Web Design: Essential Controls

Designing Web Interfaces Book - O'Reilly Webcast

View more presentations from Bill Scott. (tags: rich ajax)

Slide show from Bill Scott from his book Designing Web Interfaces.

Also, an awesome post showing 30 essential controls. Must get better at combining controls from Yahoo, and jQuery into .net framework. There's much better stuff out there.

CSLA for Silverlight

Just noticed this article by Rockford Lhotka in a blog feed regarding a new brand of CSLA for Silverlight.

Here's the CSLA site description of CSLA Light. Enables the transparent communication of the Silverlight XAML UI with CSLA.Net business objects.

Maybe good for a sample project.

User Interface Advice

Simple but strikingly true advice regarding application design.  If a user cannot find it.  It's not there.

I have often found myself getting lost in the myopic creation of great new functionality, without considering where it fits in the overall design.  Sometimes, without checking if the users of the application even use it?!?

Chunking Data Accross the Network

A recent project involved sending large PDF documents across several firewalls into an HTTP handler for display.  Unfortunately, the remoting service cannot handle more than 10 Mb of data at a time.  While the most elegant solution may be streaming through a WCF Service, this was not an option at this time.  The second most promising solution as chunking the data across the network.

Here's my implementation, where the server portion sits behind a firewall communicating through a remoting service to a HTTP Handler, which renders a PDF document.  This same technique could be used for any type of file especially considering constraints with File Uploader controls.

Server - ChunkBytes function takes three parameters: document ID (to look up path), Maximum chunk size, and offset position.

ChunkBytes(docID as integer, maxChunk as integer, offset as integer) as Byte()

'first convert file to document stream

Dim documentStream as FileStream = New FileStream(fileLocation, FileMode.Open, FileAccess.Read)

Dim newArray as Byte()

'if the offset position is greater than the length return Nothing

If offset > documentStream.length - 1 then

newArray = Nothing

Else

'create the chunk as a byte array

Dim byteCount as integer

If maxChunk > documentStream.length - offset

'if we're on the last chunk, the array size will be smaller

byteCount = documentStream.length - offset

Else

'otherwise set to maxChunk

byteCount = maxChunk

End If

'create the new array with the correct size

newArray = New Byte(byteCount - 1) {}

'position the file stream to the correct position

documentStream.Seek(offset, SeekOrigin.Begin)

'read the chunk from the filestream into the new array

documentStream.Read(newArray, 0, byteCount)

End If

Return newArray

End Function

The client in our case is on the HTTP Handler inside the ProcessRequest sub.  Each chunk is written directly to the http context, however in another setting you could collect the chunks in another array and output as needed.

'create the maximum chunk size the network can handle we're using 10 Mb

Dim maxChunk as Integer = 10 * 1024 * 1024

Dim offset as Integer = 0

'get the length of the document

Dim documentLength as Integer

'now get the first chunk

Dim documentBytes as Byte() = DocumentByte.ChunkBytes(ID, maxChunk, offset)

'keep getting the next chunk until the function returns nothing

Do Until documentBytes Is Nothing

'write the result to the context

Response.BinaryWrite(documentBytes)

'incriment the offset

offset += maxChunk

'get the next chunk

documentBytes = DocumentByte.ChunkBytes(ID, maxChunk, offset)

Loop

Image Rendering: Bicubic Interpolation

This article shows a quick fix for IE7 image rendering.  The CSS fix applies bicubic interpolation algorithm for image rendering.  I used it like this,     img {-ms-interpolation-mode:bicubic;}

I honestly had to look up this wiki article regarding bicubic interpolation.  

The first image demonstrates a bicubic interpolation implementation.

While the second image demonstrates a "nearest-neighbor" interpolation on the same data set.

Silverlight Toolkit

While I've built a simple Silverlight control, we didn't get to use it because they don't want customers to have to download the Silverlight.  

However, this could be very cool and an easier use of the technology with the Silverlight toolkit.  I use the Ajax toolkit everyday, I'm sure this one could be just as helpful.

Design Process

Great article in the Make blog regarding the design process.  Notice the loop in re-design and test/evaluate phase.  In my opinion, this iteration will consume the vast majority of development time.  We often refer to it as the refactoring stage.

This refactoring iteration is also the step which many project planners fail to allocate enough time for in their planning.