Chartbeat.js

chartbeat.js

var Chartbeat = function(opts) {

    if (!opts)
        throw new Error("Chartbeat: Please specify an api key and host!");
    if (!opts.api_key)
        throw new Error("Chartbeat: Please specify an api key!");
    if (!opts.host)
        throw new Error("Chartbeat: Please specify a host!");

    this.creds = {
        api_key: opts.api_key,
        host: opts.host,
    }

    // Placeholders
    this.data = {
        data: null,
        previous_data: null
    }

    this.tmp = {};

    this.uid = "chartbeat_" + Math.floor(Math.random()*100000000);

    // Default callback.
    // This always runs, saving the response from Chartbeat in this.data
    this.successful_fetch = function(data) {
        if (data.error)
            throw new Error(data.error);

        this.data.previous_data = this.data.data;
        this.data.data = data

        this.utils.cleanup_window(this.uid);

        return this;
    }

    this.fetch = function(type, callback, type_opts) {
        /* Parameters:
         *
         * type (string): 'pages', 'pathsummary', 'recent', 'quickstats',
         * 'toppages'; required.
         *
         * callback (function): function to wrap json
         * response from chartbeat; optional.
         *
         * type_opts (object): required for some types; example for
         * 'pathsummary' type: {"path":"/", "keys":"a", "types":"s"}
         */

        window[this.uid] = this;

        if (!callback) {
            this.tmp.callback_str = "window['" + this.uid + "'].successful_fetch";
        }

        if (typeof callback == 'function') {
            this.tmp.callback = this.utils.bind(this, function(data) {
                if (data.error)
                    throw new Error(data.error);

                callback(data);
                this.successful_fetch(data);
            });

            this.tmp.callback_str = "window['" + this.uid + "'].tmp.callback";
        }

        var fetch_options = {
            "apikey": this.creds.api_key,
            "host": this.creds.host,
            "jsonp": this.tmp.callback_str
        }

        var params = this.utils.parameterize(fetch_options);

        var url = "http://api.chartbeat.com/"+type+"/?"+params;

        if (type_opts) {
            params = params + this.utils.parameterize(type_opts);
            url = "http://api.chartbeat.com/"+type+"/?"+params;
        }

        var script = document.createElement("script");
        script.src = url;
        if (document.body.appendChild(script))
            return true;
        else
            return false;
    }

    this.utils = {
        bind: function(obj, func) {
            return function() {
                return func.apply(obj, arguments);
            }
        },

        // URL parameter string from literal object
        parameterize: function(params) {
            var str = '';
            for (param in params) {
                str += param + "=" + escape(params[param]) + "&";
            }
            str.replace(/\&$/, '');

            return str;
        },

        // Get rid of temporary global
        cleanup_window: function(str) {
            for (var v in window) {
                if (v == str) {
                    delete window[v];
                    break;
                }
            }
        }
    }
}