io.github.cs1302uga.JsoupTool Maven / Gradle / Ivy
package io.github.cs1302uga;
import static java.nio.charset.StandardCharsets.UTF_8;
import java.nio.charset.Charset;
import java.util.Optional;
import org.apache.velocity.tools.ToolContext;
import org.apache.velocity.tools.config.DefaultKey;
import org.apache.velocity.tools.generic.SafeConfig;
import org.apache.velocity.tools.generic.ValueParser;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
/**
* An Apache Velocity tool that provides utility methods to manipulate HTML code using
* jsoup HTML5 parser.
*
* @author Michael E. Cotterell
*/
@DefaultKey("soup")
public class JsoupTool extends SafeConfig {
private Charset outputEncoding = UTF_8;
/**
* Construct a {@code JsoupTool} object.
*/
public JsoupTool() {}
/**
* {@inheritDoc}
*/
@Override
protected void configure(ValueParser values) {
Optional.ofNullable(values.get(ToolContext.CONTEXT_KEY))
.filter(ToolContext.class::isInstance)
.map(ToolContext.class::cast)
.ifPresent(this::initFromContext);
} // configure
/**
* Inform this {@link io.github.cs1302uga.JsoupTool} so that it should take the
* specified {@code velocityContext} into consideration, when applicable.
*
* @param velocityContext
*/
private void initFromContext(ToolContext velocityContext) {
Optional.ofNullable(velocityContext.get("outputEncoding"))
.filter(String.class::isInstance)
.map(String.class::cast)
.map(Charset::forName)
.ifPresent(this::setOutputEncoding);
} // initFromContext
/**
* Set the output encoding.
*
* @param outputEncoding the desired output encoding
*/
protected void setOutputEncoding(Charset outputEncoding) {
this.outputEncoding = outputEncoding;
} // setOutputEncoding
/**
* Parse the supplied HTML {@code content} string using jsoup.
*
* @param content HTML content string
* @return An {@link org.jsoup.nodes.Element} that wraps the supplied {@code content}.
*/
public Element parse(String content) {
Document doc = Jsoup.parseBodyFragment(content);
doc.outputSettings().charset(outputEncoding);
return doc.body();
} // parse
/**
* Select elements in the supplied HTML {@code content} string that match the
* selector CSS query, with this element as the starting context. Matched
* elements may include this element, or any of its children.
*
* @param content HTML content string
* @param cssQuery a selector CSS-like query
* @return The selected elements.
*/
public Elements select(String content, String cssQuery) {
Element elem = parse(content);
return elem.select(cssQuery);
} // select
} // JsoupTool