Questions & Answers

[mhenke]

Hallo,

gibt es eine einfache Möglichkeit über die API, die Definition eines Feldes aus einem Formular auszulesen ?

Mittels GomSourceProvider.getGomSource() erhalte ich die komplette Definition, welche ich theoretisch selbst parsen könnte.

Es wäre allerdings schön, das Ganze mit einer API-Funktion erledigen zu können.

[mhenke · Accepted solution]

Ich habe es nun selbst mit folgender Klasse gelöst:

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.StringWriter;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

import de.espirit.firstspirit.access.store.templatestore.GomSourceProvider;

public class FormParser {
     private Document document;

     private static DocumentBuilderFactory documentFactory;
     private static XPathFactory xPathFactory;
     private static TransformerFactory transformerFactory;
     static {
          documentFactory = DocumentBuilderFactory.newInstance();
          xPathFactory = XPathFactory.newInstance();
          transformerFactory = TransformerFactory.newInstance();
     }

     public FormParser(GomSourceProvider gsp) throws ParserConfigurationException, SAXException, IOException {
          String source = gsp.getGomSource();
          DocumentBuilder builder = documentFactory.newDocumentBuilder();
          document = builder.parse(new ByteArrayInputStream(source.getBytes()));
     }

     public String getFieldDefinition(String field) throws XPathExpressionException, TransformerException {
          XPath xPath = xPathFactory.newXPath();
          XPathExpression expr = xPath.compile("//*[parent::CMS_MODULE|parent::CMS_GROUP and @name='" + field + "']");
          NodeList nl = (NodeList) expr.evaluate(document, XPathConstants.NODESET);
          if (nl.getLength() == 0) {
               return null;
          }
          return nodeToString(nl.item(0));
     }

     private String nodeToString(Node node) throws TransformerException {
          StringWriter sw = new StringWriter();
          Transformer t = transformerFactory.newTransformer();
          t.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
          t.setOutputProperty(OutputKeys.INDENT, "yes");
          t.transform(new DOMSource(node), new StreamResult(sw));
          return sw.toString();
     }
}