REL Standard Tag Library completes the SDL Tridion's Rendering Expression Language (REL) with essential functionality such as loops, conditionals, XSLT.

RSTL is a Java library of REL tags running on SDL Tridion Content Delivery and providing a standardized way of performing common tasks. Similar to Java Standard Tag Library (JSTL), the functionality includes standard looping, conditionals, formatting and transformation tags. The library is meant for developers as a productivity tool for their development.
RSTL is internally backed by a parser and provides Expression Language (EL) capability by using Java bean notation to lookup objects, variables and expressions in the Content Delivery runtime context.
The built-in LRU cache speeds up EL expression resolving by keeping last expressions in memory as parsed expression trees and only invoking their resolving to a value.
Features
- Loop tag: forEach
- Condition tags: choose, when, otherwise, if
- Managing variables: import, set, remove
- Date formatting: parseDate, formatDate
- XSL transformation: transform
- Expression Language (EL) support provides Content Delivery context lookup using Java bean notation
- Works with both Java and .NET Content Delivery installations
- Trivial installation
Supported Versions
RSTL is supported for the following SDL Tridion versions:
- 2011 GA
- 2011 SP1 (including their respective Hotfix Rollups)
- 2013 GA
- 2013 SP1
Additional Information
Most information is available on Mihai's blog under label REL at yatb.mitza.net/search/label/REL:
- yatb.mitza.net/2013/07/rel-standard-tag-library.html
- yatb.mitza.net/2013/07/rel-standard-tag-library-installation.html
- yatb.mitza.net/2013/07/rel-standard-tag-library-expression.html
Additionally, Mihai presented RSTL in a community webinar from September 2013, available at webinars.julianwraith.com/2013/07/31/september-2013-webinar