https://github.com/jOOQ/jOOX: jOOX is a recursive acronym that stands for jOOX Object Oriented XML. It is a simple wrapper for the org.w3c.dom package, to allow for fluent XML document creation and manipulation where DOM is required but too verbose.
- Lukas Eder
/*
* 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.joox.selector;
import java.util.List;
import java.util.regex.Pattern;
A utility class converting CSS selector expressions to XPath expressions.
This class is a facade for the more extensive functionality provided by the
css-selectors project created by Christer Sandberg. jOOX does
not expose that functionality publicly.
Author: Lukas Eder See Also:
/**
* A utility class converting CSS selector expressions to XPath expressions.
* <p>
* This class is a facade for the more extensive functionality provided by the
* <code>css-selectors</code> project created by Christer Sandberg. jOOX does
* not expose that functionality publicly.
*
* @author Lukas Eder
* @see <a
* href="https://github.com/chrsan/css-selectors">https://github.com/chrsan/css-selectors</a>
* @see <a
* href="http://www.w3.org/TR/selectors/#selectors">http://www.w3.org/TR/selectors/#selectors</a>
*/
public final class CSS2XPath {
A selector pattern that can be evaluated using standard DOM API
/**
* A selector pattern that can be evaluated using standard DOM API
*/
private final static Pattern SIMPLE_SELECTOR = Pattern.compile("[\\w\\-]+");
Convert a CSS selector expression to an XPath expression
/**
* Convert a CSS selector expression to an XPath expression
*/
public static final String css2xpath(String css) {
return css2xpath(css, true);
}
Convert a CSS selector expression to an XPath expression
/**
* Convert a CSS selector expression to an XPath expression
*/
public static final String css2xpath(String css, boolean isRoot) {
Scanner scanner = new Scanner(css);
List<List<Selector>> selectors = scanner.scan();
StringBuilder sb = new StringBuilder();
String selectorSeparator = "";
for (List<Selector> selector : selectors) {
sb.append(selectorSeparator);
// [#95] Append a dot if we should match only descendants of a
// non-root element
if (!isRoot) {
sb.append(".");
}
for (Selector s : selector) {
switch (s.getCombinator()) {
case CHILD:
sb.append("/");
break;
case DESCENDANT:
sb.append("//");
break;
case ADJACENT_SIBLING:
// TODO: Implement this
sb.append("?????");
break;
case GENERAL_SIBLING:
// TODO: Implement this
sb.append("?????");
break;
}
// [#163] To stay on the safe side, we need namespace unaware XPath expressions here
// Do this only for actual tag names, not e.g. * or other special characters
if (SIMPLE_SELECTOR.matcher(s.getTagName()).matches())
sb.append("*[local-name() = '").append(s.getTagName()).append("']");
else
sb.append(s.getTagName());
// [#163] This would be an XPath 2.0 syntax, not supported by Java's built-in XPath libraries
// sb.append("*:").append(s.getTagName());
if (s.hasSpecifiers()) {
for (Specifier specifier : s.getSpecifiers()) {
switch (specifier.getType()) {
case ATTRIBUTE: {
AttributeSpecifier a = ((AttributeSpecifier) specifier);
sb.append("[");
if (a.getMatch() == null) {
sb.append("@");
sb.append(a.getName());
}
else {
switch (a.getMatch()) {
case EXACT: {
sb.append("@");
sb.append(a.getName());
sb.append("='");
sb.append(a.getValue().replace("'", "\\'"));
sb.append("'");
break;
}
case CONTAINS: {
sb.append("contains(@");
sb.append(a.getName());
sb.append(", '");
sb.append(a.getValue().replace("'", "\\'"));
sb.append("')");
break;
}
case HYPHEN: {
sb.append("@");
sb.append(a.getName());
sb.append("='");
sb.append(a.getValue().replace("'", "\\'"));
sb.append("' or starts-with(@");
sb.append(a.getName());
sb.append(", '");
sb.append(a.getValue().replace("'", "\\'"));
sb.append("-')");
break;
}
case PREFIX: {
sb.append("starts-with(@");
sb.append(a.getName());
sb.append(", '");
sb.append(a.getValue().replace("'", "\\'"));
sb.append("')");
break;
}
case SUFFIX: {
endsWith(sb, a.getName(), a.getValue());
break;
}
case LIST: {
sb.append("@");
sb.append(a.getName());
sb.append("='");
sb.append(a.getValue().replace("'", "\\'"));
sb.append("' or starts-with(@");
sb.append(a.getName());
sb.append(", '");
sb.append(a.getValue().replace("'", "\\'"));
sb.append(" ')");
sb.append(" or ");
endsWith(sb, a.getName(), " " + a.getValue());
sb.append(" or contains(@");
sb.append(a.getName());
sb.append(", ' ");
sb.append(a.getValue().replace("'", "\\'"));
sb.append(" ')");
break;
}
}
}
sb.append("]");
break;
}
case NEGATION: {
sb.append("[not(");
// TODO: implement this..??
sb.append(")]");
break;
}
case PSEUDO: {
if (specifier instanceof PseudoClassSpecifier) {
PseudoClassSpecifier p = ((PseudoClassSpecifier) specifier);
String value = p.getValue();
if ("empty".equals(value))
sb.append("[not(*|@*|node())]");
else if ("first-child".equals(value))
sb.append("[not(preceding-sibling::*)]");
else if ("last-child".equals(value))
sb.append("[not(following-sibling::*)]");
else if ("only-child".equals(value))
sb.append("[not(preceding-sibling::*) and not(following-sibling::*)]");
else if ("root".equals(value))
sb.append("[not(parent::*)]");
}
else if (specifier instanceof PseudoNthSpecifier) {
PseudoNthSpecifier p = ((PseudoNthSpecifier) specifier);
String value = p.getValue();
if ("nth-child".equals(value)) {
sb.append("[count(preceding-sibling::*) = ");
sb.append(p.getArgument());
sb.append(" - 1]");
}
// TODO: Implement this...?
}
break;
}
}
}
}
}
selectorSeparator = " | ";
}
return sb.toString();
}
XPath 2.0
ends-with($str1, $str2)
is equivalent to XPath 1.0
$str2 = substring($str1, string-length($str1) - string-length($str2) + 1)
/**
* XPath 2.0<br/><br/><code>ends-with($str1, $str2)</code><br/><br/> is equivalent to XPath 1.0<br/><br/>
* <code>$str2 = substring($str1, string-length($str1) - string-length($str2) + 1)</code>
*/
private static void endsWith(StringBuilder sb, String attr, String value) {
sb.append("'");
sb.append(value.replace("'", "\\'"));
sb.append("' = substring(@");
sb.append(attr);
sb.append(", string-length(@");
sb.append(attr);
sb.append(") - string-length('");
sb.append(value.replace("'", "\\'"));
sb.append("') + 1)");
}
}