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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.
/*
* 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.
*/
package freemarker.core;
import java.io.IOException;
import freemarker.template.utility.CollectionUtils;
import freemarker.template.utility.StringUtil;
/**
* A TemplateElement representing a block of plain text.
*
* @deprected This is an internal API; don't use it.
*/
public final class TextBlock extends TemplateElement {
// We're using char[] instead of String for storing the text block because
// Writer.write(String) involves copying the String contents to a char[]
// using String.getChars(), and then calling Writer.write(char[]). By
// using Writer.write(char[]) directly, we avoid array copying on each
// write.
private char[] text;
private final boolean unparsed;
public TextBlock(String text) {
this(text, false);
}
public TextBlock(String text, boolean unparsed) {
this(text.toCharArray(), unparsed);
}
TextBlock(char[] text, boolean unparsed) {
this.text = text;
this.unparsed = unparsed;
}
void replaceText(String text) {
this.text = text.toCharArray();
}
/**
* Simply outputs the text.
*
* @deprected This is an internal API; don't call or override it.
*/
@Override
public TemplateElement[] accept(Environment env)
throws IOException {
env.getOut().write(text);
return null;
}
@Override
protected String dump(boolean canonical) {
if (canonical) {
String text = new String(this.text);
if (unparsed) {
return "<#noparse>" + text + "";
}
return text;
} else {
return "text " + StringUtil.jQuote(new String(text));
}
}
@Override
String getNodeTypeSymbol() {
return "#text";
}
@Override
int getParameterCount() {
return 1;
}
@Override
Object getParameterValue(int idx) {
if (idx != 0) throw new IndexOutOfBoundsException();
return new String(text);
}
@Override
ParameterRole getParameterRole(int idx) {
if (idx != 0) throw new IndexOutOfBoundsException();
return ParameterRole.CONTENT;
}
@Override
TemplateElement postParseCleanup(boolean stripWhitespace) {
if (text.length == 0) return this;
int openingCharsToStrip = 0, trailingCharsToStrip = 0;
boolean deliberateLeftTrim = deliberateLeftTrim();
boolean deliberateRightTrim = deliberateRightTrim();
if (!stripWhitespace || text.length == 0 ) {
return this;
}
TemplateElement parentElement = getParentElement();
if (isTopLevelTextIfParentIs(parentElement) && previousSibling() == null) {
return this;
}
if (!deliberateLeftTrim) {
trailingCharsToStrip = trailingCharsToStrip();
}
if (!deliberateRightTrim) {
openingCharsToStrip = openingCharsToStrip();
}
if (openingCharsToStrip == 0 && trailingCharsToStrip == 0) {
return this;
}
this.text = substring(text, openingCharsToStrip, text.length - trailingCharsToStrip);
if (openingCharsToStrip > 0) {
this.beginLine++;
this.beginColumn = 1;
}
if (trailingCharsToStrip > 0) {
this.endColumn = 0;
}
return this;
}
/**
* Scans forward the nodes on the same line to see whether there is a
* deliberate left trim in effect. Returns true if the left trim was present.
*/
private boolean deliberateLeftTrim() {
boolean result = false;
for (TemplateElement elem = this.nextTerminalNode();
elem != null && elem.beginLine == this.endLine;
elem = elem.nextTerminalNode()) {
if (elem instanceof TrimInstruction) {
TrimInstruction ti = (TrimInstruction) elem;
if (!ti.left && !ti.right) {
result = true;
}
if (ti.left) {
result = true;
int lastNewLineIndex = lastNewLineIndex();
if (lastNewLineIndex >= 0 || beginColumn == 1) {
char[] firstPart = substring(text, 0, lastNewLineIndex + 1);
char[] lastLine = substring(text, 1 + lastNewLineIndex);
if (StringUtil.isTrimmableToEmpty(lastLine)) {
this.text = firstPart;
this.endColumn = 0;
} else {
int i = 0;
while (Character.isWhitespace(lastLine[i])) {
i++;
}
char[] printablePart = substring(lastLine, i);
this.text = concat(firstPart, printablePart);
}
}
}
}
}
return result;
}
/**
* Checks for the presence of a t or rt directive on the
* same line. Returns true if the right trim directive was present.
*/
private boolean deliberateRightTrim() {
boolean result = false;
for (TemplateElement elem = this.prevTerminalNode();
elem != null && elem.endLine == this.beginLine;
elem = elem.prevTerminalNode()) {
if (elem instanceof TrimInstruction) {
TrimInstruction ti = (TrimInstruction) elem;
if (!ti.left && !ti.right) {
result = true;
}
if (ti.right) {
result = true;
int firstLineIndex = firstNewLineIndex() + 1;
if (firstLineIndex == 0) {
return false;
}
if (text.length > firstLineIndex
&& text[firstLineIndex - 1] == '\r'
&& text[firstLineIndex] == '\n') {
firstLineIndex++;
}
char[] trailingPart = substring(text, firstLineIndex);
char[] openingPart = substring(text, 0, firstLineIndex);
if (StringUtil.isTrimmableToEmpty(openingPart)) {
this.text = trailingPart;
this.beginLine++;
this.beginColumn = 1;
} else {
int lastNonWS = openingPart.length - 1;
while (Character.isWhitespace(text[lastNonWS])) {
lastNonWS--;
}
char[] printablePart = substring(text, 0, lastNonWS + 1);
if (StringUtil.isTrimmableToEmpty(trailingPart)) {
// THIS BLOCK IS HEINOUS! THERE MUST BE A BETTER WAY! REVISIT (JR)
boolean trimTrailingPart = true;
for (TemplateElement te = this.nextTerminalNode();
te != null && te.beginLine == this.endLine;
te = te.nextTerminalNode()) {
if (te.heedsOpeningWhitespace()) {
trimTrailingPart = false;
}
if (te instanceof TrimInstruction && ((TrimInstruction) te).left) {
trimTrailingPart = true;
break;
}
}
if (trimTrailingPart) trailingPart = CollectionUtils.EMPTY_CHAR_ARRAY;
}
this.text = concat(printablePart, trailingPart);
}
}
}
}
return result;
}
private int firstNewLineIndex() {
char[] text = this.text;
for (int i = 0; i < text.length; i++) {
char c = text[i];
if (c == '\r' || c == '\n' ) {
return i;
}
}
return -1;
}
private int lastNewLineIndex() {
char[] text = this.text;
for (int i = text.length - 1; i >= 0; i--) {
char c = text[i];
if (c == '\r' || c == '\n' ) {
return i;
}
}
return -1;
}
/**
* figures out how many opening whitespace characters to strip
* in the post-parse cleanup phase.
*/
private int openingCharsToStrip() {
int newlineIndex = firstNewLineIndex();
if (newlineIndex == -1 && beginColumn != 1) {
return 0;
}
++newlineIndex;
if (text.length > newlineIndex) {
if (newlineIndex > 0 && text[newlineIndex - 1] == '\r' && text[newlineIndex] == '\n') {
++newlineIndex;
}
}
if (!StringUtil.isTrimmableToEmpty(text, 0, newlineIndex)) {
return 0;
}
// We look at the preceding elements on the line to see if we should
// strip the opening newline and any whitespace preceding it.
for (TemplateElement elem = this.prevTerminalNode();
elem != null && elem.endLine == this.beginLine;
elem = elem.prevTerminalNode()) {
if (elem.heedsOpeningWhitespace()) {
return 0;
}
}
return newlineIndex;
}
/**
* figures out how many trailing whitespace characters to strip
* in the post-parse cleanup phase.
*/
private int trailingCharsToStrip() {
int lastNewlineIndex = lastNewLineIndex();
if (lastNewlineIndex == -1 && beginColumn != 1) {
return 0;
}
if (!StringUtil.isTrimmableToEmpty(text, lastNewlineIndex + 1)) {
return 0;
}
// We look at the elements afterward on the same line to see if we should
// strip any whitespace after the last newline
for (TemplateElement elem = this.nextTerminalNode();
elem != null && elem.beginLine == this.endLine;
elem = elem.nextTerminalNode()) {
if (elem.heedsTrailingWhitespace()) {
return 0;
}
}
return text.length - (lastNewlineIndex + 1);
}
@Override
boolean heedsTrailingWhitespace() {
if (isIgnorable(true)) {
return false;
}
for (int i = 0; i < text.length; i++) {
char c = text[i];
if (c == '\n' || c == '\r') {
return false;
}
if (!Character.isWhitespace(c)) {
return true;
}
}
return true;
}
@Override
boolean heedsOpeningWhitespace() {
if (isIgnorable(true)) {
return false;
}
for (int i = text.length - 1; i >= 0; i--) {
char c = text[i];
if (c == '\n' || c == '\r') {
return false;
}
if (!Character.isWhitespace(c)) {
return true;
}
}
return true;
}
@Override
boolean isIgnorable(boolean stripWhitespace) {
if (text == null || text.length == 0) {
return true;
}
if (stripWhitespace) {
if (!StringUtil.isTrimmableToEmpty(text)) {
return false;
}
TemplateElement parentElement = getParentElement();
boolean atTopLevel = isTopLevelTextIfParentIs(parentElement);
TemplateElement prevSibling = previousSibling();
TemplateElement nextSibling = nextSibling();
return ((prevSibling == null && atTopLevel) || nonOutputtingType(prevSibling))
&& ((nextSibling == null && atTopLevel) || nonOutputtingType(nextSibling));
} else {
return false;
}
}
private boolean isTopLevelTextIfParentIs(TemplateElement parentElement) {
return parentElement == null
|| parentElement.getParentElement() == null && parentElement instanceof MixedContent;
}
private boolean nonOutputtingType(TemplateElement element) {
return (element instanceof Macro ||
element instanceof Assignment ||
element instanceof AssignmentInstruction ||
element instanceof PropertySetting ||
element instanceof LibraryLoad ||
element instanceof Comment);
}
private static char[] substring(char[] c, int from, int to) {
char[] c2 = new char[to - from];
System.arraycopy(c, from, c2, 0, c2.length);
return c2;
}
private static char[] substring(char[] c, int from) {
return substring(c, from, c.length);
}
private static char[] concat(char[] c1, char[] c2) {
char[] c = new char[c1.length + c2.length];
System.arraycopy(c1, 0, c, 0, c1.length);
System.arraycopy(c2, 0, c, c1.length, c2.length);
return c;
}
@Override
boolean isOutputCacheable() {
return true;
}
@Override
boolean isNestedBlockRepeater() {
return false;
}
}