Merge LayoutView into ItemView.

Resolves #2253

api/item-view.yaml

@@ -6,11 +6,12 @@ extends:
   - Marionette.AbstractView
 
 description: |
-  An `ItemView` is a view that represents a single item. That item may be a `Backbone.Model` or may be a `Backbone.Collection`. Whichever it is though, it will be treated as a single item.
+  An `ItemView` is the basic view of Marionette. It can be used to render a Model or Collection. In addition, ItemViews can create and manage child views through the use of
+  [Regions]((marionette.region.md)). Regions are containers for child views.
 
-  Please see [the Marionette.AbstractView documentation](marionette.Abstractview.md) for more information on available features and functionality.
+  ItemView extends from AbstractView. For the full API, refer to [the Marionette.AbstractView documentation](marionette.abstractview.md) for inherited methods and properties.
 
-  Additionally, interactions with Marionette.Region will provide features such as `onShow` callbacks, etc. Please see [the Region documentation](marionette.region.md) for more information.
+  Unlike Backbone Views, the ItemView Class emits many events. These are most often triggered when a ItemView is displayed as a child within another ItemView or CollectionView.
 
 constructor:
   description: |

src/build/bundled.js

@@ -57,7 +57,6 @@
   // @include ../item-view.js
   // @include ../collection-view.js
   // @include ../composite-view.js
-  // @include ../layout-view.js
 
   // @include ../behavior.js
   // @include ../behaviors.js

src/build/core.js

@@ -52,7 +52,6 @@
   // @include ../item-view.js
   // @include ../collection-view.js
   // @include ../composite-view.js
-  // @include ../layout-view.js
 
   // @include ../behavior.js
   // @include ../behaviors.js

src/item-view.js

@@ -1,14 +1,23 @@
 // Item View
 // ---------
 
-// A single item view implementation that contains code for rendering
-// with underscore.js templates, serializing the view's model or collection,
-// and calling several methods on extended views, such as `onRender`.
+// The standard view. Includes view events, automatic rendering
+// of Underscore templates, nested views, and more.
 Marionette.ItemView = Marionette.AbstractView.extend({
+  regionClass: Marionette.Region,
+
+  options: {
+    destroyImmediate: false
+  },
 
   // Setting up the inheritance chain which allows changes to
   // Marionette.AbstractView.prototype.constructor which allows overriding
-  constructor: function() {
+  constructor: function(options) {
+    options = options || {};
+
+    this._firstRender = true;
+    this._initializeRegions(options);
+
     Marionette.AbstractView.apply(this, arguments);
   },
 
@@ -45,9 +54,21 @@ Marionette.ItemView = Marionette.AbstractView.extend({
   // a very specific rendering for your view. In general, though,
   // you should override the `Marionette.Renderer` object to
   // change how Marionette renders views.
+  // Subsequent renders after the first will re-render all nested
+  // views.
   render: function() {
     this._ensureViewIsIntact();
 
+    if (this._firstRender) {
+      // if this is the first render, don't do anything to
+      // reset the regions
+      this._firstRender = false;
+    } else {
+      // If this is not the first render call, then we need to
+      // re-initialize the `el` for each region
+      this._reInitializeRegions();
+    }
+
     this.triggerMethod('before:render', this);
 
     this._renderTemplate();
@@ -104,5 +125,135 @@ Marionette.ItemView = Marionette.AbstractView.extend({
     this.$el.html(html);
 
     return this;
+  },
+
+  // Add a single region, by name, to the layoutView
+  addRegion: function(name, definition) {
+    var regions = {};
+    regions[name] = definition;
+    return this._buildRegions(regions)[name];
+  },
+
+  // Add multiple regions as a {name: definition, name2: def2} object literal
+  addRegions: function(regions) {
+    this.regions = _.extend({}, this.regions, regions);
+    return this._buildRegions(regions);
+  },
+
+  // Remove a single region from the LayoutView, by name
+  removeRegion: function(name) {
+    delete this.regions[name];
+    return this.regionManager.removeRegion(name);
+  },
+
+  showChildView: function(regionName, view) {
+    return this.getRegion(regionName).show(view);
+  },
+
+  getChildView: function(regionName) {
+    return this.getRegion(regionName).currentView;
+  },
+
+  // Provides alternative access to regions
+  // Accepts the region name
+  // getRegion('main')
+  getRegion: function(region) {
+    return this.regionManager.get(region);
+  },
+
+  // Get all regions
+  getRegions: function(){
+    return this.regionManager.getRegions();
+  },
+
+  // Enable easy overriding of the default `RegionManager`
+  // for customized region interactions and business specific
+  // view logic for better control over single regions.
+  getRegionManager: function() {
+    return new Marionette.RegionManager();
+  },
+
+  // Handle destroying regions, and then destroy the view itself.
+  destroy: function() {
+    if (this.isDestroyed) { return this; }
+
+    // #2134: remove parent element before destroying the child views, so
+    // removing the child views doesn't retrigger repaints
+    if(this.getOption('destroyImmediate') === true) {
+      this.$el.remove();
+    }
+    this.regionManager.destroy();
+    return Marionette.AbstractView.prototype.destroy.apply(this, arguments);
+  },
+
+  // Internal method to initialize the regions that have been defined in a
+  // `regions` attribute on this layoutView.
+  _initializeRegions: function(options) {
+    var regions;
+    this._initRegionManager();
+
+    regions = Marionette._getValue(this.regions, this, [options]) || {};
+
+    // Enable users to define `regions` as instance options.
+    var regionOptions = this.getOption.call(options, 'regions');
+
+    // enable region options to be a function
+    regionOptions = Marionette._getValue(regionOptions, this, [options]);
+
+    _.extend(regions, regionOptions);
+
+    // Normalize region selectors hash to allow
+    // a user to use the @ui. syntax.
+    regions = this.normalizeUIValues(regions, ['selector', 'el']);
+
+    this.addRegions(regions);
+  },
+
+  // internal method to build regions
+  _buildRegions: function(regions) {
+    var defaults = {
+      regionClass: this.getOption('regionClass'),
+      parentEl: _.partial(_.result, this, 'el')
+    };
+
+    return this.regionManager.addRegions(regions, defaults);
+  },
+
+  // Internal method to re-initialize all of the regions by updating
+  // the `el` that they point to
+  _reInitializeRegions: function() {
+    this.regionManager.invoke('reset');
+  },
+
+  // Internal method to initialize the region manager
+  // and all regions in it
+  _initRegionManager: function() {
+    this.regionManager = this.getRegionManager();
+    this.regionManager._parent = this;
+
+    this.listenTo(this.regionManager, 'before:add:region', function(name) {
+      this.triggerMethod('before:add:region', name);
+    });
+
+    this.listenTo(this.regionManager, 'add:region', function(name, region) {
+      this[name] = region;
+      this.triggerMethod('add:region', name, region);
+    });
+
+    this.listenTo(this.regionManager, 'before:remove:region', function(name) {
+      this.triggerMethod('before:remove:region', name);
+    });
+
+    this.listenTo(this.regionManager, 'remove:region', function(name, region) {
+      delete this[name];
+      this.triggerMethod('remove:region', name, region);
+    });
+  },
+
+  _getImmediateChildren: function() {
+    return _.chain(this.regionManager.getRegions())
+      .pluck('currentView')
+      .compact()
+      .value();
   }
 });