diet-yadda/lib/converters/table-converter.js

A true BDD framework for JavaScript - slimmed down

/*
 * Copyright 2010 Acuminous Ltd / Energized Work Ltd
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/* jslint node: true */
"use strict";

var $ = require('../Array');
var StringUtils = require('../StringUtils');
var COLUMN_SEPARATOR_REGEX = /[\|\u2506]/;
var OUTER_BORDERS_REGEX = /^[\|\u2506]|[\|\u2506]$/g;
var DASH_REGEX = /^[\\|\u2506]?-{3,}/;


module.exports = function table_converter(value, next) {

    var rows = value.split(/\n/);
    var headings = parse_headings(rows.shift());
    var handler =  is_horizinal_separator(rows[0]) ? handle_multiline_row : handle_single_line_row;
    var table = $();
    var watermark = 0;

    try {
        $(rows).each(handler);
        next(null, collapse(table));
    } catch(err) {
        next(err);
    }

    function handle_single_line_row(row) {
        if (is_horizinal_separator(row)) throw new Error('Dashes are unexpected at this time');
        start_new_row();
        parse_fields(row);
    }

    function handle_multiline_row(row) {
        if (is_horizinal_separator(row)) return start_new_row();
        parse_fields(row);
    }

    function parse_headings(row) {
        return $(row.replace(OUTER_BORDERS_REGEX, '').split(COLUMN_SEPARATOR_REGEX)).collect(function(value) {
            return { text: StringUtils.trim(value), indentation: StringUtils.indentation(value) };
        }).naked();
    }

    function is_horizinal_separator(row) {
        return DASH_REGEX.test(row);
    }

    function start_new_row() {
        table.push({});
    }

    function parse_fields(row) {
        var fields = table.last();
        $(row.replace(OUTER_BORDERS_REGEX, '').split(COLUMN_SEPARATOR_REGEX)).each(function(field, index) {
            var column = headings[index].text;
            var indentation = headings[index].indentation;
            var text = StringUtils.rtrim(field.substr(indentation));
            if (StringUtils.isNotBlank(field) && StringUtils.indentation(field) < indentation) throw new Error('Indentation error');
            fields[column] = (fields[column] || []).concat(text);
        });
    }

    function collapse(table) {
        return table.collect(function(row) {
            var new_row = {};
            for (var heading in row) {
                new_row[heading] = row[heading].join('\n');
            }
            return new_row;
        }).naked();
    }
};