Red Hat Web Application Framework 6.1 Manuale Utente

com.arsdigita.templating.PatternStylesheetResolver

class is the new preferred

resolver and now the default setting.

5.2.2.2. Pattern Based Resolution
The

primary

implementation

of

the

stylesheet

resolver

interface

is

the

class

com.arsdigita.templating.PatternStylesheetResolver

. The core idea behind this

approach is that there is a list of abstract paths containing placeholders, of the form

::key::

. For

example, a simplified version of the default list of paths looks like:

/__ccm__/apps/::application::/xsl/::url::-::locale::.xsl
/__ccm__/apps/::application::/xsl/::url::.xsl

When resolving which stylesheet to apply, the placeholders are expanded based on the request state,

to generate a list of real paths. Since a placeholder potentially has multiple valid values for a request, a

single abstract path could expand to multiple real paths. Placeholder expansion proceeds left-to-right,

to ensure a deterministic ordering of the list of real paths.
If we consider

an example

request

for the

content

section

admin pages

at

/content/admin/index.jsp

, the placeholder expansions might be:

•

::application:: -



(content-section)

•

::url:: -



(admin, index)

•

::locale:: -



(en_US, en)

If we proceed left-to-right with this expansion, the first expansion is for

::application::

, leading

to:

/__ccm__/apps/content-section/xsl/::url::-::locale::.xsl
/__ccm__/apps/content-section/xsl/::url::.xsl

Next, the

::url::

placeholder is expanded:

/__ccm__/apps/content-section/xsl/admin-::locale::.xsl
/__ccm__/apps/content-section/xsl/admin.xsl

/__ccm__/apps/content-section/xsl/index-::locale::.xsl
/__ccm__/apps/content-section/xsl/index.xsl

Finally, the

::locale::

placeholder is expanded:

/__ccm__/apps/content-section/xsl/admin-en_US.xsl
/__ccm__/apps/content-section/xsl/admin-en.xsl
/__ccm__/apps/content-section/xsl/admin.xsl

/__ccm__/apps/content-section/xsl/index-en_US.xsl
/__ccm__/apps/content-section/xsl/index-en.xsl
/__ccm__/apps/content-section/xsl/index.xsl

Once all the placeholders have been expanded, these paths will be verified in order and the first

that exists returned as the primary stylesheet for the request. In this example the first match will

be

/__ccm__/apps/content-section/xsl/admin.xsl

.