org.makumba.analyser
Class AnalysableExpression

java.lang.Object
  javax.servlet.jsp.tagext.TagSupport
      org.makumba.analyser.AnalysableElement
          org.makumba.analyser.AnalysableExpression

All Implemented Interfaces:

Serializable, IterationTag, JspTag, Tag

Direct Known Subclasses:

CountFunctions, GenericListValueFunction

public abstract class AnalysableExpression
extends AnalysableElement

An analysable EL expression, used for creating "implicit objects" as per EL definition (see http://java.sun.com/products/jsp/2.1/docs/jsp-2_1-pfd2/javax/el/ELResolver.html) Implementations of this class can be retrieved by ELResolver-s in order to get status information, perform analysis-time tasks, etc.

Version:

$Id: AnalysableExpression.java,v 1.1 Jan 22, 2010 6:13:56 PM manu Exp $

Author:

Manuel Gay

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.makumba.analyser.AnalysableElement

AnalysableElement.FilePositionElementComparator

Field Summary

protected ELData	elData
protected String	expression
protected MultipleKey	key
protected AnalysableTag	parent

Fields inherited from class org.makumba.analyser.AnalysableElement

ANALYSIS_STATE

Fields inherited from class javax.servlet.jsp.tagext.TagSupport

id, pageContext

Fields inherited from interface javax.servlet.jsp.tagext.IterationTag

EVAL_BODY_AGAIN

Fields inherited from interface javax.servlet.jsp.tagext.Tag

EVAL_BODY_INCLUDE, EVAL_PAGE, SKIP_BODY, SKIP_PAGE

Constructor Summary

AnalysableExpression()

Method Summary

abstract void	analyze(PageCache pageCache) Performs analysis-time operations
protected void	checkNumberOfArguments(int argumentCount) Checks that the function has the expected number of arguments.
abstract void	doEndAnalyze(PageCache pageCache)
protected Tag	findParentWithClass(Class<?> clazz) Finds the first parent of this expression that is a tag of the specified type
ElementData	getElementData()
MultipleKey	getKey()
AnalysableTag	getParent()
abstract String	getPrefix() Gets the prefix of the makumba EL expression, e.g.
abstract Object	resolve(PageContext pc, PageCache pageCache) Resolves the expression at runtime
void	setELDataAtAnalysis(ELData ed) Sets the EL data and adapts the expression
abstract void	setKey(PageCache pageCache)
void	setParent(AnalysableTag parent)
void	treatELExpressionAtAnalysis(String expression)
abstract String	treatExpressionAtAnalysis(String expression) Modifies the expression before analysis.

Methods inherited from class org.makumba.analyser.AnalysableElement

checkTagFound, discardJSPParsingData, getAnalyzedElementData, getCurrentBodyTagData, getElementAfter, getElementBefore, getPageCache, getPageCache, getRunningElementData, getTagByAttribute, getTagById, getThreadElementStack, initializeThread, keepAnalysisState, setAnalyzedElementData, setRunningElementData

Methods inherited from class javax.servlet.jsp.tagext.TagSupport

doAfterBody, doEndTag, doStartTag, findAncestorWithClass, getId, getValue, getValues, release, removeValue, setId, setPageContext, setParent, setValue

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

elData

protected ELData elData

expression

protected String expression

parent

protected AnalysableTag parent

key

protected MultipleKey key

Constructor Detail

AnalysableExpression

public AnalysableExpression()

Method Detail

getElementData

public ElementData getElementData()

Specified by:

getElementData in class AnalysableElement

setELDataAtAnalysis

public void setELDataAtAnalysis(ELData ed)

Sets the EL data and adapts the expression

treatELExpressionAtAnalysis

public void treatELExpressionAtAnalysis(String expression)

setParent

public void setParent(AnalysableTag parent)

getParent

public AnalysableTag getParent()

Specified by:

getParent in interface Tag

Overrides:

getParent in class TagSupport

setKey

public abstract void setKey(PageCache pageCache)

getKey

public MultipleKey getKey()

analyze

public abstract void analyze(PageCache pageCache)

Performs analysis-time operations

Parameters:

cache - the PageCache available to this expression

doEndAnalyze

public abstract void doEndAnalyze(PageCache pageCache)

treatExpressionAtAnalysis

public abstract String treatExpressionAtAnalysis(String expression)

Modifies the expression before analysis. This is necessary because the expression that comes from page analysis is not tailored to the specific expression we want to handle

Returns:

the expression value, trimmed down to what is necessary for this kind of EL expression evaluator

getPrefix

public abstract String getPrefix()

Gets the prefix of the makumba EL expression, e.g. Value

Returns:

the prefix of this EL expression

resolve

public abstract Object resolve(PageContext pc,
                               PageCache pageCache)
                        throws LogicException

Resolves the expression at runtime

Parameters:

cache - the PageCache available to this expression

Throws:

LogicException

findParentWithClass

protected Tag findParentWithClass(Class<?> clazz)

Finds the first parent of this expression that is a tag of the specified type

Returns:

a parent Tag

checkNumberOfArguments

protected void checkNumberOfArguments(int argumentCount)
                               throws ProgrammerError

Checks that the function has the expected number of arguments. This should be enforced by the JSP compiler, but an additional check can't hurt

Throws:

ProgrammerError