postal.diagnostics/lib/postal.diagnostics.js

Wiretap add-on for postal.js allowing configurable console.logging (or other) output of messages being published through postal's message bus.

/**
 * postal.diagnostics - Wiretap add-on for postal.js allowing configurable console.logging (or other) output of messages being published through postal's message bus.
 * Author: Jim Cowart (http://freshbrewedcode.com/jimcowart)
 * Version: v0.7.4
 * Url: https://github.com/postaljs/postal.diagnostics
 * License(s): MIT, GPL
 */

(function (root, factory) {
    if (typeof define === "function" && define.amd) {
        // AMD. Register as an anonymous module.
        define(["lodash", "postal"], function (_, postal) {
            return factory(_, postal, root);
        });
    } else if (typeof module === "object" && module.exports) {
        // Node, or CommonJS-Like environments
        module.exports = function (postal) {
            return factory(require("lodash"), postal);
        };
    } else {
        // Browser globals
        factory(root._, root.postal, root);
    }
}(typeof window !== "undefined" ? window : this, function (_, postal, global, undefined) {

    postal.diagnostics = {};

    var DiagnosticsWireTap = function (options) {
        options = options || {};
        _.extend(this, {
            active: true,
            filters: [],
            name: _.uniqueId("wiretap_"),
            includeNesting: false
        }, options);

        this.removeWireTap = postal.addWireTap(_.bind(this.wiretapFn, this));

        if (postal.diagnostics[this.name]) {
            postal.diagnostics[this.name].removeWireTap();
        }
        postal.diagnostics[this.name] = this;
    };

    DiagnosticsWireTap.prototype.wiretapFn = function (data, envelope, nesting) {
        if (!this.active) {
            return;
        }
        if (!this.filters.length || _.any(this.filters, function (filter) {
            return this.applyFilter(filter, envelope);
        }, this)) {
            try {
                this.writer(this.serialize(envelope), nesting);
            } catch (exception) {
                this.writer("Unable to serialize envelope: " + exception);
            }
        }
    };

    DiagnosticsWireTap.prototype.applyFilter = function (filter, env) {
        var match = 0,
            possible = 0;
        _.each(filter, function (item, key) {
            if (env[key]) {
                possible++;
                if (_.isRegExp(item) && item.test(env[key])) {
                    match++;
                } else if (_.isObject(env[key]) && !_.isArray(env[key])) {
                    if (this.applyFilter(item, env[key])) {
                        match++;
                    }
                } else {
                    if (_.isEqual(env[key], item)) {
                        match++;
                    }
                }
            }
        }, this);
        return match === possible;
    };

    DiagnosticsWireTap.prototype.clearFilters = function () {
        this.filters = [];
    };

    DiagnosticsWireTap.prototype.removeFilter = function (filter) {
        this.filters = _.filter(this.filters, function (item) {
            return !_.isEqual(item, filter);
        });
    };

    DiagnosticsWireTap.prototype.addFilter = function (constraint) {
        if (!_.isArray(constraint)) {
            constraint = [constraint];
        }
        _.each(constraint, function (item) {
            if (this.filters.length === 0 || !_.any(this.filters, function (filter) {
                return _.isEqual(filter, item);
            })) {
                this.filters.push(item);
            }
        }, this);
    };

    DiagnosticsWireTap.prototype.serialize = function (env) {
        if (typeof JSON === "undefined") {
            throw new Error("This browser or environment does not provide JSON support");
        }
        return JSON.stringify(env, null, 4);
    };

    DiagnosticsWireTap.prototype.writer = function (output, nesting) {
        if (this.includeNesting) {
            console.log(output, "\t(nesting level: ", nesting, ")");
        } else {
            console.log(output);
        }
    };

    postal.diagnostics.DiagnosticsWireTap = DiagnosticsWireTap;

    return DiagnosticsWireTap;

}));