freemarker.core.TemplateElement Maven / Gradle / Ivy
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Google App Engine compliant variation of FreeMarker.
FreeMarker is a "template engine"; a generic tool to generate text output based on templates.
/*
* Copyright (c) 2003 The Visigoth Software Society. 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 acknowledgement:
* "This product includes software developed by the
* Visigoth Software Society (http://www.visigoths.org/)."
* Alternately, this acknowledgement may appear in the software itself,
* if and wherever such third-party acknowledgements normally appear.
*
* 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the
* project contributors may be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact [email protected].
*
* 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
* nor may "FreeMarker" or "Visigoth" appear in their names
* without prior written permission of the Visigoth Software Society.
*
* 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 VISIGOTH SOFTWARE SOCIETY 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 Visigoth Software Society. For more
* information on the Visigoth Software Society, please see
* http://www.visigoths.org/
*/
package freemarker.core;
import java.util.*;
import java.io.IOException;
import freemarker.template.*;
import freemarker.template.utility.Collections12;
/**
* Objects that represent elements in the compiled
* tree representation of the template necessarily
* descend from this abstract class.
*/
abstract public class TemplateElement extends TemplateObject {
TemplateElement parent;
// Only one of nestedBlock and nestedElements can be non-null.
TemplateElement nestedBlock;
List nestedElements;
/**
* Processes the contents of this TemplateElement and
* outputs the resulting text
*
* @param env The runtime environment
*/
abstract void accept(Environment env) throws TemplateException, IOException;
abstract public String getDescription();
// Methods to implement TemplateNodeModel
public TemplateNodeModel getParentNode() {
// return parent;
return null;
}
public String getNodeNamespace() {
return null;
}
public String getNodeType() {
return "element";
}
public TemplateSequenceModel getChildNodes() {
if (nestedElements != null) {
return new SimpleSequence(nestedElements);
}
SimpleSequence result = new SimpleSequence();
if (nestedBlock != null) {
result.add(nestedBlock);
}
return result;
}
public String getNodeName() {
String classname = this.getClass().getName();
int shortNameOffset = classname.lastIndexOf('.')+1;
return classname.substring(shortNameOffset);
}
// Methods so that we can implement the Swing TreeNode API.
public boolean isLeaf() {
return nestedBlock == null
&& (nestedElements == null || nestedElements.isEmpty());
}
public boolean getAllowsChildren() {
return !isLeaf();
}
public int getIndex(TemplateElement node) {
if (nestedBlock instanceof MixedContent) {
return nestedBlock.getIndex(node);
}
if (nestedBlock != null) {
if (node == nestedBlock) {
return 0;
}
}
else if (nestedElements != null) {
return nestedElements.indexOf(node);
}
return -1;
}
public int getChildCount() {
if (nestedBlock instanceof MixedContent) {
return nestedBlock.getChildCount();
}
if (nestedBlock != null) {
return 1;
}
else if (nestedElements != null) {
return nestedElements.size();
}
return 0;
}
public Enumeration children() {
if (nestedBlock instanceof MixedContent) {
return nestedBlock.children();
}
if (nestedBlock != null) {
return Collections.enumeration(Collections12.singletonList(nestedBlock));
}
else if (nestedElements != null) {
return Collections.enumeration(nestedElements);
}
return Collections.enumeration(Collections.EMPTY_LIST);
}
public TemplateElement getChildAt(int index) {
if (nestedBlock instanceof MixedContent) {
return nestedBlock.getChildAt(index);
}
if (nestedBlock != null) {
if (index == 0) {
return nestedBlock;
}
throw new ArrayIndexOutOfBoundsException("invalid index");
}
else if (nestedElements != null) {
return(TemplateElement) nestedElements.get(index);
}
throw new ArrayIndexOutOfBoundsException("element has no children");
}
public void setChildAt(int index, TemplateElement element) {
if(nestedBlock instanceof MixedContent) {
nestedBlock.setChildAt(index, element);
}
else if(nestedBlock != null) {
if(index == 0) {
nestedBlock = element;
element.parent = this;
}
else {
throw new IndexOutOfBoundsException("invalid index");
}
}
else if(nestedElements != null) {
nestedElements.set(index, element);
element.parent = this;
}
else {
throw new IndexOutOfBoundsException("element has no children");
}
}
public TemplateElement getParent() {
return parent;
}
// Walk the tree and set the parent field in all the nested elements recursively.
void setParentRecursively(TemplateElement parent) {
this.parent = parent;
int nestedSize = nestedElements == null ? 0 : nestedElements.size();
for (int i = 0; i < nestedSize; i++) {
((TemplateElement) nestedElements.get(i)).setParentRecursively(this);
}
if (nestedBlock != null) {
nestedBlock.setParentRecursively(this);
}
}
/**
* We walk the tree and do some cleanup
* @param stripWhitespace whether to clean up superfluous whitespace
*/
TemplateElement postParseCleanup(boolean stripWhitespace) throws ParseException {
if (nestedElements != null) {
for (int i = 0; i < nestedElements.size(); i++) {
TemplateElement te = (TemplateElement) nestedElements.get(i);
te = te.postParseCleanup(stripWhitespace);
nestedElements.set(i, te);
te.parent = this;
}
if (stripWhitespace) {
for (Iterator it = nestedElements.iterator(); it.hasNext();) {
TemplateElement te = (TemplateElement) it.next();
if (te.isIgnorable()) {
it.remove();
}
}
}
if (nestedElements instanceof ArrayList) {
((ArrayList) nestedElements).trimToSize();
}
}
if (nestedBlock != null) {
nestedBlock = nestedBlock.postParseCleanup(stripWhitespace);
if (nestedBlock.isIgnorable()) {
nestedBlock = null;
} else {
nestedBlock.parent = this;
}
}
return this;
}
boolean isIgnorable() {
return false;
}
// The following methods exist to support some fancier tree-walking
// and were introduced to support the whitespace cleanup feature in 2.2
TemplateElement prevTerminalNode() {
TemplateElement prev = previousSibling();
if (prev != null) {
return prev.getLastLeaf();
}
else if (parent != null) {
return parent.prevTerminalNode();
}
return null;
}
TemplateElement nextTerminalNode() {
TemplateElement next = nextSibling();
if (next != null) {
return next.getFirstLeaf();
}
else if (parent != null) {
return parent.nextTerminalNode();
}
return null;
}
TemplateElement previousSibling() {
if (parent == null) {
return null;
}
List siblings = parent.nestedElements;
if (siblings == null) {
return null;
}
for (int i = siblings.size() - 1; i>=0; i--) {
if (siblings.get(i) == this) {
return(i >0) ? (TemplateElement) siblings.get(i-1) : null;
}
}
return null;
}
TemplateElement nextSibling() {
if (parent == null) {
return null;
}
List siblings = parent.nestedElements;
if (siblings == null) {
return null;
}
for (int i = 0; i < siblings.size(); i++) {
if (siblings.get(i) == this) {
return (i+1) < siblings.size() ? (TemplateElement) siblings.get(i+1) : null;
}
}
return null;
}
private TemplateElement getFirstChild() {
if (nestedBlock != null) {
return nestedBlock;
}
if (nestedElements != null && nestedElements.size() >0) {
return(TemplateElement) nestedElements.get(0);
}
return null;
}
private TemplateElement getLastChild() {
if (nestedBlock != null) {
return nestedBlock;
}
if (nestedElements != null && nestedElements.size() >0) {
return(TemplateElement) nestedElements.get(nestedElements.size() -1);
}
return null;
}
private TemplateElement getFirstLeaf() {
TemplateElement te = this;
while (!te.isLeaf() && !(te instanceof Macro) && !(te instanceof BlockAssignment)) {
// A macro or macro invocation is treated as a leaf here for special reasons
te = te.getFirstChild();
}
return te;
}
private TemplateElement getLastLeaf() {
TemplateElement te = this;
while (!te.isLeaf() && !(te instanceof Macro) && !(te instanceof BlockAssignment)) {
// A macro or macro invocation is treated as a leaf here for special reasons
te = te.getLastChild();
}
return te;
}
/**
* determines whether this element's presence on a line
* indicates that we should not strip opening whitespace
* in the post-parse whitespace gobbling step.
*/
boolean heedsOpeningWhitespace() {
return false;
}
/**
* determines whether this element's presence on a line
* indicates that we should not strip trailing whitespace
* in the post-parse whitespace gobbling step.
*/
boolean heedsTrailingWhitespace() {
return false;
}
}