Legacy template fallback

The following does not apply to siteaccesses configured with legac= y_mode: true

When the standard view provider is not able to select an appropriate tem= plate for a given content, the system fallbacks to the legacy kerne= l and delegates the view selection to it. This ensures that a content is always d= isplayed and hence eases project migration from eZ Publish v4.x to v5.x

=20

Pagelayout a= nd main block=20
- Base la= yout for legacy fallback
- Block name
- Module layout=20
  - Displa= ying legacy module result
Persistent varia= ble
Assets

=20

Pagelayout and mai= n block

When falling back to the legacy kernel, the old content/vi= ew module is run to return the appropriate view for the giv= en 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 g= enerated 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 f= or legacy fallback

You can configure this by setting the ezpublish_legac= y.<siteaccess_or_siteaccess_group>.view_default_layout config key.


Example:


ezpublish/config/ezpublish.yml

=20
parameters:
    # eZ Publish 5.1+ only
    ezpublish_legacy.my_siteaccess.view_default_layout: AcmeDemoBundle::my_=
layout.html.twig=20


Block name
Internally when rendering the view coming from the legacy kernel, a Twig=
 template is created on the fly. This template extends the pagelayout you c=
onfigured and includes the content inside a block. The name of this block i=
s configurable as well (default is content).<=
/p>


ezpublish/config/ezpublish.yml

=20
parameters:
    ezpublish_legacy.<siteaccess_or_siteaccess_group>.view_default_la=
yout: AcmeDemoBundle::my_layout.html.twig
    ezpublish.content_view.content_block_name: content=20




my_layout.html.twig

=20
<!DOCTYPE html>
<html>
<head>
    <!-- ... -->
</head>
<body>
    {% block content %}{# Content will be inserted here #}{% endblock %}
</body>
</html>=20


 
Module layout

Version compatibility


The module layout setting is available from eZ Publish 5.1.


The module layout=
 can also be defined the same way as the base layout, by setting the <=
/span>ezpubl=
ish_legacy.<scope>.module_default_layout config key. This layout is use=
d to handle "non content" related legacy requests.
Displaying l=
egacy module result

This makes your base layout reusable. However, content generated by lega= cy modules (i.e. /ezinfo/about) will not be automatically inse= rted as your layout will be rendered as a regular template, receiving module_result variable coming from the legacy kernel. The solution = is to use 2 different templates, one for the global layout, and another for= legacy module rendering:

AcmeDemoBundle::layout.html.twig

=20

<!DOCTYPE html>
<html>
<head>
    <!-- Insert everything you need here that is common -->
</head>
<body>
    {% block content %}{# Regular content will be inserted here #}{% endblo=
ck %}
</body>
</html>

=20

AcmeDemoBundle::layout_legacy.html.twig

=20

{% extends "AcmeDemoBundle::layout.html.twig" %}
 
{% block content %}
    {# module_result variable is received from the legacy controller. #}
    {# It holds the legacy module result #}
    {{ module_result.content|raw }}
{% endblock %}

=20

ezpublish/config/ezpublish.yml

=20

parameters:
    ezpublish_legacy.my_siteaccess.module_default_layout: AcmeDemoBundle::l=
ayout_legacy.html.twig
    ezpublish_legacy.my_siteaccess.view_default_layout: AcmeDemoBundle::lay=
out.html.twig

=20

Persistent variable

The persistent variable is a special variable in legacy templates that y= ou can set in order to pass values from the content template to the pagelay= out. This variable, among others, is accessible from the configured Twig pa= gelayout thanks to the helper ezpublish.legacy.


Actually, all data contained in $module_result in the legacy kernel is exposed.



Access to the persistent variable

=20
<!DOCTYPE html>
<html>
<head>
    <!-- ... -->
    {% if ezpublish.legacy.has( 'content_info' ) %}
        {% set persistent_variable =3D ezpublish.legacy.get( 'content_info'=
 )['persistent_variable'] %}
    {% endif %}
</head>
<body>
    {% block content %}{# Content will be inserted here #}{% endblock %}
</body>
</html>=20


Assets
Like the persistent variable, it is possible to require css and/or javas=
cripts assets from a content template through the legacy ezscript_req=
uire() and ezcss_require() template operators.
You can easily retrieve those requested assets from the legacy template =
in the Twig pagelayout with the ezpublish.legacy helper.



Getting assets requested from a legacy template

=20
<!DOCTYPE html>
<html>
<head>
    <!-- ... -->
    {% set requested_css_files =3D ezpublish.legacy.get( 'css_files' ) %}
    {% set requested_js_files =3D ezpublish.legacy.get( 'js_files' ) %}
 
    {# "configured" assets are the ones defined in design.ini (FrontendCSSF=
ileList/FrontendJavaScriptList) #}
    {% set configured_js_files =3D ezpublish.legacy.get( 'js_files_configur=
ed' ) %}
    {% set configured_css_files =3D ezpublish.legacy.get( 'css_files_config=
ured' ) %}
</head>
<body>
    {% block content %}{# Content will be inserted here #}{% endblock %}
</body>
</html>=20



Assetic incompatibility


Warning: If you use Assetic to combine and/or compress =
your assets, please note that javascripts and stylesheets Twig tags currently don't support variable file lists, so you won't be able to use=
 them with the example above.

Legacy template fallback

Pagelayout and mai= n block

Base layout f= or legacy fallback

Block name

Module layout

Displaying l= egacy module result

Assets