SvrlReport.java

/**
 * Copyright (c) Codice Foundation
 * <p/>
 * This is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser
 * General Public License as published by the Free Software Foundation, either version 3 of the
 * License, or any later version.
 * <p/>
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
 * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details. A copy of the GNU Lesser General Public License
 * is distributed along with this program and can be found at
 * <http://www.gnu.org/licenses/lgpl.html>.
 */

package ddf.services.schematron;

import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMResult;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 * Schematron Validation Report Language (SVRL) formatted report of output from Schematron
 * validation.
 *
 * @author rodgersh
 *
 */
public class SvrlReport implements SchematronReport {
    /** SVRL report tag for assertion that failed during Schematron validation */
    private static final String ASSERT_FAIL_TAG = "svrl:failed-assert";

    /** SVRL report tag for report that failed during Schematron validation */
    private static final String REPORT_FAIL_TAG = "svrl:failed-report";

    /**
     * SVRL report tag for flag attribute in a svrl:failed-assert element that indicates if the
     * failure is an error or warning
     */
    private static final String FLAG_ATTR = "flag";

    /**
     * Value for svrl:failed-assert tag's flag attribute for warnings.
     *
     * Example: <svrl:failed-assert test="if(invalid) then 1 else not($hasInvalids)" flag="warning">
     * ... </svrl:failed-assert>
     */
    private static final String WARNING_FLAG_ATTR_TEXT = "warning";

    /**
     * Value for svrl:failed-assert tag's flag attribute for errors
     *
     * Example: <svrl:failed-assert test="if(invalid) then 1 else not($hasInvalids)" flag="error">
     * ... </svrl:failed-assert>
     */
    private static final String ERROR_FLAG_ATTR_TEXT = "error";

    private static final Logger LOGGER = LoggerFactory.getLogger(SvrlReport.class);

    /** Schematron report in DOM format */
    private DOMResult report;

    /** The root element of the report's DOM tree. */
    private Element root = null;

    /**
     * Private default constructor to prevent instantiating SvrlReport without required DOMResult
     * argument.
     */
    private SvrlReport() {

    }

    /**
     * @param result
     *            DOM-formatted results from Schematron validation
     */
    public SvrlReport(DOMResult result) {
        this.report = result;
        this.root = (Element) report.getNode().getFirstChild();
    }

    /**
     * Returns true if Schematron report is valid, false otherwise. The input document is considered
     * to be valid if it has no failed assertions for errors and no failed reports for errors. If
     * the suppressWarnings argument is true, then Schematron warnings are also included in the
     * document's validity assessment.
     *
     * @param suppressWarnings
     *            do not include Schematron warnings in determining validity
     *
     * @return true if no assert or report error messages found in SVRL report, false otherwise
     */
    @Override
    public boolean isValid(boolean suppressWarnings) {
        List<Node> errorAssertions = getAllAssertMessages(ERROR_FLAG_ATTR_TEXT);
        List<Node> errorReports = getAllReportMessages(ERROR_FLAG_ATTR_TEXT);

        if (errorAssertions.size() != 0 || errorReports.size() != 0) {
            return false;
        }

        if (!suppressWarnings) {
            List<Node> warningAssertions = getAllAssertMessages(WARNING_FLAG_ATTR_TEXT);
            List<Node> warningReports = getAllReportMessages(WARNING_FLAG_ATTR_TEXT);

            if (warningAssertions.size() != 0 || warningReports.size() != 0) {
                return false;
            }
        }

        return true;
    }

    /**
     * Retrieve all assertion messages, warnings and errors, from the SVRL report.
     *
     * @return list of XML Nodes for all assert nodes
     */
    @Override
    public NodeList getAllAssertMessages() {
        return root.getElementsByTagName(ASSERT_FAIL_TAG);
    }

    /**
     * Retrieve only the specified type of assertion messages (warnings or errors) from the SVRL
     * report.
     *
     * @parameter type the type of assert message to search for in SVRL report, "warning" or "error"
     * @return list of XML Nodes for all assert nodes of specified type
     */
    public List<Node> getAllAssertMessages(String type) {
        List<Node> assertions = new ArrayList<Node>();

        NodeList assertFailures = getAllAssertMessages();
        for (int i = 0; i < assertFailures.getLength(); i++) {
            Node assertion = assertFailures.item(i);
            NamedNodeMap attributes = assertion.getAttributes();
            Node flagNode = attributes.getNamedItem(FLAG_ATTR);
            if (flagNode != null && flagNode.getNodeValue().equals(type)) {
                assertions.add(assertion);
            }
        }

        return assertions;
    }

    /**
     * Retrieve all report messages, warnings and errors, from the SVRL report.
     *
     * @return list of XML Nodes for all report nodes
     */
    @Override
    public NodeList getAllReportMessages() {
        return root.getElementsByTagName(REPORT_FAIL_TAG);
    }

    /**
     * Retrieve only the specified type of report messages (warnings or errors) from the SVRL
     * report.
     *
     * @parameter type the type of report message to search for in SVRL report, "warning" or "error"
     * @return list of XML Nodes for all report nodes
     */
    public List<Node> getAllReportMessages(String type) {
        List<Node> reports = new ArrayList<Node>();

        NodeList reportFailures = getAllReportMessages();
        for (int i = 0; i < reportFailures.getLength(); i++) {
            Node report = reportFailures.item(i);
            NamedNodeMap attributes = report.getAttributes();
            Node flagNode = attributes.getNamedItem(FLAG_ATTR);
            if (flagNode != null && flagNode.getNodeValue().equals(type)) {
                reports.add(report);
            }
        }

        return reports;
    }

    /**
     * Get a list of all of the assertion and report error messages from the SVRL report.
     *
     * @return list of error strings
     */
    @Override
    public List<String> getErrors() {
        List<String> errors = new ArrayList<String>();

        List<Node> errorAssertions = getAllAssertMessages(ERROR_FLAG_ATTR_TEXT);
        for (Node error : errorAssertions) {
            errors.add(error.getFirstChild().getTextContent());
        }

        List<Node> errorReports = getAllReportMessages(ERROR_FLAG_ATTR_TEXT);
        for (Node error : errorReports) {
            errors.add(error.getFirstChild().getTextContent());
        }

        return errors;
    }

    /**
     * Get a list of all of the assertion and report warning messages from the SVRL report.
     *
     * @return list of warning strings
     */
    @Override
    public List<String> getWarnings() {
        List<String> warnings = new ArrayList<String>();

        List<Node> warningAssertions = getAllAssertMessages(WARNING_FLAG_ATTR_TEXT);
        for (Node warning : warningAssertions) {
            LOGGER.debug("warning(from assertions) = " + warning.getFirstChild().getTextContent());
            warnings.add(warning.getFirstChild().getTextContent());
        }

        List<Node> warningReports = getAllReportMessages(WARNING_FLAG_ATTR_TEXT);
        for (Node warning : warningReports) {
            LOGGER.debug("warning(from reports) = " + warning.getFirstChild().getTextContent());
            warnings.add(warning.getFirstChild().getTextContent());
        }

        return warnings;
    }

    /**
     * Retrieve the entire SVRL report as an XML-formatted string.
     *
     * @return XML-formatted string representation of SVRL report
     */
    @Override
    public String getReportAsText() throws TransformerException {
        Writer sw = new StringWriter();
        PrintWriter out = new PrintWriter(sw);

        TransformerFactory tfactory = TransformerFactory.newInstance();
        Transformer transformer = tfactory.newTransformer();
        Properties props = new Properties();
        props.put("method", "xml");
        props.put("indent", "yes");
        transformer.setOutputProperties(props);
        transformer.transform(new DOMSource(root), new StreamResult(out));
        out.close();

        return sw.toString();
    }

};