Titanium Alloy MVC Architecture - model-view-controller

I don't get completly the architecture of Titanium Alloy. Maybe someone can explain it better or draw me a picture? :)
What I understood is that it is a mvc architecture but not in the "basic" way... The Model is only a blueprint for the intern SQLite database. The Backbone Model also can be extended to check for correct input and duplicates. To synch with the extern the Controller is used. At least all the examples I found did that. And the View is basic with Titanium Style Sheets.

Unfortunately you have a very terse, incomplete understanding of what Alloy is, what it does, and how it does it. Fortunately for you though, there's is extensive and complete documentation that covers all this in guide form. Answers to all these high level architecture questions and more can be found here: http://docs.appcelerator.com/titanium/latest/#!/guide/Alloy_Framework

Well Alloy is indeed a framework that is based on the MVC architecture, maybe what you need is to get some insight on the design goals of MVC and how they can be achieved using the separate roles for each unit of software. Here is a very good article I would recommend: http://blog.codinghorror.com/understanding-model-view-controller/
The fact that you can specify view structures using only xml files and styling using only static properties means that Alloy is a very well implemented MVC framework as it does not allow you to mix the responsibilities of each role.
My 2 cents of understanding Alloy:
controller.js
Here place only code that handles ui element events such as clicks, taps and so on. Your controller should pick up an event and call a method belonging to some external common.js module that you should require using require(). It is fully supported in Alloy.
view.xml
Here you only specify the tree structure of your ui elements. This means what component belongs where and to which other component.
style.tss
Here you should specify anything that has to do with colors, position, layout etc.

Related

Controller in Backbone.js

I'm new to Backbone.js. I have gone through the documentation. My question is
where does the controller concept come into picture? In other words, what is a controller in Backbone.js?
I heard that the router is the controller. If so, why it is considered as a controller? Can we develop simple basic apps without the Router also? In that case what will be the controller?
To clear things a little bit here. A Router is not a Controller, It's a way to define a client-side route map (similar to Rails's routes.rb). This helps routing client-side pages to certain actions/handlers. And that's different from a controller's job which is to provide a bit of orchestration between Models and Views. And there is actually more than one way to do this using Backbone. Quoting from Backbone's documentation:
References between Models and Views can be handled several ways. Some
people like to have direct pointers, where views correspond 1:1 with
models (model.view and view.model). Others prefer to have intermediate
"controller" objects that orchestrate the creation and organization of
views into a hierarchy. Others still prefer the evented approach, and
always fire events instead of calling methods directly. All of these
styles work well.
This brings three different approaches to accomplish this. The first one is pretty straightforward which is to have the model object included as a property to the view.
The second one proposes including a third component that performs this role of orchestration. I believe this can be helpful in quite large and complex applications. For this I encourage you to look at Chaplin, a sample application architecture using Backbone.js. The guys have done a great job in separating things out and also introduced the concept of a Controller into the architecture.
The last approach is suggesting using events to mark for actions and mediator to handle these actions. For this I encourage you to look into the mediator and Publish/Subscribe JavaScript patterns.
Check out Addy Osmani`s article on MV* on the client:
http://addyosmani.com/blog/understanding-mvc-and-mvp-for-javascript-and-backbone-developers/
From the article:
In Backbone, one shares the responsibility of a controller with both the Backbone.View and Backbone.Router.
and
In this respect, contrary to what might be mentioned in the official documentation or in blog posts, Backbone is neither a truly MVC/MVP nor MVVM framework.
It's more similar to how for example iOS Cocoa Touch framework works, you shouldn't think about it like a backend MVC, backbone team itself even never mentions MVC on their website to avoid confusion people often have when coming from backend MVCs. The View in backbone is what's called in iOS a ViewController/AppController and usually your main AppController will be a View which sets the main wrapper for your application which usually you would also use as a global pub/sub system and controller for your main app logics.
Router is exactly what it say - it converts routes into set of params and passes them to the app controller to figure out what to do with them, what subview to load etc. (or if application is less sophisticated it can load/change the views straight from the router level) - It used to be called controller but it was renamed in (0.5 I believe?) to clear this confusion.
At least this is our approach - if you checked multiple tutorials in the wild you've probably seen that when it comes to Backbone there are as many approaches to this as many developers there are. And that's what is beautiful about Backbone! :)
Usually I make my own controllers, and let the router do it's thing (catching routes, and pointing towards a controller action). These controllers are home made, just javascript objects with methods on them. They take the request from the router, collect the right data (collections, models...) and take the necessary view, combine them and pass the data into the view.
from there on it's backbone again.
however recently I came arcoss a 3rd party backbone plugin called backboneMVC. Have read it's documention, but have yet to try it out myself.
It aims to take over your router and make routes based on your controllers and actions you define with it.
Take a look at that library however I cannot promise anything because I have yet to build something with it myself.

MVC for a UI Heavy App

Is MVC architecture appropriate for an app that is a UI centric app?
Example: you want to build a basic flowchart app. Does it make sense to make the GUI components the view, the "node" and "line" objects part of the model, and the click handlers the controllers?
It feels weird to me because there is not much functionality in the model here...
In your case, M is definitely not needed. So you can skip it. Nobody is forcing you to comply with MVC.
If you're using a MVC framework, then don't use features specific to M. Simple. :)
I think it would be pretty useful to use mcv in your project instead!
You have to store somewhere the input data of your charts so a model object would be ideal for that.
The view class would be a template for the boxes and every instance would have is coordinates.
Separating the data from the boxes view would allow you in the future to change aspect and behaviour of the box view without having to touch the data.
In the end you have to consider the mvc pattern not as something that help you build your application in the current state, but a way to have a clean design that you can change and improve without having to rewrite everything. So if you want to build an app that is going to grow go with MVC.

What new features would you like to see in Asp.net MVC 3?

Asp.net MVC 3 preview 1 was released at the end of last month. Are there any new features you are excited about or any features you would like to see before it is fully released?
Full support for Controllers with Generic Parameters
public GenericController<SomeType> : Controller
Generic controllers are quite possibly the greatest MVC timesaver if your doing a lot or business CRUD. There are so many similarities between the Add methods of almost every MVC project that it makes sense to abstract these operations out in a Controller that fits all scenarios.
Right now its a little hacky to create a generic controller. The MVC engine always gets the name wrong (GenericCo vs. Generic) and without full support plugin and libraries that interact with controllers just fall over when they encounter a generic one.
Make Dropdowns easier to work with
As a professional MVC tag watcher I've noticed that working with dropdowns is one of the most repeated questions on SO. The amount of Dropdown questions is a strong indication that something should be done to make it easier or less ... complex?
make checkbox list easy to work with
add T4MVC to the official release
add official helpers for OData
support one javascript library either MS Ajax or jQuery(preferably)
I wish they can add something to help developer to migrate their previous ASP.NET WebForms application.

Is WordPress MVC compliant? [closed]

Closed. This question is opinion-based. It is not currently accepting answers.
Closed 7 years ago.
Locked. This question and its answers are locked because the question is off-topic but has historical significance. It is not currently accepting new answers or interactions.
Some people consider WordPress a blogging platform, some think of it as a CMS, some refer to WordPress as a development framework. Whichever it is, the question still remains. Is WordPress MVC compliant?
I've read the forums and somebody asked about MVC about three years ago. There were some positive answers, and some negative ones. While nobody knows exactly what MVC is and everybody thinks of it in their own way, there's still a general concept that's present in all the discussions.
I have little experience with MVC frameworks and there doesn't seem to be anything about the framework itself. Most of the MVC is done by the programmer, am I right? Now, going back to WordPress, could we consider the core rewrite engine (WP_Rewrite) the controller? Queries & plugin logic as the model? And themes as the view? Or am I getting it all wrong?
Thanks ;)
Wordpress itself is not architected in MVC, but one can build very MVC oriented themes and plugins within the framework. There are several tools which can help:
WordPress MVC solutions:
Churro: # wordpress.org/extend/plugins/churro
Tina-MVC: # wordpress.org/extend/plugins/tina-mvc
Plugin Factory: # wordpress.org/extend/plugins/plugin-factory
MVCPress: http://mozey.wordpress.com/2007/01/22/mvcpress-screenshots/#comment-3634 (abandoned, but interesting ideas)
MVC threads on WordPress.org Ideas and Trac:
http://wordpress.org/extend/ideas/topic/mvc-plugin-framework
http://wordpress.org/extend/ideas/topic/complete-reestructuring
http://wordpress.org/extend/ideas/topic/rewrite-wordpress-using-mvc
http://wordpress.org/extend/ideas/topic/wordpress-theme-revamp (more on XSL than MVC)
http://core.trac.wordpress.org/ticket/12354 (on MVC in widgets)
Wordpress is kinda-sorta MVC. If anything it is a pull-type MVC layout, where the View 'pulls' data from the model. It does this in a very proceedural way, instead of using lots of different objects, but this actually makes the front end templates easier to write in a lot of ways.
This also gives the views some degree of controller logic (thus the kinda-sorta MVC).
Lets run this down:
Wordpress gets a URL. The wordpress core acts as a controller and determines what initial queries to run of the database, and by extension, what view should be loaded (category view, single post or page view, etc). It then packages that INTIAL query response and sends it to the view file.
That view file CAN be a strict display only file OR it can request additional information/queries beyond the built in one. This is the pull-type of the MVC, where the view pulls data from the model instead of the controller 'pushing' data from the model into the view.
Thus, when the view sees code to load a sidebar or widget area, it asks for that information. However, what widgets should be there is determined by the controller, which looks at the model for what widgets are in the sidebar, and then selects those that are set to show on the current page, and returns those to the view.
That each part of that isn't an object doesn't make this any less MVC. You can alter WP core without (necessarily) altering anything about a theme. Similarly, as long as you use built in functions like 'get_pages()' then the model and the database tables could change as long as those functions still returned the right data. So, the model is independent of the view, and the controller is independent as well (except when the view adds controller logic to do more than the core normally does).
While you COULD have a model object holding a number of methods and stuff like WPModel::get_pages('blah blah'), and contain everything that way, there is still fundamental separation of concerns.
View: template files
Controller: WP core
Model: the various functions that handle specific data handling.
As long as the names, arguments, etc, stay the same (or just have new ones added) then separation of concerns is maintained and one can be altered without disturbing the others.
It isn't a super-clean version of MVC, (especially when hooks get involved), but at a basic level it starts there.
And being proceedural about it isn't a bad thing IMO. A request from a website is pretty inherently proceedural: it is a process with a clear beginning and end, and just needs a procedure to process the request, get data, package it, then die. You can set up those steps with objects and object methods and OOP layouts (which would make some things easier) or you can just write alot of function calls and separate them out that way. Class members like private variables are lost that way but depending on the needs of the application... you might not care.
There is no one-grand-way to do development, and WP sits at like 20% of websites so it is doing something right. Probably something to do with not making people have to learn/memorize complex class hierarchies to get the database to answer the question 'what pages are child of page x?' and deal with that data. Could you make it that easy with OOP? yes, but if Joomla is any example of how hard it is to implement a complex custom website with OOP, then WP is FAR easier and quicker, and time is money.
As already mentioned in the comments, MVC is an architectural design pattern, not a specific framework, and no, Wordpress doesn't follow the MVC pattern.
There is a separation of views (templates) from the programming logic, but only in the frontend, not in the admin panel and a general separation of views and application logic is not inevitably MVC. An implementation of the MVC pattern usually assumes some kind of object oriented programming paradigm behind it and Wordpress is mainly implemented in a procedural way, with plain SQL queries in the PHP functions, therefore not having an actual model either.
One of the topics that periodically crops up in discussions as it relates to WordPress is the idea of WordPress and MVC.
But the thing is that MVC is not the silver bullet of web development that we try to make it out to be. Yes, it’s an awesome design pattern, and I personally think that it fits the web application model like a glove, but not every framework or platform implements that design pattern.
Case in point: WordPress is not MVC.
And that’s okay. I think we need to leave the desire of trying to shoehorn it into our projects aside especially when the pattern WordPress provides is not only sufficient, but works well when leveraged correctly.
“But I Love MVC!”
So do I! In fact, I spent the last year working on a project that more-or-less mimicked the MVC architecture.
A high-level example of MVC.
A high-level example of MVC.
For example:
Views were implemented using templates
Controllers were implemented by a combination of using function names like create, read, update, destroy, delete, and so on (even though these functions were hooked into the WordPress API
Models were functions also were called to validate and verify data prior to serializing the data. Again, this required that certain functions be hooked into WordPress to achieve the desired result.
Finally, a set of rewrite rules gave the application a clean set of predictable URLs in the format of /people/update/1 or /people/all.
What Pattern Does WordPress Implement?
WordPress implements the event-driven architecture (of which there are several variations such as the Observer Pattern).
In short, you can conceptually think of this as the following:
Things happen when WordPress is processing information.
You can register your own function to fire when these things happen.
Not too complicated, is it?
A high-level example of event-driven patterns
A high-level example of event-driven patterns
When you begin to think in terms of the paradigm in which it works rather than trying to make it work the way that you want it to work, it’s liberating. It helps to solve problems much more easily.
The bottom line is this: WordPress implements the event-driven design pattern, so even if you end up trying to implement MVC, you’re still going to have to utilize the hook system.
If you’re not careful, you can end up trying to craft the perfect architecture without actually getting your work done, and thus end up finding yourself so high up in the atmosphere of software that you’ve effectively become an architecture astronaut.
So You’re Saying Avoid Design Patterns?
Not at all! Design Patterns serve a purpose because, above all else, they basically give us solutions to previously and commonly solved problems. Use them!
But the point I’m trying to make is that we don’t need to try to force things to fit pattern just because we like the pattern. That’s not their purpose. Instead, leverage the primary pattern that your platform of choice implements – in our case, it’s an event-driven pattern – and then implement patterns where they fit (such as dependency injection or something like that).
Otherwise, it’s like trying to put your foot in a glove.
Courtesy (and totally copied :P) from : http://tommcfarlin.com/wordpress-and-mvc/
Just to update this with more recent information for people hitting this from search engines - the wp-mvc plugin http://wordpress.org/extend/plugins/wp-mvc/ goes a long way to creating a mvc framework for plugin development. You can find out more here: http://wpmvc.org/documentation/70/tutorial/
Just to add to the list of options, (I'm admittedly biased as the author,) swpMVC is a fully featured, lightweight MVC framework, inspired by Rails, Sinatra, Express, and FuelPHP. It's thoroughly documented, and while I have used and enjoyed wp-mvc, I wanted something where the models were able to populate views themselves, including form controls for interacting with said models.
I put this together largely to reduce the amount of controller code required to put together an app on top of WordPress, and the result is a very fast and effective framework that runs inside WordPress. The models are based on PHP Activerecord and 8 models are included for existing WordPress data types, including Post, PostMeta, User, UserMeta, Term, and a few more. Modeling data is very easy thanks to the activerecord library, and I've enjoyed working with this framework immensely thus far.
Also ships with underscore PHP and PHP Quick Profiler (as seen in FuelPHP.)
RokkoMVC is a micro MVC framework built especially for WordPress. The project is meant to simplify AJAX functionality in WordPress applications, as well as bringing in all the other benefits of using models, views, and controllers to your theme.
I had a bash recently at creating a plugin that makes use of a simple view-controller system, and quite liked the results, so I separated the template stuff out to its own repo. It offers object-based controllers, passing variables locally to PHP templates, template fragments (templates within templates) and components (template fragments with their own sub-controller). All in two tiny classes!
Of course, I wrote this code thinking that no other WP developer had considered the problem before ;-).
It's far from mvc, there is no kinda-sorta thing like some people say, it's either MVC or not... The fact that you write logic on the view level doesn't qualify it as a mvc framework. The reason people use it - it's easy to learn, you don't need to be hardcore php programmer, they're lazy.

What's your recommendation for architecting GWT applications? MVC, MVP or custom messaging solution?

I just started a new GWT project for a client and I'm interested in hearing people's experience with various GWT MVC architectures. On a recent project, I used both GXT MVC, as well as a custom messaging solution (based on Appcelerator's MQ). GXT MVC worked OK, but it seemed like overkill for GWT and was hard to make work with browser history. I've heard of PureMVC and GWTiger, but never used them. Our custom MQ solution worked pretty well, but made it difficult to test components with JUnit.
In addition, I've heard that Google Wave (a GWT application) is written using a Model-View-Presenter pattern. A sample MVP application was recently published, but looking at the code, it doesn't seem that intuitive.
If you were building a new GWT application, which architecture would you use? What are the pros and cons of your choice?
Thanks,
Matt
It's worth noting that google has finally written out a tutorial for designing using the mvp architecture. It clarifies a lot of the elements from the google i/o talk listed above. Take a looK: https://developers.google.com/web-toolkit/articles/mvp-architecture
I am glad this question has been asked, because GWT desperatley needs a rails-like way of structuring an application. A simple approach based on best practices that will work for 90 % of all use-cases and enables super easy testability.
In the past years I have been using my own implementation of MVP with a very passive view that enslaves itself to whatever the Presenter tells him to do.
My solution consisted of the following:
an interface per widget defining the methods to control the visual appearance
an implementing class that can be a Composite or use an external widget library
a central Presenter for a screen that hosts N views that are made up of M widgets
a central model per screen that holds the data associated with the current visual appearance
generic listener classes like "SourcesAddEvents[CustomerDTO]" (the editor does not like the real symbols for java generics here, so I used thoe brackets), because otherwise you will have lots of the same interfaces who just differ by the type
The Views get a reference to the presenter as their constructor parameter, so they can initialize their events with the presenter. The presenter will handles those events and notify other widgets/views and or call gwt-rpc that on success puts its result into the model. The model has a typical "Property[List[String]] names = ...." property change listener mechanism that is registered with the presenter so that the update of a model by an gwt-rpc request goes to all views/widgets that are interested.
With this appraoch I have gotten very easy testability with EasyMock for my AsynInterfaces. I also got the ability to easily exchange the implementation of a view/widget, because all I had to rewrite was the code that notified the presenter of some event - regardless of the underlying widget (Button, Links, etc).
Problems with my approach:
My current implementation makes it hard to synchronize data-values between the central models of different screens. Say you have a screen that displays a set of categories and another screen that lets you add/edit those items. Currently it is very hard to propagate those change events across the boundaries of the screens, because the values are cached in those models and it is hard to find our whether some things are dirty (would have been easy in a traditional web1.0-html-dumb-terminal kind of scenario with serverside declarative caching).
The constructor parameters of the views enable super-easy testing, but without a solid Dependency-Injection framework, one will have some UGLY factory/setup code inside "onModuleLoad()". At the time I started this, I was not aware of Google GIN, so when I refactor my app, I will use that to get rid of this boilerplate. An interesting example here is the "HigherLower" game inside the GIN-Trunk.
I did not get History right the first time, so it is hard to navigate from one part of my app to another. My approach is not aware of History, which is a serious downturn.
My Solutions to those problems:
Use GIN to remove the setup boilerplate that is hard to maintain
While moving from Gwt-Ext to GXT, use its MVC framework as an EventBus to attach/detach modular screens, to avoid the caching/synchronization issues
Think of some kind of "Place"-Abstraction like Ray Ryan described in his talk at I/O 09, which bridges the Event-Gap between GXT-MVC and GWTs-Hitory approach
Use MVP for widgets to isolate data access
Summary:
I dont think one can use a single "MVP" approach for an entire app. One definetly needs history for app-navigation, a eventbus like GXT-MVC to attach/detach screens, and MVP to enable easy testing of data access for widgets.
I therefore propose a layered approach that combines these three elements, since I believe that the "one-event-mvp-system"-solution wont work. Navigation/Screen-Attaching/Data-Access are three separate concerns and I will refactor my app (move to GXT) in the following months to utilize all three event-frameworks for each concerns separately (best tool for the job). All three elements need not be aware of each other. I do know that my solution only applies for GXT-projects.
When writing big GWT apps, I feel like I have to reinvent something like Spring-MVC on the client, which really sucks, because it takes a lot of time and brain-power to spit out something elegant as Spring MVC. GWT needs an app framework much more than those tiny little JS-optimizations that the compiler-guys work so hard on.
Here is a recent Google IO presentation on architecting your GWT application.
Enjoy.
-JP
If you're interested in using the MVP architecture, you might want to take a look at GWTP: http://code.google.com/p/gwt-platform/ . It's an open source MVP framework I'm working on, that supports many nice features of GWT, including code splitting and history management, with a simple annotation-based API. It is quite recent, but is already being used in a number of projects.
You should have a look at GWT Portlets. We developed the GWT Portlets Framework while working on a large HR Portal application and it is now free and open source. From the GWT Portlets website (hosted on Google code):
The programming model is somewhat similar to writing JSR168 portlets for a portal server (Liferay, JBoss Portal etc.). The "portal" is your application built using the GWT Portlets framework as a library. Application functionality is developed as loosely coupled Portlets each with an optional server side DataProvider.
Every Portlet knows how to externalize its state into a serializable PortletFactory subclass (momento / DTO / factory pattern) making important functionality possible:
CRUD operations are handled by a single GWT RPC for all Portlets
The layout of Portlets on a "page" can be represented as a tree of WidgetFactory's (an interface implemented by PortletFactory)
Trees of WidgetFactory's can be serialized and marshalled to/from XML on the server, to store GUI layouts (or "pages") in XML page files
Other important features of the framework are listed below:
Pages can be edited in the browser at runtime (by developers and/or users) using the framework layout editor
Portlets are positioned absolutely so can use scrolling regions
Portlets are configurable, indicate when they are busy loading for automatic "loading spinner" display and can be maximized
Themed widgets including a styled dialog box, a CSS styled button replacement, small toolbuttons and a HTML template driven menu
GWT Portlets is implemented in Java code and does not wrap any external Javascript libraries. It does not impose any server side framework (e.g. Spring or J2EE) but is designed to work well in conjunction with such frameworks.

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