WTF 3.12 : Coding

C# Coalesce Exploration

detlef — Tue, 09 Sep 2008 21:23:14 GMT

Recording some exploration notes on the C# Coalesce operator (??) and also trying out Leo Vildosola's Code Snippet plugin for Windows Live Writer.

   1: static private void Coalesce()

   2: {

   3:     object obj1 = null;

   4:     object obj2 = obj1 ?? string.Empty;

   5: }

   1: .method private hidebysig static void Coalesce() cil managed

   2: {

   3:     .maxstack 2

   4:     .locals init (

   5:         [0] object obj1,

   6:         [1] object obj2)

   7:     L_0000: nop

   8:     L_0001: ldnull

   9:     L_0002: stloc.0

  10:     L_0003: ldloc.0

  11:     L_0004: dup

  12:     L_0005: brtrue.s L_000d

  13:     L_0007: pop

  14:     L_0008: ldsfld string [mscorlib]System.String::Empty

  15:     L_000d: stloc.1

  16:     L_000e: ret

  17: }

18:

   1: static private void ManualCoalesce()

   2: {

   3:     object obj1 = null;

   4:     object obj2 = obj1 != null ? obj1 : string.Empty;

   5: }

   1: .method private hidebysig static void ManualCoalesce() cil managed

   2: {

   3:     .maxstack 2

   4:     .locals init (

   5:         [0] object obj1,

   6:         [1] object obj2)

   7:     L_0000: nop

   8:     L_0001: ldnull

   9:     L_0002: stloc.0

  10:     L_0003: ldloc.0

  11:     L_0004: brtrue.s L_000d

  12:     L_0006: ldsfld string [mscorlib]System.String::Empty

  13:     L_000b: br.s L_000e

  14:     L_000d: ldloc.0

  15:     L_000e: stloc.1

  16:     L_000f: ret

  17: }

18:

19:

Regular Expression Resources

detlef — Tue, 30 Oct 2007 16:16:37 GMT

A collection of regular expression tools and references for my reference. I will be incorporating this into my tools and reference list.

Tools

Expresso 3.0 - A great regular expression builder and analyzer tool.

The Regulator - A regular expression testing tool.

RegExBuddy - Builder for regular expressions. Linked with the Regular-Expressions.info reference site below.

References

Regular-Expressions.info - Nice online reference to regular expression syntax. See the RegExBuddy above.

VisiBone Regular Expressions Reference Card - Online reference card available. This site also has other great reference cards available.

Beautiful Code

detlef — Sat, 27 Oct 2007 20:50:20 GMT

I picked up Beautiful Code: Leading Programmers Explain How They Think from Borders last week and I have been enjoying it. It has awakened a need to play around with code again that is not directly related to my work. I like that the book is really a collection of essays. This separation of the topics makes it perfect for reading in short bursts and you are not stuck on a topic you are not interested in for too long. I have not hit a topic that I found boring yet so this has not posed a problem.

Host Application Code for Old XMLDocumentSplitter Class

detlef — Wed, 03 Oct 2007 16:13:41 GMT

I am including the code from my original host application for my XMLDocumentSplitter class. I will be updating this along with the utility class as well. It is interesting to see some of my coding habits from years ago.

Public Class frmMain
    Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "

' VS Generated Code Removed
#End Region

    Private m_XMLSplitter As New XMLDocumentSplitter()

    Private Sub btnSplit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSplit.Click
        If rbSplitByDocumentSize.Checked Then
            m_XMLSplitter.SplitType = XMLDocumentSplitter.SplitTypes.ByDocumentSize
            m_XMLSplitter.SplitSize = CType(txtDocumentSize.Text, Long)
        Else
            m_XMLSplitter.SplitType = XMLDocumentSplitter.SplitTypes.ByElementCount
            m_XMLSplitter.SplitSize = CType(txtElementCount.Text, Long)
        End If

        m_XMLSplitter.Split(New System.IO.StreamReader(txtSourceDocument.Text), AddressOf SplitHandler)

        MessageBox.Show(String.Format("Split '{0}' into {1} files.", txtSourceDocument.Text, m_XMLSplitter.SplitCount))
    End Sub

    Private Sub SplitHandler(ByVal count As Long, ByVal document As String)
        Dim stream_writer As New System.IO.StreamWriter(txtDestinationPath.Text & String.Format(txtDestinationFilenamePattern.Text, count))
        stream_writer.Write(document)
        stream_writer.Close()
    End Sub

    Private Sub FieldFields_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) _
            Handles txtSourceDocument.TextChanged, txtDestinationPath.TextChanged, txtDestinationFilenamePattern.TextChanged
        AdjustSplitButton()
    End Sub

    Private Sub AdjustSplitButton()
        If System.IO.File.Exists(txtSourceDocument.Text) And _
            System.IO.Directory.Exists(txtDestinationPath.Text) And _
            ValidPattern(txtDestinationFilenamePattern.Text) Then
            btnSplit.Enabled = True
        Else
            btnSplit.Enabled = False
        End If
    End Sub

    Private Function ValidPattern(ByVal pattern As String) As Boolean
        ' Pattern needs to contain '{0.*}' - very basic checking...
        Dim regexp As New System.Text.RegularExpressions.Regex("\{0.*\}")
        Return regexp.IsMatch(pattern)
    End Function

    Private Sub frmMain_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        AdjustSplitButton()
    End Sub

    Private Sub btnExit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExit.Click
        Me.Close()
    End Sub

    Private Sub RadioButtons_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) _
        Handles rbSplitByDocumentSize.CheckedChanged, rbSplitByElementCount.CheckedChanged
        If rbSplitByDocumentSize.Checked Then
            txtDocumentSize.Enabled = True : txtElementCount.Enabled = False
        Else
            txtDocumentSize.Enabled = False : txtElementCount.Enabled = True
        End If
    End Sub

    Private Sub btnSourceDocument_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSourceDocument.Click
        ' Get Source File Information
        dlgOpenFile.FileName = txtSourceDocument.Text
        If dlgOpenFile.ShowDialog() = DialogResult.OK Then
            txtSourceDocument.Text = dlgOpenFile.FileName
        End If
    End Sub

    Private Sub btnDestinationPath_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDestinationPath.Click
        ' Get Destination Path Information
        dlgSaveFile.InitialDirectory = txtDestinationPath.Text
        If dlgSaveFile.ShowDialog = DialogResult.OK Then
            txtDestinationPath.Text = dlgSaveFile.FileName
        End If
    End Sub
End Class

My Old XMLDocumentSplitter Class

detlef — Tue, 02 Oct 2007 15:58:28 GMT

I have resurrected my old XMLDocumentSplitter class from Code Project and am planning on updating it. These are on my list of things I need to bring this up to date:

Write both C# and VB.NET versions
Use an Event handler method for handling the chunks
Use the .NET 2.0 Framework and see what changes the have been made to the XmlTextReader and XmlTextWriter classes from 1.0
Better error handling
Some kind of unit testing framework to automatically test the class for regular and boundary conditions
Update GUI and command line host applications for the class
Updated article with what I have learned since I first wrote this class

Imports System.IO
Imports System.Xml

Public Class XMLDocumentSplitter
#Region "Private and Public Declarations"
    Private m_SplitType As SplitTypes
    Private m_SplitSize As Long
    Private m_SplitCount As Long
    Private m_TotalSplitSizes As Long

    Public Enum SplitTypes
        ByDocumentSize
        ByElementCount
    End Enum
#End Region
#Region "Constructors, Destructors and Initialization"
    Public Sub New(Optional ByVal split_type As SplitTypes = SplitTypes.ByDocumentSize, _
                    Optional ByVal split_size As Long = 512000)
        m_SplitType = split_type : m_SplitSize = split_size
    End Sub
#End Region
#Region "Properties"
    Public Property SplitType() As SplitTypes
        Get
            Return m_SplitType
        End Get
        Set(ByVal Value As SplitTypes)
            m_SplitType = Value
        End Set
    End Property

    Public Property SplitSize() As Long
        Get
            Return m_SplitSize
        End Get
        Set(ByVal Value As Long)
            m_SplitSize = Value
        End Set
    End Property

    Public ReadOnly Property SplitCount() As Long
        Get
            Return m_SplitCount
        End Get
    End Property

    Public ReadOnly Property TotalSplitSizes() As Long
        Get
            Return m_TotalSplitSizes
        End Get
    End Property
#End Region
#Region "Public Methods"
    Public Sub Split(ByVal text_reader As TextReader, ByVal handler As XMLDocumentSplitHandler)
        Dim document_header As String, document_footer As String
        Dim element_counter As Long = 0 : m_SplitCount = 0 : m_TotalSplitSizes = 0
        Dim empty_document As Boolean = False ' First time through is never an empty document
        Dim string_builder As New System.Text.StringBuilder
        Dim xml_text_writer As New XmlTextWriter(New StringWriter(string_builder))
        Dim xml_text_reader As New XmlTextReader(text_reader)
        xml_text_reader.Read() ' prime the pump

        ' Capture all of the items before the first element...
        While xml_text_reader.NodeType <> XmlNodeType.Element
            xml_text_writer.WriteNode(xml_text_reader, True)
        End While

        ' Prepare the document header and footer sections for use later...
        xml_text_writer.WriteStartElement(xml_text_reader.Name)
        xml_text_writer.WriteAttributes(xml_text_reader, True)
        document_header = string_builder.ToString & ">" ' Must close this manually...
        document_footer = vbCrLf & "</" & xml_text_reader.Name & ">" ' Create close element manually...
        xml_text_reader.Read() ' Skip past the root node...

        While Not xml_text_reader.EOF
            ' Only count the nodes that interest us...
            If Not IgnorableNodeType(xml_text_reader.NodeType) Then element_counter += 1 : empty_document = False
            xml_text_writer.WriteNode(xml_text_reader, True) ' Copy everything from the reader to the writer

            If (m_SplitType = SplitTypes.ByDocumentSize And (string_builder.Length - document_header.Length) >= m_SplitSize) OrElse _
                (m_SplitType = SplitTypes.ByElementCount And element_counter >= m_SplitSize) Then
                handler(m_SplitCount, string_builder.ToString & document_footer)
                m_TotalSplitSizes += string_builder.Length : m_SplitCount += 1 : element_counter = 0 ' Adjust the counters
                string_builder.Length = 0 : string_builder.Append(document_header) ' Reset the StringBuilder
                empty_document = True ' It is an empty document again...
            End If
        End While

        If Not empty_document Then
            handler(m_SplitCount, string_builder.ToString & document_footer)
            m_TotalSplitSizes += string_builder.Length : m_SplitCount += 1 ' Adjust the counters
        End If
    End Sub
#End Region
#Region "Private Methods"
    Private Function IgnorableNodeType(ByVal node_type As XmlNodeType) As Boolean
        If node_type = XmlNodeType.Whitespace OrElse _
            node_type = XmlNodeType.SignificantWhitespace OrElse _
            node_type = XmlNodeType.EndEntity OrElse _
            node_type = XmlNodeType.EndElement Then
            Return True
        Else
            Return False
        End If
    End Function
#End Region
End Class

Public Delegate Sub XMLDocumentSplitHandler(ByVal count As Long, ByVal document As String)

Revisiting Old Code

detlef — Mon, 01 Oct 2007 13:47:35 GMT

I was doing an ego search and found some of my old articles that I posted to Code Project a long time ago: Single Instance Application in VB.NET and XML Document Splitter Class. I have decided to take a look at the code and update it this week for Visual Studio 2005 and post it to my blog. I want to update these to see what new methods in the Framework exist and also to create both a VB.NET and C# version for reference.

I also need to post pieces of the code that I wrote for the Transform application that I wrote and some of the other help applications/classes/methods. Need to make an organized effort to collect and document all of these in one place.

0534.2690

Code Beautifiers

detlef — Thu, 27 Sep 2007 15:49:06 GMT

I might be doing some JavaScript client side programming for my next project, so I saw this My Great Free Online Beautifier for JavaScript that I need to save a reference to. I then starting thinking that I have seen other online code beautifiers before and wonder what was out on the net and found this Time-Savers: Code Beautifier And Formatter. I think the QuickHighlighter looks the most interesting. I will have to look through the rest of the entries and see what is useful.

I was testing how the beautified items would paste into Windows Live Writer from QuickHighlighter and I finally had to tell it to use embedded styles and pasted the html code directly into the html of the post. It looks good though:

output.WriteLine(spweb.Url + "/Lists/" + item.ParentList.Title + "/EditForm.aspx?ID=" + item.ID); 

Insert from Visual Studio is still easier, but for other quick code snippets that are not C# or VB.NET, I think this will be very useful. I have some t-sql snippets I need to capture.

TransformTester

detlef — Mon, 11 Jun 2007 12:40:41 GMT

I have added the source code and binaries for my TransformTester application to the site. The downloads can be found here. Of note, is that I started to add syntax highlighting and code completion to the application. I am still working on these classes to expand their coverage. Will post more about this application later.

Code Post Test #3

detlef — Sun, 10 Jun 2007 14:53:39 GMT

My third code post test:

        public Form1()

            InitializeComponent();

I am using the Live Writer Source Code Format Plug-In. So far I am undecided whether I will continue to use this plug-in or continue my search for a better tool. Currently, the code is not formatted when I paste it into Live Writer, but that is minor. I also am not that happy with some of the styles, but that should be easy to fix myself.

Another Code Post Test

detlef — Sun, 10 Jun 2007 14:49:04 GMT

Test 2

 public Form1()
        {
            InitializeComponent();
        }

Another Test

Test Post With Code

detlef — Sun, 10 Jun 2007 14:43:12 GMT

Testing how a post with code will look:

CompilerParameters compiler_parameters = new CompilerParameters();
            compiler_parameters.CompilerOptions = "/target:library";
            compiler_parameters.GenerateExecutable = false;
            compiler_parameters.GenerateInMemory = true;
            compiler_parameters.IncludeDebugInformation = false;

            // add some basic references
            compiler_parameters.ReferencedAssemblies.Add("mscorlib.dll");
            compiler_parameters.ReferencedAssemblies.Add("System.dll");

            CompilerResults results = new CSharpCodeProvider().CompileAssemblyFromSource(compiler_parameters, source_code);

            if (results.Errors.HasErrors)
            {
                rtbOutput.Clear();
                foreach (CompilerError error in results.Errors)
                {
                    rtbOutput.AppendText(string.Format("Line {0}, Column {1}: {2}\n", 
                        error.Line - source_start_lines, error.Column, error.ErrorText));
                }
            }
            else
            {   //get a hold of the actual assembly that was generated
                Assembly generated_assembly = results.CompiledAssembly;

                Module module = generated_assembly.GetModules()[0];
                Type type = module.GetTypes()[0];

                System.IO.StringWriter string_writer = new System.IO.StringWriter();
                object[] parameters = { string_writer };

                MethodInfo method_info = type.GetMethod("main");
                method_info.Invoke(null, parameters);

                rtbOutput.Clear();
                rtbOutput.AppendText(string_writer.ToString());
            }

Looks fine in Live Writer. Now to see what it actually looks like in CS.

Signs of a Crappy Programmer

detlef — Wed, 17 May 2006 15:05:00 GMT

Damien Katz has a great post that details the Signs You're a Crappy Programmer (and don't know it). I know I have been guilty of some of these over my career, but growth is recognizing a weakness and overcoming it.

Downloading File via FtpWebRequest in .NET 2.0

detlef — Thu, 13 Apr 2006 19:36:00 GMT

I am working on my first Code Snippet for Visual Studio 2005 and I decided to use my downloading a file via FtpWebRequest as my first snippet. Here is what I reduced the code to for inclusion in the snippet, but this is the first time that I am really utilizing the using keyword and wonder if this is correct:

FtpWebRequest request = (FtpWebRequest)FtpWebRequest.Create(@"ftp://ftp.somesite.com/somefile.txt");

request.Credentials = new NetworkCredential(@"ftp_user", @"ftp_password");

request.Method = WebRequestMethods.Ftp.DownloadFile;

using (FtpWebResponse response = (FtpWebResponse)request.GetResponse())

    using (StreamReader in_stream = new StreamReader(response.GetResponseStream()))

        using (StreamWriter out_stream = new StreamWriter(@"C:\localfile.txt", false))

            char[] buffer = new char[1024];

            while (!in_stream.EndOfStream)

                int bytes_read = in_stream.Read(buffer, 0, buffer.Length);

                out_stream.Write(buffer, 0, bytes_read);

My question is, do I need to call the Close methods on the Response and Stream objects on lines 17, 18 and 19 or does the Dispose call handle this? Will post the snippet file once I have cleaned this up some more.