“LINQ to XML” in ASP.NET – Ajaxified XML Document Filtering
LINQ to XML is a new way to play with the XML data in .NET 3.5. It is actually an XML programming API that simplifies dealing with XML documents without any need to know about additional syntaxes such as XSLT and XPath. It is designed to be a cleaner, faster and lightweight API which at the same time has the key features from XSLT and XPath. According to MSDN, its public data model is aligned as much as possible with the W3C XML Information Set.
Sample XML Data and Its Filtering with “LINQ to XML”
For sampling purposes, I just created the following XML data and add it to my demo project:
My purpose is developing a simple ajaxified web application that has a dropdown with the country names and a literal that shows the capital city of selected country name from this dropdown. For this purpose, I created my server controls with some AJAX flavor as:
Then, I organized the Page_Load event as in the following in order to query over Countries.xml:
Pay attention to the usage of XDocument class from System.Xml.Linq namespace (which is already defined in the web.config file as default) in order to load the local Countries.xml file and the new casting and access methods (such as .Descendants and .Element that I used above).
Finally, after compilation the result on the browser should be like:
When “Belgium” is selected from the dropdown, literal will show the following with a partial rendering:
I generally work with SQL Server or Access in the data layers of my web applications, therefore I barely had a chance to put my hands on XSLT and XPath deeply. But, I can say that “LINQ to XML” as a data provider seems enough even powerful for me to handle many common XML programming tasks inside my code.
You can download the demo project via here.