Flux+React vs Backbone+React [closed] - backbone.js

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What are the advantages of Flux+React over Backbone+React. Are there any performance differences in addition to the code development ease for a huge complex code base.
What if we have a 1:1 relation between the model and a react view in a application that uses Backbone+React ?

Flux is an architect pattern to build React application. So you can use Backbone models and collections inside your stores to fetch and store data.
And if want to use just React's Virtual DOM feature, there is no need to use react.js. There are a lot of libraries, adding Virtual DOM feature to your application (https://github.com/Matt-Esch/virtual-dom).
My recommendation: if you will use Flux pattern I strongly recommend you to use http://facebook.github.io/immutable-js/ (may be coupled with http://ampersandjs.com/; don't forget to define your custom sync function if you are building isomorphic application). Basically there are no any advantages using backbone models with React (backbone is heavy, it needs underscore, which is slow; I use https://lodash.com/ instead ).

IMHO Flux stores are not incompatibles with Backbone models / collections.
You can probably use Backbone collections as Flux stores, as long as you integrate them with the Flux dispatcher and you permit them to emit an event to trigger a rendering.
I'm just not sure Backbone models are meant to be immutable data structures in the first place, thus making it harder for React to optimize the rendering.
I would also say that I never really found all these Backbone models/collections methods really useful. In a Flux architecture, API requests would tend to be fired by action creators and not by the stores directly, thus permitting multiple stores to listen to the same request completion.
Where should ajax request be made in Flux app?

One nice thing about React is that it is agnostic - you can use it with Backbone models and collections without problem.
Flux is a suggested architecture, but I think the model diverges so greatly to MVC that at the end of the day it's not worth to try to use them both - Use React with Flux OR React with Backbone models and collections.
I wouldn't recommend using Backbone models/collections as Flux stores - they're not the same thing. Main reason being that a flux store can't be mutated from outside - it doesn't provide setters. A Flux store mutate it's own state in response to actions. And even if you follow the "Flux" way using Backbone models as stores, your code still has open possibilities for direct manipulation of state from outside the store that could be misused by other members of the team, for example...

Backbone's model collection is mutable while react stands upon a theme, immutability. So, Technically using Backbone+React is doing an Anti Pattern.
I have used both react+backbone and react+flux. I will definitely prefer react+flux over others.

+1 Vetrenko Maxim's answer regarding integration of backbone and the architecture pattern. Flux is a data flow pattern for React apps and can use any data store/model framework you wish.
The advantages of using Flux+React :
Easier understanding of data flow
Better code organization
easier debugging data issues with models
compartmentalize data store/model code from views
There are several model frameworks to use, I prefer www.js-data.io for React+Flux.

Flux is an architectural pattern that enforces one directional flow of data. The Flux pattern is generic and it is not specific to React applications. With Flux, the poorly defined data flow and lack of data integrity will be prevented.
If you will be choosing Backbone, you can combine those two as long as you know when to use the Flux way and the Backbone way.

Related

ReactJS - How should one separate the functionalities of components with the goal of maintaining 'separation of concerns'?

I've been coding in ReactJS for the last month. I've been reading a lot about MVC, MVVM, MVW etc. front-end architectural design patterns and this knowledge has confused me, to say the least, with what I know about React.
Up until now, my understanding was to separate components based on UI features. So given one UI feature, that component will be responsible for 1) getting the data from the backend, 2) performing any business logic to that data before, and 3) the presentation logic. To me, this sounds like one component is doing far too much and should be split.
For example, if I have a component that shows all the users in my database, this component will make the AJAX call to get this information, perform any business logic to the data, then render it as necessary in a nice pretty list (using JSX and CSS).
I can't find anything on the docs with regards to separation of concerns, so my question is, how should I go about dividing all of this logic? Is there an accepted practice?

what do I use for model and controller with Facebook's React and ES6

I'm a noob on react/es6 stack/framework. I was previously developing in Backbone/Marionette.js and recently started reading more about ES6 and React. Considering my background I'm used to having Backbone for Model and Controller (MC of MVC pattern). I have heard people using react with Backbone/Ember/Angular. What are your experiences and what are the different patterns that are trending in this area at the moment. I'll really appreciate you sharing your experiences/thoughts on this. Thanks in advance!
Facebook has proposed the Flux architecture as a way of flowing data unidirectionally into your React components. The idea is that you have a separate container (often called a "store") for all of your data. You register actions which run through a dispatcher and change your data, which then causes your view components to update.
There have been a lot of implementations of this idea. So far there isn't a single plug and play data model that's a no-brainer to use.
One implementation that has a lot of people excited right now is called Redux. Like React, it draws inspiration from the functional programming school of thought.
From the README:
The whole state of your app is stored in an object tree inside a single store.
The only way to change the state tree is to emit an action, an object describing what happened.
To specify how the actions transform the state tree, you write pure reducers.
So it's not exactly the MVC paradigm, but when combined with React you have a chain of events where the user triggers some action which changes the data and updates the view.
I recommend checking out the examples in the repo. It's a solid approach that's gaining a lot of traction. It also comes with a really neat dev tools. Hopefully in the future someone will be able to abstract away more of the boilerplate code.

Backbone js app structure

Currently am writing all my business logic inside the view class which make my view class unmanageable. Am planning to create Backbone object and move all the business logic there and invoke it from view class. Please correct me with right way of thinking
Backbone in general does not provide an entity named Controller, this is one of the reasons which Backbone called MV*. Generally user interact with views, you know well this interact means change and update over models.
"So does Backbone.js have controllers? Not really. Backbone’s views typically contain
controller logic, and routers are used to help manage application state, but neither are
true controllers according to classical MVC." (Addy Osmani Book's)
so i think your way is not incorrect, but you can improve your project structure through this solutions:
Marrionette (and also Thorax ) is a excellent framework that provide such a excellent structure for your app. You can read this annotated code and get some tip from it.
You know certainly AMD a nice api to provide modular pattern in js. Require.js a nice tool for organize your code. For more information i recommend check TodoMVC + Backbone+Require code.

What are the real-world strengths and weaknesses of the many frameworks based on backbone.js? [closed]

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Hope that someone can share their experience with some of the latest emerging backbone.js variants out there.
I have some good experience with backbone/underscore/require in several projects and I will like to take the next step towards more advanced solutions for complex application structure.
I know the following frameworks are available:
Marionette
Geppetto (based on Marionette)
Chaplin, Chaplin - chaplin-boilerplate
Vertebrae
LayoutManager
Thorax
Aura
Luca
Singool
backstack
Backbone UI
hulk
BTW - excellent starting point for big scale project
And probably I missed a few.
There is a short introduction about the differences here:
speakerdeck talk link
but it's very general. I was wondering if someone can share their experience with real life applications using these frameworks.
What is the benefit of choosing one over the other? When will marionette be a better solution over chaplin, or why is vetebrae better for certain applications, for example.
Sure, the obvious answer will be "use whats best for your needs", but I lack of the experience with these frameworks to know their strength/purpose/advantages or preferred scenarios.
Thanks!
Edit 1:
found this post:
Backbone.Marionette vs Backbone-Boilerplate
Edit 2:
Answer by Mathias schafer (Chaplin) by mail:
In short, the current structure is close to version 1.0 since it’s already used in production. We’re not planning to add big new feature or breaking API changes until 1.0.
Marionette is for sure the most comprehensive and stable library out there. It addresses several aspects of JS app development with Backbone. For example, it has a strong view layer which Backbone itself leaves completely void. Of course, you will find that some of the aspects won’t meet your demands and you might feel the need to set up a structure around Marionette.
In contrast, Chaplin focusses on a rather small, but very important aspect of Backbone apps, namely the overall app structure and module lifecycle. In this regard Chaplin is very opionated and is more like a framework than a library (like in “your code calls a library, a framework calls your code”). Chaplin provides some central classes which sit above individual application modules and control the overall app state. This gives your app a conventional structure like Ruby on Rails does it for example.
In Chaplin, you declare some routes which map to controllers, and Chaplin starts the controller once the route match. It also takes care of the disposal of old controllers, and the showing and hiding of main views, which a controller is supposed to create. This is the basic idea, but Chaplin takes care of the ugly details to make this run smoothly.
There are two principals which come along with this structure:
- Modularization, decoupling and sandboxing
- Cross-module communication using Publish/Subscribe and Mediator(s)
Of course these patterns are not new in the software development world, and Chaplin is not the only library which applies them to Backbone.js apps.
Chaplin also provides enhancements for the View layer, for example a highly sophisticated CollectionView, but in total not as much as Marionette with its Regions and Layouts. But it’s relatively easy to write such meta classes using the means Chaplin Views provide.
Most of (all of?) the frameworks that you're looking at solve the same problems, but they do it in slightly different ways with slightly different goals.
I think it's fair to say that all of these projects would solve the problems in these categories:
Provide sensible set of defaults
Reduce boilerplate code
Provide application structure on top of the BackboneJS building blocks
Extract patterns that authors use in their apps
Marionette, which I've been building since December of 2011, has a few very distinct goals and ideals in mind, as well:
Composite application architecture
Enterprise messaging pattern influence
Modularization options
Incremental use (no all-or-nothing requirement)
No server lock-in
Make it easy to change those defaults
Code as configuration / over configuration
I'm not saying none of the other frameworks have these same goals. But I think Marionette's uniqueness comes from the combination of these goals.
Composite Application Architecture
I spent more than 5 years working in thick-client, distributed software systems using WinForms and C#. I built apps for desktop, laptop (smart-client), mobile devices and web applications, all sharing a core functional set and working with the same server back-end many times. In this time, I learned the value of modularization and very rapidly moved down a path of composite application design.
The basic idea is to "compose" your application's runtime experience and process out of many smaller, individual pieces that don't necessarily know about each other. They register themselves with the overall composite application system and then they communicate through various means of decoupled messages and calls.
I've written a little bit about this on my blog, introducing Marionette as a composite application architecture for Backbone:
http://lostechies.com/derickbailey/2011/11/17/introduction-to-composite-javascript-apps/
http://lostechies.com/derickbailey/2011/12/12/composite-js-apps-regions-and-region-managers/
Message Queues / Patterns
The same large scale, distributed systems also took advantage of message queuing, enterprise integration patterns (messaging patterns), and service buses to handle the messages. This, more than anything else, had a tremendous influence on my approach to decoupled software development. I began to see single-process, in-memory WinForms applications from this perspective, and soon my server side and web application development took influence from this.
This has directly translated itself in to how I look at Backbone application design. I provide an event aggregator in Marionette, for both the high level Application object, and for each module that you create within the application.
I think about messages that I can send between my modules: command messages, event messages, and more. I also think about the server side communication as messages with these same patterns. Some of the patterns have made their way in to Marionette already, but some haven't yet.
http://lostechies.com/derickbailey/2011/07/19/references-routing-and-the-event-aggregator-coordinating-views-in-backbone-js/
http://lostechies.com/derickbailey/2012/04/03/revisiting-the-backbone-event-aggregator-lessons-learned/
http://lostechies.com/derickbailey/2009/12/23/understanding-the-application-controller-through-object-messaging-patterns/ (WinForms code, but still applicable)
Modularization
Modularization of code is tremendously important. Creating small, well encapsulated packages that have a singular focus with well defined entry and exit points is a must for any system of any significant size and complexity.
Marionette provides modularization directly through it's module definitions. But I also recognize that some people like RequireJS and want to use that. So I provide both a standard build and a RequireJS compatible build.
MyApp = new Backbone.Marionette.Application();
MyApp.module("MyModule", function(MyModule, MyApp, Backbone, Marionette, $, _){
// your module code goes here
});
(No blog post available for this, yet)
Incremental Use
This is one of the core philosophies that I bake in to every part of Marionette that I can: no "all-or-nothing" requirement for use of Marionette.
Backbone itself takes a very incremental and modular approach with all of it's building block objects. You are free to choose which ones you want to use, when. I strongly believe in this principle and strive to make sure Marionette works the same way.
To that end, the majority of the pieces that I have built in to Marionette are built to stand alone, to work with the core pieces of Backbone, and to work together even better.
For example, nearly every Backbone application needs to dynamically show a Backbone view in a particular place on the screen. The apps also need to handle closing old views and cleaning up memory when a new one is put in place. This is where Marionette's Region comes in to play. A region handles the boilerplate code of taking a view, calling render on it, and stuffing the result in to the DOM for you. Then will close that view and clean it up for you, provided your view has a "close" method on it.
MyApp.addRegions({
someRegion: "#some-div"
});
MyApp.someRegion.show(new MyView());
But you're not required to use Marionette's views in order to use a region. The only requirement is that you are extending from Backbone.View at some point in the object's prototype chain. If you choose to provide a close method, a onShow method, or others, Marionette's Region will call it for you at the right time.
http://lostechies.com/derickbailey/2011/12/12/composite-js-apps-regions-and-region-managers/
http://lostechies.com/derickbailey/2011/09/15/zombies-run-managing-page-transitions-in-backbone-apps/
No Server Lock-in
I build Backbone / Marionette apps on top of a wide variety of server technologies:
ASP.NET MVC
Ruby on Rails
Ruby / Sinatra
NodeJS / ExpressJS
PHP / Slim
Java
Erlang
... and more
JavaScript is JavaScript, when it comes to running in a browser. Server side JavaScript is awesome, too, but it has zero effect or influence on how I write my browser based JavaScript.
Because of the diversity in projects that I built and back-end technologies that my clients use, I cannot and will not lock Marionette in to a single server side technology stack for any reason. I won't provide a boilerplate project. I won't provide a ruby gem or an npm package. I want people to understand that Marionette doesn't require a specific back-end server. It's browser based JavaScript, and the back-end doesn't matter.
Of course, I fully support other people providing packages for their language and framework. I list those packages in the Wiki and hope that people continue to build more packages as they see a need. But that is community support, not direct support from Marionette.
https://github.com/derickbailey/backbone.marionette/wiki/Available-packages
Easily Change The Defaults
In my effort to reduce boilerplate code and provide sensible defaults (which is an idea that I directly "borrowed" from Tim Branyen's LayoutManager), I recognize the need for other developers to use slightly different implementations than I do.
I provide rendering based on inline <script> tags for templates, using Underscore.js templating by default. But you can replace this by changing the Renderer and/or TempalteCache objects in Marionette. These two objects provide the core of the rendering capabilities, and there are wiki pages that show how to change this out for specific templating engines and different ways of loading templates.
With v0.9 of Marionette, it gets even easier. For example, if you want to replace the use of inline template script blocks with pre-compiled templates, you only have to replace one method on the Renderer:
Backbone.Marionette.Renderer.render = function(template, data){
return template(data);
};
and now the entire application will use pre-compiled templates that you attach to your view's template attribute.
I even provide a Marionette.Async add-on with v0.9 that allows you to support asynchronously rendering views. I continuously strive to make it as easy as possible to replace the default behaviors in Marionette.
Code As Configuration
I'm a fan of "convention over configuration" in certain contexts. It is a powerful way of getting things done, and Marionette provides a little bit of this - though not too much, honestly. Many other frameworks - especially LayoutManager - provide more convention over configuration than Marionette does.
This is done with purpose and intent.
I've built enough JavaScript plugins, frameworks, add-ons and applications to know the pain of trying to get conventions to work in a meaningful and fast way. It can be done with speed, but usually at the cost of being able to change it.
To that end, I take a "code as configuration" approach to Marionette. I don't provide a lot of "configuration" APIs where you can provide an object literal with static values that change a swath of behaviors. Instead, I document the methods that each object has - both through annotated source code and through the actual API documentation - with the intent of telling you how to change Marionette to work the way you want.
By providing a clean and clear API for the Marionette objects, I create a situation where replacing the behavior of a specific object or Marionette as a whole is relatively simple and very flexible. I sacrifice the "simple" configuration API calls for the flexibility of providing your own code to make things work in the way that you want.
You won't find a "configure" or "options" API in Marionette. But you will find a large number of methods that each serve a very specific purpose, with clean signatures, that make it easy to change how Marionette works.
I'm currently using backbone with the layout manager module and handlebars as templating engine and I found really easy to set up a little application using an already existing Grails backend. Before starting using layout manager I read about Marionette and Chaplin and both seemed to me really powerful but complex. Then I remembered why I originally choosed backbone.js: simplicity. All those frameworks are adding what backbone has left out by design. I'm not saying that a framework is bad, but if I need something more complex I'll try other projects, like ember.js or sproutcore, since they have a unique codebase, written with a goal in the mind of their developers. Here we have frameworks on top of another one. Of course, backbone is a backbone not only for building applications, but also for writing some more powerful library, but the only thing I think is really poor with it is the view layer, since is missing a layout manager and the possibility of nesting views. With layout manager that gap is filled quite well.
So, my answer to your question is: start from using backbone as is, and ask yourself what is missing and what were your expectations about the framework. If you find there are too many things left out by backbone, then go and search for them in the other frameworks and choose the one is nearest your needs. And If you are still not confident in the choice, maybe backbone is not for you and you have to look some other solution (ember.js, sproutcore, ExtJs, JavaScript MVC are all good). If you have experience in writing client apps, you don't really need experience on all the framework out there to choose the right one (for you, of course)
I have studied the various frameworks build with Backbone.js and built the Vertebrae for a project at HauteLook. The project goals included... dynamic script loading, AMD module format, dependency management, build with mostly open source libraries, organize code in packages, optimize and build for one or many single page apps, host on fully cached server, e.g. no server-side scripting using only an API for data, and the funnest for me, use behaviour driven development for the project. There is a description on the project at : http://www.hautelooktech.com/2012/05/24/vertebrae-front-end-framework-built-with-backbone-js-and-requirejs-using-amd/
Our Problem:
Selected libraries (jQuery, Underscore.js, Backbone.js, RequireJS, Mustache) provide module loading, dependency management, application structure (for models, collections, views and routes), asynchronous interactions with API, various utilities and objects to manage asynchronous behaviors, e.g. (Promises) Deferreds, Callbacks. The remaining logic needed to complete the framework includes:
an object (model) to manage state of the single-page application;
a layout manager to present, arrange/transition and clear views, and
controllers which respond to routes, get/set application state, and hand off work to layout manager.
Our Solutions (implemented in Vertebrae):
Application State Manager -
The application manager stores data in memory and also persists data in browser storage to provide a resource for common data/metadata. Also provides data (state) to reconstruct the page views based on previous interactions (e.g. selected tab, applied filters). The application state manager provides a strategy for resources to retrieve state. Meant to act as a state machine.
Layout Manager -
The layout manager has one or many views as well as document (DOM) destinations for each (rendered) view. A page may transition between many views, so the layout manager keeps track of view states, e.g. rendered, not-rendered, displayed, not-displayed. You may use the layout manager to lazy load and render (detached) views that a site visitor is very likely to request, e.g. tab changes on a page. The transition between view states is managed by this object. An entire layout may be cleared so that view objects and their bindings are removed, preparing these objects for garbage collection (preventing memory leaks). The layout manager also communicates view state with controller(s).
Controller -
A controller object is called by a route handler function, and is responsible for getting relevant state (application models) to generate a page (layout), (also responsible for setting state when routes change). The controller passes dependent data (models/collections) and constructed view objects for a requested page to the layout manager. As a side-effect the use of controllers prevents the routes object from becoming bloated and tangled. A route should map to a controller which then kicks off the page view, keeping the route handling functions lean.
The Todos app is hosted both in dev mode and optimized on Heroku...
http://vertebrae-framework.herokuapp.com/
http://vertebrae-optimized.herokuapp.com/
Many of the concepts in the other frameworks are borrowed, e.g. the need to destory views to preview memory leaks as pointed out by Derick Bailey - http://lostechies.com/derickbailey/ ; the Layout Manager by Tim Branyen http://tbranyen.github.com/backbone.layoutmanager/
In summary, Backbone.js is meant to be a tool in your application the Backbone.js library does not provide all the architecture you will need to build an application, but does provide great interactions with an API and solid code structure for... Views (act like controllers too) and your data layer Models and Collections, and finally Routes. We built Vertebrae to meat the goals of our project, and decided to extract the code as a framework for others to use, learn, or whatever.
The answer to your question in my opinion is to learn from all the frameworks and use what you need to meet your goals, if you find that your project goals fit closely with one of the frameworks built with Backbone then great, otherwise built your own framework there are great examples being shared by the community. Or if you find yourself a bit lost in the direction of your application then choose something more opinionated and structured perhaps Ember.js. The great thing is there are a good assortment of choices to help you code using an (MVX) MVC like pattern with JavaScript.
I developed the Luca framework while working at BenchPrep where we used it to develop several large single page apps on top of the backbone.js library.
I had worked with ExtJS for several years prior and have stolen my favorite concepts from that framework such as the component driven architecture where you develop your views as standalone components and then join them together with other components using container views. And since it is heavily based on configuration, developing an app in Luca feels a lot like describing an object with JSON.
One advantage to this approach is the ability to re-use components across several apps or in different places in your app, with with only minor changes using Backbone's extend. It is also very easy to experiment with many different layouts / presentations of components by making only minor tweaks to the JSON configuration.
In addition to a wide range of helper / utility functions, Luca Ships with many higher level Backbone derivatives that you can piece together in any way imagineable to build a complex UI.
Views, Components, Containers
Augmented Model, View, Collection, Router classes
Configuration options that facilitate communication between Models, Collections, Views, the Application and its respective managers.
Containers ( Split / Column Layout, Grid Layout, Tab View, Card / Wizard View )
FormView with all of the standard field components, and helpers for syncing with a Backbone.Model
GridView, for generating scrollable grid elements from a Luca.Collection
CollectionView, for generating views based on a collection
Toolbars / Buttons
Twitter Bootstrap Styles and Markup For Free
Luca plays very well with the Twitter bootstrap framework. Simply by setting Luca.enableBootstrap = true, and including the CSS, your components ( such as the tab views, the toolbars, buttons, forms, fields, grids, etc ) will automatically use Twitter Bootstrap compatible markup and CSS class conventions.
Uses the Grid system for layout, and responds to most of the bootstrap base css classes in an intelligent way
Luca.Viewport and GridLayout components are setup to work with bootstrap's responsive, fluid, or static grid systems.
Aims to provide a one to one match for twitter bootstrap components, to represent them as configurable Backbone Views
The Application Component
Backbone.Model based state machine provides getter / setter methods and attribute change events as a style of application control flow
Integrated Controller component which hides / shows pages of the app in response to Backbone.Router or State Machine events
Integrated Collection Manager which keeps track of the collections you have created, allows you to scope them, group them, assign default parameters to them
A Socket Manager which is an abstraction layer on top of websocket services that makes push as easy as Backbone.Event
A Keyboard Event router which triggers named key events on components which care to respond to such events
Collection and Model Enhancements
Collections are based on backbone-query, which provides a querying interface very similar to mongoDb
enable a local storage Backbone.sync simply by setting collection.localStorage = true
automatic population of collections whose data is bootstrapped on page load
cached methods / computed properties. cache the result of collection methods, and expire the cache in response to change / add / remove events on the collection or its models
computed properties on the models. build attributes based on complex function, and automatically update the computed value in response to changes
Events and Hooks
Luca components are more liberal with the events they emit compared to the stock Backbone components. They will emit events like before:initialize, after:initialize, before:render, after:render, activation, first:activation, deactivation, first:deactivation, and this allows you to more finely tune the behavior of your components. Plus, by defining an event in the #hooks porperty on your view, it will automatically call a similarly named function for you if it exists. This prevents a lot of callback style code which improves readability.
You can also configure the Luca.Events class to publish the events to a global publish / subscribe channel, which makes building a large application easier and aids in inter module communication.
The Ruby Gem
Luca was developed specifically while working against Rails and Sinatra APIs and because of this is currently optimized for a specific stack, but it in no way locks you into a specific server.
Luca comes distributed as part of a Ruby Gem configured to work on the asset pipeline, or as a downloadable JS file.
You are not required to use Rails, or Sinatra. But if you do, I have included a lot of useful things:
Files with the .luca extension get processed as HAML with JST style variable interpolation. ( equivalent to .jst.ejs.haml ) by the asset pipeline
A Test Harness for browser, or headless Jasmine based Unit Tests along with many Backbone and Underscore test helpers.
An API endpoint for the development toolset that ships with Luca ( more on this later )
An API endpoint that allows you to use Redis as a schemaless storage engine for Luca.Collection with minimal configuration
The Development Tools
Luca applications can enable an in browser coffeescript console with Luca specific helpers and commands that aid in monitoring, inspecting, debugging Luca applications and components
With the help of the Rails Gem, and Luca's CodeMirror based component editor, you can edit the source code of the Luca Framework as well the application specific components directly in the browser, using Coffeescript. You will see immediate feedback in response to your edits, with the instances of effected objects being refreshed with the updated prototype, and you can save your changes to disk.
The Component Tester is a live sandbox for playing with the components that make up your application in isolation. It provides you with tools for modifying the component's prototype, setting up its dependencies, and configuring the component. The component will re-render immediately every time you make an edit. You can view and edit the markup that the component generates, as well as the CSS directly in the browser and see your changes immediately. This makes it a very valuable experimentation tool.
The Component Tester will soon integrate with Jasmine so you can view the results of your component unit tests in real time as you edit their code
Luca is a work in progress, but maintains a stable API ( not yet 1.0 ) and has been used in several large production apps. It is definitely a very opinionated framework, but I am working on making it more modular. I am actively working on the documentation and sample components.
I’m a co-author of Chaplin and I’ve written an in-depth comparison between Chaplin.js and Marionette.js:
http://9elements.com/io/index.php/comparison-of-marionette-and-chaplin/
This is not a “shootout” but tries to explain both approaches in a balanced way.

What problem does backbone.js solve?

When I gloss over the backbone.js site, I'm not sure what is it trying to do.
It seems somewhat popular, but why should I want to learn it? What will it do for me? Why was it made? What problem does it solve?
I find the question perfectly valid and from my point of view there is nothing wrong with inquiring about the potential use cases of a library/toolkit.
What Backbone.js does (so do several other javascript mvc implementations) is that it provides a means of organizing the code into a modular pattern known as MVC pattern which is all about separating your code into three loosely coupled layers:
Model layer dealing purely with data and associated operations
View layer being the presentational aspects
Controller layer being the binding glue layer
(different frameworks deal with this differently : Backbone implementation of controller layer comprises of client side routing capabilities).
So, on the whole backbone provides you an infrastructure using which you can deal with data through models which contain encapsulated within them the data and associated validations, which can be observed ie. you can bind events to change events.
The View layer is mostly left for the user to separate the ui into manageable isolated sections.
Here are some problems that Backbone solves for me in the JS/HTML space:
Separation of Concerns (SoC)
Composability
Testability
Component Model
Abstraction
That is not to say that this is the ONLY system that does this. There are others. Backbone does a pretty good job of helping with these things, though.
From backbonejs.org
It's all too easy to create JavaScript applications that end up as
tangled piles of jQuery selectors and callbacks
And that's exactly what backbone does, a series of callbacks on model changes and jQuery selectors to bind events.
So to answer the question, it solves nothing only to provide a way (the backbone way) of structuring code with some slight automation in the REST side of things.

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