freemarker.core.TextBlock 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.io.IOException;
/**
* A TemplateElement representing a block of plain text.
* @version $Id: TextBlock.java,v 1.17 2004/01/06 17:06:42 szegedia Exp $
*/
public final class TextBlock extends TemplateElement {
private static final char[] EMPTY_CHAR_ARRAY = new char[0];
static final TextBlock EMPTY_BLOCK = new TextBlock(EMPTY_CHAR_ARRAY, false);
// 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);
}
private TextBlock(char[] text, boolean unparsed) {
this.text = text;
this.unparsed = unparsed;
}
/**
* Simply outputs the text.
*/
public void accept(Environment env)
throws IOException
{
env.getOut().write(text);
}
public String getCanonicalForm() {
String text = new String(this.text);
if (unparsed) {
return "<#noparse>" + text + "";
}
return text;
}
public String getDescription() {
String s = new String(text).trim();
if (s.length() == 0) {
return "whitespace";
}
if (s.length() > 20) {
s = s.substring(0,20) + "...";
s = s.replace('\n', ' ');
s = s.replace('\r', ' ');
}
return "text block (" + s + ")";
}
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;
}
if (parent.parent == null && 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 (trim(lastLine).length == 0) {
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);
}
}
}
}
}
if (result) {
}
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 (trim(openingPart).length ==0) {
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 (trim(trailingPart).length == 0) {
// 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 = EMPTY_CHAR_ARRAY;
}
this.text = concat(printablePart, trailingPart);
}
}
}
}
return result;
}
/*
private String leftTrim(String s) {
int i =0;
while (i=0 ? newlineIndex1 : newlineIndex2;
if (newlineIndex1 >=0 && newlineIndex2 >=0) {
result = Math.min(newlineIndex1, newlineIndex2);
}
return result;
}
private int lastNewLineIndex() {
String content = new String(text);
return Math.max(content.lastIndexOf('\r'), content.lastIndexOf('\n'));
}
/**
* 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 (new String(text).substring(0, newlineIndex).trim().length() >0) {
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() {
String content = new String(text);
int lastNewlineIndex = lastNewLineIndex();
if (lastNewlineIndex == -1 && beginColumn != 1) {
return 0;
}
String substring = content.substring(lastNewlineIndex +1);
if (substring.trim().length() >0) {
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 substring.length();
}
boolean heedsTrailingWhitespace() {
if (isIgnorable()) {
return false;
}
for (int i=0; i=0; i--) {
char c = text[i];
if (c == '\n' || c == '\r') {
return false;
}
if (!Character.isWhitespace(c)) {
return true;
}
}
return true;
}
boolean isIgnorable() {
if (text == null || text.length == 0) {
return true;
}
if (!isWhitespace()) {
return false;
}
boolean atTopLevel = (getParent().getParent() == null);
TemplateElement prevSibling = previousSibling();
TemplateElement nextSibling = nextSibling();
return ((prevSibling == null && atTopLevel) || nonOutputtingType(prevSibling))
&& ((nextSibling == null && atTopLevel) || nonOutputtingType(nextSibling));
}
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[] trim(char[] c) {
if (c.length == 0) {
return c;
}
return new String(c).trim().toCharArray();
}
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;
}
boolean isWhitespace() {
return text == null || trim(text).length == 0;
}
}