reworked binding and unbinding

Author: fieg

doc/methods.md

@@ -11,7 +11,7 @@ jQuery.ias().bind();
 
 ### destroy
 
-Alias of [unbind](methods.html#unbind) method.
+Unbinds and destroys instance.
 
 ### extension
 

src/callbacks.js

@@ -23,13 +23,16 @@ var IASCallbacks = function () {
     var context = args[0],
         deferred = args[1],
         callbackArguments = args[2];
+
     this.isFiring = true;
 
     for (var i = 0, l = this.list.length; i < l; i++) {
-      if (false === this.list[i].fn.apply(context, callbackArguments)) {
-        deferred.reject();
+      if (this.list[i] != undefined) {
+        if (false === this.list[i].fn.apply(context, callbackArguments)) {
+          deferred.reject();
 
-        break;
+          break;
+        }
       }
     }
 

src/extension/history.js

@@ -25,13 +25,11 @@ var IASHistoryExtension = function (options) {
    * @param url
    */
   this.onPageChange = function (pageNum, scrollOffset, url) {
-    var state = {};
-
     if (!window.history || !window.history.replaceState) {
       return;
     }
 
-    state = history.state;
+    var state = history.state;
 
     history.replaceState(state, document.title, url);
   };
@@ -55,6 +53,17 @@ var IASHistoryExtension = function (options) {
     }
   };
 
+  this.onReady = function () {
+    var currentScrollOffset = this.ias.getCurrentScrollOffset(this.ias.$scrollContainer),
+        firstItemScrollThreshold = this.getScrollThresholdFirstItem();
+
+    currentScrollOffset -= this.ias.$scrollContainer.height();
+
+    if (currentScrollOffset <= firstItemScrollThreshold) {
+      this.prev();
+    }
+  };
+
   /**
    * Returns the url for the next page
    *
@@ -150,20 +159,19 @@ IASHistoryExtension.prototype.initialize = function (ias) {
  * @param ias
  */
 IASHistoryExtension.prototype.bind = function (ias) {
-  var self = this;
-
   ias.on('pageChange', jQuery.proxy(this.onPageChange, this));
   ias.on('scroll', jQuery.proxy(this.onScroll, this));
-  ias.on('ready', function () {
-    var currentScrollOffset = ias.getCurrentScrollOffset(ias.$scrollContainer),
-        firstItemScrollThreshold = self.getScrollThresholdFirstItem();
-
-    currentScrollOffset -= ias.$scrollContainer.height();
+  ias.on('ready', jQuery.proxy(this.onReady, this));
+};
 
-    if (currentScrollOffset <= firstItemScrollThreshold) {
-      self.prev();
-    }
-  });
+/**
+ * @public
+ * @param {object} ias
+ */
+IASHistoryExtension.prototype.unbind = function(ias) {
+  ias.off('pageChange', this.onPageChange);
+  ias.off('scroll', this.onScroll);
+  ias.off('ready', this.onReady);
 };
 
 /**
@@ -180,7 +188,7 @@ IASHistoryExtension.prototype.prev = function () {
     return false;
   }
 
-  ias.unbind();
+  ias.pause();
 
   var promise = ias.fire('prev', [url]);
 
@@ -189,7 +197,7 @@ IASHistoryExtension.prototype.prev = function () {
       self.renderBefore(items, function () {
         self.prevUrl = self.getPrevUrl(data);
 
-        ias.bind();
+        ias.resume();
 
         if (self.prevUrl) {
           self.prev();
@@ -199,7 +207,7 @@ IASHistoryExtension.prototype.prev = function () {
   });
 
   promise.fail(function () {
-    ias.bind();
+    ias.resume();
   });
 
   return true;

src/extension/noneleft.js

@@ -38,6 +38,14 @@ IASNoneLeftExtension.prototype.bind = function(ias) {
   ias.on('noneLeft', jQuery.proxy(this.showNoneLeft, this));
 };
 
+/**
+ * @public
+ * @param {object} ias
+ */
+IASNoneLeftExtension.prototype.unbind = function(ias) {
+  ias.off('noneLeft', this.showNoneLeft);
+};
+
 /**
  * @public
  */

src/extension/paging.js

@@ -118,6 +118,19 @@ IASPagingExtension.prototype.bind = function(ias) {
   ias.on('scroll', jQuery.proxy(this.onScroll, this), this.priority);
 };
 
+/**
+ * @public
+ * @param {object} ias
+ */
+IASPagingExtension.prototype.unbind = function(ias) {
+  try {
+    ias.off('prev', this.onPrev);
+  } catch (exception) {}
+
+  ias.off('next', this.onNext);
+  ias.off('scroll', this.onScroll);
+};
+
 /**
  * Returns current page number based on scroll offset
  *

src/extension/spinner.js

@@ -90,12 +90,24 @@ IASSpinnerExtension.prototype.bind = function(ias) {
   this.ias = ias;
 
   ias.on('next', jQuery.proxy(this.showSpinner, this));
+  ias.on('render', jQuery.proxy(this.removeSpinner, this));
 
   try {
     ias.on('prev', jQuery.proxy(this.showSpinnerBefore, this));
   } catch (exception) {}
+};
 
-  ias.on('render', jQuery.proxy(this.removeSpinner, this));
+/**
+ * @public
+ * @param {object} ias
+ */
+IASSpinnerExtension.prototype.unbind = function(ias) {
+  ias.off('next', this.showSpinner);
+  ias.off('render', this.removeSpinner);
+
+  try {
+    ias.off('prev', this.showSpinnerBefore);
+  } catch (exception) {}
 };
 
 /**

src/extension/trigger.js

@@ -58,6 +58,10 @@ var IASTriggerExtension = function(options) {
     return false;
   };
 
+  this.onRendered = function() {
+    this.enabled = true;
+  };
+
   /**
    * @param clickCallback
    * @returns {*|jQuery}
@@ -88,20 +92,33 @@ IASTriggerExtension.prototype.bind = function(ias) {
 
   this.ias = ias;
 
+  ias.on('next', jQuery.proxy(this.showTriggerNext, this), this.priority);
+  ias.on('rendered', jQuery.proxy(this.onRendered, this), this.priority);
+
   try {
     ias.on('prev', jQuery.proxy(this.showTriggerPrev, this), this.priority);
   } catch (exception) {}
+};
 
-  ias.on('next', jQuery.proxy(this.showTriggerNext, this), this.priority);
-  ias.on('rendered', function () { self.enabled = true; }, this.priority);
+/**
+ * @public
+ * @param {object} ias
+ */
+IASTriggerExtension.prototype.unbind = function(ias) {
+  ias.off('next', this.showTriggerNext);
+  ias.off('rendered', this.onRendered);
+
+  try {
+    ias.off('prev', this.showTriggerPrev);
+  } catch (exception) {}
 };
 
 /**
  * @public
  */
 IASTriggerExtension.prototype.next = function() {
   this.enabled = false;
-  this.ias.unbind();
+  this.ias.pause();
 
   if (this.$triggerNext) {
     this.$triggerNext.remove();
@@ -116,7 +133,7 @@ IASTriggerExtension.prototype.next = function() {
  */
 IASTriggerExtension.prototype.prev = function() {
   this.enabled = false;
-  this.ias.unbind();
+  this.ias.pause();
 
   if (this.$triggerPrev) {
     this.$triggerPrev.remove();

src/jquery-ias.js

@@ -28,6 +28,7 @@
     this.negativeMargin = options.negativeMargin;
     this.nextUrl = null;
     this.isBound = false;
+    this.isPaused = false;
     this.listeners = {
       next:     new IASCallbacks(),
       load:     new IASCallbacks(),
@@ -48,15 +49,15 @@
      * @private
      */
     this.scrollHandler = function() {
-      var currentScrollOffset = this.getCurrentScrollOffset(this.$scrollContainer),
-          scrollThreshold = this.getScrollThreshold()
-      ;
-
       // the throttle method can call the scrollHandler even thought we have called unbind()
-      if (!this.isBound) {
+      if (!this.isBound || this.isPaused) {
         return;
       }
 
+      var currentScrollOffset = this.getCurrentScrollOffset(this.$scrollContainer),
+          scrollThreshold = this.getScrollThreshold()
+      ;
+
       // invalid scrollThreshold. The DOM might not have loaded yet...
       if (UNDETERMINED_SCROLLOFFSET == scrollThreshold) {
         return;
@@ -320,6 +321,28 @@
       return this.listeners[event].fireWith(this, args);
     };
 
+    /**
+     * Pauses the scroll handler
+     *
+     * Note: internal use only, if you need to pause IAS use `unbind` method.
+     *
+     * @private
+     */
+    this.pause = function() {
+      this.isPaused = true;
+    };
+
+    /**
+     * Resumes the scroll handler
+     *
+     * Note: internal use only, if you need to resume IAS use `bind` method.
+     *
+     * @private
+     */
+    this.resume = function() {
+      this.isPaused = false;
+    };
+
     return this;
   };
 
@@ -337,10 +360,6 @@
     this.hidePagination();
     this.bind();
 
-    for (var i = 0, l = this.extensions.length; i < l; i++) {
-      this.extensions[i].bind(this);
-    }
-
     this.fire('ready');
 
     this.nextUrl = this.getNextUrl();
@@ -375,7 +394,12 @@
 
     this.$scrollContainer.on('scroll', $.proxy(this.throttle(this.scrollHandler, 150), this));
 
+    for (var i = 0, l = this.extensions.length; i < l; i++) {
+      this.extensions[i].bind(this);
+    }
+
     this.isBound = true;
+    this.resume();
   };
 
   /**
@@ -390,6 +414,13 @@
 
     this.$scrollContainer.off('scroll', this.scrollHandler);
 
+    // notify extensions about unbinding
+    for (var i = 0, l = this.extensions.length; i < l; i++) {
+      if (typeof this.extensions[i]['unbind'] != 'undefined') {
+        this.extensions[i].unbind(this);
+      }
+    }
+
     this.isBound = false;
   };
 
@@ -474,13 +505,13 @@
     var url = this.nextUrl,
         self = this;
 
-    this.unbind();
+    this.pause();
 
     if (!url) {
       this.fire('noneLeft', [this.getLastItem()]);
       this.listeners['noneLeft'].disable(); // disable it so it only fires once
 
-      self.bind();
+      self.resume();
 
       return false;
     }
@@ -492,13 +523,13 @@
         self.render(items, function() {
           self.nextUrl = self.getNextUrl(data);
 
-          self.bind();
+          self.resume();
         });
       });
     });
 
     promise.fail(function() {
-      self.bind();
+      self.resume();
     });
 
     return true;
@@ -520,6 +551,8 @@
 
     this.extensions.push(extension);
 
+    this.reinitialize();
+
     return this;
   };
 

test/03-extensions-test.js

@@ -51,7 +51,6 @@ describe("IAS", function () {
     };
 
     jQuery.ias().extension(new anExtension());
-    jQuery.ias().initialize();
 
     expect(spy1).toHaveBeenCalledOnce();
 
@@ -84,7 +83,6 @@ describe("IAS", function () {
 
     // now let's register the extension
     jQuery.ias().extension(new anExtension());
-    jQuery.ias().initialize();
 
     // this should now be possible and not throw an error
     jQuery.ias().on('test', function() {});

test/04-history-extension-test.js

@@ -23,8 +23,6 @@ describe("IAS", function () {
       prev: '.prev-posts a'
     }));
 
-    ias.initialize();
-
     expect(ias.prev).toBeDefined();
   });