Feeds

Project Astoria a hit at TechEd

Cleaner than SOAP

5 things you didn’t know about cloud backup

There was a buzz last week at TechEd about Project Astoria. The reason is that it promises to simplify development of web applications that deal with data - which is most of them. Astoria is a REST API for ADO.NET, and hooks into the new Entity Framework object-relational mapping layer. Therefore, it solves two problems in one go.

Here's a quick look at how it works. Let's assume you have a database which stores some information you want to present in your web application. Step one is to use Visual Studio to generate an Entity Data Model from your database.

Next, you tweak the model so it looks as close as possible to the objects you are storing. The framework should deal with the complexities of mapping collections to linked tables and so on.

Now you create a new ADO.NET Data Service (sadly, this may well be the official name for Astoria), and point the service at your model. By default a new service does not expose any data, for security reasons, but by writing an InitializeService method you can configure which objects you want to publish.

Run the service, and the objects in your model are now URL-addressable. It's pretty flexible. For example:

[serviceurl]/Products : return all the products (yes, you can do paging).

[serviceurl]/Products[2]: return the product with an ID of 2.

[serviceurl]/Products[Color eq 'Blue']: return all the blue products.

[serviceurl]/Customers[2]/Orders/:return all the orders for the customer with an ID of 2.

The data comes back in either ATOM or JSON format. Naturally, each element in the returned data includes its URL. Let's say you have an AJAX application so you are calling this service from JavaScript. Iterating through the results and populating an HTML list or table is easy, especially as Astoria includes a client JavaScript library. There is also a client library for .NET applications. You can also add or update data with HTTP PUT, or remove it with DELETE.

You can extend your Astoria API by adding arbitrary methods that have the [WebGet] (or presumably [WebPut] or [WebDelete]) attribute. You can also add "interceptors" - code that gets called just before requests are executed, to enable validation or custom security.

Presuming it works as advertised, Astoria is a more natural and concise way to handle data than SOAP web services, and easier than devising your own techniques. It should work well with other technologies such as Adobe's Flex. It will play nicely with mash-ups, since many other services out there use ATOM or JSON. It is a natural fit with AJAX and will work well with Silverlight - see here (Silverlight 1.1 Alpha required) for an example.

Astoria will not be finished in time for the initial release of Visual Studio 2008, though reading between the lines it might be done in time for SQL Server 2008. It will work with any database server for which there is an Entity Framework provider. I was assured that creating such a provider is relatively easy, if you already have an ADO.NET 2.0 provider, so it is reasonable to expect wide support.

I think this will be popular.

This article originally appeared in ITWriting.

Copyright (c) 2007, ITWriting.

A freelance journalist since 1992, Tim Anderson specialises in programming and internet development topics. He has columns in Personal Computer World and IT Week, and also contributes regularly to The Register. He writes from time to time for other periodicals including Developer Network Journal Online, and Hardcopy.

Secure remote control for conventional and virtual desktops

More from The Register

next story
BBC: We're going to slip CODING into kids' TV
Pureed-carrot-in-ice cream C++ surprise
China: You, Microsoft. Office-Windows 'compatibility'. You have 20 days to explain
Told to cough up more details as antitrust probe goes deeper
Windows 7 settles as Windows XP use finally starts to slip … a bit
And at the back of the field, Windows 8.1 is sprinting away from Windows 8
Linux turns 23 and Linus Torvalds celebrates as only he can
No, not with swearing, but by controlling the release cycle
Scratched PC-dispatch patch patched, hatched in batch rematch
Windows security update fixed after triggering blue screens (and screams) of death
This is how I set about making a fortune with my own startup
Would you leave your well-paid job to chase your dream?
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Endpoint data privacy in the cloud is easier than you think
Innovations in encryption and storage resolve issues of data privacy and key requirements for companies to look for in a solution.
Why cloud backup?
Combining the latest advancements in disk-based backup with secure, integrated, cloud technologies offer organizations fast and assured recovery of their critical enterprise data.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?