/*
* Encog(tm) Core v3.0 - Java Version
* http://www.heatonresearch.com/encog/
* http://code.google.com/p/encog-java/
* Copyright 2008-2011 Heaton Research, Inc.
*
* 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.
*
* For more information on Heaton Research copyrights, licenses
* and trademarks visit:
* http://www.heatonresearch.com/copyright
*/
package org.encog.bot.browse;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import org.encog.bot.browse.range.Div;
import org.encog.bot.browse.range.DocumentRange;
import org.encog.bot.browse.range.Form;
import org.encog.bot.browse.range.Input;
import org.encog.bot.browse.range.Link;
import org.encog.bot.browse.range.Span;
import org.encog.bot.dataunit.CodeDataUnit;
import org.encog.bot.dataunit.DataUnit;
import org.encog.bot.dataunit.TagDataUnit;
import org.encog.bot.dataunit.TextDataUnit;
import org.encog.parse.tags.Tag;
import org.encog.parse.tags.read.ReadHTML;
import org.encog.util.logging.EncogLogging;
/**
* Called to actually load a web page. This will read the HTML on a web page and
* generate the DocumentRange classes.
*
* @author jheaton
*
*/
public class LoadWebPage {
/**
* The loaded webpage.
*/
private WebPage page;
/**
* The base URL for the page being loaded.
*/
private final URL base;
/**
* The last form that was processed.
*/
private Form lastForm;
/**
* The last hierarchy element that was processed.
*/
private DocumentRange lastHierarchyElement;
/**
* Construct a web page loader with the specified base URL.
*
* @param theBase
* The base URL to use when loading.
*/
public LoadWebPage(final URL theBase) {
this.base = theBase;
}
/**
* Add the specified hierarchy element.
*
* @param element
* The hierarchy element to add.
*/
private void addHierarchyElement(final DocumentRange element) {
if (this.lastHierarchyElement == null) {
this.page.addContent(element);
} else {
this.lastHierarchyElement.addElement(element);
}
this.lastHierarchyElement = element;
}
/**
* Create a dataunit to hode the code HTML tag.
*
* @param str
* The code to create the data unit with.
*/
private void createCodeDataUnit(final String str) {
if (str.trim().length() > 0) {
final CodeDataUnit d = new CodeDataUnit();
d.setCode(str);
this.page.addDataUnit(d);
}
}
/**
* Create a tag data unit.
*
* @param tag
* The tag name to create the data unit for.
*/
private void createTagDataUnit(final Tag tag) {
final TagDataUnit d = new TagDataUnit();
d.setTag(tag.clone());
this.page.addDataUnit(d);
}
/**
* Create a text data unit.
*
* @param str
* The text.
*/
private void createTextDataUnit(final String str) {
if (str.trim().length() > 0) {
final TextDataUnit d = new TextDataUnit();
d.setText(str);
this.page.addDataUnit(d);
}
}
/**
* Find the end tag that lines up to the beginning tag.
*
* @param index
* The index to start the search on. This specifies the starting
* data unit.
* @param tag
* The beginning tag that we are seeking the end tag for.
* @return The index that the ending tag was found at. Returns -1 if not
* found.
*/
public final int findEndTag(final int index, final Tag tag) {
int depth = 0;
int count = index;
while (count < this.page.getDataSize()) {
final DataUnit du = this.page.getDataUnit(count);
if (du instanceof TagDataUnit) {
final Tag nextTag = ((TagDataUnit) du).getTag();
if (tag.getName().equalsIgnoreCase(nextTag.getName())) {
if (nextTag.getType() == Tag.Type.END) {
if (depth == 0) {
return count;
} else {
depth--;
}
} else if (nextTag.getType() == Tag.Type.BEGIN) {
depth++;
}
}
}
count++;
}
return -1;
}
/**
* Load a web page from the specified stream.
*
* @param is
* The input stream to load from.
* @return The loaded web page.
*/
public final WebPage load(final InputStream is) {
this.page = new WebPage();
loadDataUnits(is);
loadContents();
return this.page;
}
/**
* Load the web page from a string that contains HTML.
*
* @param str
* A string containing HTML.
* @return The loaded WebPage.
*/
public final WebPage load(final String str) {
try {
final ByteArrayInputStream bis = new ByteArrayInputStream(str
.getBytes());
final WebPage result = load(bis);
bis.close();
return result;
} catch (final IOException e) {
EncogLogging.log(e);
throw new BrowseError(e);
}
}
/**
* Using the data units, which should have already been loaded by this time,
* load the contents of the web page. This includes the title, any links and
* forms. Div tags and spans are also processed.
*/
protected final void loadContents() {
for (int index = 0; index < this.page.getDataSize(); index++) {
final DataUnit du = this.page.getDataUnit(index);
if (du instanceof TagDataUnit) {
final Tag tag = ((TagDataUnit) du).getTag();
if (tag.getType() != Tag.Type.END) {
if (tag.getName().equalsIgnoreCase("a")) {
loadLink(index, tag);
} else if (tag.getName().equalsIgnoreCase("title")) {
loadTitle(index, tag);
} else if (tag.getName().equalsIgnoreCase("form")) {
loadForm(index, tag);
} else if (tag.getName().equalsIgnoreCase("input")) {
loadInput(index, tag);
}
}
if (tag.getType() == Tag.Type.BEGIN) {
if (tag.getName().equalsIgnoreCase("div")) {
loadDiv(index, tag);
} else if (tag.getName().equalsIgnoreCase("span")) {
loadSpan(index, tag);
}
}
if (tag.getType() == Tag.Type.END) {
if (tag.getName().equalsIgnoreCase("div")) {
if (this.lastHierarchyElement != null) {
this.lastHierarchyElement =
this.lastHierarchyElement
.getParent();
}
} else if (tag.getName().equalsIgnoreCase("span")) {
if (this.lastHierarchyElement != null) {
this.lastHierarchyElement =
this.lastHierarchyElement
.getParent();
}
}
}
}
}
}
/**
* Load the data units. Once the lower level data units have been loaded,
* the contents can be loaded.
*
* @param is
* The input stream that the data units are loaded from.
*/
protected final void loadDataUnits(final InputStream is) {
final StringBuilder text = new StringBuilder();
int ch;
final ReadHTML parse = new ReadHTML(is);
boolean style = false;
boolean script = false;
while ((ch = parse.read()) != -1) {
if (ch == 0) {
if (style) {
createCodeDataUnit(text.toString());
} else if (script) {
createCodeDataUnit(text.toString());
} else {
createTextDataUnit(text.toString());
}
style = false;
script = false;
text.setLength(0);
createTagDataUnit(parse.getTag());
if (parse.getTag().getName().equalsIgnoreCase("style")) {
style = true;
} else if (parse.getTag().getName().equalsIgnoreCase(
"script")) {
script = true;
}
} else {
text.append((char) ch);
}
}
createTextDataUnit(text.toString());
}
/**
* Called by loadContents to load a div tag.
*
* @param index
* The index to begin at.
* @param tag
* The beginning div tag.
*/
private void loadDiv(final int index, final Tag tag) {
final Div div = new Div(this.page);
final String classAttribute = tag.getAttributeValue("class");
final String idAttribute = tag.getAttributeValue("id");
div.setIdAttribute(idAttribute);
div.setClassAttribute(classAttribute);
div.setBegin(index);
div.setEnd(findEndTag(index + 1, tag));
addHierarchyElement(div);
}
/**
* Called by loadContents to load a form on the page.
*
* @param index
* The index to begin loading at.
* @param tag
* The beginning tag.
*/
protected final void loadForm(final int index, final Tag tag) {
final String method = tag.getAttributeValue("method");
final String action = tag.getAttributeValue("action");
final Form form = new Form(this.page);
form.setBegin(index);
form.setEnd(findEndTag(index + 1, tag));
if ((method == null) || method.equalsIgnoreCase("GET")) {
form.setMethod(Form.Method.GET);
} else {
form.setMethod(Form.Method.POST);
}
if (action == null) {
form.setAction(new Address(this.base));
} else {
form.setAction(new Address(this.base, action));
}
this.page.addContent(form);
this.lastForm = form;
}
/**
* Called by loadContents to load an input tag on the form.
*
* @param index
* The index to begin loading at.
* @param tag
* The beginning tag.
*/
protected final void loadInput(final int index, final Tag tag) {
final String type = tag.getAttributeValue("type");
final String name = tag.getAttributeValue("name");
final String value = tag.getAttributeValue("value");
final Input input = new Input(this.page);
input.setType(type);
input.setName(name);
input.setValue(value);
if (this.lastForm != null) {
this.lastForm.addElement(input);
} else {
this.page.addContent(input);
}
}
/**
* Called by loadContents to load a link on the page.
*
* @param index
* The index to begin loading at.
* @param tag
* The beginning tag.
*/
protected final void loadLink(final int index, final Tag tag) {
final Link link = new Link(this.page);
final String href = tag.getAttributeValue("href");
if (href != null) {
link.setTarget(new Address(this.base, href));
link.setBegin(index);
link.setEnd(findEndTag(index + 1, tag));
this.page.addContent(link);
}
}
/**
* Called by loadContents to load a span.
*
* @param index
* The index to begin loading at.
* @param tag
* The beginning tag.
*/
private void loadSpan(final int index, final Tag tag) {
final Span span = new Span(this.page);
final String classAttribute = tag.getAttributeValue("class");
final String idAttribute = tag.getAttributeValue("id");
span.setIdAttribute(idAttribute);
span.setClassAttribute(classAttribute);
span.setBegin(index);
span.setEnd(findEndTag(index + 1, tag));
addHierarchyElement(span);
}
/**
* Called by loadContents to load the title of the page.
*
* @param index
* The index to begin loading at.
* @param tag
* The beginning tag.
*/
protected final void loadTitle(final int index, final Tag tag) {
final DocumentRange title = new DocumentRange(this.page);
title.setBegin(index);
title.setEnd(findEndTag(index + 1, tag));
this.page.setTitle(title);
}
}