barcode programming in c# Figure 9-3. Accessing Northwind via the SQL Server data provider in visual basic

Generation ECC200 in visual basic Figure 9-3. Accessing Northwind via the SQL Server data provider

queries. Not only does this avoid confusion, but it also means that if you do switch to a case-sensitive installation, then it will not be necessary to alter the query.

We look at integrating the open source Jakarta Apache search engine Lucene with a portlet in 10. Your search engine should index as many of your content sources as possible, but it will probably need to be broken down into different collections for different classes of users. The metadata for the content will become fields in Lucene s search index for advanced searching. Commercial search engine vendors should provide portlets that plug into any portal server that implements the standard.

cmdnon.CommandText = sqldel;

Often, your first task in processing a concrete language is to bring the language fragments under the type discipline of F#. This section shows how to transform the data contained in the XML from the previous section into an instance of the recursive type shown here. This kind of type is usually called an abstract syntax tree (AST): open System.Drawing type Scene = | Ellipse of RectangleF | Rect of RectangleF | Composite of Scene list This example uses the types PointF and RectangleF from the System.Drawing namespace, although you can equally define your own types to capture the information carried by the leaves of the tree. Listing 9-1 shows a recursive transformation to convert XML documents like the one used in the previous section into the type Scene.

Data can be held in a memory-resident state called a cursor. It is like a table, as it has rows and columns of data, but that s where the similarity ends. There are no indexes, for example. A cursor is used to build up a set of data for processing one row at a time.

By default, all methods, properties, and events are passed through subclasses and can change. This can be used to modify the behavior of another MediaElement. Clients think they re working with a VideoElement when they re actually working with a ProxyElement that wraps a VideoElement. This is incredibly useful for plug-ins. Here are two examples of using ProxyElement:

The portlet container may buffer the output of the portlet for performance reasons. The portlet containers stores the portlet s output in a buffer. When the buffer is full, the portlet container will send the buffer s contents back to the end user s web browser. If the portlet is finished writing content, the portlet container will send the final incomplete buffer as well. For the most part, this buffering is going on behind the scenes of your portlet application. You may need greater control over output buffering if your portlet is taking a long time to accomplish a task, and the portlet is providing a status report. The portlet may set its requested buffer size with the setBufferSize() method on RenderResponse. The portlet container will provide a buffer that is the same size or greater. After content has been written to the portlet s output, setBufferSize() will throw an IllegalStateException.