apeman-app-json/lib/create.js

apeman app to serve dynamic json.

/**
 * apeman app to send json response.
 * @memberof module:apeman-app-json/lib
 * @function create
 * @param {object} [options] - Optional settings.
 * @param {number} [options.spaces=2] - JSON spaces
 * @param {string} [options.contentType='application/json; charset=UTF-8;'] - Content type for header
 * @param {string} [options.name='json'] - Property name of response to set the function.
 * @returns {function} - Defined app function.
 */

"use strict";

var argx = require('argx'),
    objnest = require('objnest');

/** @lends create */
function create(options) {
    var args = argx(arguments);
    options = objnest.expand(args.pop('object') || {});

    var spaces = options.spaces || 2,
        contentType = options.contentType || 'application/json; charset=UTF-8;',
        name = options.name || 'json';

    function json(data) {
        if (typeof(data) === 'string') {
            data = JSON.parse(data);
        }
        var res = this,
            body = JSON.stringify(data, null, spaces);
        res.setHeader('Content-Length', Buffer.byteLength(body));
        res.setHeader('Content-Type', contentType);
        res.end(body);
    }


    /**
     * Defined app.
     * @function app
     * @param {object} req - Request object.
     * @param {object} res - Response object.
     * @param {function} next - Pass to next handler.
     */
    function app(req, res, next) {
        res[name] = res[name] || json;
        next();
    }

    // Description of this app.
    app.$desc = "Define json response function.";
    return app;
}

module.exports = create;