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Liferay Portal Template FreeMarker
/*
* 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.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import freemarker.template.SimpleScalar;
import freemarker.template.SimpleSequence;
import freemarker.template.TemplateCollectionModelEx;
import freemarker.template.TemplateException;
import freemarker.template.TemplateHashModel;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;
import freemarker.template.TemplateModelIterator;
import freemarker.template.TemplateNumberModel;
import freemarker.template.TemplateScalarModel;
import freemarker.template.TemplateSequenceModel;
import freemarker.template._ObjectWrappers;
import freemarker.template._TemplateAPI;
import freemarker.template._VersionInts;
import freemarker.template.utility.Constants;
/**
* {@code target[keyExpression]}, where, in FM 2.3, {@code keyExpression} can be string, a number or a range,
* and {@code target} can be a hash or a sequence.
*/
final class DynamicKeyName extends Expression {
private static final int UNKNOWN_RESULT_SIZE = -1;
private final Expression keyExpression;
private final Expression target;
private boolean lazilyGeneratedResultEnabled;
DynamicKeyName(Expression target, Expression keyExpression) {
this.target = target;
this.keyExpression = keyExpression;
target.enableLazilyGeneratedResult();
}
@Override
TemplateModel _eval(Environment env) throws TemplateException {
TemplateModel targetModel = target.eval(env);
if (targetModel == null) {
if (env.isClassicCompatible()) {
return null;
} else {
throw InvalidReferenceException.getInstance(target, env);
}
}
TemplateModel keyModel = keyExpression.eval(env);
if (keyModel == null) {
if (env.isClassicCompatible()) {
keyModel = TemplateScalarModel.EMPTY_STRING;
} else {
keyExpression.assertNonNull(null, env);
}
}
if (keyModel instanceof TemplateNumberModel) {
int index = keyExpression.modelToNumber(keyModel, env).intValue();
return dealWithNumericalKey(targetModel, index, env);
}
if (keyModel instanceof TemplateScalarModel) {
String key = EvalUtil.modelToString((TemplateScalarModel) keyModel, keyExpression, env);
return dealWithStringKey(targetModel, key, env);
}
if (keyModel instanceof RangeModel) {
return dealWithRangeKey(targetModel, (RangeModel) keyModel, env);
}
throw new UnexpectedTypeException(keyExpression, keyModel, "number, range, or string",
new Class[] { TemplateNumberModel.class, TemplateScalarModel.class, Range.class }, env);
}
static private Class[] NUMERICAL_KEY_LHO_EXPECTED_TYPES;
static {
NUMERICAL_KEY_LHO_EXPECTED_TYPES = new Class[1 + NonStringException.STRING_COERCABLE_TYPES.length];
NUMERICAL_KEY_LHO_EXPECTED_TYPES[0] = TemplateSequenceModel.class;
for (int i = 0; i < NonStringException.STRING_COERCABLE_TYPES.length; i++) {
NUMERICAL_KEY_LHO_EXPECTED_TYPES[i + 1] = NonStringException.STRING_COERCABLE_TYPES[i];
}
}
private TemplateModel dealWithNumericalKey(TemplateModel targetModel,
int index,
Environment env)
throws TemplateException {
if (targetModel instanceof TemplateSequenceModel) {
TemplateSequenceModel tsm = (TemplateSequenceModel) targetModel;
int size;
try {
size = tsm.size();
} catch (Exception e) {
size = Integer.MAX_VALUE;
}
return index < size ? tsm.get(index) : null;
}
if (targetModel instanceof LazilyGeneratedCollectionModel
&& ((LazilyGeneratedCollectionModel) targetModel).isSequence()) {
if (index < 0) {
return null;
}
TemplateModelIterator iter = ((LazilyGeneratedCollectionModel) targetModel).iterator();
for (int curIndex = 0; iter.hasNext(); curIndex++) {
TemplateModel next = iter.next();
if (index == curIndex) {
return next;
}
}
return null;
}
// Fall back to get a character from a string
try {
String s = target.evalAndCoerceToPlainText(env);
try {
return new SimpleScalar(s.substring(index, index + 1));
} catch (IndexOutOfBoundsException e) {
if (index < 0) {
throw new _MiscTemplateException("Negative index not allowed: ", Integer.valueOf(index));
}
if (index >= s.length()) {
throw new _MiscTemplateException(
"String index out of range: The index was ", Integer.valueOf(index),
" (0-based), but the length of the string is only ", Integer.valueOf(s.length()) , ".");
}
throw new RuntimeException("Can't explain exception", e);
}
} catch (NonStringException e) {
throw new UnexpectedTypeException(
target, targetModel,
"sequence or " + NonStringException.STRING_COERCABLE_TYPES_DESC,
NUMERICAL_KEY_LHO_EXPECTED_TYPES,
(targetModel instanceof TemplateHashModel
? "You had a numerical value inside the []. Currently that's only supported for "
+ "sequences (lists) and strings. To get a Map item with a non-string key, "
+ "use myMap?api.get(myKey)."
: null),
env);
}
}
private TemplateModel dealWithStringKey(TemplateModel targetModel, String key, Environment env)
throws TemplateException {
if (targetModel instanceof TemplateHashModel) {
return((TemplateHashModel) targetModel).get(key);
}
throw new NonHashException(target, targetModel, env);
}
private TemplateModel dealWithRangeKey(TemplateModel targetModel, RangeModel range, Environment env)
throws TemplateException {
// We can have 3 kind of left hand operands ("targets"): sequence, lazily generated sequence, string
final TemplateSequenceModel targetSeq;
final LazilyGeneratedCollectionModel targetLazySeq;
final String targetStr;
if (targetModel instanceof TemplateSequenceModel) {
targetSeq = (TemplateSequenceModel) targetModel;
targetLazySeq = null;
targetStr = null;
} else if (targetModel instanceof LazilyGeneratedCollectionModel
&& ((LazilyGeneratedCollectionModel) targetModel).isSequence()) {
targetSeq = null;
targetLazySeq = (LazilyGeneratedCollectionModel) targetModel;
targetStr = null;
} else {
targetSeq = null;
targetLazySeq = null;
try {
targetStr = target.evalAndCoerceToPlainText(env);
} catch (NonStringException e) {
throw new UnexpectedTypeException(
target, target.eval(env),
"sequence or " + NonStringException.STRING_COERCABLE_TYPES_DESC,
NUMERICAL_KEY_LHO_EXPECTED_TYPES, env);
}
}
final int rangeSize = range.size(); // Warning: Value is meaningless for right unbounded sequences
final boolean rightUnbounded = range.isRightUnbounded();
final boolean rightAdaptive = range.isRightAdaptive(); // Always true if rightUnbounded
// Empty ranges are accepted even if the begin index is out of bounds. That's because a such range
// produces an empty sequence, which thus doesn't contain any illegal indexes.
if (!rightUnbounded && rangeSize == 0) {
return emptyResult(targetSeq != null);
}
final int firstIdx = range.getBegining();
if (firstIdx < 0) {
throw new _MiscTemplateException(keyExpression,
"Negative range start index (", Integer.valueOf(firstIdx),
") isn't allowed for a range used for slicing.");
}
final int step = range.getStep(); // Currently always 1 or -1
final int targetSize;
final boolean targetSizeKnown; // Didn't want to use targetSize = -1, as we don't control the seq.size() impl.
if (targetStr != null) {
targetSize = targetStr.length();
targetSizeKnown = true;
} else if (targetSeq != null) {
targetSize = targetSeq.size();
targetSizeKnown = true;
} else if (targetLazySeq instanceof TemplateCollectionModelEx) {
// E.g. the size of seq?map(f) is known, despite that the elements are lazily calculated.
targetSize = ((TemplateCollectionModelEx) targetLazySeq).size();
targetSizeKnown = true;
} else {
targetSize = Integer.MAX_VALUE;
targetSizeKnown = false;
}
if (targetSizeKnown) {
// Right-adaptive increasing ranges can start 1 after the last element of the target, because they are like
// ranges with exclusive end index of at most targetSize. Hence a such range is just an empty list of
// indexes, and thus it isn't out-of-bounds.
// Right-adaptive decreasing ranges has exclusive end -1, so it can't help on a too high firstIndex.
// Right-bounded ranges at this point aren't empty, so firstIndex == targetSize can't be allowed.
if (rightAdaptive && step == 1 ? firstIdx > targetSize : firstIdx >= targetSize) {
throw new _MiscTemplateException(keyExpression,
"Range start index ", Integer.valueOf(firstIdx), " is out of bounds, because the sliced ",
(targetStr != null ? "string" : "sequence"),
" has only ", Integer.valueOf(targetSize), " ",
(targetStr != null ? "character(s)" : "element(s)"),
". ", "(Note that indices are 0-based).");
}
}
// Calculate resultSize. Note that:
// - It might will be UNKNOWN_RESULT_SIZE when targetLazySeq != null.
// - It might will be out-of-bounds if !targetSizeKnown (otherwise we validate if the range is correct)
final int resultSize;
if (!rightUnbounded) {
final int lastIdx = firstIdx + (rangeSize - 1) * step; // Note: lastIdx is inclusive
if (lastIdx < 0) {
if (!rightAdaptive) {
throw new _MiscTemplateException(keyExpression,
"Negative range end index (", Integer.valueOf(lastIdx),
") isn't allowed for a range used for slicing.");
} else {
resultSize = firstIdx + 1;
}
} else if (targetSizeKnown && lastIdx >= targetSize) {
if (!rightAdaptive) {
throw new _MiscTemplateException(keyExpression,
"Range end index ", Integer.valueOf(lastIdx), " is out of bounds, because the sliced ",
(targetStr != null ? "string" : "sequence"),
" has only ", Integer.valueOf(targetSize), " ", (targetStr != null ? "character(s)" : "element(s)"),
". (Note that indices are 0-based).");
} else {
resultSize = Math.abs(targetSize - firstIdx);
}
} else {
resultSize = rangeSize;
}
} else { // rightUnbounded
resultSize = targetSizeKnown ? targetSize - firstIdx : UNKNOWN_RESULT_SIZE;
}
if (resultSize == 0) {
return emptyResult(targetSeq != null);
}
if (targetSeq != null) {
// In principle we should take lazilyGeneratedResultEnabled into account, but that wouldn't be backward
// compatible. For example, with lazily generated sequence result <#list xs[b..e] as x> would behave
// differently if xs is modified inside the #list nested content.
ArrayList resultList = new ArrayList<>(resultSize);
int srcIdx = firstIdx;
for (int i = 0; i < resultSize; i++) {
resultList.add(targetSeq.get(srcIdx));
srcIdx += step;
}
// List items are already wrapped:
return new SimpleSequence(resultList, _ObjectWrappers.SAFE_OBJECT_WRAPPER);
} else if (targetLazySeq != null) {
// As a targetLazySeq can only occur if a new built-in like ?filter or ?map was used somewhere in the target
// expression, in this case we can return lazily generated sequence without breaking backward compatibility.
if (step == 1) {
return getStep1RangeFromIterator(targetLazySeq.iterator(), range, resultSize, targetSizeKnown);
} else if (step == -1) {
return getStepMinus1RangeFromIterator(targetLazySeq.iterator(), range, resultSize);
} else {
throw new AssertionError();
}
} else {
final int exclEndIdx;
if (step < 0 && resultSize > 1) {
if (!(range.isAffectedByStringSlicingBug() && resultSize == 2)) {
throw new _MiscTemplateException(keyExpression,
"Decreasing ranges aren't allowed for slicing strings (as it would give reversed text). "
+ "The index range was: first = ", Integer.valueOf(firstIdx),
", last = ", Integer.valueOf(firstIdx + (resultSize - 1) * step));
} else {
// Emulate the legacy bug, where "foo"[n .. n-1] gives "" instead of an error (if n >= 1).
// Fix this in FTL [2.4]
exclEndIdx = firstIdx;
}
} else {
exclEndIdx = firstIdx + resultSize;
}
return new SimpleScalar(targetStr.substring(firstIdx, exclEndIdx));
}
}
private TemplateModel getStep1RangeFromIterator(
final TemplateModelIterator targetIter, final RangeModel range, int resultSize, boolean targetSizeKnown)
throws TemplateModelException {
final int firstIdx = range.getBegining();
final int lastIdx = firstIdx + (range.size() - 1); // Note: meaningless if the range is right unbounded
final boolean rightAdaptive = range.isRightAdaptive();
final boolean rightUnbounded = range.isRightUnbounded();
if (lazilyGeneratedResultEnabled) {
TemplateModelIterator iterator = new TemplateModelIterator() {
private boolean elementsBeforeFirsIndexWereSkipped;
private int nextIdx;
@Override
public TemplateModel next() throws TemplateModelException {
ensureElementsBeforeFirstIndexWereSkipped();
if (!rightUnbounded && nextIdx > lastIdx) {
// We fail because the consumer of this iterator hasn't used hasNext() properly.
throw new _TemplateModelException(
"Iterator has no more elements (at index ", Integer.valueOf(nextIdx), ")");
}
if (!rightAdaptive && !targetIter.hasNext()) {
// We fail because the range was wrong, not because of the consumer of this iterator .
throw newRangeEndOutOfBoundsException(nextIdx, lastIdx);
}
TemplateModel result = targetIter.next();
nextIdx++;
return result;
}
@Override
public boolean hasNext() throws TemplateModelException {
ensureElementsBeforeFirstIndexWereSkipped();
return (rightUnbounded || nextIdx <= lastIdx) && (!rightAdaptive || targetIter.hasNext());
}
public void ensureElementsBeforeFirstIndexWereSkipped() throws TemplateModelException {
if (elementsBeforeFirsIndexWereSkipped) {
return;
}
skipElementsBeforeFirstIndex(targetIter, firstIdx);
nextIdx = firstIdx;
elementsBeforeFirsIndexWereSkipped = true;
}
};
return resultSize != UNKNOWN_RESULT_SIZE && targetSizeKnown // targetSizeKnown => range end was validated
? new LazilyGeneratedCollectionModelWithAlreadyKnownSize(iterator, resultSize, true)
: new LazilyGeneratedCollectionModelWithUnknownSize(iterator, true);
} else { // !lazilyGeneratedResultEnabled
List resultList = resultSize != UNKNOWN_RESULT_SIZE
? new ArrayList(resultSize)
: new ArrayList();
skipElementsBeforeFirstIndex(targetIter, firstIdx);
collectElements: for (int nextIdx = firstIdx; rightUnbounded || nextIdx <= lastIdx; nextIdx++) {
if (!targetIter.hasNext()) {
if (!rightAdaptive) {
throw newRangeEndOutOfBoundsException(nextIdx, lastIdx);
}
break collectElements;
}
resultList.add(targetIter.next());
}
// List items are already wrapped:
return new SimpleSequence(resultList, _ObjectWrappers.SAFE_OBJECT_WRAPPER);
}
}
private void skipElementsBeforeFirstIndex(TemplateModelIterator targetIter, int firstIdx) throws TemplateModelException {
int nextIdx = 0;
while (nextIdx < firstIdx) {
if (!targetIter.hasNext()) {
throw new _TemplateModelException(keyExpression,
"Range start index ", Integer.valueOf(firstIdx),
" is out of bounds, as the sliced sequence only has ", nextIdx, " elements.");
}
targetIter.next();
nextIdx++;
}
}
private _TemplateModelException newRangeEndOutOfBoundsException(int nextIdx, int lastIdx) {
return new _TemplateModelException(keyExpression,
"Range end index ", Integer.valueOf(lastIdx), " is out of bounds, as sliced sequence " +
"only has ", nextIdx, " elements.");
}
// Because the order has to be reversed, we have to "buffer" the stream in this case.
private TemplateModel getStepMinus1RangeFromIterator(TemplateModelIterator targetIter, RangeModel range,
int resultSize)
throws TemplateException {
int highIndex = range.getBegining();
// Low index was found to be valid earlier. So now something like [2..*-9] becomes to [2..0] in effect.
int lowIndex = Math.max(highIndex - (range.size() - 1), 0);
final TemplateModel[] resultElements = new TemplateModel[highIndex - lowIndex + 1];
int srcIdx = 0; // With an Iterator we can only start from index 0
int dstIdx = resultElements.length - 1; // Write into the result array backwards
while (srcIdx <= highIndex && targetIter.hasNext()) {
TemplateModel element = targetIter.next();
if (srcIdx >= lowIndex) {
resultElements[dstIdx--] = element;
}
srcIdx++;
}
if (dstIdx != -1) {
throw new _MiscTemplateException(DynamicKeyName.this,
"Range top index " + highIndex + " (0-based) is outside the sliced sequence of length " +
srcIdx + ".");
}
return new SimpleSequence(Arrays.asList(resultElements), _ObjectWrappers.SAFE_OBJECT_WRAPPER);
}
private TemplateModel emptyResult(boolean seq) {
return seq
? (_TemplateAPI.getTemplateLanguageVersionAsInt(this) < _VersionInts.V_2_3_21
? new SimpleSequence(_ObjectWrappers.SAFE_OBJECT_WRAPPER)
: Constants.EMPTY_SEQUENCE)
: TemplateScalarModel.EMPTY_STRING;
}
@Override
void enableLazilyGeneratedResult() {
lazilyGeneratedResultEnabled = true;
}
@Override
public String getCanonicalForm() {
return target.getCanonicalForm()
+ "["
+ keyExpression.getCanonicalForm()
+ "]";
}
@Override
String getNodeTypeSymbol() {
return "...[...]";
}
@Override
boolean isLiteral() {
return constantValue != null || (target.isLiteral() && keyExpression.isLiteral());
}
@Override
int getParameterCount() {
return 2;
}
@Override
Object getParameterValue(int idx) {
return idx == 0 ? target : keyExpression;
}
@Override
ParameterRole getParameterRole(int idx) {
return idx == 0 ? ParameterRole.LEFT_HAND_OPERAND : ParameterRole.ENCLOSED_OPERAND;
}
@Override
protected Expression deepCloneWithIdentifierReplaced_inner(
String replacedIdentifier, Expression replacement, ReplacemenetState replacementState) {
return new DynamicKeyName(
target.deepCloneWithIdentifierReplaced(replacedIdentifier, replacement, replacementState),
keyExpression.deepCloneWithIdentifierReplaced(replacedIdentifier, replacement, replacementState));
}
}
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