freemarker.template.instruction
Class IfElseInstruction

java.lang.Object
  freemarker.template.instruction.IfElseInstruction

All Implemented Interfaces:

Instruction, TemplateProcessor, java.io.Serializable

public final class IfElseInstruction
extends java.lang.Object
implements Instruction, TemplateProcessor, java.io.Serializable

A instruction that handles if-elseif-else functionality. The initial "if" clause is held in a single variable. If any else or elseif clauses are encountered, they are stored in a List of IfInstructions. The List is not constructed until the first else or elseif is encountered.

See Also:

Serialized Form

Field Summary

Fields inherited from interface freemarker.template.instruction.Instruction

ASSIGN_END, BREAK, CASE, COMMENT_END, COMPRESS_END, DEFAULT, ELSE, ELSEIF, FOREACH_END, FUNCTION_END, IF_END, LIST_END, NONE, NOPARSE_END, SWITCH_END, TRANSFORM_END

Fields inherited from interface freemarker.template.TemplateProcessor

BREAK, EXIT, OK, UNCOMPILED_TEMPLATE

Constructor Summary

IfElseInstruction(Expression condition)
Constructs a new if/else instruction without the first block.

Method Summary

void	addTest(ElseInstruction instruction) Adds a new test to the if/else instruction.
TemplateProcessor	callBuilder(TemplateBuilder builder) A TemplateBuilder can call this method to have an Instruction call it back to be built.
int	getEndType() Determine what type of end instruction this is, if any.
boolean	isEndInstruction() Is this an end instruction?
short	process(TemplateWriteableHashModel modelRoot, java.io.Writer out, TemplateRuntimeHandler eventHandler) Evaluate the <if ...
void	setIfBlock(TemplateProcessor block) Adds the main block to the first "if" statement.
java.lang.String	toString() Returns a string representation of the object.

Methods inherited from class java.lang.Object

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

Constructor Detail

IfElseInstruction

public IfElseInstruction(Expression condition)

Constructs a new if/else instruction without the first block.

Parameters:

condition - the condition for the first if

Throws:

java.lang.NullPointerException - condition is null

Method Detail

setIfBlock

public void setIfBlock(TemplateProcessor block)

Adds the main block to the first "if" statement. For if/else, this is a special case.

Parameters:

block - the block to be processed if the first "if" statement is true

addTest

public void addTest(ElseInstruction instruction)

Adds a new test to the if/else instruction. Each test is evaluated in the order they are added using this method.

Parameters:

instruction - the "if" instruction to be evaluated and executed

Throws:

java.lang.NullPointerException - instruction is null

isEndInstruction

public boolean isEndInstruction()

Is this an end instruction?

Specified by:

isEndInstruction in interface Instruction

Returns:

false, indicating that this is not an end instruction

getEndType

public int getEndType()

Determine what type of end instruction this is, if any.

Specified by:

getEndType in interface Instruction

Returns:

NONE, indicating that this is not an end instruction

callBuilder

public TemplateProcessor callBuilder(TemplateBuilder builder)
                              throws ParseException

A TemplateBuilder can call this method to have an Instruction call it back to be built. This implementation throws an UnsupportedOperationException indicating that this is not yet production code.

Specified by:

callBuilder in interface Instruction

Parameters:

builder - the builder to be called back by this method

Throws:

ParseException

process

public short process(TemplateWriteableHashModel modelRoot,
                     java.io.Writer out,
                     TemplateRuntimeHandler eventHandler)
              throws java.io.IOException

Evaluate the <if ... > instruction.

Specified by:

process in interface TemplateProcessor

Parameters:

modelRoot - the root node of the data model.

out - a Writer to send the output to.

eventHandler - a TemplateEventAdapter for handling any events that occur during processing.

Returns:

an exit code indicating how the process terminated, typically used for short-circuiting template processing

Throws:

java.io.IOException - an IO error occurred during processing

toString

public java.lang.String toString()

Returns a string representation of the object.

Overrides:

toString in class java.lang.Object

Returns:

a String representing this instruction subtree