From a92401f157874bfc7f1182365da43ac6f632f6d5 Mon Sep 17 00:00:00 2001
From: danielgrippi <danielgrippi@gmail.com>
Date: Wed, 4 Jan 2012 10:32:19 -0800
Subject: [PATCH] prevent further pagination if user has fetched all posts for
 a given stream

---
 public/javascripts/app/views/stream_view.js   | 13 +++++-
 .../javascripts/app/views/stream_view_spec.js | 40 ++++++++++++++++---
 2 files changed, 46 insertions(+), 7 deletions(-)

diff --git a/public/javascripts/app/views/stream_view.js b/public/javascripts/app/views/stream_view.js
index 36b513746..43b887b8c 100644
--- a/public/javascripts/app/views/stream_view.js
+++ b/public/javascripts/app/views/stream_view.js
@@ -23,7 +23,7 @@ app.views.Stream = Backbone.View.extend({
   },
 
   infScroll : function() {
-    if(this.isLoading()) { return }
+    if(this.allContentLoaded || this.isLoading()) { return }
 
     var $window = $(window);
     var distFromTop = $window.height() + $window.scrollTop();
@@ -41,6 +41,8 @@ app.views.Stream = Backbone.View.extend({
     return this._loading && !this._loading.isResolved();
   },
 
+  allContentLoaded : false,
+
   addPost : function(post) {
     var postView = new app.views.Post({ model: post });
 
@@ -53,8 +55,15 @@ app.views.Stream = Backbone.View.extend({
     return this;
   },
 
-  collectionFetched: function() {
+  collectionFetched: function(collection, response) {
     this.$("#paginate").remove();
+
+    if(collection.parse(response).length == 0) {
+      this.allContentLoaded = true;
+      $(window).unbind('scroll')
+      return
+    }
+
     $(this.el).append($("<a>", {
       href: this.collection.url(),
       id: "paginate"
diff --git a/spec/javascripts/app/views/stream_view_spec.js b/spec/javascripts/app/views/stream_view_spec.js
index 5e9a78246..5fa69b01d 100644
--- a/spec/javascripts/app/views/stream_view_spec.js
+++ b/spec/javascripts/app/views/stream_view_spec.js
@@ -3,10 +3,9 @@ describe("app.views.Stream", function(){
     // should be jasmine helper
     window.current_user = app.user({name: "alice", avatar : {small : "http://avatar.com/photo.jpg"}});
 
-    var posts = $.parseJSON(spec.readFixture("multi_stream_json"))["posts"];
-
-    this.collection = new app.collections.Stream(posts);
+    this.posts = $.parseJSON(spec.readFixture("multi_stream_json"))["posts"];
 
+    this.collection = new app.collections.Stream(this.posts);
     this.view = new app.views.Stream({collection : this.collection});
 
     // do this manually because we've moved loadMore into render??
@@ -17,8 +16,11 @@ describe("app.views.Stream", function(){
   })
 
   describe("initialize", function(){
-
     it("binds an infinite scroll listener", function(){
+      spyOn($.fn, "scroll");
+
+      new app.views.Stream();
+      expect($.fn.scroll).toHaveBeenCalled()
     })
   })
 
@@ -57,12 +59,20 @@ describe("app.views.Stream", function(){
         expect(this.view.collection.fetch).toHaveBeenCalled();
       })
 
-      it("does not call fetch", function(){
+      it("does not call fetch if the collection is loading", function(){
         spyOn(this.view, "isLoading").andReturn(true)
 
         this.view.infScroll();
         expect(this.view.collection.fetch).not.toHaveBeenCalled();
       })
+
+      it("does not call fetch if all content has been fetched", function(){
+        spyOn(this.view, "isLoading").andReturn(false)
+        this.view.allContentLoaded = true;
+
+        this.view.infScroll();
+        expect(this.view.collection.fetch).not.toHaveBeenCalled();
+      })
     })
 
     it("does not fetch new content when the user is not at the bottom of the page", function(){
@@ -75,4 +85,24 @@ describe("app.views.Stream", function(){
       expect(this.view.collection.fetch).not.toHaveBeenCalled();
     })
   })
+
+  describe("collectionFetched", function(){
+    it("sets this.allContentLoaded if there are no more posts left to load", function(){
+      expect(this.view.allContentLoaded).toBe(false)
+      this.view.collectionFetched(this.collection, {posts : []})
+      expect(this.view.allContentLoaded).toBe(true)
+    })
+
+    it("unbinds scroll if there are no more posts left to load", function(){
+      spyOn($.fn, "unbind")
+      this.view.collectionFetched(this.collection, {posts : []})
+      expect($.fn.unbind).toHaveBeenCalled()
+    })
+
+    it("does not set this.allContentLoaded if there was a non-empty response from the server", function(){
+      expect(this.view.allContentLoaded).toBe(false)
+      this.view.collectionFetched(this.collection, {posts : this.posts})
+      expect(this.view.allContentLoaded).toBe(false)
+    })
+  })
 })