HtmlTableWriter.java

package com.github.lwhite1.tablesaw.io.html;

import com.github.lwhite1.tablesaw.api.Table;
import com.github.lwhite1.tablesaw.columns.Column;
import com.google.common.annotations.VisibleForTesting;
import org.apache.commons.lang3.StringUtils;

import java.util.List;

/**
 * Static utility that Writes outlier tables in html table format for display
 */
final public class HtmlTableWriter {

    /**
     * Private constructor to prevent instantiation
     */
    private HtmlTableWriter() {
    }

    public static String write(Table table, String missing) {

        StringBuilder builder = new StringBuilder();
        builder.append(header(table.columnNames()));
        builder.append("<tbody>")
                .append('\n');
        for (int row : table.rows()) {
            builder.append(row(row, table, missing));
        }
        builder.append("</tbody>");
        return builder.toString();
    }

    /**
     * Returns a string containing the html output of one table row
     */
    @VisibleForTesting
    static String row(int row, Table table, String missing) {
        StringBuilder builder = new StringBuilder()
                .append("<tr>");

        for (Column col : table.columns()) {
            builder
                    .append("<td>")
                    .append(String.valueOf(col.getString(row)))
                    .append("</td>");
        }
        builder
                .append("</tr>")
                .append('\n');
        return builder.toString();
    }

    @VisibleForTesting
    static String header(List<String> columnNames) {
        StringBuilder builder = new StringBuilder()
                .append("<thead>")
                .append('\n')
                .append("<tr>");
        for (String name : columnNames) {
            builder
                    .append("<th>")
                    .append(splitCamelCase(splitOnUnderscore(name)))
                    .append("</th>");
        }
        builder
                .append("</tr>")
                .append('\n')
                .append("</thead>")
                .append('\n');

        return builder.toString();
    }

    // todo move to utils
    private static String splitCamelCase(String s) {
        return StringUtils.join(
                StringUtils.splitByCharacterTypeCamelCase(s),
                ' '
        );
    }

    // todo move to utils
    static String splitOnUnderscore(String s) {
        return StringUtils.join(
                StringUtils.split(s, '_'),
                ' '
        );
    }
}