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Posted to dev@velocity.apache.org by ge...@locus.apache.org on 2000/11/20 00:26:35 UTC
cvs commit: jakarta-velocity/src/java/org/apache/velocity/runtime/directive Macro.java
geirm 00/11/19 15:26:35
Added: src/java/org/apache/velocity/runtime/directive Macro.java
Log:
Pluggable Directive to handle the Velocimacro definition #macro( name arg1 arg2 ...). Used inline in parsing to process and register the VM. Does not render any output or init itself or its AST.
Revision Changes Path
1.1 jakarta-velocity/src/java/org/apache/velocity/runtime/directive/Macro.java
Index: Macro.java
===================================================================
/*
* The Apache Software License, Version 1.1
*
* Copyright (c) 2000 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
/**
* Macro.java
*
* Macro implements the macro definition directive of VTL.
*
* example :
*
* #macro( isnull $i )
* #if( $i )
* $i
* #end
* #end
*
* This object is used at parse time to mainly process and register the
* macro. It is used inline in the parser when processing a directive.
*
* @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a>
* @version $Id: Macro.java,v 1.1 2000/11/19 23:26:35 geirm Exp $
*/
package org.apache.velocity.runtime.directive;
import java.io.Writer;
import java.io.IOException;
import java.util.TreeMap;
import org.apache.velocity.Context;
import org.apache.velocity.runtime.parser.node.Node;
import org.apache.velocity.runtime.parser.Token;
import org.apache.velocity.runtime.Runtime;
public class Macro extends Directive
{
private static boolean bDebug_ = false;
public String getName() { return "macro"; }
public int getType() { return BLOCK; }
/**
* render() doesn't do anything in the final output rendering.
* There is no output from a #macro() directive.
*/
public boolean render(Context context, Writer writer, Node node)
throws IOException
{
/*
* do nothing : We never render. The VelocimacroProxy object does that
*/
return true;
}
public void init(Context context, Node node) throws Exception
{
/*
* again, don't do squat. We want the AST of the macro block to hang off of this
* but we don't want to init it... it's useless...
*/
return;
}
/**
* Used by Parser.java to process VMs withing the parsing process
*
* processAndRegister() doesn't actually render the macro to the output
* Processes the macro body into the internal representation used by the
* VelocimacroProxy objects, and if not currently used, adds it
* to the macro Factory
*/
public void processAndRegister( Node node)
throws IOException
{
String strError = "";
/*
* There must be at least one arg to #macro,
* the name of the VM. Note that 0 following
* args is ok for naming blocks of HTML
*/
int iNumArgs = node.jjtGetNumChildren();
/*
* this number is the # of args + 1. The + 1
* is for the block tree
*/
if (iNumArgs < 2)
{
/*
* error - they didn't name the macro or
* define a block
*/
Runtime.error("#macro error : Velocimacro must have name as 1st argument to #macro()");
return;
}
/*
* get the arguments to the use of the VM
*/
String strArgs[] = getArgArray( node );
/*
* now, try and eat the code block. Pass the root.
*/
String strMacroArray[] = getASTAsStringArray( node.jjtGetChild(iNumArgs - 1) );
/*
* make a big string out of our macro
*/
StringBuffer strTemp = new StringBuffer();
for( int i=0; i < strMacroArray.length; i++)
strTemp.append( strMacroArray[i] );
String strMacro = strTemp.toString();
/*
* now, using the macro body string and the arg list, index all the tokens in the arglist
*/
TreeMap tmArgIndexMap = getArgIndexMap( strMacro, strArgs);
/*
* now, try to add it. The Factory controls permissions, so just give it a whack...
*/
int iMacroArgs = strArgs.length - 1;
boolean bRet = Runtime.addVelocimacro( strArgs[0], strMacro, strArgs, strMacroArray, tmArgIndexMap );
if (bRet)
Runtime.info("Velocimacro : added new VM " + strArgs[0] + "," + iMacroArgs );
else
Runtime.warn("Velocimacro : VM addition rejected : " + strArgs[0] + " Check VM permissions and defaults." );
return;
}
/**
* using the macro body and the arg list, creates a TreeMap of the indices of the args in the body
* Makes for fast and efficient patching at runtime
*/
private TreeMap getArgIndexMap( String strMacro, String strArgArray[] )
{
TreeMap tm = new TreeMap();
/*
* run through the buffer for each paramter, and remember where they go. We have to do this
* all at once to avoid confusing later replacement attempts with the activity of earlier ones
*/
for (int i=1; i<strArgArray.length; i++)
{
/*
* keep going until we don't get any matches
*/
int iIndex = 0;
while( ( iIndex = strMacro.indexOf( strArgArray[i], iIndex )) != -1 )
{
tm.put(new Integer( iIndex ), new Integer( i ));
iIndex++;
}
}
return tm;
}
/**
* creates an array containing the literal
* strings in the macro arguement
*/
private String[] getArgArray( Node node )
{
/*
* remember : this includes the block tree
*/
int iNumArgs = node.jjtGetNumChildren();
iNumArgs--; // avoid the block tree...
String strArgs[] = new String[ iNumArgs ];
int i = 0;
/*
* eat the args
*/
while( i < iNumArgs )
{
strArgs[i] = node.jjtGetChild(i).getFirstToken().image;
i++;
}
if (bDebug_)
{
System.out.println("Macro.getArgArray() : #args = " + iNumArgs );
System.out.print( strArgs[0] + "(" );
for ( i = 1; i < iNumArgs; i++)
System.out.print(" " + strArgs[i] );
System.out.println(" )");
}
return strArgs;
}
/**
* Returns an array of the literal rep of the AST
*/
private String [] getASTAsStringArray( Node rootNode )
{
/*
* this assumes that we are passed in the root
* node of the code block
*/
Token t = rootNode.getFirstToken();
Token tLast = rootNode.getLastToken();
/*
* now, run down the part of the tree bounded by
* our first and last tokens
*/
int iCount = 0;
while( t != tLast )
{
iCount++;
t = t.next;
}
/*
* account for the last one
*/
iCount++;
/*
* now, do it for real
*/
String strArray[] = new String[iCount];
iCount = 0;
t = rootNode.getFirstToken();
while( t != tLast )
{
strArray[iCount++] = t.image;
t = t.next;
}
/*
* make sure we get the last one...
*/
strArray[iCount] = t.image;
return strArray;
}
}