Author: hlship
Date: Tue Apr 28 17:56:59 2009
New Revision: 769481
URL: http://svn.apache.org/viewvc?rev=769481&view=rev
Log:
TAP5-214: Document use of asset: and context: to reference assets directly from
a template file
Modified:
tapestry/tapestry5/trunk/src/site/apt/guide/assets.apt
Modified: tapestry/tapestry5/trunk/src/site/apt/guide/assets.apt
URL:
http://svn.apache.org/viewvc/tapestry/tapestry5/trunk/src/site/apt/guide/assets.apt?rev=769481&r1=769480&r2=769481&view=diff
==============================================================================
--- tapestry/tapestry5/trunk/src/site/apt/guide/assets.apt (original)
+++ tapestry/tapestry5/trunk/src/site/apt/guide/assets.apt Tue Apr 28 17:56:59
2009
@@ -27,7 +27,7 @@
private Asset banner;
+----+
- Assets are located within <domains>; these domains are identified by the
prefix on the Inject annotation's value.
+ Assets are located within <domains>; these domains are identified by the
prefix on the Path annotation's value.
If the prefix is omitted, the value will be interpreted as a path relative
to the Java class file itself, within
the "classpath:" domain. This is often used when creating component
libraries, where the assets used by the components
@@ -37,7 +37,25 @@
to access the underlying files, and those APIs, unlike Tapestry, are case
sensitive. Be aware that some <operating systems> (such as Windows)
are case insenitive, which may mask errors that will be revealed at
deployment (if the deployment operating system is case sensitive,
such as Linux).
-
+
+Assets in Templates
+
+ Assets can also be referenced directly in templates. Two binding prefixes
exist for this: "asset:" and "context:".
+ The "asset:" prefix can obtain assets from the classpath (the default) or
from the web context (by specifying
+ the "context:" domain explicitly):
+
+----
+ <img src="asset:context:image/tapestry_banner.gif" alt="Banner"/>
+----
+
+ Because accessing context assets is so common, the "context:" binding prefix
was introduced:
+
+----
+ <img src="context:image/tapestry_banner.gif" alt="Banner"/>
+----
+
+
+
Relative Assets
You can use relative paths with domains (if you omit the prefix):
@@ -117,5 +135,15 @@
and therefore will be aggresively cached in the client browser. Changing the
version number changes the path the browser
sees, which forces the browser to load the new and changed version of the
asset.
+ In addition, context assets will use the URL prefix
<<</assets/ctx/>>><app-version><<</>>>.
+
+
+Performance Notes
+
+ Assets are expected to be entirely static (not changing while the
application is deployed). When Tapestry generates a URL
+ for an asset, either on the classpath or from the context, the URL includes
a version number (as discussed in the previous section).
+ Further, the asset will get a <far future expires header>, which will
encourage the client browser to cache the
+ asset.
-
\ No newline at end of file
+ In addition, Tapestry will {{{compress.html}GZIP compress}} the content of
<all> assets (if the asset
+ is compressable, and the client supports it).
\ No newline at end of file
