Allow SpEl expressions to be evaluated from JSPs [SPR-6827]

[spring-projects-issues]

Keith Donald opened SPR-6827 and commented

As a user, I would like to be able to evaluate SpEL expressions from my JSPs to take advantage of all that SpEL has to offer, such as the ability to invoke methods on Java objects. The EvaluationContext should expose access to the same variables standard EL expressions have access to, such as page scope and request scope.

We should look at a dedicated spring:eval tag for this, as well as opportunities to directly hook into the JSP engine itself so standard ${exp} syntax can be used for evaluating SpEL expressions.

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Affects: 3.0 GA

Issue Links:

• SpEL does not expose field-level annotations when setting bean properties [SPR-6745] #11411 SpEL does not expose field-level annotations when setting bean properties ("depends on")
• Create a Unified EL implementation with Spring EL [SPR-6080] #10748 Create a Unified EL implementation with Spring EL ("depends on")

[spring-projects-issues]

Keith Donald commented

This question was asked on stack overflow here:
http://stackoverflow.com/questions/1945143/replacing-el-in-jsp-with-spel-from-spring-3-0

[spring-projects-issues]

Keith Donald commented

Implicit variables that should be resolvable per the JSP specification are listed here:
http://java.sun.com/javaee/6/docs/api/javax/servlet/jsp/el/ImplicitObjectELResolver.html

[spring-projects-issues]

Keith Donald commented

Based on documentation at http://juel.sourceforge.net/guide/service.html, we should be able to plug SpEL in as a Unified EL provider in a JSP 2.1 environment by implementing javax.el.ExpressionFactory and adhering to the Service Provider contract.

[spring-projects-issues]

Keith Donald commented

Annotation-driven formatting of properties by EL via JSP tag doesn't work without this fix.

[spring-projects-issues]

Keith Donald commented

Added spring:eval tag to "http://www.springframework.org/tags" tag library. Integration with JSP EL engine will be handled in #10748.