package org.apache.velocity.runtime.parser.node;
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
import org.apache.commons.lang.text.StrBuilder;
import org.apache.velocity.context.Context;
import org.apache.velocity.exception.MethodInvocationException;
import org.apache.velocity.runtime.parser.ParserConstants;
import org.apache.velocity.runtime.parser.Token;
/**
* Utilities for dealing with the AST node structure.
*
* @author <a href="mailto:[email protected]">Jason van Zyl</a>
* @author <a href="mailto:[email protected]">Geir Magnusson Jr.</a>
* @version $Id: NodeUtils.java 687386 2008-08-20 16:57:07Z nbubna $
*/
public class NodeUtils
{
/**
* @deprecated use getSpecialText(Token t)
*/
public static String specialText(Token t)
{
if (t.specialToken == null || t.specialToken.image.startsWith("##") )
{
return "";
}
return getSpecialText(t).toString();
}
/**
* Collect all the <SPECIAL_TOKEN>s that
* are carried along with a token. Special
* tokens do not participate in parsing but
* can still trigger certain lexical actions.
* In some cases you may want to retrieve these
* special tokens, this is simply a way to
* extract them.
* @param t the Token
* @return StrBuilder with the special tokens.
*/
public static StrBuilder getSpecialText(Token t)
{
StrBuilder sb = new StrBuilder();
Token tmp_t = t.specialToken;
while (tmp_t.specialToken != null)
{
tmp_t = tmp_t.specialToken;
}
while (tmp_t != null)
{
String st = tmp_t.image;
for(int i = 0, is = st.length(); i < is; i++)
{
char c = st.charAt(i);
if ( c == '#' || c == '$' )
{
sb.append( c );
}
/*
* more dreaded MORE hack :)
*
* looking for ("\\")*"$" sequences
*/
if ( c == '\\')
{
boolean ok = true;
boolean term = false;
int j = i;
for( ok = true; ok && j < is; j++)
{
char cc = st.charAt( j );
if (cc == '\\')
{
/*
* if we see a \, keep going
*/
continue;
}
else if( cc == '$' )
{
/*
* a $ ends it correctly
*/
term = true;
ok = false;
}
else
{
/*
* nah...
*/
ok = false;
}
}
if (term)
{
String foo = st.substring( i, j );
sb.append( foo );
i = j;
}
}
}
tmp_t = tmp_t.next;
}
return sb;
}
/**
* complete node literal
* @param t
* @return A node literal.
*/
public static String tokenLiteral( Token t )
{
// Look at kind of token and return "" when it's a multiline comment
if (t.kind == ParserConstants.MULTI_LINE_COMMENT)
{
return "";
}
else if (t.specialToken == null || t.specialToken.image.startsWith("##"))
{
return t.image;
}
else
{
StrBuilder special = getSpecialText(t);
if (special.length() > 0)
{
return special.append(t.image).toString();
}
return t.image;
}
}
/**
* Utility method to interpolate context variables
* into string literals. So that the following will
* work:
*
* #set $name = "candy"
* $image.getURI("${name}.jpg")
*
* And the string literal argument will
* be transformed into "candy.jpg" before
* the method is executed.
*
* @deprecated this method isn't called by any class
*
* @param argStr
* @param vars
* @return Interpoliation result.
* @throws MethodInvocationException
*/
public static String interpolate(String argStr, Context vars) throws MethodInvocationException
{
// if there's nothing to replace, skip this (saves buffer allocation)
if( argStr.indexOf('$') == -1 )
return argStr;
StrBuilder argBuf = new StrBuilder();
for (int cIdx = 0, is = argStr.length(); cIdx < is;)
{
char ch = argStr.charAt(cIdx);
if( ch == '$' )
{
StrBuilder nameBuf = new StrBuilder();
for (++cIdx ; cIdx < is; ++cIdx)
{
ch = argStr.charAt(cIdx);
if (ch == '_' || ch == '-'
|| Character.isLetterOrDigit(ch))
nameBuf.append(ch);
else if (ch == '{' || ch == '}')
continue;
else
break;
}
if (nameBuf.length() > 0)
{
Object value = vars.get(nameBuf.toString());
if (value == null)
argBuf.append("$").append(nameBuf.toString());
else
argBuf.append(value.toString());
}
}
else
{
argBuf.append(ch);
++cIdx;
}
}
return argBuf.toString();
}
}
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