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An OSGi bundle for Saxon-HE
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2013 Saxonica Limited.
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is "Incompatible With Secondary Licenses", as defined by the Mozilla Public License, v. 2.0.
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
package net.sf.saxon.s9api;
import net.sf.saxon.expr.StaticContext;
import net.sf.saxon.expr.sort.RuleBasedSubstringMatcher;
import net.sf.saxon.expr.sort.SimpleCollation;
import net.sf.saxon.lib.NamespaceConstant;
import net.sf.saxon.lib.StringCollator;
import net.sf.saxon.sxpath.*;
import net.sf.saxon.trans.DecimalFormatManager;
import net.sf.saxon.trans.DecimalSymbols;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.type.ValidationException;
import net.sf.saxon.value.DecimalValue;
import net.sf.saxon.value.SequenceType;
import java.net.URI;
import java.net.URISyntaxException;
import java.text.Collator;
import java.text.RuleBasedCollator;
import java.util.Iterator;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
/**
* An XPathCompiler object allows XPath queries to be compiled. The compiler holds information that
* represents the static context for an XPath expression.
*
* To construct an XPathCompiler, use the factory method
* {@link Processor#newXPathCompiler}.
*
* An XPathCompiler may be used repeatedly to compile multiple
* queries. Any changes made to the XPathCompiler (that is, to the
* static context) do not affect queries that have already been compiled.
* An XPathCompiler may be used concurrently in multiple threads, but
* it should not then be modified once initialized.
*
* Changes to an XPathCompiler are cumulative. There is no simple way to reset
* the XPathCompiler to its initial state; instead, simply create a new
* XPathCompiler.
*
* The XPathCompiler has the ability to maintain a cache of compiled
* expressions. This is active only if enabled by calling {@link #setCaching(boolean)}.
* If caching is enabled, then the compiler will recognize an attempt to compile
* the same expression twice, and will avoid the cost of recompiling it. The cache
* is emptied by any method that changes the static context for subsequent expressions,
* for example, {@link #setBaseURI(java.net.URI)}. Unless the cache is emptied,
* it grows indefinitely: compiled expressions are never discarded.
*
* @since 9.0
*/
public class XPathCompiler {
private Processor processor;
private IndependentContext env;
private ItemType requiredContextItemType;
/*@Nullable*/ private Map cache = null;
//private Map symbolsMap = new HashMap();
/**
* Protected constructor
*
* @param processor the s9api Processor
*/
protected XPathCompiler(Processor processor) {
this.processor = processor;
env = new IndependentContext(processor.getUnderlyingConfiguration());
}
/**
* Get the Processor from which this XPathCompiler was constructed
*
* @return the Processor to which this XPathCompiler belongs
* @since 9.3
*/
public Processor getProcessor() {
return processor;
}
/**
* Set whether XPath 1.0 backwards compatibility mode is to be used. In backwards compatibility
* mode, more implicit type conversions are allowed in XPath expressions, for example it
* is possible to compare a number with a string. The default is false (backwards compatibility
* mode is off).
*
* @param option true if XPath 1.0 backwards compatibility is to be enabled, false if it is to
* be disabled.
*/
public void setBackwardsCompatible(boolean option) {
if (cache != null) {
cache.clear();
}
env.setBackwardsCompatibilityMode(option);
}
/**
* Ask whether XPath 1.0 backwards compatibility mode is in force.
*
* @return true if XPath 1.0 backwards compatibility is enabled, false if it is disabled.
*/
public boolean isBackwardsCompatible() {
return env.isInBackwardsCompatibleMode();
}
/**
* Say whether XPath expressions compiled using this XPathCompiler are
* schema-aware. They will automatically be schema-aware if the method
* {@link #importSchemaNamespace(String)} is called. An XPath expression
* must be marked as schema-aware if it is to handle typed (validated)
* input documents.
*
* @param schemaAware true if expressions are to be schema-aware, false otherwise
* @since 9.3
*/
public void setSchemaAware(boolean schemaAware) {
env.setSchemaAware(schemaAware);
}
/**
* Ask whether XPath expressions compiled using this XPathCompiler are
* schema-aware. They will automatically be schema-aware if the method
* {@link #importSchemaNamespace(String)} is called. An XPath expression
* must be marked as schema-aware if it is to handle typed (validated)
* input documents.
*
* @return true if expressions are to be schema-aware, false otherwise
* @since 9.3
*/
public boolean isSchemaAware() {
return env.isSchemaAware();
}
/**
* Say whether an XPath 2.0 or XPath 3.0 processor is required.
*
* @param version Must be numerically equal to 1.0, 2.0 or 3.0. Currently
* support for XPath 3.0 is incomplete: check the release notes.
* Setting the option to 1.0 requests an XPath 2.0 processor running in 1.0 compatibility mode;
* this is equivalent to setting the language version to 2.0 and backwards compatibility mode to true.
* @throws IllegalArgumentException if the version is not numerically equal to 1.0, 2.0 or 3.0.
* @since 9.3
*/
public void setLanguageVersion(String version) {
if (cache != null) {
cache.clear();
}
DecimalValue dv;
try {
dv = (DecimalValue) DecimalValue.makeDecimalValue(version, true).asAtomic();
} catch (ValidationException err) {
throw new IllegalArgumentException("Language version must be in the form of a decimal number");
}
if (DecimalValue.ONE.equals(dv)) {
dv = DecimalValue.TWO;
env.setBackwardsCompatibilityMode(true);
}
if (!DecimalValue.ONE.equals(dv) && !DecimalValue.TWO.equals(dv) && !DecimalValue.THREE.equals(dv)) {
throw new IllegalArgumentException("Unknown XPath language version " + version);
}
env.setXPathLanguageLevel(dv);
}
/**
* Ask whether an XPath 2.0 or XPath 3.0 processor is being used
*
* @return version: "2.0" or "3.0"
* @since 9.3
*/
public String getLanguageVersion() {
return (env.getXPathLanguageLevel().equals(DecimalValue.TWO) ? "2.0" : "3.0");
}
/**
* Set the static base URI for XPath expressions compiled using this XPathCompiler. The base URI
* is part of the static context, and is used to resolve any relative URIs appearing within an XPath
* expression, for example a relative URI passed as an argument to the doc() function. If no
* static base URI is supplied, then the current working directory is used.
*
* @param uri the base URI to be set in the static context. This must be an absolute URI, or null
* to indicate that no static base URI is available.
*/
public void setBaseURI(URI uri) {
if (cache != null) {
cache.clear();
}
if (uri == null) {
env.setBaseURI(null);
} else {
if (!uri.isAbsolute()) {
throw new IllegalArgumentException("Supplied base URI must be absolute");
}
env.setBaseURI(uri.toString());
}
}
/**
* Get the static base URI for XPath expressions compiled using this XPathCompiler. The base URI
* is part of the static context, and is used to resolve any relative URIs appearing within an XPath
* expression, for example a relative URI passed as an argument to the doc() function. If no
* static base URI has been explicitly set, this method returns null.
*
* @return the base URI from the static context
*/
public URI getBaseURI() {
try {
return new URI(env.getBaseURI());
} catch (URISyntaxException err) {
throw new IllegalStateException(err);
}
}
/**
* Declare a namespace binding as part of the static context for XPath expressions compiled using this
* XPathCompiler
*
* @param prefix The namespace prefix. If the value is a zero-length string, this method sets the default
* namespace for elements and types.
* @param uri The namespace URI. It is possible to specify a zero-length string to "undeclare" a namespace;
* in this case the prefix will not be available for use, except in the case where the prefix
* is also a zero length string, in which case the absence of a prefix implies that the name
* is in no namespace.
* @throws NullPointerException if either the prefix or uri is null.
*/
public void declareNamespace(String prefix, String uri) {
if (cache != null) {
cache.clear();
}
env.declareNamespace(prefix, uri);
}
/**
* Import a schema namespace: that is, add the element and attribute declarations and type definitions
* contained in a given namespace to the static context for the XPath expression.
*
* This method will not cause the schema to be loaded. That must be done separately, using the
* {@link SchemaManager}. This method will not fail if the schema has not been loaded (but in that case
* the set of declarations and definitions made available to the XPath expression is empty). The schema
* document for the specified namespace may be loaded before or after this method is called.
*
* This method does not bind a prefix to the namespace. That must be done separately, using the
* {@link #declareNamespace(String, String)} method.
*
* @param uri The schema namespace to be imported. To import declarations in a no-namespace schema,
* supply a zero-length string.
* @since 9.1
*/
public void importSchemaNamespace(String uri) {
if (cache != null) {
cache.clear();
}
env.getImportedSchemaNamespaces().add(uri);
env.setSchemaAware(true);
}
/**
* Say whether undeclared variables are allowed. By default, they are not allowed. When
* undeclared variables are allowed, it is not necessary to predeclare the variables that
* may be used in the XPath expression; instead, a variable is automatically declared when a reference
* to the variable is encountered within the expression.
*
* @param allow true if undeclared variables are allowed, false if they are not allowed.
* @since 9.2
*/
public void setAllowUndeclaredVariables(boolean allow) {
if (cache != null) {
cache.clear();
}
env.setAllowUndeclaredVariables(allow);
}
/**
* Ask whether undeclared variables are allowed. By default, they are not allowed. When
* undeclared variables are allowed, it is not necessary to predeclare the variables that
* may be used in the XPath expression; instead, a variable is automatically declared when a reference
* to the variable is encountered within the expression.
*
* @return true if undeclared variables are allowed, false if they are not allowed.
* @since 9.2
*/
public boolean isAllowUndeclaredVariables() {
return env.isAllowUndeclaredVariables();
}
/**
* Declare a variable as part of the static context for XPath expressions compiled using this
* XPathCompiler. It is an error for the XPath expression to refer to a variable unless it has been
* declared. This method declares the existence of the variable, but it does not
* bind any value to the variable; that is done later, when the XPath expression is evaluated.
* The variable is allowed to have any type (that is, the required type is item()*).
*
* @param qname The name of the variable, expressions as a QName
*/
public void declareVariable(QName qname) {
if (cache != null) {
cache.clear();
}
env.declareVariable(qname.getNamespaceURI(), qname.getLocalName());
//declaredVariables.add(var);
}
/**
* Declare a variable as part of the static context for XPath expressions compiled using this
* XPathCompiler. It is an error for the XPath expression to refer to a variable unless it has been
* declared. This method declares the existence of the variable, and defines the required type
* of the variable, but it does not bind any value to the variable; that is done later,
* when the XPath expression is evaluated.
*
* @param qname The name of the variable, expressed as a QName
* @param itemType The required item type of the value of the variable
* @param occurrences The allowed number of items in the sequence forming the value of the variable
* @throws SaxonApiException if the requiredType is syntactically invalid or if it refers to namespace
* prefixes or schema components that are not present in the static context
*/
public void declareVariable(QName qname, ItemType itemType, OccurrenceIndicator occurrences) throws SaxonApiException {
if (cache != null) {
cache.clear();
}
XPathVariable var = env.declareVariable(qname.getNamespaceURI(), qname.getLocalName());
var.setRequiredType(
SequenceType.makeSequenceType(
itemType.getUnderlyingItemType(), occurrences.getCardinality()));
}
/**
* Declare the static type of the context item. If this type is declared, and if a context item
* is supplied when the query is invoked, then the context item must conform to this type (no
* type conversion will take place to force it into this type).
*
* @param type the required type of the context item
* @since 9.3
*/
public void setRequiredContextItemType(ItemType type) {
requiredContextItemType = type;
env.setRequiredContextItemType(type.getUnderlyingItemType());
}
/**
* Get the required type of the context item. If no type has been explicitly declared for the context
* item, an instance of AnyItemType (representing the type item()) is returned.
*
* @return the required type of the context item
* @since 9.3
*/
public ItemType getRequiredContextItemType() {
return requiredContextItemType;
}
/**
* Bind a collation URI to a collation
*
* @param uri the absolute collation URI
* @param collation a {@link Collator} object that implements the required collation
* @throws IllegalArgumentException if an attempt is made to rebind the standard URI
* for the Unicode codepoint collation
* @since 9.4
*/
public void declareCollation(String uri, final java.text.Collator collation) {
if (uri.equals(NamespaceConstant.CODEPOINT_COLLATION_URI)) {
throw new IllegalArgumentException("Cannot declare the Unicode codepoint collation URI");
}
StringCollator saxonCollation;
if (collation instanceof RuleBasedCollator) {
saxonCollation = new RuleBasedSubstringMatcher((RuleBasedCollator) collation);
} else {
saxonCollation = new SimpleCollation(collation);
}
env.getCollationMap().setNamedCollation(uri, saxonCollation);
}
/**
* Declare the default collation
*
* @param uri the absolute URI of the default collation. This URI must have been bound to a collation
* using the method {@link #declareCollation(String, Collator)}
* @throws IllegalStateException if the collation URI has not been registered, unless it is the standard
* Unicode codepoint collation which is registered implicitly
* @since 9.4
*/
public void declareDefaultCollation(String uri) {
if (env.getCollationMap().getNamedCollation(uri) == null) {
throw new IllegalStateException("Unknown collation " + uri);
}
env.getCollationMap().setDefaultCollationName(uri);
}
/**
* Say whether the compiler should maintain a cache of compiled expressions.
*
* @param caching if set to true, caching of compiled expressions is enabled.
* If set to false, any existing cache is cleared, and future compiled expressions
* will not be cached until caching is re-enabled. The cache is also cleared
* (but without disabling future caching)
* if any method is called that changes the static context for compiling
* expressions, for example {@link #declareVariable(QName)} or
* {@link #declareNamespace(String, String)}.
* @since 9.3
*/
public void setCaching(boolean caching) {
if (caching) {
if (cache == null) {
cache = new ConcurrentHashMap();
}
} else {
cache = null;
}
}
/**
* Ask whether the compiler is maintaining a cache of compiled expressions
*
* @return true if a cache is being maintained
* @since 9.3
*/
public boolean isCaching() {
return cache != null;
}
/**
* Compile an XPath expression, supplied as a character string.
*
* @param source A string containing the source text of the XPath expression
* @return An XPathExecutable which represents the compiled xpath expression object.
* The XPathExecutable may be run as many times as required, in the same or a different thread.
* The XPathExecutable is not affected by any changes made to the XPathCompiler once it has been compiled.
* @throws SaxonApiException if any static error is detected while analyzing the expression
*/
public XPathExecutable compile(String source) throws SaxonApiException {
if (cache != null) {
synchronized (this) {
XPathExecutable expr = cache.get(source);
if (expr == null) {
expr = internalCompile(source);
cache.put(source, expr);
}
return expr;
}
} else {
return internalCompile(source);
}
}
private XPathExecutable internalCompile(String source) throws SaxonApiException {
try {
env.getDecimalFormatManager().checkConsistency();
} catch (net.sf.saxon.trans.XPathException e) {
throw new SaxonApiException(e);
}
IndependentContext ic = env;
if (ic.isAllowUndeclaredVariables()) {
// self-declaring variables modify the static context. The XPathCompiler must not change state
// as the result of compiling an expression, so we need to copy the static context.
ic = new DedicatedStaticContext(env);
for (Iterator iter = env.iterateExternalVariables(); iter.hasNext(); ) {
XPathVariable var = (XPathVariable) iter.next();
XPathVariable var2 = ic.declareVariable(var.getVariableQName());
var2.setRequiredType(var.getRequiredType());
}
}
try {
XPathEvaluator eval = new XPathEvaluator(processor.getUnderlyingConfiguration());
eval.setStaticContext(ic);
XPathExpression cexp = eval.createExpression(source);
cexp.getInternalExpression().getExecutable().setCollationMap(env.getCollationMap());
return new XPathExecutable(cexp, processor, ic);
} catch (XPathException e) {
throw new SaxonApiException(e);
}
}
/**
* Compile and evaluate an XPath expression, supplied as a character string, with a given
* context item.
*
* @param expression A string containing the source text of the XPath expression
* @param contextItem The context item to be used for evaluating the expression. This
* may be null if the expression is to be evaluated with no context item.
* @return the result of evaluating the XPath expression with this context item. Note that
* the result is an iterable, so that it can be used in a construct such as
* for (XdmItem item : xpath.evaluate("//x", doc) {...}
* @throws SaxonApiException if any static error is detected while analyzing the expression,
* or if any dynamic error is detected while evaluating it.
* @since 9.3
*/
public XdmValue evaluate(String expression, /*@Nullable*/ XdmItem contextItem) throws SaxonApiException {
XPathSelector selector = compile(expression).load();
if (contextItem != null) {
selector.setContextItem(contextItem);
}
return selector.evaluate();
}
/**
* Compile and evaluate an XPath expression whose result is expected to be
* a single item, with a given context item. The expression is supplied as
* a character string.
*
* @param expression A string containing the source text of the XPath expression
* @param contextItem The context item to be used for evaluating the expression. This
* may be null if the expression is to be evaluated with no context item.
* @return the result of evaluating the XPath expression with this context item.
* If the result is a singleton it is returned as an XdmItem; if it is an empty
* sequence, the return value is null. If the expression returns a sequence of more than one item,
* any items after the first are ignored.
* @throws SaxonApiException if any static error is detected while analyzing the expression,
* or if any dynamic error is detected while evaluating it.
* @since 9.3
*/
public XdmItem evaluateSingle(String expression, /*@Nullable*/ XdmItem contextItem) throws SaxonApiException {
XPathSelector selector = compile(expression).load();
if (contextItem != null) {
selector.setContextItem(contextItem);
}
return selector.evaluateSingle();
}
/**
* Compile an XSLT 2.0 pattern, supplied as a character string. The compiled pattern behaves as a boolean
* expression which, when evaluated in a particular context, returns true if the context node matches
* the pattern, and false if it does not. An error is reported if there is no context item or it the context
* item is not a node.
*
* @param source A string conforming to the syntax of XSLT 2.0 patterns
* @return An XPathExecutable representing an expression which evaluates to true when the context node matches
* the pattern, and false when it does not.
* @throws SaxonApiException if the pattern contains static errors: for example, if its syntax is incorrect,
* or if it refers to undeclared variables or namespaces
* @since 9.1
*/
public XPathExecutable compilePattern(String source) throws SaxonApiException {
try {
env.getDecimalFormatManager().checkConsistency();
} catch (net.sf.saxon.trans.XPathException e) {
throw new SaxonApiException(e);
}
try {
XPathEvaluator eval = new XPathEvaluator(processor.getUnderlyingConfiguration());
eval.setStaticContext(env);
XPathExpression cexp = eval.createPattern(source);
return new XPathExecutable(cexp, processor, env);
} catch (XPathException e) {
throw new SaxonApiException(e);
}
}
/**
* Registers the required decimal format properties
*
* @param format The name of the decimal format
* @param property The decimal symbols name to update
* @param value The value to update the decimal symbol property
* @throws SaxonApiException if there are two conflicting definitions of the named decimal-format
* @since 9.4
*/
public void setDecimalFormatProperty(QName format, String property, String value) throws SaxonApiException {
DecimalFormatManager dfm = env.getDecimalFormatManager();
if (dfm == null) {
dfm = new DecimalFormatManager();
env.setDecimalFormatManager(dfm);
}
DecimalSymbols symbols = dfm.getNamedDecimalFormat(format.getStructuredQName());
try {
if (property.equals("decimal-separator")) {
symbols.setDecimalSeparator((value));
} else if (property.equals("grouping-separator")) {
symbols.setGroupingSeparator((value));
} else if (property.equals("infinity")) {
symbols.setInfinity(value);
} else if (property.equals("NaN")) {
symbols.setNaN(value);
} else if (property.equals("minus-sign")) {
symbols.setMinusSign((value));
} else if (property.equals("percent")) {
symbols.setPercent((value));
} else if (property.equals("per-mille")) {
symbols.setPerMille((value));
} else if (property.equals("zero-digit")) {
symbols.setZeroDigit((value));
} else if (property.equals("digit")) {
symbols.setDigit((value));
} else if (property.equals("pattern-separator")) {
symbols.setPatternSeparator((value));
} else {
throw new IllegalArgumentException("**** Unknown decimal format attribute " + property);
}
} catch (XPathException e) {
throw new SaxonApiException(e);
}
}
/**
* Escape-hatch method to get the underlying static context object used by the implementation.
*
* @return the underlying static context object. In the current implementation this will always
* be an instance of {@link IndependentContext}.
*
* This method provides an escape hatch to internal Saxon implementation objects that offer a finer and
* lower-level degree of control than the s9api classes and methods. Some of these classes and methods may change
* from release to release.
* @since 9.1
*/
public StaticContext getUnderlyingStaticContext() {
return env;
}
}