From 5e5b301d0d2f8df453328ccbcf8f48432e3ff6b2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jannis=20Mo=C3=9Fhammer?= <jannis.mosshammer@netways.de>
Date: Fri, 21 Jun 2013 15:33:06 +0200
Subject: [PATCH] Add support for lazy module loading

When the X-Icinga-Module-Enable header is send, the
modulemanager automatically tries to load javascript files for
that module. This is realized by adding the 'registerHeaderListener'
method to the async manager, which allows to listen to specific headers
and firing callbacks if a response with the specified header is retrieved.

Also the tests have changed a bit, requireNow should be used when using
the requiremock, so a require always loads files new.

refs #4092
refs #3753
---
 application/controllers/ModulesController.php |  6 +-
 public/js/icinga/icinga.js                    |  8 ++-
 public/js/icinga/util/async.js                | 34 ++++++++--
 test/js/test/icinga/moduleTest.js             | 62 +++++++++++++++++--
 4 files changed, 99 insertions(+), 11 deletions(-)

diff --git a/application/controllers/ModulesController.php b/application/controllers/ModulesController.php
index f8f40a3b3..afd3b9178 100755
--- a/application/controllers/ModulesController.php
+++ b/application/controllers/ModulesController.php
@@ -35,7 +35,11 @@ class ModulesController extends ActionController
     public function enableAction()
     {
         $this->manager->enableModule($this->_getParam('name'));
-        $this->redirectNow('modules/overview?_render=body');
+        $this->manager->loadModule($this->_getParam('name'));
+        $this->getResponse()->setHeader('X-Icinga-Enable-Module', $this->_getParam('name')); 
+        $this->replaceLayout = true; 
+        $this->indexAction();
+
     }
 
     public function disableAction()
diff --git a/public/js/icinga/icinga.js b/public/js/icinga/icinga.js
index ff59321f6..d538ab552 100755
--- a/public/js/icinga/icinga.js
+++ b/public/js/icinga/icinga.js
@@ -19,16 +19,19 @@ define([
         var failedModules = [];
 
         var initialize = function () {
+            registerLazyModuleLoading();
             enableInternalModules();
-
+            
             containerMgr.registerAsyncMgr(async);
             containerMgr.initializeContainers(document);
             log.debug("Initialization finished");
 
             enableModules();
         };
-
         
+        var registerLazyModuleLoading = function() {
+            async.registerHeaderListener("X-Icinga-Enable-Module", loadModuleScript, this);
+        };
 
         var enableInternalModules = function() {
             $.each(internalModules,function(idx,module) {
@@ -37,6 +40,7 @@ define([
         };
 
         var loadModuleScript = function(name) {
+            console.log("Loading ", name);
             moduleMgr.enableModule("modules/"+name+"/"+name, function(error) {
                 failedModules.push({
                     name: name,
diff --git a/public/js/icinga/util/async.js b/public/js/icinga/util/async.js
index 15a6be7df..1b564b176 100644
--- a/public/js/icinga/util/async.js
+++ b/public/js/icinga/util/async.js
@@ -3,7 +3,8 @@
     "use strict";
     var asyncMgrInstance = null;
 
-    define(['icinga/container','logging','icinga/behaviour','jquery'],function(containerMgr,log,behaviour,$) {
+    define(['icinga/container','logging','jquery'],function(containerMgr,log,$) {
+        var headerListeners = {};
 
         var pending = {
 
@@ -18,12 +19,30 @@
             return target;
         };
 
-        var handleResponse = function(html) {
+        var applyHeaderListeners = function(headers) {
+            for (var header in headerListeners) {
+                if (headers.getResponseHeader(header) === null) {
+                    // see if the browser/server converts headers to lowercase
+                    if (headers.getResponseHeader(header.toLowerCase()) === null) {
+                        continue;
+                    }
+                    header = header.toLowerCase();
+                }
+                var value = headers.getResponseHeader(header);
+                var listeners = headerListeners[header];
+                for (var i=0;i<listeners.length;i++) {
+                    listeners[i].fn.apply(listeners[i].scope, [value, header, headers]);
+                }
+            }
+        };
 
+        var handleResponse = function(html, status, response) {
+            applyHeaderListeners(response); 
             if(this.destination) {
                 containerMgr.updateContainer(this.destination,html,this);
             } else {
-                containerMgr.createPopupContainer(html,this);
+            // tbd
+            // containerMgr.createPopupContainer(html,this);
             }
         };
 
@@ -49,6 +68,8 @@
 
         var CallInterface = function() {
 
+            this.__internalXHRImplementation = $.ajax; 
+
             this.clearPendingRequestsFor = function(destination) {
                 if(!$.isArray(pending)) {
                     pending = [];
@@ -68,7 +89,7 @@
             };
 
             this.createRequest = function(url,data) {
-                var req = $.ajax({
+                var req = this.__internalXHRImplementation({
                     type   : data ? 'POST' : 'GET',
                     url    :  url,
                     data   : data,
@@ -101,6 +122,11 @@
             this.loadCSS = function(name) {
 
             };
+
+            this.registerHeaderListener = function(header, fn, scope) {
+                headerListeners[header] = headerListeners[header] || [];
+                headerListeners[header].push({fn: fn, scope:scope});
+            };
         };
         return new CallInterface();
     });
diff --git a/test/js/test/icinga/moduleTest.js b/test/js/test/icinga/moduleTest.js
index 494d0264a..d525a4d56 100644
--- a/test/js/test/icinga/moduleTest.js
+++ b/test/js/test/icinga/moduleTest.js
@@ -9,12 +9,12 @@
 // {{LICENSE_HEADER}}
 var should = require("should");
 var rjsmock = require("requiremock.js");
+var asyncMock = require("asyncmock.js");
 
-var BASE = "../../../../public/js/";
-require(BASE+"icinga/module.js");
-
+requireNew("icinga/module.js");
 var module = rjsmock.getDefine(); 
 GLOBAL.document = $('body');
+
 /**
 * Test module that only uses eventhandlers and 
 * no custom logic
@@ -195,6 +195,9 @@ describe('The icinga module bootstrap', function() {
         var testClick = false;
         rjsmock.registerDependencies({
             "icinga/module": module,
+            "icinga/util/async" : {
+                registerHeaderListener: function() {}
+            },
             "modules/test/test" : {
                 eventHandler: {
                     "a.test" : {
@@ -214,7 +217,7 @@ describe('The icinga module bootstrap', function() {
             ]
         });
         tearDownTestDOM();
-        require(BASE+"icinga/icinga.js");
+        requireNew("icinga/icinga.js");
         var icinga = rjsmock.getDefine();
         $('body').append($("<a class='test'></a>"));
         $('a.test').click();
@@ -223,4 +226,55 @@ describe('The icinga module bootstrap', function() {
         should.equal(icinga.getFailedModules()[0].name, "test2");
         tearDownTestDOM(); 
     });
+
+    it("Should load modules lazily when discovering a X-Icinga-Enable-Module header", function() {
+        rjsmock.purgeDependencies();
+
+        requireNew("icinga/util/async.js");
+        var async = rjsmock.getDefine();
+        
+        rjsmock.registerDependencies({
+            "icinga/module": module,
+            "icinga/util/async": async,
+            "modules/test/test" : {
+                eventHandler: {
+                    "a.test" : {
+                        click : function() {
+                            testClick = true;
+                        }
+                    }  
+                }
+            },
+            "icinga/container" : {
+                registerAsyncMgr: function() {},
+                initializeContainers: function() {}
+            },
+            "modules/list" : [
+            ]
+        });
+
+        tearDownTestDOM();
+        
+        requireNew("icinga/icinga.js");
+        var icinga = rjsmock.getDefine();
+
+        var testClick = false;
+        // The module shouldn't be loaded
+        $('body').append($("<a class='test'></a>"));
+        $('a.test').click();
+        should.equal(testClick, false, "Unregistered module was loaded");
+         
+        asyncMock.setNextAsyncResult(async,"result", false, {
+            "X-Icinga-Enable-Module" : "test"
+        });
+        async.createRequest();
+         // The module shouldn't be loaded
+        $('body').append($("<a class='test'></a>"));
+        $('a.test').click();
+        should.equal(testClick, true, "Module wasn't automatically loaded on header!");
+         
+
+        tearDownTestDOM(); 
+
+    });
 });