gravatar.js

var md5 = require('md5'),
    querystring = require('querystring');


exports.BASE_AVATAR_URL = 'www.gravatar.com/avatar/';


function isBrowser() {
    return (typeof(window) !== 'undefined');
}

exports.trim = function (str) {
    return str.replace(/^\s+/, '').replace(/\s+$/, '');
};

exports.hash = function (email) {
    return md5.hex(exports.trim(email).toLowerCase());
};

/**
 * Generates an avatar URL from an email address
 *
 * @param email {String}
 * @param options {Object} - (optional)
 *
 * Options:
 *
 * - email {String} - The email address to get the avatar for.
 * - hash {String} - The pre-hashed email address (alternative to using email)
 *
 * - size {Number} - Size in pixels of the desired avatar image.
 *     By default, images are presented at 80px by 80px if no size parameter
 *     is supplied
 *
 * - default_image {String} - a URL to a default image to use if the user has
 *     no avatar, can also be set to the following predefined options:
 *
 *     - 404:        do not load any image if none is associated with the email
 *                   hash, instead return an HTTP 404 (File Not Found) response
 *     - mm:         (mystery-man) a simple, cartoon-style silhouetted outline
 *                   of a person (does not vary by email hash)
 *     - identicon:  a geometric pattern based on an email hash
 *     - monsterid:  a generated 'monster' with different colors, faces, etc
 *     - wavatar:    generated faces with differing features and backgrounds
 *     - retro:      awesome generated, 8-bit arcade-style pixelated faces
 *
 * - force_default {Boolean} - forces the use of the default image
 *
 * - rating {String} - Gravatar allows users to self-rate their images so that
 *     they can indicate if an image is appropriate for a certain audience. By
 *     default, only 'G' rated images are displayed unless you indicate that
 *     you would like to see higher ratings. Available options:
 *
 *     - g:   suitable for display on all websites with any audience type.
 *     - pg:  may contain rude gestures, provocatively dressed individuals,
 *            the lesser swear words, or mild violence.
 *     - r:   may contain such things as harsh profanity, intense violence,
 *            nudity, or hard drug use.
 *     - x:   may contain hardcore sexual imagery or extremely disturbing
 *            violence.
 *
 * - secure {Boolean} - force https, if not set, the current protocol is used
 *     (if running in the browser), otherwise specifies no protocol or '//'.
 *
 * - extension {String} - optional image extension to use in the url (eg .jpg)
 */

exports.avatarURL = function (options) {
    options = options || {};
    var hash = options.hash || exports.hash(options.email);
    var params = {};

    if (options.size) {
        params.size = options.size;
    }
    if (options.force_default) {
        params.forcedefault = 'y';
    }
    if (options.default_image) {
        params['default'] = options.default_image;
    }
    if (options.rating) {
        params.rating = options.rating;
    }
    if (options.secure === undefined && isBrowser()) {
        options.secure = location.protocol === 'https:';
    }
    var ext = '';
    if (options.extension) {
        ext = '.' + options.extension.replace(/^\./, '');
    }
    return (options.secure ? 'https://': '//') +
           exports.BASE_AVATAR_URL + hash + ext + '?' +
           querystring.stringify(params);
};