I'd like to resume discussion on a proposal circulated by James Strachan on March 13, 2002, about turning the implementation of JSTL's expression language (EL) into a reusable component and moving it from the Standard Taglib, an implementation of JSTL hosted by jakarta-taglibs, to jakarta-commons, in order to make it available to a larger number of projects.
James' original proposal received some positive feedback from the taglibs-dev community. Below is a draft proposal for a formal submission to jakarta-commons, following the format of the jakarta-commons charter at http://jakarta.apache.org/commons/charter.html. (0) Rationale The JSP Standard Tag Library (JSTL), version 1.0, introduced the concept of an Expression Language (EL), whose main goal is to provide page authors with an easy way to access and manipulate application data without requiring the use of scriptlets JSP 2.0 adopted the EL specification from JSTL, and expanded its scope: EL expressions are no longer limited to JSTL action attributes, but may be used in any standard or custom action attribute declared to accept a runtime expression. In addition, EL expressions may now also be used directly in template text outside of any actions. JSP 2.0 also added an important feature to the EL specification: EL functions, which allow page authors to invoke static methods in Java classes from EL expressions. Additionally, JSP 2.0 allows programmatic access and customization of the EL evaluator through a set of standard interfaces and abstract classes. Currently, there are a number of projects (including Tomcat 5 and Java Server Faces) that leverage the EL implementation of the Standard Taglib. In addition, there seems to be interest in leveraging the EL in the context of scripting workflow activities using custom tag libraries. In order to make the EL implementation available to Tomcat 5, the Tomcat team defined a new "ant" target for the Standard Taglib that builds just the EL portion and packages it in a JAR file ("jsp20el.jar") which is stored in Tomcat's common/lib directory. This approach has always been considered an interim solution only, until the EL implementation would move from the Standard Taglib to a more visible location such as jakarta-commons. (1) Scope of the package The package shall provide an implementation of the Expression Language specification which is part of the JSP 2.0 standard. (1.5) Interaction with other packages The package shall provide an implementation of the standard interfaces and abstract classes of the javax.servlet.jsp.el package, which is defined in the JSP 2.0 specification. (2) Identify the initial source for the package The initial codebase will be taken from the Standard Taglib project hosted at jakarta-taglibs. The source of the Standard Taglib is available as part of the jakarta-taglibs nightly source distribution at http://jakarta.apache.org/builds/jakarta-taglibs/nightly/src/ (2.1) Identify the base name for the package The base name of the package shall be org.apache.commons.el (2.2) Identify the coding conventions for this package The package follows Sun's Java coding conventions (see http://java.sun.com/docs/codeconv/html/CodeConvTOC.doc.html). (3) Identify any Jakarta-Commons resources to be created (3.1) Mailing list The package shall use the jakarta-commons mailing list. (3.2) CVS repositories The package shall use a root branch of the jakarta-commons CVS. (3.3) Bugzilla The package shall be listed as the "EL" component under the "Commons" project in Bugzilla. (3.4) Jyve FAQ (when available) n/a (4) Identify the initial set of committers to be listed in the Status File. The initial set of committers will be identical to the set of committers of the Standard Taglib project. Thoughts? Jan -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
