origins/src/js/loglevel.js

JavaScript client for Origins REST service

/*! loglevel - v0.6.0 - https://github.com/pimterry/loglevel - (c) 2014 Tim Perry - licensed MIT */
;(function (undefined) {
    var undefinedType = "undefined";

    (function (name, definition) {
        if (typeof module !== 'undefined') {
            module.exports = definition();
        } else if (typeof define === 'function' && typeof define.amd === 'object') {
            define(definition);
        } else {
            this[name] = definition();
        }
    }('log', function () {
        var self = {};
        var noop = function() {};

        function realMethod(methodName) {
            if (typeof console === undefinedType) {
                return noop;
            } else if (console[methodName] === undefined) {
                if (console.log !== undefined) {
                    return boundToConsole(console, 'log');
                } else {
                    return noop;
                }
            } else {
                return boundToConsole(console, methodName);
            }
        }

        function boundToConsole(console, methodName) {
            var method = console[methodName];
            if (method.bind === undefined) {
                if (Function.prototype.bind === undefined) {
                    return functionBindingWrapper(method, console);
                } else {
                    try {
                        return Function.prototype.bind.call(console[methodName], console);
                    } catch (e) {
                        // In IE8 + Modernizr, the bind shim will reject the above, so we fall back to wrapping
                        return functionBindingWrapper(method, console);
                    }
                }
            } else {
                return console[methodName].bind(console);
            }
        }

        function functionBindingWrapper(f, context) {
            return function() {
                Function.prototype.apply.apply(f, [context, arguments]);
            };
        }

        var logMethods = [
            "trace",
            "debug",
            "info",
            "warn",
            "error"
        ];

        function replaceLoggingMethods(methodFactory) {
            for (var ii = 0; ii < logMethods.length; ii++) {
                self[logMethods[ii]] = methodFactory(logMethods[ii]);
            }
        }

        function cookiesAvailable() {
            return (typeof window !== undefinedType &&
                    window.document !== undefined &&
                    window.document.cookie !== undefined);
        }

        function localStorageAvailable() {
            try {
                return (typeof window !== undefinedType &&
                        window.localStorage !== undefined);
            } catch (e) {
                return false;
            }
        }

        function persistLevelIfPossible(levelNum) {
            var localStorageFail = false,
                levelName;

            for (var key in self.levels) {
                if (self.levels.hasOwnProperty(key) && self.levels[key] === levelNum) {
                    levelName = key;
                    break;
                }
            }

            if (localStorageAvailable()) {
                /*
                 * Setting localStorage can create a DOM 22 Exception if running in Private mode
                 * in Safari, so even if it is available we need to catch any errors when trying
                 * to write to it
                 */
                try {
                    window.localStorage['loglevel'] = levelName;
                } catch (e) {
                    localStorageFail = true;
                }
            } else {
                localStorageFail = true;
            }

            if (localStorageFail && cookiesAvailable()) {
                window.document.cookie = "loglevel=" + levelName + ";";
            }
        }

        var cookieRegex = /loglevel=([^;]+)/;

        function loadPersistedLevel() {
            var storedLevel;

            if (localStorageAvailable()) {
                storedLevel = window.localStorage['loglevel'];
            }

            if (storedLevel === undefined && cookiesAvailable()) {
                var cookieMatch = cookieRegex.exec(window.document.cookie) || [];
                storedLevel = cookieMatch[1];
            }

            if (self.levels[storedLevel] === undefined) {
                storedLevel = "WARN";
            }

            self.setLevel(self.levels[storedLevel]);
        }

        /*
         *
         * Public API
         *
         */

        self.levels = { "TRACE": 0, "DEBUG": 1, "INFO": 2, "WARN": 3,
            "ERROR": 4, "SILENT": 5};

        self.setLevel = function (level) {
            if (typeof level === "number" && level >= 0 && level <= self.levels.SILENT) {
                persistLevelIfPossible(level);

                if (level === self.levels.SILENT) {
                    replaceLoggingMethods(function () {
                        return noop;
                    });
                    return;
                } else if (typeof console === undefinedType) {
                    replaceLoggingMethods(function (methodName) {
                        return function () {
                            if (typeof console !== undefinedType) {
                                self.setLevel(level);
                                self[methodName].apply(self, arguments);
                            }
                        };
                    });
                    return "No console available for logging";
                } else {
                    replaceLoggingMethods(function (methodName) {
                        if (level <= self.levels[methodName.toUpperCase()]) {
                            return realMethod(methodName);
                        } else {
                            return noop;
                        }
                    });
                }
            } else if (typeof level === "string" && self.levels[level.toUpperCase()] !== undefined) {
                self.setLevel(self.levels[level.toUpperCase()]);
            } else {
                throw "log.setLevel() called with invalid level: " + level;
            }
        };

        self.enableAll = function() {
            self.setLevel(self.levels.TRACE);
        };

        self.disableAll = function() {
            self.setLevel(self.levels.SILENT);
        };

        loadPersistedLevel();
        return self;
    }));
})();