Introduction

The purpose of many systems is to retrieve data from a database and display it to the user. After the user has changed the data, the system stores the updates in the DB.
Since the flow of information is essential between the Db and the user interface, you might be inclined to bind these two ‘pieces’ together to reduce the amount of code and improve
application performance. However, this seemingly natural approach has some significant problems.

We face the speech

A first problem is that the user interface tends to change much more frequently than the data storage system.
Another problem with the coupling of data and user interface pieces is that business applications tend to incorporate business logic that goes well over the transmission of data.
To address and solve these and other problems have been introduced several architectural patterns such as MVC (Model – View – Controller).
MVC and MVP as MVVP represent patterns or templates to separate the User Interface and the corporate domain. Yet we can say that MVC defines a way of organizing user interface elements and services to businesses, without adding unwanted dependencies and improve the overall manageability of the products.
More specifically MVC is a pattern-oriented presentation; nTier and Layered architectures (which is what most people seem to indicate when they use the term “n-tier”) is
relate the physical and logical application.
Layered architecture does not need to be installed on a separate layer (tiers). Similarly, the MVC can be used for the presentation layer of an architecture Layered (and possibly multi-level ‘tiered’) or it can be used for monolithic application.

A reference to explore http://genehughson.wordpress.com/2012/01/09/layered-architectures-sculpting-the-big-ball-of-mud/

The first basic rule, if you want to remain closely linked to the philosophy of the model is that proper implementazionde MVC must be avoided dependencies (M) to Model (V) and view (C) Controller. This is the real ‘core’ of the pattern. Ultimately, if M has no dependency on V or C, the application is not ‘following the MVC pattern.

In MVC:

M does not have NO dependence C or V
C has no dependency on M and V
V dependence has only M

The idea is:

V raises event without knowing what Controller shall manage.
M changes without knowing what Controller or Vista if neither will.

As can be noted, C has dependencies with M and V. Thus, the elements of C can rely directly on elements of M and V (without any indirection or other model).

So the MVC (Model-View-Controller) divides an application into three components.

The MODEL contains the core functionality and data.
The VIEW displays information to the user.
The Controller handles user input.

View and Controller together form the user interface. A change in the propagation mechanism ensures consistency between the user interface and the model.

MVC and software layers

Martin Fowler defines the pattern “Layered Application” as a way to organize software into a set of logical layers for the purpose of managing dependencies and the creation
plug components. He mentions at least three layers: Presentation, Business and Data Access Domaian.
The MVC pattern defines an approach to the interaction between the components of the Business and Presentation Domain. So, it’s just a way to create a “connection” to connect two of all
these layers of software (MVC is not equivalent to the Three Layers). In addition, MVC is not provided with other relations between applizazioni such as persistence, security or scalability.

MVC and n-tier

Fowler and Trowbridge consider “n-tier” as a distribution model: a way to organize the infrastructure for running applications developed.
According to them, a web application can be distributed in three levels: client, web applications and data. In essence, it says that some components of the application can be deployed
on a set of client machines, other components of a whole host of web applications and other components in a set of server host data.
For solutions more stringent safety and operational requirements, you may want to consider some moving components to other additional levels.

Considering these three levels, MVC defines an approach to connect the components of presentation at the client (for example a mobile phone or internet applications)
with some components of the service-level web applications. MVC does not define anything about this interaction between the web, application layer and data layer
(MVC is not equivalent to the three levels).
The MVC pattern can be applied in applications that use only one level. For example, desktop development environments such as Eclipse and Netbeans apply the MVC pattern and
run on a single level.

Some Links

There is a web page with a summary of the patterns from the book by Martin Fowler, “Patterns of Enterprise Application Architecture (P of EAA)”
http://martinfowler.com/eaaCatalog/ e http://martinfowler.com/eaaDev/uiArchs.html

Trowbridge has published, in turn, an updated catalog in the book Microsoft: “Enterprise Solution Patterns Using Microsoft. NET”
http://msdn.microsoft.com/en-us/library/ff647095.aspx

Is possible to download the book in PDF format from Microsoft
http://www.microsoft.com/downloads/details.aspx?FamilyId=3C81C38E-ABFC-484F-A076-CF99B3485754&displaylang=en&displaylang=en

This is the link to Microsoft ‘Patterns & Practices’
link http://www.linkedin.com/redirect?url=http%3A%2F%2Fmsdn%2Emicrosoft%2Ecom%2Fen-us%2Flibrary%2Fff649643%2Easpx&urlhash=mt5m&_t=tracking_disc

CrismerLaPignola

Windows Azure Vs. Joomla:

during a hangout with one of the experts on Cloud Micrososft I had the opportunity to understand what microsoft offers in terms of cloud and in particular what Azure and how they can be exploited to CMS like Joomla, known open source. From the video specially recorded by Andrea Rossi, I hope to clarify ideas to others, users and readers of this blog. A special thanks to Flavio Vito Lorusso https://plus.google.com/u/0/110876671173148361468
who has taken the time to compare.

Some of the topics covered:

•  performance
• security
• WebMatrix
• Costs
• Quality of service
• Compatibility with CMS like Joomla but also other Open Source

Good vision.

CrismerLaPignola

RSS Feeds are a fantastic website feature that tend to be underused or misunderstood. I’m not going to cover the basics in this tutorial, so if you’ve never heard of RSS, watch RSS in Plain English by commoncraft.

There are two ways to use RSS feeds in Joomla. Firstly you can display feeds from third party websites and this is managed using the Newsfeeds component in the Joomla Administrator. The second feature is creating a feed of your content so visitors can become subscribers and get notified when you make updates to your website. It’s this second use of news feeds that I will discuss in this tutorial.

The easiest way to test this function is to use a web browser that notifies you when it finds a page containing a reference to an RSS feed. I’ll be demonstrating using Google Chrome which, when I last checked, doesn’t come with a notification option as standard. You have to go to the Chrome Web Store, search for RSS and install the RSS Subscription Notification by Google. Then when you visit a page that includes a reference to an RSS feed, the standard RSS icon is displayed towards the top right of the browser window.

Core Joomla RSS Feeds

This is a standard Joomla installation that includes the sample data. The home page does indeed display an RSS icon. And clicking this displays two types of feeds that when selected allow you to add the feed to your preferred RSS screen reader. So far, so good. But now let’s take a look at the example pages. When I chooseSingle Article, the RSS icon disappears. It’s also not there for Article Categories. But it returns for Article Category Blog, Article Category List and Featured Articles. This is normal Joomla behaviour. Category blog pages, category list pages and featured articles pages have a corresponding RSS feed. Other page types do not. I guess the thinking is that RSS feeds are about notifying people when a new article is created. This can happen on those type of pages, but not individual article pages.

Let’s take a look at the category blog page example again. When you look at the RSS feed for that page, you’ll see that it lists all articles in that category. Perhaps that makes sense technically, but for a lot of sites, it isn’t the experience you want to provide. It would be better to have a single feed for all your articles. That way the RSS feed will be the same on all pages and subscribers will get notified when an article is added to any category.

Free RSS Feed Extension

Doing this requires a free extension called Ninja RSS Syndicator available at Ninjaforge. Download the extension, but then go back and look for Addons and get the Ninja RSS Syndicator Module too. Install both of these via Extension Manager. Then go to Components - Ninja-rss-syndicator - Feeds - New. There is a distinct lack of documentation for this extension – did I mention it was free – but most of the defaults will be fine. Give it a name that corresponds to the feed contents. The feed I am creating will display all articles so I’ll call it All Articles. Then I recommend changing sort order to Created date descending which means the newest article will be displayed at the top of the list. Have a think about the rest of the options, and Save & Close.

At this stage, nothing has changed on the frontend. The default Joomla feeds are still displayed. Go to Module Manager and search for rss. Edit this and change the title to something like RSS Feed. Place it into your desired template position, make sure that the Status is Published and specify that the module should appear on all pages, or whatever you like. You can experiment with the various options, but the default settings will do in this example. Save the module and note that an RSS icon now appears in the position you specified. Clicking that icon activates the subscribe function which varies between web browsers.

Disable the Joomla Core Feeds

Activating the module also adds an RSS feed reference to the source code. This means when the visitor clicks the RSS icon in their browser, they get three options; the original two feeds and your new one. This may be what you want. This allows the visitor to subscribe to just the articles in a particular category or all articles. Personally I prefer to provide a single feed. To disable the standard Joomla feeds, return to Administrator and go to Article Manager - Options - Integration and change Show Feed Link to Hide. This should fix it in theory, but if you have a look now, it’s still the same. The sample data in Joomla overrides some of the global settings. If you find this happening on your pages, check the menu item for the page. Under Integration Options, change Show Feed Link to Use Global.

Now when I click the RSS icon, the browser doesn’t give me a choice and instead opens the subscription window. And that’s how to create your own Joomla RSS Feeds – for free! 

Richard Pearce for version english

Official Link :  http://www.buildajoomlawebsite.com/blog/tutorial/getting-started-with-rss-feeds 

CrismerLaPignola

This website was created with the aim of sharing information about the computer world by focusing on developing software solutions like Enterprise and Web Application. Also wants to introduce the use of open source tools and languages ​​as one of the best ways to get high quality results without spending huge sums due to licensing increasingly expensive.
Not meant to be exhaustive but to give input and general guidelines that can lead the reader to further information. Also wants to be a site informaizione and support, a useful tool to see at any time.

Here are some of the issues taken into consideration:

• General Computer Science

• General programming

• Microsoft technologies – desktop and web

• Open Source Technologies

• Database design

• Design Pattern

• Framework MVC

• SEO and Web Marketing

CrismerLaPignola