crosstab - npm Package Compare versions

Comparing version 0.2.5 to 0.2.6

bower.json

 {
   "name": "crosstab",
-  "version": "v0.2.5",
+  "version": "v0.2.6",
   "homepage": "https://github.com/tejacques/crosstab",
@@ -5,0 +5,0 @@ "authors": [

package.json

 {
   "name": "crosstab",
-  "version": "0.2.5",
+  "version": "0.2.6",
   "description": "A utility library for cross-tab communication using localStorage.",
@@ -5,0 +5,0 @@ "author": "Tom Jacques <[e-mail]>",

README.md

@@ -57,3 +57,3 @@ # crosstab [![NPM version][npm-img]][npm-url] [![Build Status][travis-img]][travis-url]
 
-crosstab registers event handlers like this:
+crosstab registers and unregisters event handlers like this:
 
@@ -70,8 +70,8 @@ ```JavaScript
 var message = {
-    id: util.generateId(),    // The unique ID of this message
-    event: event,             // The name of the event
-    data: data,               // The data to pass
-    destination: destination, // The destination tab
-    origin: crosstab.id,      // The origin tab
-    timestamp: util.now()     // The time the message was created
+    id: string,          // The unique ID of this message
+    event: string,       // The name of the event
+    data: any,           // The data passed
+    destination: string, // The destination tab
+    origin: string,      // The origin tab
+    timestamp: number    // The time the message was created
 };
@@ -86,13 +86,59 @@ ```
 
-I wanted to be able to have robust cross tab communication for the purpose of resource sharing (such as websockets). Though there are some libraries which have a similar goal, they all had subtle issues. This library aims to be the most correct it can be for supported browsers. This library was created with inspiration from the excellent [intercom.js](https://github.com/diy/intercom.js/) library, and addresses several of it's shortcomings:
+I wanted to be able to have robust cross tab communication for the purpose of resource sharing (such as websockets). Though there are some libraries which have a similar goal, they all had subtle issues. This library aims to be the most correct it can be for supported browsers. This library was created with inspiration from the [intercom.js](https://github.com/diy/intercom.js/) library, and addresses several of it's shortcomings by dropping support for IE8 and using a lockless system that is entirely event driven. IE8 can still be used with crosstab by using the [tejacques/IE8-EventListener](https://github.com/tejacques/IE8-EventListener) EventListener polyfill
 
-* intercom.js doesn't implement proper locking.
- * does not guarantee that one tab holds the lock at a time (in fact this is impossible to guarantee flat out, but can be guaranteed within defined execution times).
- * locking on functions that throw will break.
- * Updates to any localStorage item will cause the locks to attempt to be acquired instead of only removals of the lock.
-* in trying to support IE8 message broadcasting in intercom.js has a race condition where messages can be dropped.
-* intercom.js leaks memory by maintaining a state of every message id received (also in an attempt to support IE8)
+Contributing
+------------
 
-crosstab solves these issues by dropping support for IE8 and using a lockless system that is entirely event driven (IE8 cannot pass messages via localStorage events, which is why intercom.js requires locking, because it supports IE8).
+Contributions are welcome and encouraged, you can contribute in several different ways, by filing issues, commenting on discussions, or contributing code.
 
+### Filing issues ###
+
+Please use the issue tracker for discussions and bug reports. For bug reports, please include as much detail as possible.
+
+These will help determine/resolve your issue:
+
+* Clear description of the problem or unexpexted behavior
+* Clear description of the expected result or output
+* Steps to reproduce
+* Steps you have taken to debug it yourself
+* Minimal reproducible example with self contained and runnable JS code
+
+### Contributing Code ###
+
+#### Project Workflow ####
+
+We use roughly the [Github Workflow](https://guides.github.com/introduction/flow/). You should:
+
+* Create an issue for the feature/bug
+* Fork the project
+* Create a new branch
+* Commit changes
+* Submit a pull request to the master branch
+
+#### Tests ####
+
+Tests can be run with the following command:
+
+```.sh
+grunt test
+```
+
+* Tests must pass
+* Tests should be added for each bug/feature that is added
+* All tests should be self-contained
+* If test is determined to be too difficult to create for an issue, there does not need to be a test for it
+
+#### Getting Started ####
+
+```.sh
+git clone https://github.com/tejacques/crosstab
+cd crosstab
+npm install
+grunt
+```
+
+You can now access:
+* Examples: [http://localhost:9000](http://localhost:9000)
+* Tests: [http://localhost:9000/test/mocha_test.html](http://localhost:9000/test/mocha_test.html)
+
 [downloads-img]: https://img.shields.io/npm/dm/crosstab.svg
@@ -99,0 +145,0 @@ [npm-url]: https://npmjs.org/package/crosstab

src/crosstab.js

 /*!
- * crosstab JavaScript Library v0.2.5
+ * crosstab JavaScript Library v0.2.6
  * https://github.com/tejacques/crosstab
@@ -79,6 +79,20 @@ *
 
-    util.forEachObj = function (thing, fn) {
-        for (var key in thing) {
-            if (thing.hasOwnProperty(key)) {
-                fn.call(thing, thing[key], key);
+    var toString = Object.prototype.toString;
+
+    util.isArray = Array.isArray || function (arr) {
+        return arr instanceof Array;
+    };
+
+    util.isNumber = function (num) {
+        return typeof num === 'number';
+    };
+
+    util.isFunction = function (fn) {
+        return typeof fn === 'function';
+    };
+
+    util.forEachObj = function (obj, fn) {
+        for (var key in obj) {
+            if (obj.hasOwnProperty(key)) {
+                fn.call(obj, obj[key], key);
             }
@@ -88,5 +102,6 @@ }
 
-    util.forEachArr = function (thing, fn) {
-        for (var i = 0; i < thing.length; i++) {
-            fn.call(thing, thing[i], i);
+    util.forEachArr = function (arr, fn) {
+        var len = arr.length
+        for (var i = 0; i < len; i++) {
+            fn.call(arr, arr[i], i, arr);
         }
@@ -96,3 +111,3 @@ };
     util.forEach = function (thing, fn) {
-        if (Object.prototype.toString.call(thing) === '[object Array]') {
+        if (util.isArray(thing)) {
             util.forEachArr(thing, fn);
@@ -114,3 +129,3 @@ } else {
     util.filter = function (thing, fn) {
-        var isArr = Object.prototype.toString.call(thing) === '[object Array]';
+        var isArr = util.isArray(thing);
         var res = isArr ? [] : {};
@@ -149,19 +164,67 @@
     // --- Events ---
-    // node.js style events, with the main difference being object based
-    // rather than array based, as well as being able to add/remove
-    // events by key.
+    // node.js style events, with the main difference being able
+    // to add/remove events by key.
     util.createEventHandler = function () {
         var events = {};
+        var subscribeKeyToListener = {};
 
+        var findHandlerByKey = function(event, key) {
+            var handler;
+            if (subscribeKeyToListener[event]) {
+                handler = subscribeKeyToListener[event][key];
+            }
+            return handler;
+        };
+
+        var findHandlerIndex = function (event, listener) {
+            var listenerIndex = -1;
+            var eventList = events[event];
+            if (eventList && listener) {
+                var len = eventList.length || 0;
+                for(var i = 0; i < len; i++) {
+                    if (eventList[i] === listener) {
+                        listenerIndex = i;
+                        break;
+                    }
+                }
+            }
+            return listenerIndex;
+        };
+
         var addListener = function (event, listener, key) {
-            key = key || listener;
             var handlers = listeners(event);
-            handlers[key] = listener;
 
-            return key;
+            var storedHandler = findHandlerByKey(event, key);
+            var listenerIndex;
+
+            if (storedHandler === undefined) {
+                listenerIndex = handlers.length;
+                handlers[listenerIndex] = listener;
+
+                if (!subscribeKeyToListener[event]) {
+                    (subscribeKeyToListener[event] = {});
+                }
+
+                if (key) {
+                    subscribeKeyToListener[event][key] = listener;
+                }
+            } else {
+                listenerIndex = findHandlerIndex(event, storedHandler);
+                handlers[listenerIndex] = listener;
+            }
+
+            return key || listener;
         };
 
         var removeListener = function (event, key) {
-            if (events[event] && events[event][key]) {
-                delete events[event][key];
+            var handler = util.isFunction(key)
+                ? key
+                : findHandlerByKey(event, key);
+
+            var listenerIndex = findHandlerIndex(event, handler);
+            if (listenerIndex === -1) return false;
+
+            if (events[event] && events[event][listenerIndex]) {
+                events[event].splice(listenerIndex, 1);
+                delete subscribeKeyToListener[event][key];
                 return true;
@@ -173,9 +236,18 @@ }
         var removeAllListeners = function (event) {
+            var successful = false;
             if (event) {
                 if (events[event]) {
                     delete events[event];
+                    successful = true;
                 }
+                if (subscribeKeyToListener[event]) {
+                    delete subscribeKeyToListener[event];
+                    successful = successful && true;
+                }
             } else {
                 events = {};
+                subscribeKeyToListener = {};
+                successful = true;
             }
+            return successful;
         };
@@ -188,3 +260,3 @@
             util.forEach(handlers, function (listener) {
-                if (typeof (listener) === 'function') {
+                if (util.isFunction(listener)) {
                     listener.apply(this, args);
@@ -197,4 +269,3 @@ }
             // Generate a unique id for this listener
-            var handlers = listeners(event);
-            while (!key || handlers[key]) {
+            while (!key || (findHandlerByKey(event, key) !== undefined)) {
                 key = util.generateId();
@@ -213,10 +284,24 @@ }
         var listeners = function (event) {
-            var handlers = events[event] = events[event] || {};
+            var handlers = events[event] = events[event] || [];
             return handlers;
         };
 
+        var destructor = function() {
+            removeAllListeners();
+        };
+
         return {
             addListener: addListener,
+            destructor: destructor,
             on: addListener,
-            off: removeListener,
+            off: function(event, key) {
+                var argsLen = arguments.length;
+                if (!argsLen) {
+                    return removeAllListeners();
+                } else if (argsLen === 1) {
+                    return removeAllListeners(event);
+                } else {
+                    return removeListener(event, key);
+                }
+            },
             once: once,
@@ -243,3 +328,4 @@ emit: emit,
         removeListener: eventHandler.removeListener,
-        removeAllListeners: eventHandler.removeAllListeners
+        removeAllListeners: eventHandler.removeAllListeners,
+        destructor: eventHandler.destructor
     };
@@ -304,3 +390,4 @@
 
-    function beforeUnload() {
+    function unload() {
+        crosstab.stopKeepalive = true;
         var numTabs = 0;
@@ -319,2 +406,4 @@ util.forEach(util.tabs, function (tab, key) {
         }
+
+        util.events.destructor();
     }
@@ -483,2 +572,3 @@
     crosstab.once = util.events.once;
+    crosstab.off = util.events.off;
 
@@ -620,3 +710,3 @@ // --- Crosstab supported ---
         window.addEventListener('storage', onStorageEvent, false);
-        window.addEventListener('beforeunload', beforeUnload, false);
+        window.addEventListener('unload', unload, false);
 
@@ -623,0 +713,0 @@ util.events.on('PING', function (message) {

test/test-crosstab.js

@@ -80,3 +80,3 @@ // =========== Iframe Tools ==============
 
-    it ('should be a function', function () {
+    it('should be a function', function () {
         expect(window.crosstab).to.be.a('function');
@@ -102,2 +102,86 @@ });
 
+    it('should invoke event listeners in the order they added', function () {
+        var msg = "TestMessage";
+        var order = [];
+
+        // http://stackoverflow.com/questions/280713/elements-order-in-a-for-in-loop
+        crosstab.on('test', function(message) {
+            expect((message || {}).data).to.be(msg);
+            order.push(2);
+        }, 'second');
+        crosstab.on('test', function(message) {
+            order.push(3);
+        }, '3');
+        crosstab.on('test', function(message) {
+            order.push(1);
+        }, 'first');
+        crosstab.on('test', function(message) {
+            expect((message || {}).data).to.be(msg);
+            order.push(101);
+        });
+        crosstab.on('test', function(message) {
+            order.push(102);
+        });
+
+        crosstab.broadcast('test', msg);
+        expect(order).to.eql([2, 3, 1, 101, 102]);
+    });
+
+    it('should not invoke event listener after unsubscribing', function() {
+        var msg = "test";
+        var received;
+        var offSuccessful;
+        var listeners = crosstab.util.events.listeners;
+
+        // -------------------------------
+        // unsubscribe with event + key
+        // -------------------------------
+        var evt1 = 'test-1';
+        crosstab.on(evt1, function(message) {
+            received = message.data + '-1';
+        }, 'first');
+        crosstab.broadcast(evt1, msg);
+        expect(received).to.eql(msg + '-1');
+
+        // unsubscribe with event + non-exist key
+        received = undefined;
+        offSuccessful = crosstab.off(evt1, 'non-exist');
+        expect(offSuccessful).to.eql(false);
+        crosstab.broadcast(evt1, msg);
+        expect(received).to.eql(msg + '-1');
+
+        // unsubscribe with event + key
+        var listenersLen = listeners(evt1).length;
+        received = undefined;
+        offSuccessful = crosstab.off(evt1, 'first');
+        expect(offSuccessful).to.eql(true);
+        crosstab.broadcast(evt1, msg);
+        expect(received).to.be(undefined);
+        expect(listeners(evt1).length).to.be(listenersLen-1);
+
+        // -------------------------------
+        // unsubscribe with event
+        // -------------------------------
+        var evt2 = 'test-2';
+        crosstab.on(evt2, function(message) {
+            received = message.data + '-1';
+        }, 'first');
+        crosstab.broadcast(evt2, msg);
+        expect(received).to.eql(msg + '-1');
+
+        // unsubcribe with non-exist event
+        received = undefined;
+        offSuccessful = crosstab.off('non-exist');
+        expect(offSuccessful).to.eql(false);
+        crosstab.broadcast(evt2, msg);
+        expect(received).to.eql(msg + '-1');
+
+        // unscribe with event
+        received = undefined;
+        offSuccessful = crosstab.off(evt2);
+        expect(offSuccessful).to.eql(true);
+        crosstab.broadcast(evt2, msg);
+        expect(received).to.be(undefined);
+    });
+
     it('should only trigger callback once for crosstab.once', function () {
@@ -104,0 +188,0 @@ var msg = "TestOnce";

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Total package byte prevSize

72157

increased by10.16%

Lines of code

1150

increased by15%

Number of lines in readme file

148

increased by45.1%

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