Pablo M. Cibraro (aka Cibrax)

La serie de videos que grabe con Miguel Angel Saenz y Ariel Schapiro de Microsoft Argentina acerca del proyecto “Liike” de Patterns & Practices para desarrollos de aplicaciones mobiles con HTML 5 ha sido publicada en channel9.

Apache Cordova is one of those projects that recently caught my attention for developing applications in mobile. This project previously known as PhoneGap was donated by Adobe to the Apache Foundation to be part of a new and attractive open source alternative for developing mobile applications.  If you haven’t heard of it before, it basically provides the required infrastructure to run native applications in different mobile platforms such as IOS, Android, and Windows Phone 7 using an hybrid approach with an embedded browser. There is a thin native layer that provides access to different native features in phone through an standard object model in JavaScript, so the developers can write their applications using HTML 5 and have access to different features through that model. Therefore, the two most important components in this project are the native layer and the JavaScript component model, which are supported across the different platforms.

A common scenario for many web applications running in the cloud is to integrate with existing systems through web services (no matter the messaging style they use). Although in these scenarios, an SLA is typically used as an agreement between the two parties to assure certain level of availability, many things can still fail. Therefore, it is always a good idea to have a mechanism in place to handle any possible error condition and retry the execution when it is possible.

Moving to the cloud can represent a big challenge for many organizations when it comes to reusing existing infrastructure. For applications that drive existing business processes in the organization, reusing IT assets like active directory represent good part of that challenge. For example, a new web mobile application that sales representatives can use for interacting with an existing CRM system in the organization.

In case you are developing a new web application with Node.js for Windows Azure, you might notice there is no easy way to debug the application unless you are developing in an integrated IDE like Cloud9. For those that develop applications locally using a text editor (or WebMatrix) and Windows Azure Powershell for Node.js, it requires some steps not documented anywhere for the moment.

Hypermedia is one of those concepts really hard to grasp when building Http aware APIs (or Web API’s). As human beings, we are constantly dealing with hypermedia in the existing web by following links or posting data from some forms that take us to a next level.

ASP.NET Web API provides a very similar model to MVC for resolving dependencies using a service locator pattern. What you basically do is to provide the implementation of that service locator to return any of the requested dependencies, and that implementation is typically tied to a DI container. 

The Http status codes for reporting errors to clients can mainly be categorized on two groups, client errors and server errors. Any status code under 500 is considered an issue generated by something wrong on the request message sent by the client. For example, 404 for resource not found, 400 for bad request (some invalid data in the request message) or 403 for forbidden (an unauthorized operation) are some of the most well know client errors.  On the hand, any other code over 500 is considered as a problem on the server side such as 500 for internal server error or 503 for server unavailable. This kind of error means that something unexpected happened on the server side while processing the request but it is not the client fault.