which template file SilverStripe tries to load when rendering certain objects.

For example, pretend you have a RoadRunnerPage class that extends Page. In SilverStripe 3, you would define a template for this page in themes/example/templates/Layout/RoadRunnerPage.ss. If you decide to move RoadRunnerPage to App\Web\RoadRunnerPage, you'll need to move the template to themes/example/templates/App/Web/Layout/RoadRunnerPage.ss.

This is a good point to commit your changes to your source control system before moving on to the next step.

Step 4 - Update codebase with references to newly namespaced classes

All core PHP classes in SilverStripe 4 have been namespaced. For example, DataObject is now called SilverStripe\ORM\DataObject. Your project codebase, config files and language files need be updated to reference those newly namespaced classes. This will include explicit references in your PHP code, but also string that contain the name of a class.

If you've opted to namespace your own code in the previous step, those references will need to be updated as well.

Automatically update namespaced references with the upgrade command

If you've installed the upgrader, you can use the upgrade command to update references to namespaced classes.

The upgrade command will update PHP files, YML configuration files, and YML language files.

Before running the upgrade command

Each core SilverStripe 4 module includes a .upgrade.yml that defines the equivalent fully qualified name of each class. Most third party SilverStripe modules that have been upgraded to be compatible with SilverStripe 4, also include a .upgrade.yml.

If you've namespaced your own project, you'll need to provide your own .upgrade.yml file . If you've used the upgrader to namespace your project, that file will have been created for you.

The upgrade command will try to update some strings that reference the old name of some classes. In some cases this might not be what you want. You can tell the upgrader to skip specific strings by using the @skipUpgrade flag in your PHPDoc comment. For example:

/** @skipUpgrade */
return Injector::inst()->get('ProductService');

Running the upgrade command

Execute the upgrade command with this command.

upgrade-code upgrade ./mysite/ --write

If you omit the --write flag you will get a preview of what change the upgrader will apply to your codebase. This can be helpful if you if you are tweaking your .upgrade.yml or if you are trying to identify areas where you should add a @skipUpgrade statement,

You can also tweak which rules to apply with the --rule flag. There's 3 options that can be provided: code, config, and lang. For example, the following command will only upgrade lang and config files:

upgrade-code upgrade ./mysite/ --rule=config --rule=lang

The upgrade command can alter big chunks of your codebase. While it works reasonably well in most use case, you should not trust it blindly. You should take time to review all changes applied by the upgrade command and confirm you are happy with them.

Manually update namespaced references

If you decide to update your namespace references by hand, you'll need to go through the entire code base and update them all from the old non-namespaced SilverStripe classes to the new namespaced equivalent. If you are referencing classes from third party modules that have been namespaced, you'll need to update those as well.

Update explicit references to classes in your code

Wherever your code explicitly references a SilverStripe class, it will need to be updated to the new namespaced equivalent. You can either update the reference to use the fully qualified name of the class or you can add a use statement to your file.

For example take the following SilverStripe 3 class. DataObject and FieldList need to point to their namespace equivalents.

<?php
namespace App\Web\Products;

class ExplosiveTennisBall extends DataObject
{

    public function getCMSFields()
        {
           return FieldList::create([]);
        }

}

You can add use statements at the top of your file to reference the fully qualified name of DataObject and FieldList.

<?php
namespace App\Web\Products;

use SilverStripe\ORM\DataObject;
use SilverStripe\Forms\FieldList;

class ExplosiveTennisBall extends DataObject
{
// ...

Alternatively, you can update the references to the fully qualified names.

<?php
namespace App\Web\Products;

class ExplosiveTennisBall extends SilverStripe\ORM\DataObject
{

    public function getCMSFields()
        {
           return SilverStripe\Forms\FieldList::create([]);
        }

}

Update string references to classes

In many cases, SilverStripe expects to be provided the name of a class as a string. Typical scenarios include:

• defining an has_one or has_many relationship on a DataObject
• requesting an instance of class via the Injector
• specifying managed models for a ModelAdmin.

Those string need to use the fully qualified name of their matching classes. Take for example the following class.

<?php
namespace App\Web\Products;

use SilverStripe\ORM\DataObject;

class ExplosiveTennisBall extends DataObject
{
    private static $has_one = [
        'Thumbnail' => 'Image'
    ];

    private static $has_many = [
        'Tags' => 'BlogPost'
    ];


    public function getShippingCost()
    {
        return Injector::inst('ProductService')->calculateCost($this);
    }
}

Image, BlogPost, and ProductService represent classes. Those strings need to be updated to specify the full namespace.

The best way of achieving this is to use the ::class PHP magic class constant which will return the fully qualified name of a class.

Our example could be update to:

<?php
namespace App\Web\Products;

use SilverStripe\ORM\DataObject;
use SilverStripe\Assets\Image;
use SilverStripe\Blog\Model\BlogPost;
use App\Web\ProductService;

class ExplosiveTennisBall extends DataObject
{
    private static $has_one = [
        'Thumbnail' => Image::class
    ];

    private static $has_many = [
        'Tags' => BlogPost::class
    ];


    public function getShippingCost()
    {
        return Injector::inst(ProductService::class)->calculateCost($this);
    }
}

Alternatively, you can spell out the full qualified name of each class in a string. For example, 'Image' would become 'SilverStripe\\Assets\\Image'. Note the use of the double backslash — this is necessary because the backslash is an escape character.

Update references to classes in your YML config

YAML configuration files can reference SilverStripe classes. Those references also need to use the fully qualified name of each class.

Take for example the following SilverStripe 3 YAML configuration file.

Injector:
  ProductService:
    properties:
      RoadRunnerSpeed: 99999999
      CoyoteSpeed: 1

BlogPost:
  extensions:
    - HasOneExplosiveTennisBallExtension

Email:
  admin_email: no-reply@example.com

In SilverStripe 4, this will become:

SilverStripe\Core\Injector\Injector:
  App\Web\ProductService:
    properties:
      RoadRunnerSpeed: 99999999
      CoyoteSpeed: 1

SilverStripe\Blog\Model\BlogPost:
  extensions:
    - App\Web\Extensions\HasOneExplosiveTennisBallExtension

SilverStripe\Control\Email\Email:
  admin_email: no-reply@example.com

Update references to classes in your language files

Translation keys are normally tied to classes. If you override SilverStripe's default translation or if you are localising your own project, you'll need to update those references to use the fully qualified name of each class.

For example, let's say you had the following translation file in mysite/lang/eng.yml.

en:
  Member:
    SINGULARNAME: Coyote
  RoadRunner:
    SALUTATION: Beep Beep

In SilverStripe 4, it would become:

en:
  SilverStripe\Security\Member:
    SINGULARNAME: Coyote
  App\Web\RoadRunner:
    SALUTATION: Beep Beep

Finalising namespace updates

You'll need to perform the following steps manually, even if you've used the automated rewrite of namespaces previously.

DataObject database tables will default to use a namespaced name. For example, if you have a class under App\Web\Products\ExplosiveTennisBall that extends DataObject, the matching table in your database will be called App_Web_Products_ExplosiveTennisBall.

You can define a private static $table_name property on your DataObjects to use more convenient table names. For example, private static $table_name = 'ExplosiveTennisBall';.

In your PHP code, calls to the _t() method should be updated to use the full namespace of the target class.

<?php

# Old SilverStripe 3 way
$translation = _t('CMSMain.ACCESS', "Access to ''{title}'' section", ['title' => 'Products']);

# New SilverStripe 4
use SilverStripe\CMS\Controllers\CMSMain;
// ...
$translation = _t(CMSMain::class .'.ACCESS', "Access to ''{title}'' section", ['title' => 'Products']);

If you're calling _t() to retrieve a translation for the current class, you can also use __CLASS__ or self::class. For example:

<?php
namespace App\Web\Services;

class ProductService
{
    public function getTranslation()
    {
        # Those two lines are equivalent.
        $translation = _t(__CLASS__ . '.PRODUCT', 'Product');
        $translation = _t(self::class . '.PRODUCT', 'Product');
        return $translation;
    }
}

Avoid using `static::class` or `parent::class` to retrieve translated string. It will retrieve unpredictable values bases on the class inheritance.

If your template files contain translatable strings, they also need to be updated to referenced the namespaced classes.

For example, <%t Member.SINGULARNAME 'Member' %> would become <%t SilverStripe\Security\Member.SINGULARNAME 'Member' %>.

Your codebase should now be referencing valid SilverStripe 4 classes. This means that your classes can be loaded at runtime. However, your codebase will still be using an outdated API.

This is a good point to commit your changes to your source control system before moving on to the next step.

Step 5 - Updating your codebase to use SilverStripe 4 API

This is the most intricate and potentially time-consuming part of the upgrade. It involves going through your entire codebase to remove references to deprecated APIs and update your project logic.

Automatically update deprecated API references with the inspect command

The upgrader has an inspect command that can flag deprecated API usage, and in some cases, update your codebase to the SilverStripe 4 equivalent. This does require you to carefully review each change and warning to make sure the updated logic still work as intended. Even so, it is a huge time-saver compared to reviewing your code base manually.

Note that the inspect command loads your files with PHP interpreter. So basic syntax errors — for example, extending a class that does not exists — will cause an immediate failure. For this reason, you need to complete Step 4 - Update codebase with references to newly namespaced classes before running the inspect command.

upgrade-code inspect ./mysite/ --write

You can omit the --write flag if you just want to view the proposed changes without applying them. You can run the command on a specific subdirectory or file. This can be more manageable if you have a big project to go through.

Like the upgrade command, inspect gets its list of API changes from .upgrade.yml files. So you may get upgrade suggestions and substitution from third party modules. You can even include your own project specific changes in your .upgrade.yml if you want.

Sample output of the inspect command

Here's some sample output of what you might get back the inspect command.

upgrade-code inspect ./mysite/Models/Coyote.php

Running post-upgrade on "/var/www/SS_example/mysite/code/Models/Coyote.php"
[2018-06-06 13:35:38] Applying ApiChangeWarningsRule to Coyote.php...
modified:	Coyote.php
@@ -68,7 +68,7 @@
     {
         // Getting a reference to Coyote's list of crazy ideas
-        $manyManyRelation = $this->manyManyComponent('CrazyIdeas');
+        $manyManyRelation = $this->getSchema()->manyManyComponent('CrazyIdeas');
         return $manyManyRelation;
     }

Warnings for Coyote.php:
 - Coyote.php:20 SS_Cache: Using symfony/cache now (https://docs.silverstripe.org/en/4/changelogs/4.0.0#cache)
 - Coyote.php:42 SilverStripe\Control\Director::setUrlParams(): Method removed
 - Coyote.php:71 SilverStripe\ORM\DataObject->manyManyComponent(): DataObject->manyManyComponent() moved to DataObjectSchema. Access through getSchema(). You must manually add static::class as the first argument to manyManyComponent()
Changes not saved; Run with --write to commit to disk

Manually update deprecated API references

SilverStripe 4 introduces many of small and big API changes. To update deprecated API references manually, you have to go through each one of your project files.

Read the SilverStripe 4 change logs for a comprehensive list of what has changed.

Finalising the deprecated API update

At this stage, your site should be using only SilverStripe 4 API logic.

You still have some minor clean up tasks and configuration tweaks to apply, but you're almost done.

This is a good point to commit your changes to your source control system before moving on to the next step.

Step 6 - Update your entry point

The location of SilverStripe's entry file has changed. Your project and server environment will need to adjust the path to this file from framework/main.php to index.php.

Update your index.php file

You can get a copy of the SilverStripe 4 index.php file at:

• vendor/silverstripe/recipe-core/public/index.php if you are upgrading to SilverStripe 4.1 or above
• vendor/silverstripe/recipe-core/index.php if you are upgrading to SilverStripe 4.0

If you've modified your SilverStripe 3 index.php, you'll need to reconcile those changes with the index.php file you got from recipe-core. Otherwise, just use the generic index.php file recipe-core provides.

Copy your new index.php to your project's web root. Unlike SilverStripe 3, index.php must be present in your web root.

Update your server configuration

If you're using a .htaccess file or web.config file to handle your server configuration, you can get the generic SilverStripe 4 version of those file from:

• vendor/silverstripe/recipe-core/public if you are upgrading to SilverStripe 4.1 or above
• vendor/silverstripe/recipe-core/ if you are upgrading to SilverStripe 4.0

Just like index.php, if you've modified your server configuration file from the one that shipped with SilverStripe 3, you'll need to reconcile your changes into the version retrieve from recipe-core.

Refer to the installation instruction for your platform if your server configuration is not managed via a .htaccess or web.config file.

Finalising the entry point upgrade

At this stage, you could in theory run your project in SilverStripe 4.

This is a good point to commit your changes to your source control system before moving on to the next step.

Step 7 - Update project structure (optional)

SilverStripe 4 introduces a new recommended project structure. Adopting the recommended project structure is optional, but will become mandatory in SilverStripe 5.

You may skip this step if you want.

Automatically switch to the new structure with the reorganise command

The reorganise command can automatically update your project to use the new recommended structure.

It will search your code and find any occurrence of mysite. It won't replace those occurrence with app however.

upgrade-code reorganise --write

Omit the --write flag if you just want to preview your changes

Manually switch to the new structure

Simply rename your mysite fold to app. Then rename app/code to app/src.

Finalising the reorganise structure

If you've implemented the new PSR-4 auto-loading logic in your composer.json file you'll need to update your namespace mapping.

For example, let's say you had the following autoload attribute in your composer.json.

{
    // ...
    "autoload": {
        "classmap": [
            "mysite/code/Page.php",
            "mysite/code/PageController.php"
        ],
        "psr-4": {
            "App\\Web\\": "mysite/code/"
        }
    },
    // ...
}

It will become this:

{
    // ...
    "autoload": {
        "classmap": [
            "app/src/Page.php",
            "app/src/PageController.php"
        ],
        "psr-4": {
            "App\\Web\\": "app/src/"
        }
    },
    // ...
}

You'll need to update the project attribute for your ModuleManifest in your app/src/mysite.yml file. It should now look something like this:

SilverStripe\Core\Manifest\ModuleManifest:
  project: app

At this stage, your project should be functional with the recommended project structure.

Note, that if you've explicitly reference any static assets (images, css, js) under mysite, you'll need to rewrite those references.

This is a good point to commit your changes to your source control system before moving on to the next step.

Step 8 - Switch to public web-root (optional)

SilverStripe 4.1 introduces the concept of public web-root this allows you to move all publicly accessible assets under a public folder. This has security benefits as it minimises the possibility that files that are not meant to be access directly get accidentally exposed.

This step is optional and requires SilverStripe 4.1 or greater. It will become mandatory in SilverStripe 5.

Automatically switch to the public web root

The webroot upgrader command will automatically move your files for you.

upgrade-code webroot --write

Omit the --write flag if you want to preview the change.

If you are using a modified index.php, .htaccess, or web.config, you will get a warning.

Manually switch to using the public web root

• Create a public folder in the root of your project
• Move the following files and folder to your new public folder
  • index.php
  • .htaccess
  • webconfig.php
  • assets
  • Any favicon files
  • Other common files that should be accssible in your project webroot (example: robots.txt)
• Delete the root resources directory if present.
• Run the following command composer vendor-expose to make static assets files accessible via the public directory.

If you are upgrading from SilverStripe 4.0 to SilverStripe 4.1 (or above), you'll need to update index.php before moving it to the public folder. You can get a copy of the generic index.php file from vendor/silverstripe/recipe-core/public. If you've made modifications to your index.php file, you'll need to replicate those into the new public/index.php file.

Finalising the web root migration

You'll need to update your server configuration to point to the public directory rather than the root of your project.

Update your .gitignore file so assets and resources are still ignored when located under the public folder.

Your project should still be functional, although you may now be missing some static assets.

This is a good point to commit your changes to your source control system before moving on to the next step.

Step 9 - Move away from hardcoded paths for referencing static assets

SilverStripe 4 introduces a new way to reference static assets like images and css. This enable innovations like moving SilverStripe module vendor folder or the public web root.

This change is mandatory if you've completed either:

• Step 7 - Update project structure
• Step 8 - Switch to public web-root

Otherwise, it is strongly recommended, but not mandatory.

Exposing your project static assets

If you have folders under app or mysite that need to be accessible for your project's web root, you need to say so in your composer.json file by adding an entry under extra.expose.

For example, let's say you have scripts, images and css folders under app. You can expose them by adding this content to your composer.json file:

{
    // ...
    "extra": {
        "branch-alias": {
            "4.x-dev": "4.2.x-dev"
        },
        "expose": [
            "app/scripts",
            "app/images",
            "app/css"
        ]
    },
    // ...
}

For the change to take affect, run the following command: composer vendor-expose.

Referencing static assets in your PHP code

Wherever you would have use an hardcoded path, you can now use the projectname: path/to/file.css syntax.

projectname is controlled by the project property of SilverStripe\Core\Manifest\ModuleManifest in your YML configuration. This configuration file should look like this:

SilverStripe\Core\Manifest\ModuleManifest:
  project: app

To add some javascript and css files to your requirements from your PHP code, you could use this syntax:

use SilverStripe\View\Requirements;

# Load your own style and scripts
Requirements::css('app: css/styles.css');
Requirements::script('app: scripts/client.css');

# Load some assets from a module.  
Requirements::script('silverstripe/blog: js/main.bundle.js');

You can SilverStripe\Core\Manifest\ModuleLoader to get the web path of file.

ModuleLoader::getModule('app')->getResource('images/road-runner.jpg')->getRelativePath();

You can use SilverStripe\View\ThemeResourceLoader to access files from your theme:

$themeFolderPath = ThemeResourceLoader::inst()->getPath('simple');
$themesFilePath = ThemeResourceLoader::inst()->findThemedResource('css/styles.css');

For classes that expect icons, you can specify theme with:

class ListingPage extends \Page
{
    private static $icon = 'app: images/sitetree_icon.png';
}

class MyCustomModelAdmin extends \SilverStripe\Admin\ModelAdmin
{
    private static $menu_icon = 'app: images/modeladmin_icon.png';
}

Referencing static assets in template files

SS template files accept a similar format for referencing static assets. Go through your assets files and remove hardcoded references.

<img src="$ModulePath(app)/images/coyote.png" />
<% require css("app: css/styles.css") %>

Finalising removal of hardcoded paths for referencing static assets

All your assets should be loading properly now.

This is a good point to commit your changes to your source control system before moving on to the next step.

Step 10 - Running your upgraded site for the first time

You're almost across the finish line.

Run a dev build

Rnn a dev/build either on the command line or in your browser.

./vendor/bin/sake dev/build

This should migrate your existing data to the new SilverStripe 4 structure.

Migrating files

Since the structure of the File DataObject has changed, a new task MigrateFileTask has been added to assist in migration of legacy files (see file migration documentation).

./vendor/bin/sake dev/tasks/MigrateFileTask

Any other script that needs running.

Some third party modules may include their own migration tasks. Take a minute to consult the release notes of your third party dependencies to make sure you have miss anything.

List of Major API Changes

This is a list of the most common API changes that might affect you.

Read the changelogs for a comprehensive list of everything that is new in SilverStripe 4:

• (SilverStripe 4.0.0 change logs)[/changelogs/4.0.0/]
• (SilverStripe 4.1.0 change logs)[/changelogs/4.1.0/]
• (SilverStripe 4.2.0 change logs)[/changelogs/4.2.0/].

Object class replaced by traits The Object class has been superceded by three traits:

• Injectable: Provides MyClass::create() and MyClass::singleton()
• Configurable: Provides MyClass::config()
• Extensible: Provides all methods related to extensions (E.g. add_extension()). $this->class no longer recommended, should use static::class or get_class($classObject) instead.

Rewrite literal table names
Use $table = SilverStripe\ORM\DataObject::getSchema()->tableForField($model, $field) instead of $model directly.

Rewrite literal class names
For example, referencing the class name 'Member' should be Member::class or if you're in YML config it should be SilverStripe\Security\Member.

Template locations and references
Templates require the folder path inside the templates folder, and Core templates are placed in paths following the class namespace, e.g. FormField is now SilverStripe/Forms/FormField.
When using the <% include %> syntax, you can leave out the Includes folder in the path.

Config settings should be set to private static
We no longer support public static $config_item on classes, it now needs to be private static $config_item.

Module paths can't be hardcoded
Modules may not be placed in a deterministic folder (e.g. /framework), you should use getters on the Module object instead.

Please see the changelogs for more details on ways that the getters on the Module object could be used.

Adapt tooling to modules in vendor folder SilverStripe modules are now placed in the vendor folder like many other composer package.

Modules need to declare which files need to be exposed via the new vendor-plugin, using symlinks to link to files from the publically accessible resources folder.

SS_Log replaced with PSR-3 logging SilverStripe 4 introduces PSR-3 compatible logger interfaces. Services can access the logger using the LoggerInterface::class service.

Please see the changelogs for more details on how to implement logging.

Upgrade app/_config.php The globals $database and $databaseConfig are deprecated. You should upgrade your site _config.php files to use the .env configuration.
conf/ConfigureFromEnv.php is no longer used, and references to this file should be deleted.

Session object removes static methods Session object is no longer statically accessible via Session::inst(). Instead, Session is a member of the current request.

Extensions are now singletons This means that state stored in private/protected variables are now shared across all objects which use this extension.
It is recommended to refactor the variables to be stored against the owner object.

Explicit text casting on template variables Calling $MyField on a DataObject in templates will by default cast MyField as Text which means it will be safely encoded.
You can change the casting for this by defining a casting config on the DataObject:

    private static $casting = [
        'MyField' => 'HTMLText'
    ];