Thorax
An opinionated, battle tested Backbone + Handlebars framework to build large scale web applications.
Quick Start
Features
Hello World
Thorax is used to build some of the biggest Backbone applications in the world but it's easy to get started.
var view = new Thorax.View({
greeting: "Hello",
template: Handlebars.compile("{{greeting}} world!")
});
view.appendTo('body');
Easy Data Binding
By default every property of your view is automatically available in the template. If a model is bound its attributes will also be made available.
var view = new Thorax.View({
greeting: 'Hello',
model: new Thorax.Model({
location: 'world!'
}),
template: ...
});
Then in your template:
{{greeting}} {{location}}
Context Control
Don't like every property in your view being available in your template, or need to modify some model attributes? Just specify a context
method to control what your template sees:
var view = new Thorax.View({
model: new Thorax.Model({
greeting: 'hello'
}),
context: function() {
return {
greeting: this.model.get('greeting').toUpperCase()
};
},
template: ...
});
Then in your template:
{{greeting}}
Collection Rendering
Easily render collections with the collection
helper. Thorax will make sure that your view stays current as models in your collection are added, removed or updated.
var view = new Thorax.View({
collection: new Thorax.Collection([{
title: 'Finish screencast',
done: true
}]),
template: ...
});
Then in your template:
{{#collection tag="ul"}}
<li>
<input type="checkbox" {{#done}}checked{{/done}}
{{title}}
</li>
{{else}}
<li>No todos yet.</li>
{{/collection}}
jQuery and Zepto Integration
Thorax extends the jQuery or Zepto $
object to allow you to get a reference to the nearest bound model
, collection
, or view
.
var view = new Thorax.View({
events: {
'change input[type=checkbox]': function(event) {
var model = $(event.target).model();
model.set({done: event.target.checked});
}
}
});
Event Enhancements
Thorax extends the events hash to let you listen to view events in addition to DOM events, and let's you pass a hash of model
or collection
events to listenTo
when a model or collection is bound to your view.
var view = new Thorax.View({
events: {
rendered: function() {}
model: {
change: function() {}
}
},
model: new Thorax.Model()
});
Thorax also adds inheritable events to view classes, just call on
on any class to listen for a DOM, view, model or collection event on any view.
Thorax.View.on('eventName', handler);
Form Handling
Easily capture entered form data with the serialize
method which also provides event hooks for form validation. Models bound to the view will also automatically populate
your forms.
var view = new Thorax.View({
events: {
'submit form': function(event) {
event.preventDefault();
var attrs = this.serialize();
this.collection.add(attrs);
}
},
collection: new Thorax.Collection()
});
Embeddable Views
Easily embed one view within another with the view
helper.
var view = new Thorax.View({
child: new Thorax.View(...),
template: ...
});
Then in your template:
{{view child}}
Layouts and Lifecycle
Thorax.LayoutView
provides a container to place your views, and triggers lifecycle events on views placed within them. Layouts can be embedded in other views as well.
var layout = new Thorax.LayoutView();
layout.appendTo('body');
var view = new Thorax.View({
events: {
ready: function() {},
destroyed: function() {}
}
})
layout.setView(view);
Server Side Rendering
Thorax allows for rendering outside of the normal browser context using environments such as Fruit Loops or PhantomJS to render content in the initial server response and then restore the view hierarchy on the client render. Rendering in such a manner allows for Thorax applications to expose their content for SEO purposes as well as speed up the perceived initial page load.
The restore process is well suited for handling distinctions between user and public data, allowing for the server response to include only public, long cache-able, content. The client can then augment this data with any user specific data on restoration.
Getting Started
Tutorials/Examples
Using the Thorax Generator, you can generate a Todos example application. You can also generate a blank application and build it out to match the Todos example app. This is a great way to learn by doing.
Read an overview of the features of Thorax, as well as some of the theory behind some of the implementation details.
Backbone Fundamentals also covers Lumbar's approach to modular application development and routing, which is used in all of the seed projects except the standalone and Rails seeds.
TodoMVC
See the TodoMVC Thorax implementation and its source code. There is also a Lumbar flavored version of the implementation.
kenwheeler has an example Parse-Todos implementation of Thorax combined with Parse.
Examples
Resources
Thorax Yeoman Generator
The Thorax Generator will ask you questions before generating a new blank or predefined base project. This is the recommended way to get started.
The Thorax Generator also provides it's own extensive documentation and aims to help you understand how to setup a full stack Thorax application, including a minimal node express server and deployment instructions.
Bower component
Thorax is available as a Bower component. Just run bower install thorax
in your project.
Thorax is tested against these dependencies (you can paste this in your bower.json
:
"dependencies": {
"jquery": "1.9.0",
"underscore": "1.4.4",
"zepto": "1.0.0",
"handlebars": "1.0.0",
"backbone": "1.0.0"
}
Note that either jQuery or Zepto is required, but not both.
cdnjs
Thorax is available on cdnjs, each build includes jQuery 1.9.0 (or Zepto 1.0.0rc1 on mobile), Backbone 0.9.9, Underscore 1.4.2 and Handlebars 1.0.0rc6.
Playground
When combined with CoffeeScript small Thorax apps can be written in a single file. This is ideal for creating small test apps within JSFiddle. Thorax can be selected as a framework (near the bottom of the list) in any fiddle, or you can try out any of the fiddles below:
API Reference
Registry
Thorax creates a special hash for each type of class to store all subclasses in your application. The use of Thorax.Views
and Handlebars.templates
(usually defined by Handlebars) is required to allow the view
, template
and other helper methods to operate, but the use of Thorax.Models
and Thorax.Collections
are optional and provided for consistency.
Class | Registry |
---|
Thorax.View | Thorax.Views |
Thorax.Model | Thorax.Models |
Thorax.Collection | Thorax.Collections |
templates | Handlebars.templates |
name klass.prototype.name
If a name
property is passed to any Thorax classes' extend
method the resulting class will be automatically set in the corresponding registry.
//set class
Thorax.View.extend({
name: "my-view"
});
//get class
Thorax.Views["my-view"]
templates Handlebars.templates
A hash of templates, used by various Thorax helpers. If using the Lumbar or Rails boilerplate projects or the Thorax Generator this hash will be automatically generated from the files in your templates
directories. To manually add a template to the hash:
Handlebars.templates['my-template-name'] = Handlebars.compile('template string');
If a View
has the same name
as a template in the templates
hash, its `template' property will be automatically assigned.
Thorax.View
Thorax.View
provides additive functionality over Backbone.View
but breaks compatibility in one important way in that it does not use an options
object. All properties passed to the constructor become available on the instance:
var view = new Thorax.View({
key: "value"
});
view.key === "value"
By default all instance properties are available in the template context. So when setting a key on the view it will by default be available in the template.
template view.template
Assign a template to a view. This may be a string or a function which receives a single context
argument and returns a string. If the view has a name
and a template of the same name
is available the template
will be auto-assigned.
new Thorax.View({
template: Handlebars.compile("{{key}}")
});
render view.render([content])
Renders the view's template
updating the view's el
with the result, triggering the rendered
event.
view.render();
render
can also accept a content argument that may be an element, string or a template function:
view.render('custom html');
restore view.restore(element, forceRerender)
Attempts to restore a given view with the passed element
. Should this fail the view will be rerendered automatically. Rerendering may be forced by setting the forceRerender
parameter to truthy. See Server Rendering for further discussion.
context view.context()
Used by render
to determine what attributes are available in the view's template
. The default context function returns this
+ this.model.attributes
if a model
is present on the view. The context
method may be overridden to provide a custom context:
new Thorax.View({
template: Handlebars.compile('{{key}}'),
context: function() {
return _.defaults(this.model.attributes, {
key: 'value'
});
}
});
appendTo view.appendTo(element)
Appends the view to a given element
which may be a CSS selector or DOM element. ensureRendered
will be called and a ready
event will be triggered. This is the preferred way to append your outer most view onto a page.
renderTemplate view.renderTemplate(name [,context])
Renders a given template with the view's context
or the given context argument.
ensureRendered view.ensureRendered()
Ensure that the view has been rendered at least once.
conditionalRender view.conditionalRender([flag])
Renders the view if and only if shouldRender(flag)
is true. Useful for ensuring that updates occur while still deferring final rendering until the view has been inserted into the DOM.
When flag
is undefined
this is effectively the opposite behavior of ensureRendered
.
shouldRender view.shouldRender([flag])
Returns true
if the view should be rendered based on flag
and the current rendered state.
flag
may be:
true
: Always renderfalse
: Never renderundefined
: Render only if the view has been rendered previously
html view.html([content])
Get or set the innerHTML
of the view, without triggering the rendered
event.
_addChild view.addChild(child)
Register a view as being a child of the parent. This will release
the child view when the parent is released.
this.childView = this._addChild(new ChildView);
If you are embedding a child view with the view
helper this is automatically done for you. Use this when there are cases where the child would not be embedded, either due to the parent not rendering or the view helper being inside of a conditional.
children view.children
A hash of child view's indexed by cid
. Child views may become attached to the parent with the view
helper or may be automatically attached HelperView
instances created by helpers created with registerViewHelper
(such as the collection
and empty
helpers).
parent view.parent
If a view was embedded inside another with the view
helper, or a generated HelperView
(for instance the collection
or empty
helpers) it will have a parent
view attribute. In the case of HelperView
s, the parent
will be the view that declared the helper in its template.
retain view.retain([owner])
Prevents a view from being destroyed if it would otherwise be. If a parent is destroyed all its children will be destroyed, or if it was previously passed to setView
Given the code below:
a.retain();
Application.setView(a);
Application.setView(b);
Application.setView(c);
b
will be destroyed, and a
will not be.
When the optional owner
parameter is passed, the retain reference count will automatically be reduced when the owner view is destroyed.
Views that have been retained must be released via release
or they will leak.
This is done automatically for views that are connected to an existing element via the el
attribute.
release view.release()
Release a view that was previously retained. If release
is called and the view has a reference count of zero it will be destroyed, which will release all children, remove all events, unbind all models and collections, call remove
and trigger the destroyed
event.
release
is usually called automatically if a view was attached to a LayoutView
with the setView
method, and another view is then passed to setView
.
Generally this method is not needed unless you are retain
ing views.
setModel view.setModel(model [,options])
Setting model
in the constructor will automatically call setModel
, so the following are equivalent:
var view = new Thorax.View({
model: myModel
});
// identical functionality as above
view.setModel(myModel);
Sets the model
attribute of a view then attempts to fetch the model if it has not yet been populated. Once set the default context
implementation will merge the model's attributes
into the context, so any model attributes will automatically become available in a template. In addition any events declared via view.on({model: events})
will be bound to the model with listenTo
.
Accepts any of the following options:
- fetch - Boolean, whether to fetch the model when it is set, defaults to true.
- success - Callback on fetch success, defaults to noop
- render - Render on the view on model:change? Defaults to undefined
true
: Always render on changefalse
: Never render on changeundefined
: Rerender if we have already been rendered
- populate - Call
populate
with the model's attributes when it is set? Defaults to true.
- Pass
populate: {children: false}
to prevent child views from having their inputs populated. - Pass
populate: {context: true}
to populate using the view's context rather than directly populating from the model's attributes.
- errors - When the model triggers an
error
event, trigger the event on the view? Defaults to true
setCollection view.setCollection(collection [,options])
Setting collection
in the constructor will automatically call setCollection
, so the following are equivalent:
var view = new Thorax.View({
collection: myCollection
});
// identical functionality as above
view.setCollection(myCollection);
Sets the collection
attribute of a view then attempts to fetch the collection if it has not yet been populated. In addition any events declared via view.on({collection: events})
will be bound to the collection with listenTo
.
Accepts any of the following options:
- render - Whether to render the collection if it is populated, or render it after it has been loaded. Defaults to undefined
true
: Always render on changefalse
: Never render on changeundefined
: Rerender if we have already been rendered
- fetch - Whether or not to try to call
fetch
on the collection if shouldFetch
returns true - success - Callback on fetch success, defaults to noop
- errors - Whether or not to trigger an
error
event on the view when an error
event is triggered on the collection - change - Whether or not to call
updateItem
when a model's change
event fires. Defaults to true.
Note that while any view may bind a collection only a CollectionView
will actually render a collection. A regular Thorax.View
may declare a collection
helper which in turn will generate and embed a CollectionView
.
serialize view.serialize([event], callback [,options])
Serializes a form. callback
will receive the attributes from the form, followed by a release
method which must be called before the form can be submitted again. callback
will only be called if validateInput
returns nothing or an empty array. options
may contain:
set
- defaults to true, whether or not to set the attributes if valid on a model if one was set with setModel
validate
- defaults to true, whether or not to call validateInput
during serializationchildren
- defaults to true, whether or not to serialize inputs in child viewssilent
- defaults to true, whether or not to pass silent: true
to model.set
Each form input in your application should contain a corresponding label. Since you may want to re-use the same form multiple times in the same view a @cid
attribute with a unique value is provided to each render call of each template:
<label for="{{@cid}}-last-name"/>
<input name="last-name" id="{{@cid}}-last-name" value="Beastridge"/>
<label for="{{@cid}}-address[street]"/>
<input name="address[street]" value="123 Chestnut" id="{{@cid}}-address[street]"/>
new Thorax.View({
events: {
"submit form": function(event) {
this.serialize(event, function(attributes, release) {
attributes["last-name"] === "Beastridge";
attributes.address.street === "123 Chestnut";
//form is locked to prevent duplicate submission
//until release is called
release();
});
}
}
});
serialize
Triggers the following events:
serialize
- called before validation with serialized attributesvalidate
- with an attributes hash and errors array after validateInput
is calledinvalid
- with an errors array, if validateInput
returned an array with any errorsroot
- the root element to serialize within, defaults to this.$el
If your view uses inputs with non standard names (or no names, multiple inputs with the same name, etc), use the serialize
event:
this.on('serialize', _.bind(function(attributes) {
attributes.custom = this.$('.my-input').val();
}, this));
populate view.populate([attributes] [,options])
Populate the form fields in the view with the given attributes. The keys of the attributes should correspond to the names of the inputs. populate
is automatically called with the response from view.context()
when setModel
is called. By default this is just model.attributes
.
view.populate({
"last-name": "Beastridge"
address: {
street: "123 Chestnut"
}
});
populate
triggers a populate
event. If your view uses inputs with non standard names (or no names, multiple inputs with the same name, etc), use this event:
this.on('populate', _.bind(function(attributes) {
this.$('.my-input').val(attributes.custom);
}, this));
To prevent child views from having their inputs populated use:
view.populate(object, {
children: false
});
validateInput view.validateInput(attributes)
Validate the attributes created by serialize
, must return an array or nothing (if valid). It's recommended that the array contain hashes with name
and message
attributes, but arbitrary data or objects may be passed. If the array has a zero length the attributes are considered to be valid. Returning an array with any errors will trigger the invalid
event.
validateInput: function(attributes) {
var errors = [];
if (attributes.password && !attributes.password.match(/.{6,11}/)) {
errors.push({name: 'password', message: 'Invalid Password'});
}
return errors;
}
Thorax.HelperView
registerViewHelper Handlebars.registerViewHelper(name [,viewClass] ,callback)
Note that this differs from Handlebars.registerHelper
. Registers a helper that will create and append a new HelperView
instance, with its template
attribute set to the value of the captured block. callback
will receive any arguments passed to the helper followed by a HelperView
instance. Named arguments to the helper will be present on options
attribute of the HelperView
instance.
A HelperView
instance differs from a regular view instance in that it has a parent
attribute which is always set to the declaring view, and a context
which always returns the value of the parent
's context method. The collection
, empty
and other built in block view helpers are created with registerViewHelper
.
A helper that re-rendered a HelperView
every time an event was triggered on the declaring view could be implemented as:
Handlebars.registerViewHelper('on', function(eventName, helperView) {
helperView.listenTo(helperView.parent, eventName, function() {
helperView.render();
});
});
An example use of this would be to have a counter that would increment each time a button was clicked. In Handlebars:
{{#on "incremented"}}{{i}}{/on}}
{{#button trigger="incremented"}}Add{{/button}}
And the corresponding view class:
new Thorax.View({
events: {
incremented: function() {
++this.i;
}
},
initialize: function() {
this.i = 0;
},
template: ...
});
In addition, if a view class is specified as the second argument to registerViewHelper
, the helper will always initialize a view of that class instead of a HelperView
:
Handlebars.registerViewHelper('collection',
Thorax.CollectionHelperView, function(collection, view) {
});
Thorax.LayoutView
A view to contain a single other view which will change over time, (multi-pane single page applications for instance), triggering a series of events . By default this class has no template. If one is specified use the layout-element
helper to determine where setView
will place a view. A Thorax.LayoutView
is a subclass of Thorax.View
and may be treated as a view in every regard (i.e. embed multiple LayoutView
instances in a parent view with the view
helper).
setView view.setView(view [,options])
Set the current view on the LayoutView
, triggering activated
, ready
and deactivated
events on the current and previous view during the lifecycle. ensureRendered
is called on views passed to setView
. By default destroy
is called on the previous view when the new view is set.
To implement animations using setView
pass a transition
callback to setView
which will receive the new view being set, the old view (if present), append, remove and complete functions which will execute the needed DOM and view operations.
layout.setView(newView, {
transition: function(newView, oldView, append, remove, complete) {
append();
yourAnimation(function() {
remove();
complete();
});
}
});
getView view.getView()
Get the current view that was previously set with setView
.
Thorax.Model
Enhances Backbone.Model
with the concept of whether or not the model is populated and whether or not it should be automatically fetched. Note that when passing a model to view.setModel
it must be an instance of Thorax.Model
and not Backbone.Model
.
isEmpty model.isEmpty()
Used by the empty
helper. In a collection the implementations of isEmpty
and isPopulated
differ, but in a model isEmpty
is an alias for !isPopulated
.
isPopulated model.isPopulated()
Used by setModel
to determine whether or not to fetch the model. The default implementation checks to see if any keys that are not id
and are not default values have been set.
Thorax.Collection
Enhances Backbone.Collection
with the concept of whether or not the collection is populated and whether or not it should be automatically fetched. Note that when passing a collection to view.setCollection
it must be an instance of Thorax.Collection
and not Backbone.Collection
.
isEmpty collection.isEmpty()
Used by the empty
helper and the emptyTemplate
and emptyItem
options of a CollectionView
to check whether a collection is empty. A collection is only treated as empty if it isPopulated
and zero length.
isPopulated collection.isPopulated()
Used by setCollection
to determine whether or not to fetch the collection.
Thorax.CollectionView
A class that renders an itemTemplate
or itemView
for each item in a collection
passed to it in its constructor, or via setCollection
. The view will automatically update when items are added, removed or changed.
The collection
helper will automatically create and embed a CollectionView
instance for you. If programmatic access to the view's methods are needed (for instance calling appendItem
or specifying an itemFilter
) it's best to create a CollectionView
directly and embed it with the view
helper as you would any other view.
itemTemplate view.itemTemplate
A template name or template function to use when rendering each model. If using the collection
helper the passed block will become the itemTemplate
. Defaults to view.name + '-item'
itemView view.itemView
A view class to be initialized for each item. Can be used in conjunction with itemTemplate
.
itemContext view.itemContext(model, index)
A function in the declaring view to specify the context for an itemTemplate
, receives model and index as arguments. itemContext
will not be used if an itemView
is specified as the itemView
's own context
method will instead be used.
A collection helper may specify a specific function to use as the itemContext
if there are multiple collections in a view:
{{#collection todos item-context="todosItemContext"}}
itemFilter view.itemFilter(model, index)
A method, which if present will filter what items are rendered in a collection. Receives model
and index
and must return boolean. The filter will be applied when models' fire a change event, or models are added and removed from the collection. To force a collection to re-filter, call updateFilter
on the view or collection view.
Items are hidden and shown with $.hide
and $.show
rather than being removed or appended. In performance critical views with large collections consider filtering the collection before it is passed to the view or on the server.
A collection helper may specify a specific function to use as the itemFilter
if there are multiple collections in a view:
{{#collection todos item-filter="todosItemFilter"}}
updateFilter view.updateFilter()
If using itemFilter
, call this method to force the collection view to re-filter.
emptyTemplate view.emptyTemplate
A template name or template function to display when the collection is empty. If used in a collection
helper the inverse block will become the emptyTemplate
. Defaults to view.name + '-empty'
emptyView view.emptyView
A view class to create an instance of when the collection is empty. Can be used in conjunction with emptyTemplate
.
loadingTemplate view.loadingTemplate
A template name or template function to display when the collection is loading.
loadingView view.loadingView
A view class to create an instance of when the collection is loading. Can be used in conjunction with loadingTemplate
.
loadingPlacement view.loadingPlacement()
An index to place the loadingView
or loadingTemplate
at. Defaults to this.collection.length
.
appendItem view.appendItem(modelOrView [,index] [,options])
Append a model (which will used to generate a new itemView
or render an itemTemplate
) or a view at a given index in the CollectionView
. If passing a view as the first argument index
may be a model which will be used to look up the index.
By default this will trigger a rendered:item
event, silent: true
may be passed in the options hash to prevent this. To also prevent the appended item from being filtered if an itemFilter
is present pass filter: false
in the options hash.
removeItem view.removeItem(model)
Remove an item from the view.
updateItem view.updateItem(model)
Equivalent to calling removeItem
then appendItem
. Note that this is mainly meant to cover edge cases, by default changing a model will update the needed item (whether using itemTemplate
or itemView
).
Thorax.Util
tag Thorax.Util.tag(name, htmlAttributes [,content] [,context])
Generate an HTML string. All built in HTML generation uses this method. If context
is passed any Handlebars references inside of the htmlAttributes values will rendered with the context.
Thorax.Util.tag("div", {
id: "div-{{number}}"
}, "content of the div", {
number: 3
});
Thorax.ServerMarshal
The ServerMarshal
provides a mechanism for sharing data between server rendered content and the views that restore upon the HTML on the client.
When dealing with simple primitives that may be serialized via JSON the values are stored directly in the server marshal store JSON object. For more complex objects such as models, collections, and views, a path relative to the handlebars rendering context is saved as a reference that can be resolved against the client-side equivalents.
store Thorax.ServerMarshal.store($el, name, data, dataIds, options)
Associates the given data with $el
in the server marshal data store. May be restored on the client side via the Thorax.ServerMarshal.load
API.
$el
the $
instance associated with the given elementname
the name of the data point to be saveddata
data to be stored. May be an array, object, or primitive value. Complex values must contain only primitive values or have proper associated dataIds
element to allow for lookup on the client side.dataIds
context paths associated with the data defined in data
, if available.options
options object. This object generally mirrors the options object passed to handlebars helpers, which may be passed directly. Fields may include:
data
current handlebars data object
contextPath
current context path for execution scoperoot
current handlebars root rendering contextview
current view being rendered
Data storage rules:
- Numbers, Strings, Booleans, Nulls, and Objects with a
toJSON
implementation as all stringified - When
dataIds
is a string value, the context path is stored for the data
field - When paired with a matching
dataId
structure, Arrays and objects are evaluated to one level deep.
- Primitive values fitting above are stringified
- All other objects are store the context path by combining
options.data.contextPath
and dataIds[key]
- Otherwise a
server-marshal-object
error is thrown
The contextPath
value is a data field tracked within Handlebars helpers. This is is the "path" from the root of the context that a particular handlebars lookup resolves to and is used to lookup the helper parameters at restore time. As a general rule if you are calling fn
or inverse
with a different context than you were called with then you will likely need to update the contextPath
value. The appendContextPath
helper is available for simple path updates:
data.contextPath = Handlebars.Utils.appendContextPath(data.contextPath, 'foo');
load Thorax.ServerMarshal.load(el, name, parentView, context)
Returns the named server data for a given element.
el
element to load data forname
data item nameparentView
the view instance that contains this particular elementcontext
the rendering context
For complex objects, parentView
and context
will be used to lookup any context path objects saved from the server side. context
values take priority over parentView
values to match the behavior of the rendering pipeline.
serialize Thorax.ServerMarshal.serialize()
Retrieves the stringified representation of the marshal data set. Generally this does not need to be called explicitly as an onEmit
handler will ensure that the data is output for the client exec.
destory Thorax.ServerMarshal.destroy($el)
Removes any marshal data that may be associated with a given element.
$
$.view $(event.target).view([options])
Get a reference to the nearest parent view. Pass helper: false
to options to exclude HelperView
s from the lookup. Useful when registering DOM event handlers:
$(event.target).view();
$.model $(event.target).model([view])
Get a reference to the nearest bound model. Can be used with any $
object but most useful in event handlers.
$(event.target).model();
A view
may be optionally passed to limit the lookup to a specific view.
$.collection $(event.target).collection([view])
Get a reference to the nearest bound collection. Can be used with any $
object but most useful in event handlers.
$(event.target).collection();
A view
may be optionally passed to limit the lookup to a specific view.
Event Enhancements
Thorax adds inheritable class events for all Thorax classes and significant enhancements to the Thorax.View event handling.
Inheritable Events ViewClass.on(eventName, callback)
All Thorax classes have an on
method to observe events on all instances of the class. Subclasses inherit their parents' event handlers. Accepts any arguments that can be passed to viewInstance.on
or declared in the events
hash.
Thorax.View.on({
'click a': function(event) {
}
});
Model Events
When a model is bound to a view with setModel
(automatically called by passing a model
option in the constructor) any events on the model can be observed by the view in this way. For instance to observe any model change
event when it is bound to any view:
Thorax.View.on({
model: {
change: function() {
// "this" will refer to the view
}
}
});
Collection Events
When a collection is bound to a view with setCollection
(automatically called by passing a collection
option in the constructor) any events on the collection can be observed by the view in this way. For instance to observe any collection reset
event when it is bound to any view:
Thorax.View.on({
collection: {
reset: function() {
// "this" will refer to the view
}
}
});
View Events view.events.viewEventName
The events
hash has been enhanced to allow view events to be registered along side DOM events:
Thorax.View.extend({
events: {
'click a': function(event) {},
rendered: function() {}
}
});
DOM Events view.on(eventNameAndSelector, callback [,context])
The on
method will now accept event strings in the same format as the events hash, for instance click a
. Events separated by a space will still be treated as registering multiple events so long as the event name does not start with a DOM event name (click
, change
, mousedown
etc).
DOM events observed in this way will only operate on the view itself. If the view embeds other views with the view
helper that would match the event name and selector, they will be ignored. For instance declaring:
view.on('click a', function(event) {})
Will only listen for clicks on a
elements within the view. If the view has children that has a
elements, this handler will not observe clicks on them.
DOM events may be prefixed with the special keyword nested
which will apply the event to all elements in child views:
view.on('nested click a', function() {})
Thorax will add an attribute to the event named originalContext
that will be the Element
object that would have been set as this
had the handler been registered with jQuery / Zepto:
$('a').on('click', function() {});
view.on('click a', function(event) {
// event.originalContext === what "this" would be in the
// first handler
});
When doing a server render, all DOM event handlers are silently discarded, as the majority do not make sense and environments such as Fruit Loops do not support. Code that relies on DOM events such as submit
will need to take this into account.
_addEvent view._addEvent(eventParams)
This method is never called directly, but can be specified to override the behavior of the events
hash or any event arguments passed to on
. For each event declared in either manner _addEvent
will be called with a hash containing:
- type "view" || "DOM"
- name (DOM events will begin with ".delegateEvents")
- originalName
- selector (DOM events only)
- handler
All of the behavior described in this section is implemented via this method, so if overriding make sure to call Thorax.View.prototype._addEvent
in your child view.
Data Loading
Queuing
Thorax wraps fetch
(and therefore load
) on models and collections with a queuing mechanism to ensure that multiple sync
calls for the same url will not trigger multiple HTTP requests. To force a fetch
or load
call to create a new HTTP request regardless of whether an identical request is in the queue use the resetQueue
option:
model.fetch({
resetQueue: true
success: function() {}
});
bindToRoute Thorax.Util.bindToRoute(callback [,failback])
Used by model.load
and collection.load
. Binds the callback to the current route. If the browser navigtates to another route in the time between when the callback is bound and when it is executed, callback will not be called. Else failback will be called if present.
routerMethod: function() {
var callback = Thorax.Util.bindToRoute(function() {
//callback called if browser is still on route
});
setTimeout(callback, 5000);
}
load modelOrCollection.load(callback [,failback] [,options])
Calls fetch
on the model or collection ensuring the callbacks will only be called if the route does not change. callback
and failback
will be used as arguments to bindToRoute
. options
will be passed to the fetch
call on the model or collection if present.
routerMethod: function(id) {
var view = new Thorax.View();
var model = new Application.Model({id: id});
model.load(function() {
//callback only called if browser still on this route
view.setModel(model);
myLayoutView.setView(view);
}, function() {
//failback only called if browser has left this route
});
}
Triggers load:start
and load:end
events on the model or collection, and additionally on a view if it has bound the object via setModel
or setCollection
.
By default the events will propagate to a root object set with setRootObject
. Pass background: true
as an option to prevent the event from being triggered on the rootObject.
setRootObject Thorax.setRootObject(obj)
Set the root object that will receive load:start
and load:end
events if the load:start
was not a background
event. This is useful to implement a global loading indicator.
loadHandler Thorax.loadHandler(startCallback, endCallback)
Generates an load:start
event handler that when triggered will then monitor the associated object for a load:end
event. If the duration between the start and the end events exceed _loadingTimeoutDuration
then the start
and end
callbacks will be triggered at the appropriate times to allow the display of a loading UI.
view.on("load:start", Thorax.loadHandler(
function(message, background, object) {
view.$el.addClass("loading");
},
function(background, object) {
view.$el.removeClass("loading");
}));
_loadingClassName view._loadingClassName
Class name to add and remove from a view's el
when it is loading. Defaults to loading
.
_loadingTimeoutDuration view._loadingTimeoutDuration
Timeout duration in seconds before a load:start
callback will be triggered. Defaults to 0.33 seconds. If for instance the load:end
event was triggered 0.32 seconds after the load:start
event the load:start
callback would not be called.
_loadingTimeoutEndDuration view._loadingTimeoutEndDuration
Just like _loadingTimeoutDuration
but applies to load:end
. Defaults to 0.10 seconds.
Template Helpers
template {{template name [options]}}
Embed a template inside of another, as a string. An associated view (if any) will not be initialized. By default the template will be called with the current context but extra options may be passed which will be added to the context.
{{template "path/to/template" key="value"}}
If a block is used, the template will have a variable named @yield
available that will contain the contents of the block.
{{#template "child"}}
content in the block will be available in a variable
named "@yield" inside the template "child"
{{/template}}
This is useful when a child template will be called from multiple different parents.
super {{super}}
Embed the template
from the parent view within the child template.
{{super}}
view {{view name [options]}}
Embed one view in another. The first argument may be the name of a new view to initialize or a reference to a view that has already been initialized.
{{view "path/to/view" key="value"}}
{{view viewInstance}}
If a block is specified it will be assigned as the template
to the view instance:
{{#view viewInstance}}
viewInstance will have this block
set as its template property
{{/view}}
element {{element name [options]}}
Embed a DOM element in the view. This uses a placeholder technique to work, if the placeholder must be of a certain type in order to be valid (for instance a tbody
inside of a table
) specify a tag
option.
{{element domElement tag="tbody"}}
button {{#button methodName [htmlAttributes...]}}
Creates a button
tag that will call the specified methodName on the view when clicked. Arbitrary HTML attributes can also be specified.
{{#button "methodName" class="btn"}}Click Me{{/button}}
The tag name may also be specified:
{{#button "methodName" tag="a" class="btn"}}A Link{{/button}}
A trigger
attribute will trigger an event on the declaring view:
{{#button trigger="eventName"}}Button{{/button}}
A button can have both a trigger
attribute and a method to call:
{{#button "methodName" trigger="eventName"}}Button{{/button}}
The method may also be specified as a method
attribute:
{{#button method="methodName"}}Button{{/button}}
url {{url urlString expand-tokens=bool}}
Prepends "#" if Backbone.history.pushSate
is disabled or prepends Backbone.history.root
if it is enabled. If expand-tokens=true
is passed, then any handlebars tokens will be resolved with the current context. For example if the context had an id
attribute {{id}}
would be replaced with the value of id
:
{{url "articles/{{id}}" expand-tokens=true}}
Multiple arguments can be passed and will be joined with a "/":
{{url "articles" id}}
link {{#link url [htmlAttributes...]}}
Creates an a
tag that will call Backbone.history.navigate()
with the given url when clicked. Passes the url
parameter to the url
helper with the current context. Do not use this method for creating external links. Like the url
helper, multiple arguments may be passed as well as an expand-tokens
option.
{{#link "articles/{{id}}" expand-tokens=true class="article-link"}}Link Text{{/link}}
To call a method from an a
tag use the button
helper:
{{#button "methodName" tag="a"}}My Link{{/button}}
Like the button
helper, a trigger
attribute may be specified that will trigger an event on the declaring view in addition to navigating to the specified url:
{{#link "articles" id trigger="customEvent"}}Link Text{{/link}}
The href attribute is required but may also be specified as an attribute:
{{#link href="articles/{{id}}" expand-tokens=true}}Link Test{{/link}}
collection {{collection [collection] [options...]}}
Creates and embeds a CollectionView
instance, updating when items are added, removed or changed in the collection. If a block is passed it will be used as the item-template
, which will be called with a context of the model.attributes
for each model in the collection.
{{#collection tag="ul"}}
<li>{{modelAttr}}</li>
{{/collection}}
Options may contain tag
, class
, id
and the following attributes which will map to the generated CollectionView
instance:
item-template
→ itemTemplate
item-view
→ itemView
empty-template
→ emptyTemplate
empty-view
→ emptyView
loading-template
→ loadingTemplate
loading-view
→ loadingView
item-context
→ itemContext
item-filter
→ itemFilter
Any of the options can be specified as variables in addition to strings:
{{collection item-view=itemViewClass}}
By default the collection helper will look for this.collection
, but if your view contains multiple collections a collection argument may be passed:
{{collection myCollection}}
When rendering this.collection
many properties will be forwarded from the view that is declaring the collection helper to the generated CollectionView
instance:
itemTemplate
itemView
itemContext
itemFilter
emptyTemplate
emptyView
loadingTemplate
loadingView
loadingPlacement
As a result the following two views are equivalent:
// render with collection helper, collection
// properties are forwarded
var view = new Thorax.View({
collection: new Thorax.Collection(),
itemView: MyItemClass,
itemContext: function(model, i) {
return model.attributes;
},
template: Handlebars.compile('{{collection}}')
});
// directly create collection view, no property
// forwarding will occur
var view = new Thorax.View({
collectionView: new Thorax.CollectionView({
collection: new Thorax.Collection(),
itemView: MyItemClass
itemContext: function(model, i) {
return model.attributes;
}
}),
template: Handlebars.compile('{{view collectionView}}')
});
empty {{#empty [modelOrCollection]}}
A conditional helper much like if
that calls isEmpty
on the specified object. In addition it will bind events to re-render the view should the object's state change from empty to not empty, or vice versa.
{{#empty collection}}
So empty!
{{else}}
{{#collection}}{{/collection}}
{{/empty}}
To embed a row within a collection
helper if it the collection is empty, specify an empty-view
or empty-template
. Or use the else
block of the collection
helper:
{{#collection tag="ul"}}
<li>Some very fine data</li>
{{else}}
<li>So very empty</li>
{{/collection}}
collection-element {{collection-element [htmlAttributes...]}}
By default Thorax.CollectionView
instances have no template. Items will be appended to and removed from the view's el
. Alternatively a template can be specified and collection-element
used to specify where the individual items in a collection will be rendered.
<div>
{{collection-element tag="ul" class="my-list"}}
</div>
layout-element {{layout-element [htmlAttributes...]}}
By default Thorax.LayoutView
instances have no template, setView
will append directly to the view's el
. Alternatively a template can be specified and a layout-element
and setView
will append to that element.
<ul>
{{layout-element tag="li" id="my-layout"}}
</ul>
loading {{#loading}}
A block helper to use when the view is loading. For collection specific loading the CollectionView
accepts loadingView
and loadingTemplate
options to append an item in a collection when it is loading.
{{#loading}}
View is loading a model or collection.
{{else}}
View is not loading a model or collection.
{{/loading}}
Catalog of Built-in Events
rendered rendered ()
Triggered on a view when the rendered
method is called.
child child (instance)
Triggered on a view every time a child view is appended into the view with the view
helper.
ready ready (options)
Triggered when a view is appended to the DOM with appendTo
or when a view is appended to a LayoutView
via setView
. Setting focus and other behaviors that depend on the view being present in the DOM should be handled in this event.
This event propagates to all children, including children that will be bound after the view is created. options
will contain a target
view, which is the view that triggered the event.
activated activated (options)
Triggered on a view immediately after it was passed to a LayoutView
's setView
method. Like ready
this event propagates to children and the options
hash will contain a target
view.
deactivated deactivated (options)
Triggered on a view when it was previously passed to the setView
method on a LayoutView
, and then another view is passed to setView
. Triggered when the current view's el
is still attached to the parent. Like ready
this event propagates to children and the options
hash will contain a target
view.
destroyed destroyed ()
Triggered on a view when the release
method is called and the reference count is zero. Useful for implementing custom view cleanup behaviors. release
will be also be called if it was previously passed to the setView
method on a LayoutView
, and then another view is passed to setView
.
change:view:start change:view:start (newView [,oldView] ,options)
Trigged on a Thorax.LayoutView
immediately after setView
is called.
change:view:end change:view:end (newView [,oldView] ,options)
Trigged on a Thorax.LayoutView
after setView
is called, the old view has been destroyed (if present) and the new view has been attached to the DOM and had its ready
event triggered.
helper helper (name [,args...] ,helperView)
Triggered on a view when a view helper (such as collection
, empty
, etc) create a new HelperView
instance.
helper:name helper:name ([,args...] ,helperView)
Triggered on a view when a given view helper creates a new HelperView
instance.
{{#collection cats}}{{/collection}}
view.on('helper:collection', function(collection, collectionView) {
});
serialize serialize (attributes)
Triggered on a view when serialize
is called, before validateInput
is called with the serialized attributes.
validate validate (attributes, errors)
Triggered on a view when serialize
is called, passed an attributes hash and errors array after validateInput
is called. Use in combination with the invalid
event to display and clear errors from your views.
Thorax.View.on({
validate: function(attributes, errors) {
//clear previous errors if present
},
invalid: function(errors) {
errors.forEach(function(error) {
//lookup input by error.name
//display error from error.message
});
}
});
invalid invalid (errors)
Triggered on a view when serialize
is called, if validateInput
returned an array with any errors.
populate populate (attributes)
Triggered on a view when populate
is called. Passed a hash containing the attributes that the view will be populated with.
load:start load:start (message, background, target)
Triggered on a model or collection by fetch
or load
and on a view if it has bound the model or collection with setModel
or setCollection
. Always generate a handler for a load:start
event with Thorax.loadHandler
.
load:end load:end (target)
Triggered on a model or collection by fetch
or load
and on a view if it has bound the model or collection with setModel
or setCollection
. Never observe this directly, always use Thorax.loadHandler
on load:start
.
rendered:collection rendred:collection (collectionView, collection)
Triggered on a CollectionView
or the view calling the collection
helper every time render
is called on the CollectionView
.
rendered:item rendered:item (collectionView, collection, model, itemElement, index)
Triggered on a CollectionView
or the view calling the collection
helper every time an item is rendered in the CollectionView
.
rendered:empty rendered:empty (collectionView, collection)
Triggered on a CollectionView
or the view calling the collection
helper every time the emptyView
or emptyTemplate
is rendered in the CollectionView
.
restore restore(forceRerender)
Triggered when the view is being restored to the current element. Listeners should be aware that it's possible for a rerender to occur while the restore event has triggered and should be able to handle this case gracefully. after-restore
may provide a better option for cases that need to apply DOM changes after any potential render operations. If the current restore process will force a rerender then the forceRerender
parameter will be truthy.
after-restore after-restore()
Triggered when the view has been restored and possibly rerendered to the current element. If the current restore process will force a rerender then the forceRerender
parameter will be truthy.
restore:collection restore:collection(collectionView, el)
Triggered on a CollectionView
or a view calling the collection
helper when the collection is restored.
restore:item restore:item(collectionView, el)
Triggered on a CollectionView
or a view calling the collection
helper upon restoring an individual item element in the collection.
restore:empty restore:empty(collectionView, el)
Triggered on a CollectionView
or a view calling the collection
helper when a restore operation includes an empty view or template.
restore:fail restore:fail(info)
Triggered when a particular view can not be restored. info
may be a free form object but generally it will have a type
field, outlined below, and a view
field listing the view instance that failed.
Types:
previously-rendered
: View has been rendered alreadyremaining
: View has children that were not restored and must do a partial rerendernot-restorable
: View was explicitly marked as not restorableserialize
: Unable to marshal one or more of the parameters passed to the helpercollection-remove
: Item removed due to not being found in client-side collectioncollection-missing
: Item rendered due to not existing in server-side collectioncollection-depthed-query
: Attempted to use an inline collection item or empty template with ../
references.
HTML Attributes
Thorax and its view helpers generate a number of custom HTML attributes that may be useful in debugging or generating CSS selectors to be used as arguments to $
or to create CSS. The *-cid
attributes are generally used only internally. See $.model
, $.collection
and $.view
to get a reference to objects directly from the DOM. The *-name
attributes will only be present if the given objects have a name
property.
<tr>
<td>`data-view-restore`</td>
<td>View elements rendered on the server side. `true` signifies that restoring is possible. `false` that it's explicitly disallowed.</td>
</tr>
<tr>
<td>`data-view-helper-restore`</td>
<td>Helper View elements rendered on the server side. Provides the name of the helper view.</td>
</tr>
<tr>
<td>`data-server-data`</td>
<td>Elements with `ServerMarshal` data associated with them.</td>
</tr>
Attribute Name | Attached To |
---|
`data-view-cid` | Every view instances' `el` |
`data-view-name` | Same as above, only present on named views |
`data-collection-cid` | Element generated by the `collection helper` |
`data-collection-name` | Same as above, only present when the bound collection is named |
`data-collection-empty` | Set to "true" or "false" depending on whether the bound collection `isEmpty` |
`data-collection-element` | Set by the `collection-element`, determines where a collection in a `CollectionView` will be rendered. |
`data-view-empty` | Collection view's empty element |
`data-model-cid` | A view's `el` if a model was bound to the view or each item element inside of elements generated by the collection helper |
`data-model-id` | A view's `el` if a model was bound to the view or each item element inside of elements generated by the collection helper |
`data-model-name` | Same as above, only present if the model is named |
`data-layout-cid` | The element generated by the `layout` helper or `el` inside of a `LayoutView` or `ViewController` instance |
`data-view-helper` | Elements generated by various helpers including `collection` and `empty` from the collection plugin |
`data-call-method` | Elements generated by the `link` and `button` helpers |
`data-trigger-event` | Elements generated by the `link` and `button` helpers |
When creating CSS selectors it's recommended to use the generated attributes (especially data-view-name
) rather than assigning custom IDs or class names for the sole purpose of styling.
[data-view-name="my-view-name"] {
border: 1px solid #ddd;
}
Error Handling
Certain critical code paths are executed using the bindSection
and runSection
APIs. Should code executed on these paths throw, additional information regarding the code location, etc may be logged and used for debugging.
Override these APIs with your own logging / debugging handler or utilize Costanza for an enhanced error tracking.
onException Thorax.onException(name, error, info)
Logs exceptions when they occur. Passed to the function are a unique identifier, name
, the thrown exception, error
, and an object containing any additional information, info
. The default implementation is null
instead of a function which makes Thorax not intervene with the exception process at all. The typical use case for this method is if you use an error reporting service, such as Costanza, or in this example, Raven.js:
Throax.onException = function(name, error) {
Raven.captureException(error);
};
bindSection Thorax.bindSection(name, info, callback)
Wraps a callback
in an error wrapper. Included with the callback
is an identifying name
value and any relevant information, info
that may help debugging the exception.
By default this calls Thorax.onException
if it has been defined and an exception is thrown. Implementors may override this method to provide additional error handling before exceptions occur.
runSection Thorax.runSection(name, info, callback)
Immediately executed version of bindSection
. The default implementation delegates to bindSection
.
Server Rendering
Server side rendering is designed around Fruit Loops, but may be performed in any environment that supports the $
API as well as a few core APIs used to control the page life cycle.
$serverSide
Boolean flag set to true when rendering server side content.FruitLoops.emit()
Called when the page should be sent back to the client.FruitLoops.onEmit(calback)
Registers a callback
which will be called just prior to the emit operation.
Restore Process
The restore process involves walking the DOM hierarchy looking for nodes that are annotated with the data-view-restore
attribute. When such a node is found Thorax will attempt to restore based on a variety of steps discussed in the Restore Methods section below.
This process is kicked off by either an explicit call to View.restore
or by calling LayoutView.setView
on a previously restored layout view.
The application restore process might look something like:
var appEl = $('[data-view-name="application"]');
if (appEl.length) {
// Restore the application view explicitly
Application.restore(appEl);
} else {
$('body').append(Application.el);
Application.render();
}
Followed by normal controller execution, ultimately culminating in setView
call, which will restore the rendered child.
Restore Methods
There is no definitive algorithm for restoring views, instead the following heuristics are used. In the event of a mismatch the restore:fail
event will be emitted on the candidate view with additional debugging information regarding what portion of the heuristic failed.
General Rules
If the candidate view instance has already been rendered then the previous element will be replaced with the existing view element. This case is tracked by restore:fail
with a type field of prev-render
.
By default restore operations are depth first recursive. This allows for restore operations to partially rerender content for the minimal number of rerender operations.
Any view that is explicitly marked with data-view-restore=false
will be rerendered on the client. This shortcircuits the tree traversal and causes all children to be rerendered as well.
setView
calls
When setView
is called an attempt will be made to restore the view to the layout view's child element if marked for restore. This assumes that the view is a named view. Should it not be a rerender will occur.
Helper Views
Elements rendered via a helper view such as view
or collection
will automatically be restored. This is done by saving the parameters passed to the helper view into the server marshal store. On restore the helper view will be executed in a similar manner to the initial execution, with the distinction that the restore
method will be called after the view has initialized.
When using helper views the restore might be forced to rerender if utilizing helpers that do no properly set the contextPath
or if passed a depthed parameter, i.e. {{view ../foo}}
as these can not be safely resolved. This is tracked via the restore:fail
event with type serialize
and is determined on the server-side.
Additionally helpers that utilize subexpressions to resolve complex values are unable to be restored via path lookup and will force a rerender.
Collection Views
Collection views follow the same restore rules as helper views but add the ability to restore nested child views.
Rerender cases (additional to the helper cases):
- Use of a block helper that has a
../
reference:
{{#collection}}{{../foo}}{{/collection}}
- Use of collections that do not have an
id
value.
Note that overriding renderItem
is allowed but discouraged as this has additional overhead vs. providing an itemView
or itemTemplate
value. This also applies to renderEmpty
.
Best Practices
In general there are a number of things that help avoid rerender cases.
Logging
While in development mode tracking the number of times that a rerender case is triggered is vital for ensuring that the restore behavior is actually benefiting the site.
This might be as simple as a global logger on the restore:fail
event:
View.on('restore:fail', function(info) {
console.log('restore:fail', info);
});
Custom Restore Logic
It's recommended that views needing custom restore behavior do so by providing a restore
event listener rather than overriding the restore
method. This is due to the manner in which partial restores are implemented, delegating to the super class implementation may cause a rerender meaning any non-restored children are rerendered as well.
Should a view absolutely need to prevent the default restore behavior it can override the restore
method but it must manually remove the data-view-restore
attribute and also perform any child traversal necessary.
For most situations it should not be necessary to provide a custom restore implementation but cases that implement custom view insertion logic, i.e. calling DOM methods to insert the child view, will likely need to provide some level of custom restore logic. Ex:
CustomView.on('restore', function() {
var child = this.$('.child-view');
if (child.length) {
this.childView.restore(child);
}
});
Data Loading
Since pending fetch operations might rerender the content of a just restored view, it's recommended that the JSON content is cached in a manner that is accessible on the initial page load to avoid unnecessary rendering operations after restore. Fruit Loops offers such a system via the $serverCache
local variable. Should this not be possible, the thorax rendering pipeline will handle any the restore and subsequent rerender properly.
Note that there are issues that might arise if a different model data source is used on the client vs. the server, a personalized vs public data source for example. When such data is loaded prior to the restore operation, it might be necessary to provide a custom restore step that checks if this data has changed and rerender as there is no clean way for Thorax to determine if a model's data has changed between the two states.
Error Codes
button-trigger
button
helper must have a method name as the first argument or a 'trigger', or a 'method' attribute specified.
link-href
link
helper requires an href as the first argument or an href
attribute.
collection-element-helper
collection-element
helper must be declared inside of a CollectionView
super-parent
Cannot use super
helper when parent has no name or template.
view-helper-hash-args
Hash arguments are not allowed in the view
helper as templates should not introduce side effects to view instances.
layout-element-helper
layout-element
helper must be used within a LayoutView
.
mixed-fetch
Both set
and reset
were passed to fetch
, must use one or the other.
nested-render
render
was called which triggered an event handler which in turn called render
. Infinite recursion was halted.
handlebars-no-data
Handlebars template compiled without data, use: Handlebars.compile(template, {data: true})
insert-destroyed
A helper view that has been destroyed was inserted into the view.
void-tag-content
A void tag such as img
was rendered with content
in Thorax.Util.tag
.
server-marshal-object
A complex object was serialized without a proper context path to lookup the object on the client side. See Thorax.ServerMarshal for more discussion on context paths.
fn-view-unregistered
$.view
found a view element that was inserted manually into the DOM and was not registered with _addChild
or retain
. Call parent._addChild(view)
or view.retain()
on view insertion or instantiation.