• Disable session-based stage setting in Versioned (see #1578)
  • Deprecated FunctionalTest::useDraftSite(). You should use querystring args instead for setting stage.


App folder name

The standard 'mysite' code naming convention has changed in 4.2. Although existing sites can continue to use 'mysite/code` to store their base project code, the recommendation and new default is to store code in app/src.

Additionally, we reinforce the recommendation to use psr-4 autoloading in your project to speed up class loading.

In order to upgrade a site to use app/src folder:

  • Rename the folder mysite to app and code to src.
  • Update your app/_config/mysite.yml config to the below:
Name: myproject
  project: app
  • add psr-4 for your root project files and namespace. An example composer.json below shows how this might look:
    "autoload": {
        "psr-4": {
            "TractorCow\\MyWebsite\\": "app/src/"
        "classmap": [
  • Ensure you flush your site with ?flush=all Note: In 5.0 the app folder will be fixed to app and cannot be soft-coded via mysite.yml

Disable session-based stage setting

When viewing a versioned record (usually pages) in "draft" mode, SilverStripe used to record this mode in the session for further requests. This has the advantage of transparently working on XHR and API requests, as well as authenticated users navigating through other views.

These subsequent requests no longer carried an explicit stage query parameter, which meant the same URL might show draft or live content depending on your session state. While most HTTP caching layers deal gracefully with this variation by disabling any caching when a session cookie is present, there is a small chance that draft content is exposed to unauthenticated users for the lifetime of the cache.

Due to this potential risk for information leakage, we have decided to only rely on the stage query parameter. If you are consistently using the built-in SiteTree->Link() and Controller->Link() methods to get URLs, this change likely won't affect you.

If you are manually concatenating URLs to SilverStripe controllers rather than through their Link() methods (in custom PHP or JavaScript), or have implemented your own Link() methods on controllers exposing versioned objects, you'll need to check your business logic.

Alternatively, you can opt-out of this security feature via YAML configuration:

  use_session: true

Check our versioning docs for more details.

New Versioned API

The following methods have been added to SilverStripe\Versioned\Versioned class:

  • withVersionedMode() Allows users to execute a closure which may internally modify the current stage, but will guarantee these changes are reverted safely on return. Helpful when temporarily performing a task in another stage or view mode.
  • get_draft_site_secured() / set_draft_site_secured() Enables the explicit toggle of draft site security. By setting this to false, you can expose a draft mode to unauthenticated users. Replaces unsecuredDraftSite session var.
  • get_default_reading_mode() / set_default_reading_mode() The default reading mode is now configurable. Any non-default reading mode must have querystring args to be visible. This will be the mode choosen for requests that do not have these args. Note that the default mode for CMS is now draft, but is live on the frontend.

A new class SilverStripe\Versioned\ReadingMode has also been added to assist with conversion of the reading mode between:

  • Reading mode string
  • DataQuery parameters
  • Querystring parameters

SiteTreeLinkTracking has been split and refactored into two extensions, and now no longer applies exclusively to HTMLContent areas on SiteTree objects, but now all DataObject classes.

  • SiteTreeLinkTracking -> Tracks links between any object and SiteTree objects, generated from [sitetree_link] shortcodes in html areas.
  • FileLinkTracking -> Tracks links between any object and File objects, generated from [image] and [file_link] shortcodes in html areas.

Note that the ImageTracking property has been deprecated in favour of FileTracking, which includes and tracks non-image files as well.

By default HasBrokenFile and HasBrokenLink properties are still supported, but only for SiteTree objects by default. Non-SiteTree objects will still have both FileTracking and LinkTracking relations available for tracking linked records.

In addition, File::BackLinkTracking() and SiteTree::BackLinkTracking() are now polymorphic, and may now both contain non-SiteTree objects. Polymorphic many_many through relations are currently experimentally supported.

User code which relies on SiteTree-only results for these properties will need to be updated to consider other types.

Additionally, the SiteTree_LinkTracking and SiteTree_ImageTracking tables no longer exist, and are replaced by the SiteTreeLink and FileLink many_many through joining classes instead. Code which relies on raw SQL queries to these tables will need to be updated.

SiteTreeFileExtension is deprecated, and has it's functionality baked directly into File dataobject.

New upgrader command

The SilverStripe upgrader tool can now be used to convert your _ss_environment.php file to an equivalent .env file when migrating a SilverStripe 3 project to SilverStripe 4.

cd ~/my-project-root
upgrade-code environment --write

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