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// Copyright (c) 2003-present, Jodd Team (http://jodd.org)
// 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.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS 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 COPYRIGHT HOLDER OR 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.
package jodd.lagarto.dom;
import jodd.csselly.CSSelly;
import jodd.csselly.Combinator;
import jodd.csselly.CssSelector;
import java.util.ArrayList;
import java.util.Collection;
import java.util.LinkedList;
import java.util.List;
/**
* Node selector selects DOM nodes using {@link CSSelly CSS3 selectors}.
* Group of queries are supported.
*/
public class NodeSelector {
protected final Node rootNode;
public NodeSelector(final Node rootNode) {
this.rootNode = rootNode;
}
// ---------------------------------------------------------------- selector
/**
* Selects nodes using CSS3 selector query.
*/
public List select(final String query) {
Collection> selectorsCollection = CSSelly.parse(query);
return select(selectorsCollection);
}
/**
* Selected nodes using pre-parsed CSS selectors. Take in consideration
* collection type for results grouping order.
*/
public List select(final Collection> selectorsCollection) {
List results = new ArrayList<>();
for (List selectors : selectorsCollection) {
processSelectors(results, selectors);
}
return results;
}
/**
* Process selectors and keep adding results.
*/
protected void processSelectors(final List results, final List selectors) {
List selectedNodes = select(rootNode, selectors);
for (Node selectedNode : selectedNodes) {
if (!results.contains(selectedNode)) {
results.add(selectedNode);
}
}
}
/**
* Selects nodes using CSS3 selector query and returns the very first one.
*/
public Node selectFirst(final String query) {
List selectedNodes = select(query);
if (selectedNodes.isEmpty()) {
return null;
}
return selectedNodes.get(0);
}
/**
* Selects nodes using {@link NodeFilter node filter}.
*/
public List select(final NodeFilter nodeFilter) {
List nodes = new ArrayList<>();
walk(rootNode, nodeFilter, nodes);
return nodes;
}
/**
* Selects nodes using {@link NodeFilter node filter} and return the very first one.
*/
public Node selectFirst(final NodeFilter nodeFilter) {
List selectedNodes = select(nodeFilter);
if (selectedNodes.isEmpty()) {
return null;
}
return selectedNodes.get(0);
}
// ---------------------------------------------------------------- internal
protected void walk(final Node rootNode, final NodeFilter nodeFilter, final List result) {
int childCount = rootNode.getChildNodesCount();
for (int i = 0; i < childCount; i++) {
Node node = rootNode.getChild(i);
if (nodeFilter.accept(node)) {
result.add(node);
}
walk(node, nodeFilter, result);
}
}
protected List select(final Node rootNode, final List selectors) {
// start with the root node
List nodes = new ArrayList<>();
nodes.add(rootNode);
// iterate all selectors
for (CssSelector cssSelector : selectors) {
// create new set of results for current css selector
List selectedNodes = new ArrayList<>();
for (Node node : nodes) {
walk(node, cssSelector, selectedNodes);
}
// post-processing: filter out the results
List resultNodes = new ArrayList<>();
int index = 0;
for (Node node : selectedNodes) {
boolean match = filter(selectedNodes, node, cssSelector, index);
if (match) {
resultNodes.add(node);
}
index++;
}
// continue with results
nodes = resultNodes;
}
return nodes;
}
/**
* Walks over the child notes, maintaining the tree order and not using recursion.
*/
protected void walkDescendantsIteratively(final LinkedList nodes, final CssSelector cssSelector, final List result) {
while (!nodes.isEmpty()) {
Node node = nodes.removeFirst();
selectAndAdd(node, cssSelector, result);
// append children in walking order to be processed right after this node
int childCount = node.getChildNodesCount();
for (int i = childCount - 1; i >= 0; i--) {
nodes.addFirst(node.getChild(i));
}
}
}
/**
* Finds nodes in the tree that matches single selector.
*/
protected void walk(final Node rootNode, final CssSelector cssSelector, final List result) {
// previous combinator determines the behavior
CssSelector previousCssSelector = cssSelector.getPrevCssSelector();
Combinator combinator = previousCssSelector != null ?
previousCssSelector.getCombinator() :
Combinator.DESCENDANT;
switch (combinator) {
case DESCENDANT:
LinkedList nodes = new LinkedList<>();
int childCount = rootNode.getChildNodesCount();
for (int i = 0; i < childCount; i++) {
nodes.add(rootNode.getChild(i));
// recursive
// selectAndAdd(node, cssSelector, result);
// walk(node, cssSelector, result);
}
walkDescendantsIteratively(nodes, cssSelector, result);
break;
case CHILD:
childCount = rootNode.getChildNodesCount();
for (int i = 0; i < childCount; i++) {
Node node = rootNode.getChild(i);
selectAndAdd(node, cssSelector, result);
}
break;
case ADJACENT_SIBLING:
Node node = rootNode.getNextSiblingElement();
if (node != null) {
selectAndAdd(node, cssSelector, result);
}
break;
case GENERAL_SIBLING:
node = rootNode;
while (true) {
node = node.getNextSiblingElement();
if (node == null) {
break;
}
selectAndAdd(node, cssSelector, result);
}
break;
} }
/**
* Selects single node for single selector and appends it to the results.
*/
protected void selectAndAdd(final Node node, final CssSelector cssSelector, final List result) {
// ignore all nodes that are not elements
if (node.getNodeType() != Node.NodeType.ELEMENT) {
return;
}
boolean matched = cssSelector.accept(node);
if (matched) {
// check for duplicates
if (result.contains(node)) {
return;
}
// no duplicate found, add it to the results
result.add(node);
}
}
/**
* Filter nodes.
*/
protected boolean filter(final List currentResults, final Node node, final CssSelector cssSelector, final int index) {
return cssSelector.accept(currentResults, node, index);
}
}