Package org.apache.velocity.runtime.directive

Class RuntimeMacro

java.lang.Object

org.apache.velocity.runtime.directive.Directive

org.apache.velocity.runtime.directive.RuntimeMacro

All Implemented Interfaces:

java.lang.Cloneable, DirectiveConstants

public class RuntimeMacro
extends Directive

This class acts as a proxy for potential macros. When the AST is built this class is inserted as a placeholder for the macro (whether or not the macro is actually defined). At render time we check whether there is a implementation for the macro call. If an implementation cannot be found the literal text is rendered.

Since:

1.6

Field Summary

Fields

Modifier and Type	Field	Description
private java.lang.String	badArgsErrorMsg	badArgsErrorMsg will be non null if the arguments to this macro are deamed bad at init time, see the init method.
private java.lang.String	literal	Literal text of the macro
private java.lang.String	macroName	Name of the macro
private Node	node	Node of the macro call
protected boolean	strictRef	Indicates if we are running in strict reference mode.

Fields inherited from class org.apache.velocity.runtime.directive.Directive

rsvc

Fields inherited from interface org.apache.velocity.runtime.directive.DirectiveConstants

BLOCK, LINE

Constructor Summary

Constructors

Constructor	Description
RuntimeMacro(java.lang.String macroName)	Create a RuntimeMacro instance.

Method Summary

Modifier and Type	Method	Description
private java.lang.String	getLiteral()	It is probably quite rare that we need to render the macro literal so do it only on-demand and then cache the value.
java.lang.String	getName()	Return name of this Velocimacro.
java.lang.String	getScopeName()	Override to always return "macro".
int	getType()	Velocimacros are always LINE type directives.
void	init(RuntimeServices rs, InternalContextAdapter context, Node node)	Intialize the Runtime macro.
boolean	render(InternalContextAdapter context, java.io.Writer writer, Node node)	Velocimacro implementation is not known at the init time.
boolean	render(InternalContextAdapter context, java.io.Writer writer, Node node, Renderable body)	This method is used with BlockMacro when we want to render a macro with a body AST.

Methods inherited from class org.apache.velocity.runtime.directive.Directive

getColumn, getLine, getTemplateName, isScopeProvided, makeScope, postRender, preRender, setLocation, setLocation

Methods inherited from class java.lang.Object

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

Field Detail

macroName

private java.lang.String macroName

Name of the macro

literal

private java.lang.String literal

Literal text of the macro

node

private Node node

Node of the macro call

strictRef

protected boolean strictRef

Indicates if we are running in strict reference mode.

badArgsErrorMsg

private java.lang.String badArgsErrorMsg

badArgsErrorMsg will be non null if the arguments to this macro are deamed bad at init time, see the init method. If his is non null, then this macro cannot be rendered, and if there is an attempt to render we throw an exception with this as the message.

Constructor Detail

RuntimeMacro

public RuntimeMacro(java.lang.String macroName)

Create a RuntimeMacro instance. Macro name and source template stored for later use.

Parameters:

macroName - name of the macro

Method Detail

getName

public java.lang.String getName()

Return name of this Velocimacro.

Specified by:

getName in class Directive

Returns:

The name of this Velocimacro.

getScopeName

public java.lang.String getScopeName()

Override to always return "macro". We don't want to use the macro name here, since when writing VTL that uses the scope, we are within a #macro call. The macro name will instead be used as the scope name when defining the body of a BlockMacro.

Overrides:

getScopeName in class Directive

getType

public int getType()

Velocimacros are always LINE type directives.

Specified by:

getType in class Directive

Returns:

The type of this directive.

init

public void init(RuntimeServices rs,
                 InternalContextAdapter context,
                 Node node)

Intialize the Runtime macro. At the init time no implementation so we just save the values to use at the render time.

Overrides:

init in class Directive

Parameters:

rs - runtime services

context - InternalContextAdapter

node - node containing the macro call

getLiteral

private java.lang.String getLiteral()

It is probably quite rare that we need to render the macro literal so do it only on-demand and then cache the value. This tactic helps to reduce memory usage a bit.

render

public boolean render(InternalContextAdapter context,
                      java.io.Writer writer,
                      Node node)
               throws java.io.IOException,
                      ResourceNotFoundException,
                      ParseErrorException,
                      MethodInvocationException

Velocimacro implementation is not known at the init time. So look for a implementation in the macro libaries and if finds one renders it. The actual rendering is delegated to the VelocimacroProxy object. When looking for a macro we first loot at the template with has the macro call then we look at the macro lbraries in the order they appear in the list. If a macro has many definitions above look up will determine the precedence.

Specified by:

render in class Directive

Parameters:

context -

writer -

node -

Returns:

true if the rendering is successful

Throws:

java.io.IOException

ResourceNotFoundException

ParseErrorException

MethodInvocationException

render

public boolean render(InternalContextAdapter context,
                      java.io.Writer writer,
                      Node node,
                      Renderable body)
               throws java.io.IOException,
                      ResourceNotFoundException,
                      ParseErrorException,
                      MethodInvocationException

This method is used with BlockMacro when we want to render a macro with a body AST.

Parameters:

context -

writer -

node -

body - AST block that was enclosed in the macro body.

Returns:

true if the rendering is successful

Throws:

java.io.IOException

ResourceNotFoundException

ParseErrorException

MethodInvocationException