To what extent deferred EL expressions will be supported in JSP 2.1 and in Tomcat 6 in particular?
After reading couple of introductory articles and the JSP2.1 spec I have understood that deferred expressions are possible in JSP tags. But I cannot make much from the following paragraph from the spec: === cut here === JSP.2.3.3 Deferred Value An EL expression is parsed using ExpressionFactory.createValueExpression() (with an expected type equal to the type specified in the TLD). The expression is not evaluated. The result of parsing the expression is passed directly to the setter method of the tag attribute, whose argument type must be javax.el.ValueExpression. This allows for deferred evaluation of EL expressions. When the expression is evaluated by the tag handler, the value is coerced to the expected type. If a static value is provided, it is converted to a ValueExpression where isLiteralText() returns true. === cut here === * What does it mean that it is not evaluated? * What is the result of parsing? (An example would help). * What is a tag attribute setter? Do I need to define setter method right in the tag in which I use deferred expression? Other questions are: * Custom tags can be made deferred expression-aware, what about JSTL? * Will container update server-side properties corresponding to deferred expression in a JSP tag like it will do for JSF? Simpler, will deferred expression work as rvalue in JSP tag? * If the answer on previous question is Yes, then can someone compare deferred expressions in JSP2.1 with Struts HTML taglib + BeanUtils? * If container will update server-side properties, when and how does this happen? Only on POST? Can the input phase (postback in JSF terms) be identified with some special request parameter? Thanks, Michael. --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
