@axway/api-builder-runtime/lib/formatters/csv.js

API Builder Runtime

var json2csv = require('json2csv');

/**
 * Formats the body as CSV.
 * @param req
 * @param resp
 * @param body
 * @param singular
 * @param plural
 * @param callback
 * @returns {*}
 */
exports.format = function csvFormatter(req, resp, body, singular, plural, callback) {

	/**
	 * Is the var a basic value?
	 * @param v
	 * @returns {boolean}
	 */
	function isValue(v) {
		return !v || typeof v !== 'object';
	}

	/**
	 * is the var an object?
	 * @param v
	 * @returns {boolean}
	 */
	function isObject(v) {
		return !isValue(v) && !Array.isArray(v);
	}
	/**
	 * is the var (arr/obj) empty
	 * @param v
	 * @returns {boolean}
	 */
	function isEmpty(v) {
		return Object.keys(v).length === 0;
	}

	resp && resp.set('Content-Type', 'text/csv');
	body = body[plural] || body[singular] || body;
	body = JSON.parse(JSON.stringify(body));
	if (isValue(body)) { // it's just a single value. return it.
		return callback(null, body.toString());
	}
	if (isEmpty(body)) {
		return callback(null, '');
	}
	if (isObject(body)) {
		body = [ body ];
	}

	// it's now an array
	var cols = { value: false, object: false };
	for (var i = 0; i < body.length; i++) {
		var row = body[i];
		if (isValue(row)) {
			cols.value = true;
		}
		if (Array.isArray(row)) {
			// no support for embedded arrays in csv
			return callback(new Error('Cannot format embedded arrays as csv'));
		}
		if (isObject(row)) {
			cols.object = true;
		}
	}

	if (cols.object && !cols.value) {
		// response is made up of objects
		var fields = body.length && Object.keys(body[0]);
		if (!fields) {
			return callback(new Error('Cannot format as CSV'));
		}
		try {
			const opts = {
				fields,
				newLine: '\n'
			};
			const parser = new json2csv.Parser(opts);
			const csv = parser.parse(body);

			return callback(null, csv);
		} catch (ex) {
			callback(ex);
		}
		// there are just values
	} else if (cols.object && cols.value) {
		// we won't format csv where there is a mix of objects and values
		return callback(new Error('Cannot format a mix of objects and values as CSV'));
	} else {
		// single dimensional array of values
		return callback(null, body.join(','));
	}
};

exports.defaultMimeType = 'text/csv';