When the standard view provider is not able to select an appropriate template for a given content, the system fallbacks to the legacy kernel and delegates the view selection to it. This ensures that a content is always displayed and hence eases project migration from eZ Publish v4.x to v5.x
Pagelayout and main block
When falling back to the legacy kernel, the old
content/view module is run to return the appropriate view for the given content. However, the pagelayout is not rendered as it needs to be still rendered by Twig in the Symfony part, for consistency. In this regard, the system uses the Decorator design pattern to include the generated view in your layout.
For this to work, you need to configure 2 things :
- Which template you want to use as a base template for legacy fallback
- The name of the block to use in your layout
Base layout for legacy fallback
You can configure this by setting the
ezpublish_legacy.view.default_layout config key.
This configuration is application global only for now.
Internally when rendering the view coming from the legacy kernel, a Twig template is created on the fly. This template extends the pagelayout you configured and includes the content inside a block. The name of this block is configurable as well (default is
The persistent variable is a special variable in legacy templates that you can set in order to pass values from the content template to the pagelayout. This variable, among others, is accessible from the configured Twig pagelayout thanks to the helper
Actually, all data contained in
$module_result in the legacy kernel is exposed.
ezcss_require() template operators.
You can easily retrieve those requested assets from the legacy template in the Twig pagelayout with the
Warning: If you use Assetic to combine and/or compress your assets, please note that
stylesheets Twig tags currently don't support variable file lists, so you won't be able to use them with the example above.