csv-to-convertor

csv-to-json-functional.js

/**
 * @param {Array} keys Array of keys. By definition from [RFC 4180](https://www.rfc-editor.org/rfc/rfc4180), it will be the first line of the file.
 * @returns {Function}
 */
const csv_array_to_json = (keys) =>
{
    /**
     * @param {Array} item Values
     * @returns {Object} A JSON format interface.
     */
    return item =>
    {
        const convert_to_json_item = (key, key_id) => ([ key, item[key_id] ]);
        const key_values = keys.map(convert_to_json_item);
        return Object.fromEntries( key_values );
    };
}

/**
 * > Each record is located on a separate line, delimited by a line break (CRLF).
 * >
 * > ~ Definition of the CSV Format, *RFC 4180*.
 */
const extract_source_array = ( input ) =>
{
    try {
        return input.split( "\n" ).map( item => item.split( "," ) );
    } catch (error) {
        console.warn( error );
        return [];
    }
};

/**
 * > There maybe an optional header line appearing as the first line
 * > of the file with the same format as normal record lines.
 * >
 * > ~ Definition of the CSV Format, *RFC 4180*.
 */
const extract_keys = source_array => source_array[0] ?? [];

/**
 * CSV values.
 * @param {Array} source_array 
 * @returns {Array} Values
 */
const extract_values = source_array => source_array.slice( 1 ) ?? [];

/**
 * Convert CSV to JSON.
 * @see [RFC 4180](https://www.rfc-editor.org/rfc/rfc4180)
 * @param {String} input A CSV string.
 * @returns {Array} A JSON object format of CSV.
 */
const csv_convertor = (input = "") =>
{
    const source_array = extract_source_array(input);
    const keys = extract_keys(source_array);
    const values = extract_values(source_array);
    return values.map(csv_array_to_json(keys));
};

export default csv_convertor;

csv-to-json-object-oriented.js

/**
 * @param {Array} keys Array of keys. By definition from [RFC 4180](https://www.rfc-editor.org/rfc/rfc4180), it will be the first line of the file.
 * @returns {Function}
 */
function csv_array_to_json(keys)
{
    /**
     * @param {Array} item Values
     * @returns {Object} A JSON format interface.
     */
    const main = item =>
    {
        const convert_to_json_item = (key, key_id) => ([ key, item[key_id] ]);
        return Object.fromEntries( keys.map(convert_to_json_item) );
    };
    return main;
}

class CsvArray
{
    /**
     * @see [RFC 4180](https://www.rfc-editor.org/rfc/rfc4180)
     * @param {String} source A CSV string.
     */
    constructor(source = "")
    {
        this.source = source;
    }
    /**
     * > Each record is located on a separate line, delimited by a line break (CRLF).
     * >
     * > ~ Definition of the CSV Format, *RFC 4180*.
     */
    get source_array()
    {
        if( typeof( this.source ) !== "string" )
        {
            return [];
        }
        try {
            const extracted_row = this.source.split("\n");
            const extract_col = item => item.split(",");
            return extracted_row.map( extract_col );
        } catch (error) {
            console.warn( error );
            return [];
        }
    }
    /**
     * > There maybe an optional header line appearing as the first line
     * > of the file with the same format as normal record lines.
     * >
     * > ~ Definition of the CSV Format, *RFC 4180*.
     */
    get keys()
    {
        return this.source_array[0] ?? [];
    }
    /**
     * CSV values.
     * @returns {Array} Values
     */
    get values()
    {
        return this.source_array.slice( 1 ) ?? [];
    }
    /**
     * The JSON item array.
     */
    get json_array()
    {
        return this.values.map( csv_array_to_json( this.keys ) );
    }
}

/**
 * Convert CSV to JSON.
 * @see [RFC 4180](https://www.rfc-editor.org/rfc/rfc4180)
 * @param {String} input A CSV string.
 * @returns {Array} A JSON object format of CSV.
 */
const csv_convertor = (input = "") => (new CsvArray( input )).json_array;

export default csv_convertor;