com.offerready.xslt.DocumentGenerator Maven / Gradle / Ivy
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package com.offerready.xslt;
import com.databasesandlife.util.DomParser;
import com.databasesandlife.util.MD5Hex;
import com.databasesandlife.util.Timer;
import com.databasesandlife.util.gwtsafe.ConfigurationException;
import com.offerready.xslt.WeaklyCachedXsltTransformer.DocumentTemplateInvalidException;
import com.offerready.xslt.WeaklyCachedXsltTransformer.Xslt;
import com.offerready.xslt.WeaklyCachedXsltTransformer.XsltCompilationThreads;
import com.offerready.xslt.destination.DocumentGenerationDestination;
import lombok.SneakyThrows;
import org.apache.fop.apps.FopConfParser;
import org.apache.fop.apps.FopFactoryBuilder;
import org.apache.fop.apps.MimeConstants;
import org.apache.fop.apps.io.ResourceResolverFactory;
import org.apache.xmlgraphics.io.URIResolverAdapter;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.xml.sax.SAXException;
import javax.annotation.CheckForNull;
import javax.annotation.Nonnull;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.URIResolver;
import javax.xml.transform.dom.DOMResult;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.sax.SAXResult;
import javax.xml.transform.stream.StreamResult;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.io.StringWriter;
import java.net.URI;
import java.nio.charset.StandardCharsets;
import java.util.function.Function;
/**
* An object capable of generating a document for a particular XSLT file.
*
* This object executes XSLT, and in addition:
*
*
* - Stylevision hacks. It has hacks to change the XSLT produced by StyleVision into that which can be accepted by
* the free version of Saxon called Saxon-HE.
*
*
- Conversion after XSLT. After the XSLT is applied, the resulting XML can be further processed.
* XSL-FO to PDF, convert HTML to XML, and convert XML to JSON.
*
*
* Objects of this class reference the complied XSLT transfomer.
* As long as you need to access the XSLT, retain a link to this object.
* Creating a new object might involve the XSLT being re-complied (depending on the cache in {@link WeaklyCachedXsltTransformer}).
*
* A DocumentGenerator (or "all documents which can be generated") should not be added to e.g. Wicket sessions as
* these cannot be serialized (and would be big even if they could.)
*/
public class DocumentGenerator {
protected final @Nonnull DocumentOutputDefinition defn;
protected final @Nonnull WeaklyCachedXsltTransformer transformer;
protected @CheckForNull File fopBaseDirOrNull = null, fopConfigOrNull = null, imagesBase = null;
public static class StyleVisionXslt implements Xslt {
public final @Nonnull File xsltFile;
public StyleVisionXslt(@Nonnull File x) { xsltFile = x; }
@Override public @Nonnull String calculateCacheKey() { return MD5Hex.md5(xsltFile); }
@SneakyThrows(IOException.class)
@Override public @Nonnull Document parseDocument() throws ConfigurationException {
final Document result;
try { result = DomParser.newDocumentBuilder().parse(xsltFile); } // DOM Object
catch (SAXException e) { throw new ConfigurationException("XSLT file '" + xsltFile.getAbsolutePath() + "' is not valid XML"); }
// XSLT files produced by Stylevision have and this causes file to be written,
// meaning that we can't stream the result to the browser. If we remove the attribute, all is good.
var allResultDocumentTags = result.getElementsByTagNameNS(
"http://www.w3.org/1999/XSL/Transform", "result-document");
for (var i = 0; i < allResultDocumentTags.getLength(); i++) {
var a = allResultDocumentTags.item(i).getAttributes();
if (a.getNamedItem("href") != null) a.removeNamedItem("href");
}
return result;
}
}
public DocumentGenerator(
@Nonnull XsltCompilationThreads threads, @Nonnull DocumentOutputDefinition defn,
@Nonnull Function newXslt
)
throws ConfigurationException {
this.defn = defn;
if (defn.xsltFileOrNull == null)
this.transformer = WeaklyCachedXsltTransformer.getIdentityTransformer();
else
this.transformer = WeaklyCachedXsltTransformer.getTransformerOrScheduleCompilation(
threads, defn.xsltFileOrNull.getAbsolutePath(), newXslt.apply(defn.xsltFileOrNull));
}
public DocumentGenerator(@Nonnull XsltCompilationThreads threads, @Nonnull DocumentOutputDefinition defn)
throws ConfigurationException {
this(threads, defn, StyleVisionXslt::new);
}
public void setFopConfigOrNull(@CheckForNull File fopBaseDirOrNull, @CheckForNull File fopConfigOrNull) {
this.fopBaseDirOrNull = fopBaseDirOrNull;
this.fopConfigOrNull = fopConfigOrNull;
}
public void setImagesBase(@Nonnull File imagesBase) {
this.imagesBase = imagesBase;
}
@SneakyThrows({TransformerException.class, IOException.class})
protected void writePlainXml(@Nonnull DocumentGenerationDestination response, @Nonnull Document xml) {
var systemProperties = System.getProperties();
systemProperties.remove("javax.xml.transform.TransformerFactory");
System.setProperties(systemProperties);
response.setContentType("text/plain; charset=UTF-8");
var transformer = TransformerFactory.newInstance().newTransformer();
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
transformer.setOutputProperty(OutputKeys.ENCODING, StandardCharsets.UTF_8.name());
transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");
var source = new DOMSource(xml);
var result = new StreamResult(response.getOutputStream());
transformer.transform(source, result);
response.getOutputStream().close();
}
@SneakyThrows({TransformerException.class, IOException.class, SAXException.class})
protected void writePdfFromXslFo(@Nonnull OutputStream pdf, @Nonnull Document fo, @CheckForNull URIResolver uriResolverOrNull) {
try (var ignored = new Timer("Create PDF from XSL-FO")) {
// Get a FOP instance (can convert XSL-FO into PDF)
FopFactoryBuilder builder;
if (fopConfigOrNull != null) {
FopConfParser parser;
if (uriResolverOrNull == null) parser = new FopConfParser(fopConfigOrNull);
else parser = new FopConfParser(fopConfigOrNull, new URIResolverAdapter(uriResolverOrNull));
builder = parser.getFopFactoryBuilder();
} else {
if (uriResolverOrNull == null) builder = new FopFactoryBuilder(URI.create("https://www.example.com/"));
else builder = new FopFactoryBuilder(URI.create("https://www.example.com/"), new URIResolverAdapter(uriResolverOrNull));
}
if (imagesBase != null) builder.setBaseURI(imagesBase.toURI());
var fopFactory = builder.build();
if (fopBaseDirOrNull != null) fopFactory.getFontManager().setResourceResolver(
ResourceResolverFactory.createDefaultInternalResourceResolver(fopBaseDirOrNull.toURI()));
var foUserAgent = fopFactory.newFOUserAgent();
var fop = fopFactory.newFop(MimeConstants.MIME_PDF, foUserAgent, pdf);
// Setup JAXP using identity transformer
var factory = TransformerFactory.newInstance();
var transformer = factory.newTransformer(); // identity transformer
// Resulting SAX events (the generated FO) must be piped through to FOP
var res = new SAXResult(fop.getDefaultHandler());
// Start XSLT transformation and FOP processing
transformer.transform(new DOMSource(fo), res);
}
}
public void assertTemplateValid() throws DocumentTemplateInvalidException {
transformer.assertValid();
}
/**
* @param response this is closed by this method
* @param transform if false, then don't do transformation, but output XML instead (for debugging)
* @param uriResolverOrNull if not null, pass an object which can, for example, fetch or create images via programmatic logic
* @param language for example "de" to choose different XSLT params (placeholder values). Or null to just use the default.
*/
@SneakyThrows(IOException.class)
public void transform(
@Nonnull DocumentGenerationDestination response, @Nonnull Document xml,
boolean transform, @CheckForNull URIResolver uriResolverOrNull,
@CheckForNull String language
) throws DocumentTemplateInvalidException, TransformerException {
if ( ! transform) {
writePlainXml(response, xml);
return;
}
var xslt = transformer.newTransformer();
for (var placeholderValue : defn.xsltParameters.get(language).entrySet())
xslt.setParameter(placeholderValue.getKey(), placeholderValue.getValue());
switch (defn.outputConversion) {
case xmlToJson:
response.setContentType((defn.contentType == null ? "application/json" : defn.contentType) + "; charset=UTF-8");
var xmlOutput = new StringWriter();
try (var ignored = new Timer("XSLT Transformation")) {
xslt.transform(new DOMSource(xml), new StreamResult(xmlOutput));
}
var json = new JsonXmlConverter().convertXmlToJson(xmlOutput.toString());
try (var outputStream = response.getOutputStream()) {
outputStream.write(json.getBytes(StandardCharsets.UTF_8));
}
break;
case xslFoToPdf:
response.setContentType(defn.contentType == null ? "application/pdf" : defn.contentType);
var xslFo = new DOMResult();
try (var ignored = new Timer("XSLT Transformation to XSL-FO")) {
xslt.transform(new DOMSource(xml), xslFo);
}
try (var outputStream = response.getOutputStream()) {
writePdfFromXslFo(outputStream, (Document) xslFo.getNode(), uriResolverOrNull);
}
break;
case excelXmlToExcelBinary:
response.setContentType(defn.contentType == null ? "application/ms-excel" : defn.contentType);
try (var outputStream = response.getOutputStream()) {
xslt.transform(new DOMSource(xml), new SAXResult(new ExcelGenerator(defn.inputDecimalSeparator, outputStream)));
}
break;
default:
response.setContentType((defn.contentType == null ? "text/plain" : defn.contentType) + "; charset=UTF-8");
try (var outputStream = response.getOutputStream()) {
var result = new StreamResult(outputStream);
xslt.setOutputProperty(OutputKeys.ENCODING, StandardCharsets.UTF_8.name());
try (var ignored = new Timer("XSLT Transformation")) { xslt.transform(new DOMSource(xml), result); }
}
break;
}
}
}