org.modeshape.jcr.query.xpath.XPathParser Maven / Gradle / Ivy
/*
* ModeShape (http://www.modeshape.org)
*
* Licensed 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 org.modeshape.jcr.query.xpath;
import static org.modeshape.common.text.TokenStream.ANY_VALUE;
import java.util.ArrayList;
import java.util.List;
import org.modeshape.common.CommonI18n;
import org.modeshape.common.text.ParsingException;
import org.modeshape.common.text.Position;
import org.modeshape.common.text.TokenStream;
import org.modeshape.common.text.TokenStream.CharacterStream;
import org.modeshape.common.text.TokenStream.Tokenizer;
import org.modeshape.common.text.TokenStream.Tokens;
import org.modeshape.common.text.XmlNameEncoder;
import org.modeshape.common.xml.XmlCharacters;
import org.modeshape.jcr.GraphI18n;
import org.modeshape.jcr.api.query.qom.Operator;
import org.modeshape.jcr.query.model.Order;
import org.modeshape.jcr.query.model.TypeSystem;
import org.modeshape.jcr.query.xpath.XPath.Add;
import org.modeshape.jcr.query.xpath.XPath.And;
import org.modeshape.jcr.query.xpath.XPath.AnyKindTest;
import org.modeshape.jcr.query.xpath.XPath.AttributeNameTest;
import org.modeshape.jcr.query.xpath.XPath.AttributeTest;
import org.modeshape.jcr.query.xpath.XPath.AxisStep;
import org.modeshape.jcr.query.xpath.XPath.CommentTest;
import org.modeshape.jcr.query.xpath.XPath.Comparison;
import org.modeshape.jcr.query.xpath.XPath.Component;
import org.modeshape.jcr.query.xpath.XPath.ContextItem;
import org.modeshape.jcr.query.xpath.XPath.DescendantOrSelf;
import org.modeshape.jcr.query.xpath.XPath.DocumentTest;
import org.modeshape.jcr.query.xpath.XPath.ElementTest;
import org.modeshape.jcr.query.xpath.XPath.Except;
import org.modeshape.jcr.query.xpath.XPath.FilterStep;
import org.modeshape.jcr.query.xpath.XPath.FunctionCall;
import org.modeshape.jcr.query.xpath.XPath.Intersect;
import org.modeshape.jcr.query.xpath.XPath.KindTest;
import org.modeshape.jcr.query.xpath.XPath.Literal;
import org.modeshape.jcr.query.xpath.XPath.NameTest;
import org.modeshape.jcr.query.xpath.XPath.Negation;
import org.modeshape.jcr.query.xpath.XPath.NodeComparison;
import org.modeshape.jcr.query.xpath.XPath.NodeComparisonOperator;
import org.modeshape.jcr.query.xpath.XPath.NodeTest;
import org.modeshape.jcr.query.xpath.XPath.Or;
import org.modeshape.jcr.query.xpath.XPath.OrderBy;
import org.modeshape.jcr.query.xpath.XPath.OrderBySpec;
import org.modeshape.jcr.query.xpath.XPath.ParenthesizedExpression;
import org.modeshape.jcr.query.xpath.XPath.PathExpression;
import org.modeshape.jcr.query.xpath.XPath.ProcessingInstructionTest;
import org.modeshape.jcr.query.xpath.XPath.SchemaAttributeTest;
import org.modeshape.jcr.query.xpath.XPath.SchemaElementTest;
import org.modeshape.jcr.query.xpath.XPath.StepExpression;
import org.modeshape.jcr.query.xpath.XPath.Subtract;
import org.modeshape.jcr.query.xpath.XPath.TextTest;
import org.modeshape.jcr.query.xpath.XPath.Union;
import org.modeshape.jcr.value.ValueFormatException;
/**
* A component that parses an XPath query string and creates an abstract syntax tree representation. The supported grammar is
* defined by JCR 1.0, and is a subset of what is allowed by the W3C XPath 2.0 specification.
*/
public class XPathParser {
private final TypeSystem typeSystem;
private final XmlNameEncoder decoder = new XmlNameEncoder();
public XPathParser( TypeSystem context ) {
this.typeSystem = context;
}
public Component parseXPath( String xpath ) {
Tokenizer tokenizer = new XPathTokenizer(false); // skip comments
TokenStream tokens = new TokenStream(xpath, tokenizer, true).start(); // case sensitive!!
return parseXPath(tokens);
}
protected Component parseXPath( TokenStream tokens ) {
return parseExpr(tokens);
}
protected Component parseExpr( TokenStream tokens ) {
Component result = parseExprSingle(tokens);
if (tokens.matches(',')) {
throw new ParsingException(tokens.nextPosition(), "Multiple XPath expressions are not supported");
}
return result;
}
protected Component parseExprSingle( TokenStream tokens ) {
if (tokens.matches("for", "$", ANY_VALUE, "IN")) {
throw new ParsingException(tokens.nextPosition(), "XPath 'for' expressions are not supported");
}
if (tokens.matches("some", "$", ANY_VALUE, "IN")) {
throw new ParsingException(tokens.nextPosition(), "XPath 'some' expressions are not supported");
}
if (tokens.matches("every", "$", ANY_VALUE, "IN")) {
throw new ParsingException(tokens.nextPosition(), "XPath 'every' expressions are not supported");
}
if (tokens.matches("if", "(", ANY_VALUE, "IN")) {
throw new ParsingException(tokens.nextPosition(), "XPath if-then-else expressions are not supported");
}
return parseOrExpr(tokens);
}
protected Component parseOrExpr( TokenStream tokens ) {
Component result = parseAndExpr(tokens);
while (tokens.canConsume("or")) {
result = new Or(result, parseInstanceofExpr(tokens));
}
return result;
}
protected Component parseAndExpr( TokenStream tokens ) {
Component result = parseInstanceofExpr(tokens);
while (tokens.canConsume("and")) {
result = new And(result, parseInstanceofExpr(tokens));
}
return result;
}
protected Component parseInstanceofExpr( TokenStream tokens ) {
Component result = parseTreatExpr(tokens);
if (tokens.matches("instance", "of")) {
throw new ParsingException(tokens.nextPosition(), "XPath 'instance of' expressions are not supported");
}
return result;
}
protected Component parseTreatExpr( TokenStream tokens ) {
Component result = parseCastableExpr(tokens);
if (tokens.matches("treat", "as")) {
throw new ParsingException(tokens.nextPosition(), "XPath 'treat as' expressions are not supported");
}
return result;
}
protected Component parseCastableExpr( TokenStream tokens ) {
Component result = parseCastExpr(tokens);
if (tokens.matches("castable", "as")) {
throw new ParsingException(tokens.nextPosition(), "XPath 'castable as' expressions are not supported");
}
return result;
}
protected Component parseCastExpr( TokenStream tokens ) {
Component result = parseComparisonExpr(tokens);
if (tokens.matches("cast", "as")) {
throw new ParsingException(tokens.nextPosition(), "XPath 'cast as' expressions are not supported");
}
return result;
}
protected Component parseComparisonExpr( TokenStream tokens ) {
Component result = parseRangeExpr(tokens);
// General comparison is optional ...
Operator operator = parseGeneralComp(tokens);
if (operator == null) parseValueComp(tokens);
if (operator != null) {
return new Comparison(result, operator, parseRangeExpr(tokens));
}
NodeComparisonOperator nodeComp = parseNodeComp(tokens);
if (nodeComp != null) {
return new NodeComparison(result, nodeComp, parseRangeExpr(tokens));
}
return result;
}
protected Component parseValueComp( TokenStream tokens ) {
if (tokens.matchesAnyOf("eq", "ne", "lt", "le", "gt")) {
throw new ParsingException(tokens.nextPosition(),
"XPath value comparisons using 'eq', 'ne', 'lt', 'le', or 'gt' are not supported");
}
return null;
}
protected NodeComparisonOperator parseNodeComp( TokenStream tokens ) {
if (tokens.matches("is") || tokens.matches("<", "<") || tokens.matches(">", ">")) {
throw new ParsingException(tokens.nextPosition(), "XPath 'is', '<<' and '>>' expressions are not supported");
}
return null;
}
protected Component parseRangeExpr( TokenStream tokens ) {
Component result = parseAdditiveExpr(tokens);
if (tokens.matches("to")) {
throw new ParsingException(tokens.nextPosition(), "XPath range expressions with 'to' are not supported");
}
return result;
}
protected Component parseAdditiveExpr( TokenStream tokens ) {
Component result = parseMultiplicativeExpr(tokens);
while (true) {
if (tokens.canConsume("+")) {
result = new Add(result, parseMultiplicativeExpr(tokens));
} else if (tokens.canConsume("-")) {
result = new Subtract(result, parseMultiplicativeExpr(tokens));
} else {
break; // no more additions
}
}
return result;
}
protected Component parseMultiplicativeExpr( TokenStream tokens ) {
Component result = parseUnaryExpr(tokens);
if (tokens.matchesAnyOf("+", "div", "idiv", "mod")) {
throw new ParsingException(tokens.nextPosition(),
"XPath multiplicative expressions using '+', 'div', 'idiv', or 'mod' are not supported");
}
return result;
}
protected Component parseUnaryExpr( TokenStream tokens ) {
boolean negative = false;
// Technically more than one +/- are allowed by the spec
while (tokens.matchesAnyOf("+", "-")) {
if (tokens.canConsume("-")) negative = true;
tokens.canConsume("+");
}
Component result = parseUnionExpr(tokens);
return negative ? new Negation(result) : result;
}
protected Component parseUnionExpr( TokenStream tokens ) {
Component result = parseIntersectExceptExpr(tokens);
while (true) {
if (tokens.canConsumeAnyOf("union", "|")) {
result = new Union(result, parseIntersectExceptExpr(tokens));
} else {
break; // no more
}
}
return result;
}
protected Component parseIntersectExceptExpr( TokenStream tokens ) {
Component result = parseValueExpr(tokens);
while (true) {
if (tokens.canConsumeAnyOf("intersect")) {
result = new Intersect(result, parseValueExpr(tokens));
} else if (tokens.canConsumeAnyOf("except")) {
result = new Except(result, parseValueExpr(tokens));
} else {
break; // no more
}
}
return result;
}
protected Component parseValueExpr( TokenStream tokens ) {
return parsePathExpr(tokens);
}
protected PathExpression parsePathExpr( TokenStream tokens ) {
boolean relative = true;
boolean prependDependentOrSelf = false;
if (tokens.canConsume('/')) {
if (tokens.canConsume('/')) {
if (!tokens.hasNext()) {
// See http://www.w3.org/XML/2007/qt-errata/xpath20-errata.html#E3
throw new ParsingException(tokens.previousPosition(), "'//' is not a valid XPath expression");
}
prependDependentOrSelf = true;
}
relative = false;
}
PathExpression relativeExpr = parseRelativePathExpr(tokens);
PathExpression result = new PathExpression(relative, relativeExpr.getSteps(), relativeExpr.getOrderBy());
if (prependDependentOrSelf) {
result.getSteps().add(0, new DescendantOrSelf());
}
return result;
}
protected PathExpression parseRelativePathExpr( TokenStream tokens ) {
List steps = new ArrayList();
steps.add(parseStepExpr(tokens));
while (tokens.canConsume('/')) {
if (tokens.canConsume('/')) {
steps.add(new DescendantOrSelf());
}
if (tokens.hasNext()) {
steps.add(parseStepExpr(tokens));
}
}
OrderBy orderBy = parseOrderBy(tokens); // may be null
return new PathExpression(true, steps, orderBy);
}
protected StepExpression parseStepExpr( TokenStream tokens ) {
KindTest kindTest = parseKindTest(tokens);
if (kindTest != null) {
// Now parse the predicates ...
List predicates = parsePredicates(tokens);
return new AxisStep(kindTest, predicates);
}
if (tokens.matches('(') || tokens.matches('.') || tokens.matches(XPathTokenizer.QUOTED_STRING)
|| tokens.matches(ANY_VALUE, "(") || tokens.matches(ANY_VALUE, ":", ANY_VALUE, "(")) {
// We know its a filter expression (though literals don't fit this pattern) ...
return parseFilterExpr(tokens);
}
AxisStep result = parseAxisStep(tokens);
if (result != null) return result;
// It must be the remaining kind of filter expression ...
return parseFilterExpr(tokens);
}
protected AxisStep parseAxisStep( TokenStream tokens ) {
NodeTest nodeTest = null;
if (tokens.canConsume('@')) {
// Abbreviated forward step with an attribute...
nodeTest = new AttributeNameTest(parseNameTest(tokens));
} else if (tokens.matches('*')) {
// Abbreviated forward step with an wildcard element ...
nodeTest = parseNodeTest(tokens);
} else if (tokens.matches("child", ":", ":") || tokens.matches("attribute", ":", ":") || tokens.matches("self", ":", ":")
|| tokens.matches("descendant", ":", ":") || tokens.matches("descendant-or-self", ":", ":")
|| tokens.matches("following-sibling", ":", ":") || tokens.matches("following", ":", ":")
|| tokens.matches("namespace", ":", ":")) {
// No non-abbreviated forward steps allowed
throw new ParsingException(
tokens.nextPosition(),
"XPath non-abbreviated forward steps (e.g., 'child::', 'attribute::', 'self::', 'descendant::', 'descendant-or-self::', 'following-sibling::', 'following::', or 'namespace::') are not supported");
} else if (tokens.matches("..")) {
// No abbreviated reverse steps allowed ...
throw new ParsingException(tokens.nextPosition(), "XPath abbreviated reverse steps (e.g., '..') are not supported");
} else if (tokens.matches("parent", ":", ":") || tokens.matches("ancestor-or-self", ":", ":")
|| tokens.matches("preceding-sibling", ":", ":") || tokens.matches("preceding", ":", ":")
|| tokens.matches("ancestor", ":", ":")) {
// No non-abbreviated reverse steps allowed ...
throw new ParsingException(
tokens.nextPosition(),
"XPath non-abbreviated reverse steps (e.g., 'parent::', 'ancestor::', 'ancestor-or-self::', 'preceding-or-sibling::', or 'preceding::') are not supported");
} else if (tokens.matches(ANY_VALUE, ":", ANY_VALUE)
&& tokens.matches(XPathTokenizer.NAME, XPathTokenizer.SYMBOL, XPathTokenizer.NAME)) {
// This is probably a forward step with a (qualified) name test ...
nodeTest = parseQName(tokens);
} else if (tokens.matches(XPathTokenizer.NAME)) {
// This is probably a forward step with an unqualified name test ...
nodeTest = parseNodeTest(tokens);
} else {
return null;
}
// Parse the predicates
List predicates = parsePredicates(tokens);
return new AxisStep(nodeTest, predicates);
}
protected List parsePredicates( TokenStream tokens ) {
List predicates = new ArrayList();
while (tokens.canConsume('[')) {
predicates.add(collapse(parseExpr(tokens)));
tokens.consume(']');
}
return predicates;
}
protected FilterStep parseFilterExpr( TokenStream tokens ) {
Component primaryExpr = parsePrimaryExpr(tokens);
List predicates = parsePredicates(tokens);
return new FilterStep(primaryExpr, predicates);
}
protected Component parsePrimaryExpr( TokenStream tokens ) {
if (tokens.matches('(')) {
return parseParenthesizedExpr(tokens);
}
if (tokens.matches('.')) {
return parseContextItemExpr(tokens);
}
if (tokens.matches(XPathTokenizer.QUOTED_STRING)) {
return parseStringLiteral(tokens);
}
if (tokens.matches(ANY_VALUE, "(") || tokens.matches(ANY_VALUE, ":", ANY_VALUE, "(")) {
return parseFunctionCall(tokens);
}
return parseNumericLiteral(tokens);
}
protected ContextItem parseContextItemExpr( TokenStream tokens ) {
tokens.consume('.');
return new ContextItem();
}
protected ParenthesizedExpression parseParenthesizedExpr( TokenStream tokens ) {
tokens.consume('(');
if (tokens.canConsume(')')) {
return new ParenthesizedExpression();
}
Component expr = collapse(parseExpr(tokens));
tokens.consume(')');
return new ParenthesizedExpression(expr);
}
protected Literal parseNumericLiteral( TokenStream tokens ) {
Position pos = tokens.nextPosition();
String sign = "";
if (tokens.canConsume('-')) sign = "-";
else if (tokens.canConsume('+')) sign = "";
// Try to parse this value as a number ...
String number = tokens.consume();
if (number.indexOf(".") != -1) {
String value = sign + number;
if (value.endsWith("e") && (tokens.matches('+') || tokens.matches('-'))) {
// There's more to the number ...
value = value + tokens.consume() + tokens.consume(); // +/-EXP
}
try {
// Convert to a double and then back to a string to get canonical form ...
String canonical = typeSystem.getDoubleFactory().asString(value);
return new Literal(canonical);
} catch (ValueFormatException e) {
String msg = GraphI18n.expectingLiteralAndUnableToParseAsDouble.text(value, pos.getLine(), pos.getColumn());
throw new ParsingException(pos, msg);
}
}
// try to parse an a long ...
String value = sign + number;
try {
// Convert to a long and then back to a string to get canonical form ...
String canonical = typeSystem.getLongFactory().asString(value);
return new Literal(canonical);
} catch (ValueFormatException e) {
String msg = GraphI18n.expectingLiteralAndUnableToParseAsLong.text(value, pos.getLine(), pos.getColumn());
throw new ParsingException(pos, msg);
}
}
protected Literal parseStringLiteral( TokenStream tokens ) {
boolean removeQuotes = tokens.matches(XPathTokenizer.QUOTED_STRING);
String value = tokens.consume();
if (removeQuotes) value = removeQuotes(value);
return new Literal(value);
}
protected FunctionCall parseFunctionCall( TokenStream tokens ) {
NameTest name = parseQName(tokens);
tokens.consume("(");
List args = new ArrayList();
if (!tokens.matches(')')) {
do {
args.add(collapse(parseExprSingle(tokens)));
} while (tokens.canConsume(","));
}
tokens.consume(")");
return new FunctionCall(name, args);
}
protected Operator parseGeneralComp( TokenStream tokens ) {
if (tokens.canConsume("!", "=")) return Operator.NOT_EQUAL_TO;
if (tokens.canConsume("=")) return Operator.EQUAL_TO;
if (tokens.canConsume("<", "=")) return Operator.LESS_THAN_OR_EQUAL_TO;
if (tokens.canConsume(">", "=")) return Operator.GREATER_THAN_OR_EQUAL_TO;
if (tokens.canConsume("<")) return Operator.LESS_THAN;
if (tokens.canConsume(">")) return Operator.GREATER_THAN;
return null;
}
protected NodeTest parseNodeTest( TokenStream tokens ) {
KindTest kind = parseKindTest(tokens);
if (kind != null) return kind;
return parseNameTest(tokens);
}
protected NameTest parseNameTest( TokenStream tokens ) {
NameTest wildcard = parseWildcard(tokens);
if (wildcard != null) return wildcard;
return parseQName(tokens);
}
protected NameTest parseQName( TokenStream tokens ) {
String firstPart = parseNCName(tokens);
if (tokens.canConsume(':')) {
String secondPart = tokens.consume();
return new NameTest(decode(firstPart), decode(secondPart));
}
return new NameTest(null, decode(firstPart));
}
protected String decode( String string ) {
return decoder.decode(string);
}
protected String parseNCName( TokenStream tokens ) {
String name = tokens.consume();
if (!XmlCharacters.isValidNcName(name)) {
throw new ParsingException(tokens.previousPosition(), "Expected valid NCName but found " + name);
}
return name;
}
protected NameTest parseWildcard( TokenStream tokens ) {
if (tokens.canConsume('*')) {
if (tokens.canConsume(':')) {
if (tokens.canConsume('*')) {
return new NameTest(null, null);
}
String localName = tokens.consume();
return new NameTest(null, decode(localName));
}
return new NameTest(null, null);
}
if (tokens.matches(XPathTokenizer.NAME, XPathTokenizer.SYMBOL, XPathTokenizer.SYMBOL)
&& tokens.matches(TokenStream.ANY_VALUE, ":", "*")) {
String prefix = tokens.consume();
tokens.consume(':');
tokens.consume('*');
return new NameTest(decode(prefix), null);
}
return null;
}
protected NameTest parseItemType( TokenStream tokens ) {
return parseQName(tokens);
}
protected NameTest parseAtomicType( TokenStream tokens ) {
return parseQName(tokens);
}
protected KindTest parseKindTest( TokenStream tokens ) {
KindTest result = parseAnyKindTest(tokens);
if (result == null) result = parseDocumentTest(tokens);
if (result == null) result = parseElementTest(tokens);
if (result == null) result = parseAttributeTest(tokens);
if (result == null) result = parseSchemaElementTest(tokens);
if (result == null) result = parseSchemaAttributeTest(tokens);
if (result == null) result = parsePITest(tokens);
if (result == null) result = parseCommentTest(tokens);
if (result == null) result = parseTextTest(tokens);
return result;
}
protected AnyKindTest parseAnyKindTest( TokenStream tokens ) {
if (tokens.canConsume("node", "(", ")")) {
return new AnyKindTest();
}
return null;
}
protected ProcessingInstructionTest parsePITest( TokenStream tokens ) {
if (tokens.canConsume("processing-instruction", "(")) {
if (tokens.canConsume(")")) return new ProcessingInstructionTest(null);
String nameOrStringLiteral = tokens.consume();
tokens.consume(")");
return new ProcessingInstructionTest(nameOrStringLiteral);
}
return null;
}
protected CommentTest parseCommentTest( TokenStream tokens ) {
if (tokens.canConsume("comment", "(", ")")) {
return new CommentTest();
}
return null;
}
protected TextTest parseTextTest( TokenStream tokens ) {
if (tokens.canConsume("text", "(", ")")) {
return new TextTest();
}
return null;
}
protected DocumentTest parseDocumentTest( TokenStream tokens ) {
if (tokens.canConsume("document-node", "(")) {
// Document test ...
ElementTest elementTest = parseElementTest(tokens);
DocumentTest result = null;
if (elementTest != null) {
result = new DocumentTest(elementTest);
} else {
SchemaElementTest schemaTest = parseSchemaElementTest(tokens);
result = schemaTest != null ? new DocumentTest(schemaTest) : null;
}
tokens.consume(")");
return result;
}
return null;
}
protected ElementTest parseElementTest( TokenStream tokens ) {
if (tokens.canConsume("element", "(")) {
if (tokens.canConsume(")") || tokens.canConsume("*", ")")) {
return new ElementTest(new NameTest(null, null), new NameTest(null, null));
}
ElementTest result = null;
NameTest elementName = parseNameTest(tokens);
if (tokens.canConsume(",")) {
NameTest typeName = parseNameTest(tokens);
result = new ElementTest(elementName, typeName);
tokens.canConsume('?'); // just eat this
} else {
result = new ElementTest(elementName, new NameTest(null, null));
}
tokens.consume(")");
return result;
}
return null;
}
protected SchemaElementTest parseSchemaElementTest( TokenStream tokens ) {
if (tokens.canConsume("schema-element", "(")) {
NameTest elementDeclarationName = parseNameTest(tokens);
SchemaElementTest result = new SchemaElementTest(elementDeclarationName);
tokens.consume(")");
return result;
}
return null;
}
protected AttributeTest parseAttributeTest( TokenStream tokens ) {
if (tokens.canConsume("attribute", "(")) {
if (tokens.canConsume(")") || tokens.canConsume("*", ")")) {
return new AttributeTest(new NameTest(null, null), new NameTest(null, null));
}
AttributeTest result = null;
NameTest attributeName = parseNameTest(tokens);
if (tokens.canConsume(",")) {
NameTest typeName = parseNameTest(tokens);
result = new AttributeTest(attributeName, typeName);
} else {
result = new AttributeTest(attributeName, new NameTest(null, null));
}
tokens.consume(")");
return result;
}
return null;
}
protected SchemaAttributeTest parseSchemaAttributeTest( TokenStream tokens ) {
if (tokens.canConsume("schema-attribute", "(")) {
NameTest attributeDeclarationName = parseNameTest(tokens);
SchemaAttributeTest result = new SchemaAttributeTest(attributeDeclarationName);
tokens.consume(")");
return result;
}
return null;
}
protected void parseSingleType( TokenStream tokens ) {
}
protected void parseSequenceType( TokenStream tokens ) {
}
protected OrderBy parseOrderBy( TokenStream tokens ) {
if (tokens.canConsume("order", "by")) {
List specs = new ArrayList();
do {
OrderBySpec spec = parseOrderBySpec(tokens);
specs.add(spec);
} while (tokens.canConsume(','));
if (!specs.isEmpty()) return new OrderBy(specs);
}
return null;
}
protected OrderBySpec parseOrderBySpec( TokenStream tokens ) {
if (tokens.canConsume('@')) {
NameTest attributeName = parseQName(tokens);
Order order = Order.ASCENDING;
if (tokens.canConsume("ascending")) order = Order.ASCENDING;
else if (tokens.canConsume("descending")) order = Order.DESCENDING;
return new OrderBySpec(order, attributeName);
}
if (tokens.matches("jcr", ":", "score", "(")) {
FunctionCall scoreFunction = parseFunctionCall(tokens);
Order order = Order.ASCENDING;
if (tokens.canConsume("ascending")) order = Order.ASCENDING;
else if (tokens.canConsume("descending")) order = Order.DESCENDING;
return new OrderBySpec(order, scoreFunction);
}
PathExpression path = this.parsePathExpr(tokens);
if (!path.isRelative()) {
throw new ParsingException(tokens.nextPosition(),
"Expected either 'jcr:score(tableName)', '@', "
+ "or '/@' but absolute path was found "
+ tokens.consume());
}
List steps = path.getSteps();
if (steps.size() != 2) {
throw new ParsingException(tokens.nextPosition(),
"Expected either 'jcr:score(tableName)', '@', "
+ "or '/@' but was found "
+ tokens.consume());
}
if (!(((AxisStep)steps.get(0)).getNodeTest() instanceof NameTest)) {
throw new ParsingException(tokens.nextPosition(),
"Expected '/@' but was found "
+ tokens.consume());
}
if (!(((AxisStep)steps.get(1)).getNodeTest() instanceof AttributeNameTest)) {
throw new ParsingException(tokens.nextPosition(),
"Expected '/@' but was found "
+ tokens.consume());
}
Order order = Order.ASCENDING;
if (tokens.canConsume("ascending")) {
order = Order.ASCENDING;
} else if (tokens.canConsume("descending")) {
order = Order.DESCENDING;
}
return new OrderBySpec(order, path);
}
/**
* Remove any leading and trailing single-quotes or double-quotes from the supplied text.
*
* @param text the input text; may not be null
* @return the text without leading and trailing quotes, or text if there were no square brackets or quotes
*/
protected String removeQuotes( String text ) {
assert text != null;
if (text.length() > 2) {
char first = text.charAt(0);
// Need to remove these only if they are paired ...
if (first == '"' || first == '\'') {
int indexOfLast = text.length() - 1;
char last = text.charAt(indexOfLast);
if (last == first) {
text = text.substring(1, indexOfLast);
}
}
}
return text;
}
protected Component collapse( Component component ) {
return component.collapse();
}
/**
* A {@link org.modeshape.common.text.TokenStream.Tokenizer} implementation that parses single- and double-quoted strings,
* symbols, words consisting of {@link org.modeshape.common.text.TokenStream.CharacterStream#isNextValidXmlNcNameCharacter()
* NCName}s (as defined by the Namespaces in XML 1.0
* specification), XPath comments,and {@link #OTHER other} single-character tokens. Quoted phrases are delimited by
* single-quote and double-quote characters (which may be escaped within the quote). XPath comments begin with a "(:" and end
* with a ":)".
*/
public static class XPathTokenizer implements TokenStream.Tokenizer {
/**
* The token type for tokens that represent an unquoted string containing a character sequence made up of non-whitespace
* and non-symbol characters.
*/
public static final int NAME = 2 << 0;
/**
* The token type for tokens that consist of an individual "symbol" character. The set of characters includes:
* (){}*.,;+%?$!<>|=:-[]^/\#@
*/
public static final int SYMBOL = 2 << 1;
/**
* The token type for tokens that consist of all the characters within single-quotes, double-quotes, or square brackets.
*/
public static final int QUOTED_STRING = 2 << 2;
/**
* The token type for tokens that consist of all the characters between "(:" and ":)".
*/
public static final int COMMENT = 2 << 3;
/**
* The token type for tokens that consist of single characters that are not a {@link #SYMBOL}, valid {@link #NAME}, or
* {@link #QUOTED_STRING}.
*/
public static final int OTHER = 2 << 4;
private final boolean useComments;
public XPathTokenizer( boolean useComments ) {
this.useComments = useComments;
}
@Override
public void tokenize( CharacterStream input,
Tokens tokens ) throws ParsingException {
while (input.hasNext()) {
char c = input.next();
switch (c) {
case ' ':
case '\t':
case '\n':
case '\r':
// Just skip these whitespace characters ...
break;
case ')':
case '{':
case '}':
case '*':
case '.':
case ',':
case ';':
case '+':
case '%':
case '?':
case '$':
case '!':
case '<':
case '>':
case '|':
case '=':
case ':':
case '-':
case '[':
case ']':
case '^':
case '/':
case '\\':
case '#':
case '@':
tokens.addToken(input.position(input.index()), input.index(), input.index() + 1, SYMBOL);
break;
case '\'':
case '\"':
int startIndex = input.index();
char closingChar = c;
Position pos = input.position(startIndex);
boolean foundClosingQuote = false;
while (input.hasNext()) {
c = input.next();
if (c == closingChar && input.isNext(closingChar)) {
c = input.next(); // consume the next closeChar since it is escaped
} else if (c == closingChar) {
foundClosingQuote = true;
break;
}
}
if (!foundClosingQuote) {
String msg = CommonI18n.noMatchingDoubleQuoteFound.text(pos.getLine(), pos.getColumn());
if (closingChar == '\'') {
msg = CommonI18n.noMatchingSingleQuoteFound.text(pos.getLine(), pos.getColumn());
}
throw new ParsingException(pos, msg);
}
int endIndex = input.index() + 1; // beyond last character read
tokens.addToken(pos, startIndex, endIndex, QUOTED_STRING);
break;
case '(':
startIndex = input.index();
if (input.isNext(':')) {
// This is a comment ...
pos = input.position(startIndex);
while (input.hasNext() && !input.isNext(':', ')')) {
c = input.next();
}
if (input.hasNext()) input.next(); // consume the ':'
if (input.hasNext()) input.next(); // consume the ')'
if (useComments) {
endIndex = input.index() + 1; // the token will include the closing ':' and ')' characters
tokens.addToken(pos, startIndex, endIndex, COMMENT);
}
} else {
tokens.addToken(input.position(startIndex), input.index(), input.index() + 1, SYMBOL);
break;
}
break;
default:
startIndex = input.index();
pos = input.position(startIndex);
// Read as long as there is a valid XML character ...
int tokenType = (XmlCharacters.isValidNcNameStart(c)) ? NAME : OTHER;
while (input.isNextValidXmlNcNameCharacter()) {
c = input.next();
}
endIndex = input.index() + 1; // beyond last character that was included
tokens.addToken(pos, startIndex, endIndex, tokenType);
}
}
}
}
}
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