org.structr.csv.GetCsvHeadersFunction.java Source code

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Here is the source code for org.structr.csv.GetCsvHeadersFunction.java

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/**
 * Copyright (C) 2010-2018 Structr GmbH
 *
 * This file is part of Structr <http://structr.org>.
 *
 * Structr is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * Structr 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with Structr.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.structr.csv;

import java.io.StringReader;
import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVParser;
import org.apache.commons.csv.QuoteMode;
import org.structr.schema.action.ActionContext;
import org.structr.web.function.UiFunction;

public class GetCsvHeadersFunction extends UiFunction {

    public static final String ERROR_MESSAGE_FROM_CSV = "Usage: ${get_csv_headers(source[, delimiter[, quoteChar[, recordSeparator]]])}. Example: ${get_csv_headers('COL1;COL2;COL3\none;two;three')}";
    public static final String ERROR_MESSAGE_FROM_CSV_JS = "Usage: ${{Structr.getCsvHeaders(source[, delimiter[, quoteChar[, recordSeparator]]])}}. Example: ${{Structr.getCsvHeaders('COL1;COL2;COL3\none;two;three')}}";

    @Override
    public String getName() {
        return "get_csv_headers()";
    }

    @Override
    public Object apply(final ActionContext ctx, final Object caller, final Object[] sources) {

        try {

            assertArrayHasMinLengthAndMaxLengthAndAllElementsNotNull(sources, 1, 4);

            try {

                final String source = sources[0].toString();
                String delimiter = ";";
                String quoteChar = "\"";
                String recordSeparator = "\n";

                switch (sources.length) {

                case 4:
                    recordSeparator = (String) sources[3];
                case 3:
                    quoteChar = (String) sources[2];
                case 2:
                    delimiter = (String) sources[1];
                    break;
                }

                CSVFormat format = CSVFormat.newFormat(delimiter.charAt(0)).withHeader();
                if (quoteChar.length() > 0) {
                    format = format.withQuote(quoteChar.charAt(0));
                } else {
                    format = format.withQuote(null);
                }

                format = format.withRecordSeparator(recordSeparator);
                format = format.withIgnoreEmptyLines(true);
                format = format.withIgnoreSurroundingSpaces(true);
                format = format.withQuoteMode(QuoteMode.ALL);

                try (final CSVParser parser = new CSVParser(new StringReader(source), format)) {

                    return parser.getHeaderMap().keySet();
                }

            } catch (Throwable t) {

                logException(t, "{}: Exception for parameter: {}",
                        new Object[] { getName(), getParametersAsString(sources) });
            }

            return "";

        } catch (IllegalArgumentException e) {

            logParameterError(caller, sources, e.getMessage(), ctx.isJavaScriptContext());
            return usage(ctx.isJavaScriptContext());
        }
    }

    @Override
    public String usage(boolean inJavaScriptContext) {
        return (inJavaScriptContext ? ERROR_MESSAGE_FROM_CSV_JS : ERROR_MESSAGE_FROM_CSV);
    }

    @Override
    public String shortDescription() {
        return "Parses the given CSV string and returns a list of column headers";
    }
}