From 696a795c122bd5e0173a4792f3faae4bddce9804 Mon Sep 17 00:00:00 2001
From: David Baumgold <david@davidbaumgold.com>
Date: Mon, 24 Jun 2013 15:21:27 -0400
Subject: [PATCH] Don't remove all chapters on closing EditTextbook view

Previously, the code would dynamically add a chapter on render() if the textbook
had no chapters, and would remove all empty chapters when the edit view was closed.
Now, the render method doesn't modify the model at all anymore (yay!) and when the
edit view is closed, remove all empty chapters but be sure to leave at least one
left.
---
 .../coffee/spec/models/textbook_spec.coffee   |  6 ++---
 .../coffee/spec/views/textbook_spec.coffee    | 22 +++++++++++--------
 cms/static/js/models/textbook.js              |  2 +-
 cms/static/js/views/textbook.js               | 14 +++++++-----
 4 files changed, 25 insertions(+), 19 deletions(-)

diff --git a/cms/static/coffee/spec/models/textbook_spec.coffee b/cms/static/coffee/spec/models/textbook_spec.coffee
index 4dd236b505..037fdf7312 100644
--- a/cms/static/coffee/spec/models/textbook_spec.coffee
+++ b/cms/static/coffee/spec/models/textbook_spec.coffee
@@ -14,11 +14,11 @@ describe "CMS.Models.Textbook", ->
     it "should not show chapters by default", ->
         expect(@model.get("showChapters")).toBeFalsy()
 
-    it "should have an empty ChapterSet by default", ->
+    it "should have a ChapterSet with one chapter by default", ->
         chapters = @model.get("chapters")
         expect(chapters).toBeInstanceOf(CMS.Collections.ChapterSet)
-        expect(chapters.isEmpty()).toBeTruthy()
-        expect(chapters.length).toEqual(0)
+        expect(chapters.length).toEqual(1)
+        expect(chapters.at(0).isEmpty()).toBeTruthy()
 
     it "should be empty by default", ->
         expect(@model.isEmpty()).toBeTruthy()
diff --git a/cms/static/coffee/spec/views/textbook_spec.coffee b/cms/static/coffee/spec/views/textbook_spec.coffee
index b890caa4aa..848afe9830 100644
--- a/cms/static/coffee/spec/views/textbook_spec.coffee
+++ b/cms/static/coffee/spec/views/textbook_spec.coffee
@@ -89,12 +89,6 @@ describe "CMS.Views.EditTextbook", ->
             @view.render()
             expect(@view.$("input[name=textbook-name]").val()).toEqual("Life Sciences")
 
-        it "should create an empty chapter when it is rendered, if there are no chapters", ->
-            expect(@model.get("chapters").length).toEqual(0)
-            @view.render()
-            expect(@model.get("chapters").length).toEqual(1)
-            expect(@model.get("chapters").last().isEmpty()).toBeTruthy()
-
         it "should allow you to create new empty chapters", ->
             @view.render()
             numChapters = @model.get("chapters").length
@@ -122,13 +116,23 @@ describe "CMS.Views.EditTextbook", ->
             expect(@collection.save).not.toHaveBeenCalled()
             expect(@collection.editing).toBeUndefined()
 
-        it "does not save empty chapters on cancel", ->
+        it "removes all empty chapters on cancel if the model has a non-empty chapter", ->
             chapters = @model.get("chapters")
-            origLength = chapters.length
+            chapters.at(0).set("name", "non-empty")
             @view.render()
             chapters.add([{}, {}, {}]) # add three empty chapters
+            expect(chapters.length).toEqual(4)
             @view.$(".action-cancel").click()
-            expect(chapters.length).toEqual(origLength)
+            expect(chapters.length).toEqual(1)
+            expect(chapters.at(0).get('name')).toEqual("non-empty")
+
+        it "removes all empty chapters on cancel except one if the model has no non-empty chapters", ->
+            chapters = @model.get("chapters")
+            @view.render()
+            chapters.add([{}, {}, {}]) # add three empty chapters
+            expect(chapters.length).toEqual(4)
+            @view.$(".action-cancel").click()
+            expect(chapters.length).toEqual(1)
 
 
 describe "CMS.Views.ListTextbooks", ->
diff --git a/cms/static/js/models/textbook.js b/cms/static/js/models/textbook.js
index 42112a4d96..669f80c55b 100644
--- a/cms/static/js/models/textbook.js
+++ b/cms/static/js/models/textbook.js
@@ -2,7 +2,7 @@ CMS.Models.Textbook = Backbone.AssociatedModel.extend({
     defaults: function() {
         return {
             name: "",
-            chapters: new CMS.Collections.ChapterSet(),
+            chapters: new CMS.Collections.ChapterSet([{}]),
             showChapters: false
         };
     },
diff --git a/cms/static/js/views/textbook.js b/cms/static/js/views/textbook.js
index 16ff5444c8..d09930c2a5 100644
--- a/cms/static/js/views/textbook.js
+++ b/cms/static/js/views/textbook.js
@@ -78,10 +78,6 @@ CMS.Views.EditTextbook = Backbone.View.extend({
             name: this.model.escape('name'),
             errors: null
         }));
-        var chapters = this.model.get('chapters');
-        if (chapters.length === 0) {
-            chapters.add([{}]);
-        }
         this.addAll();
         return this;
     },
@@ -153,8 +149,14 @@ CMS.Views.EditTextbook = Backbone.View.extend({
         } else {
             // remove empty chapters from textbook
             var chapters = this.model.get("chapters");
-            chapters.remove(chapters.filter(
-                function(chapter) { return chapter.isEmpty(); }));
+            var emptyChapters = chapters.filter(function(chapter) {
+                return chapter.isEmpty(); });
+            if (chapters.length === emptyChapters.length) {
+                // make sure that there's always at least one chapter remaining
+                // in the chapterset, even if it's empty
+                emptyChapters = _.tail(emptyChapters);
+            }
+            chapters.remove(emptyChapters);
         }
         textbooks.trigger('render');
         return this;