ASP.NET Garage

Ajax request

2009-05-14T08:21:00.000-07:00

Simple reusable asynchronous multibrowser ajax function.

Call a page by javascript and pass the html result to a function when it arrives (. The url to load by HTTP GET method, and the callback function name are passed as parameters. All the litteral content of the result page is passed as parameter.

Note: some security features, like in Firefox, can block AJAX request to other domains than the domain of the calling webpage (where the script is executed from).


function ajaxRequest(url, callbackFunction)
{
   var xmlhttp=false;
   /*@cc_on @*/
   /*@if (@_jscript_version >= 5)
    // JScript gives us Conditional compilation, we can cope with old IE versions.
    // and security blocked creation of the objects.
     try {
      xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
     } catch (e) {
      try {
       xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
      } catch (E) {
       xmlhttp = false;
      }
     }
    @end @*/
   if (!xmlhttp && typeof XMLHttpRequest!='undefined')
   {
     xmlhttp = new XMLHttpRequest();
   }
    xmlhttp.open("GET", url,true);
    if(callbackFunction != null)
    {
        xmlhttp.onreadystatechange=function()
        {
           if (xmlhttp.readyState  == 4)
               {
                   callbackFunction(xmlhttp.responseText);
               }
       }
      
    }
   xmlhttp.send(null);

}
function sampleCallBackFunction(httpResponseText)
{
   alert(httpResponseText);
}
// sample calls
//
ajaxRequest("http://www.someurl.com",sampleCallBackFunction);
ajaxRequest(document.location,sampleCallBackFunction);//show current page source

Parse HTML Table with RegEx in .NET

2009-03-25T05:17:00.000-07:00

This is used to parse an html table. Practical to obtain results from a web page, formatted in a table.

The algorithm requires to know the number of colums to parse. Then, using regex, it loops in all the lines of the tables, and the content of each column of theeese line is inside the m.Groups[index].Value.


public void ParseHtmlTable(string html)
{

 /// Basic html table pattern
 string columnPattern = @"\<TD[^\>]*\>([^\<]*)\<\/TD\>";
 string betweenColumnsPattern = @"[^\<]*";


 /// Construct the global pattern for a given nomber of columns
 int nbColums = 11;

 StringBuilder sbPattern = new StringBuilder();
 for (int i = 0; i < nbColums; i++)
 {
     sbPattern.Append(columnPattern);
     sbPattern.Append(betweenColumnsPattern);
 }
 sbPattern.Append(columnPattern);

 /// Parse the result 
 Regex r = new Regex(sbPattern.ToString(), RegexOptions.IgnoreCase);

 foreach (Match m in r.Matches(html))
 {
     // example
     string insideCell1 = m.Groups[0].Value;
     string insideCell2 = m.Groups[2].Value;

     /// do things..


 }
}

Helper library to read CSV file

2009-03-20T05:42:00.000-07:00

Here is an interesting and very well done library to read CSV files, fast and without problems:

http://www.codeproject.com/KB/database/CsvReader.aspx

With this library, excel sheets can be save as CSVs and opened safely by any .NET application without any other dependencies (jet provider, office automation or else).

Delimited string helper class in C#

2009-02-13T07:50:00.000-08:00

Build delimited strings with less code!

Having to build a string with elements delimited with special characters for a CSV file, a HTTP GET request or any other purpose?
How many times did you made a loop to construct the string, having to user a flag to check if the delimiter have to be added, either at the beginning or the end or the string, to make sure chere is not an intrusive delimiter in the result? To make sure the string don't have the delimiter at the beginning or at the end?

This simple class uses a StringBuilder to construct a key / value string delimited with a given character or string just between elements.


using System;
using System.Text;


/// <summary>
/// To construct a string delimited only between elements.
/// 
/// Simple helper class to construct dynamically a delimited string
/// with the delimiter inserted automatically only between elements,
/// not at the beginnig nor at the end of the resulting string.
///
/// Uses a StringBuilder as the inner builder.
/// Denis Sauvé
/// </summary>
public class DelimitedStringBuilder
{
    protected string delimiter = null;
    protected StringBuilder sb = new StringBuilder(); 
// inner StringBuilder, as StringBuilder class cannot be inherited
    /// <summary>
    /// New instance of a DelimitedStringBuilder with delimiter between elements
    /// </summary>
    /// <param name="delimiter">delemiter to use (",", "\n", etc)</param>
    public DelimitedStringBuilder(string delimiter)
    {
        this.delimiter = delimiter;
    }
    public void Append(string stringToAppend)
    {
        if (sb.Length >0)
            if (delimiter != null) sb.Append(delimiter);
        sb.Append(stringToAppend);        
    }
    public override string ToString()
    {
        return sb.ToString();
    }
    public StringBuilder InnerStringBuilder
    {
        get
        {
            return this.sb;
        }
    }

}

Note: you have to make sure the delimiter is not in the keys nor in the values... But tThe Append() method could be modified easilly to check that.

Simple XML validation helper using XmlReader

2008-11-20T11:51:00.000-08:00

Purpose: simply validate a xml file against a xsd file, in C#.

I would appreciate a one single line validation method from one of the multiple xml .NET classes, but there seems to be none with the framework. I fouded some examples too complicated for nothing on the web. So I created this helper.

It can be used in two ways:

1- Static single line call:


bool success = XMLValidationHelper.Validate("myFile.xml", "mySchema.xsd");

2- Using helper object to collect the first error message occured:


XMLValidationHelper validator = new XMLValidationHelper("myFile.xml", "mySchema.xsd");
validator.Validate();
if (!validator.IsValid)
{
 // do something...

}

Here is the class:


using System;
using System.Xml;
using System.Xml.Schema;
using System.Text;

/// <summary>
/// Helper class to check a XML against a XSD file
/// </summary>
public class XMLValidationHelper
{

   string xmlFileName, xsdFileName;
   string exceptionMessage;
   bool isValid = false;

   public string ExceptionMessage
   {
       get { return exceptionMessage; }
       set { exceptionMessage = value; }
   }

   public XMLValidationHelper(string xmlFileName, string xsdFileName)
   {
       this.xmlFileName = xmlFileName;
       this.xsdFileName = xsdFileName;
   }

   /// <summary>
   /// Global validation state of the xml against the xsd
   /// </summary>
   public bool IsValid
   {
       get { return isValid; }
       set { isValid = value; }
   }

   /// <summary>
   /// Read the document and collects the validation exceptions if any.
   /// </summary>
   /// <returns></returns>
   public bool Validate()
   {

       XmlReader schemaReader = XmlReader.Create(this.xsdFileName);

       /// validation settings
       XmlReaderSettings settings = new XmlReaderSettings();
       settings.ValidationType = ValidationType.Schema;
       settings.ValidationFlags =
           System.Xml.Schema.XmlSchemaValidationFlags.ReportValidationWarnings;
       settings.Schemas.Add("", schemaReader);


       XmlReader myReader = XmlReader.Create(this.xmlFileName, settings);
       this.isValid = true;
       try
       {
           while (!myReader.EOF)
               myReader.Read();

       }

       catch (System.Xml.Schema.XmlSchemaException validationException)
       {
           this.isValid = false;
           this.exceptionMessage = validationException.Message;
       }
       finally
       {
           schemaReader.Close();
           myReader.Close();
       }
       return this.isValid;
   }


   public static bool Validate(string xmlFileName, string xsdFileName)
   {
       XMLValidationHelper instantHelper = new XMLValidationHelper(xmlFileName, xsdFileName);
       return instantHelper.Validate();
   }


}

Capturing strings between stopwords

2008-04-17T16:28:00.000-07:00


private string StringBetween(string beginTag, string endTag, string texteToParse)
{
    System.Collections.Specialized.StringCollection coll = StringsBetween(beginTag, endTag, texteToParse);
    if (coll.Count == 0) return "";
    else return coll[0];
}
private System.Collections.Specialized.StringCollection StringsBetween(string beginTag, string endTag, string texteToParse)
{
    System.Collections.Specialized.StringCollection result = new System.Collections.Specialized.StringCollection();
    int pos1, pos2;
    pos1 = 0;
    pos2 = -1;
    pos1 = texteToParse.IndexOf(beginTag);
    while (pos1 > -1)
    {
        pos2 = texteToParse.IndexOf(endTag, pos1 + beginTag.Length);
        if (pos2 > -1)
        {
            result.Add(texteToParse.Substring(pos1 + beginTag.Length, pos2 - (pos1 + beginTag.Length)));
            pos1 = texteToParse.IndexOf(beginTag, pos2 + endTag.Length);

        }
        else
            pos1 = -1;

    }
    return result;
}

Simple way to create a Culture in .NET

2008-02-28T12:28:00.000-08:00

Here is the simplest way to create a new culture in .NET, from an existing culture.

I needed a way to have french format dates (YYYY-MM-DD) and dot symbol (.) as decimal separator in an web application. Since javascript only recognize dot as decimal separator, having to use french cultures, either "fr-FR" or "fr-CA", is a pain because the decimal specified in theese is the coma. I wanted everything from the french culture, but a dot as decimal separator, and there is no way to do this without creating a new culture.

A new culture can be created from scratch. Here is a detailed article about this.

However, the following code simply copy an existing culture, changes it, and register in with a new name ("fr-CA-QC").

The process of revistering required administrator privilege on the machine where the code is running. The code below only have to be run once.


/// Original culture
CultureInfo cultureInfo = new CultureInfo("fr-CA");
RegionInfo regionInfo = new RegionInfo(cultureInfo.Name);

/// New Culture, with a new name ("fr-CA-QC")
/// if culture already exists, we need to unregister it for overwriting:
/// CultureAndRegionInfoBuilder.Unregister("fr-CA-QC");
CultureAndRegionInfoBuilder builder =
  new CultureAndRegionInfoBuilder("fr-CA-QC",
  CultureAndRegionModifiers.None);

// load in the data from the original culture and region
builder.LoadDataFromCultureInfo(cultureInfo);
builder.LoadDataFromRegionInfo(regionInfo);

// make custom changes to the culture
builder.NumberFormat.NumberDecimalSeparator = ".";
builder.NumberFormat.CurrencyDecimalSeparator = ".";

/// Create this culture on this computer (NEED ADMINISTRATOR PRIVILEGES)
builder.Register();

This can be executed in a simple windows or console application. After that, any application running on the same computer or server can use this new culture with the name defined above.

Now, I just have to include theese attributes in my web.config files and I will no more have culture problems:


<globalization culture="fr-CA-QC" uiCulture="fr-CA-QC" ...

Object property/fields cloner

2008-02-05T12:08:00.000-08:00

Here is a class using reflection to transfer property or field values from an object to another, instead of copying values one by one like this:

b.Address = a.Address
b.Age = a.Age
b.Color = a.Color
b.Surname = a.Surname
b.Boss = a.Boss
[...]

Instead, this helper method will be used like this:
PropertyCopier.CopyPropertiesToTargetObject(a,b)

That's it. Object b now have same property values as a.


Imports System.Reflection

''' <summary>
''' Helper class using reflection to copy all fiels and/or properties
''' from a object A to object B
''' </summary>
''' <remarks></remarks>
Public Class PropertyCopier

    ''' flags to get all instance fields, even privates
    Private Shared flags As BindingFlags = BindingFlags.NonPublic Or BindingFlags.[Public] Or BindingFlags.Instance

#Region " To copy object property values "

    ''' <summary>
    ''' Copy all property values from sourceObject to targetObject
    ''' Private and public properties values will be cloned from sourceObject to targetObject when property name exists on the two object
    ''' </summary>
    ''' <param name="sourceObject">Oject from which fields values will be copied</param>
    ''' <param name="targetObject">Object which will have copied property values</param>
    ''' <remarks>
    ''' By default, only properties having same value types are cloneed
    ''' </remarks>
    Public Shared Sub CopyPropertiesToTargetObject(ByVal sourceObject As Object, ByVal targetObject As Object)
        CopyPropertiesToTargetObject(sourceObject, targetObject, True)
    End Sub

    ''' <summary>
    ''' Copy all property values from sourceObject to targetObject
    ''' Private and public properties values will be cloned from sourceObject to targetObject when property name exists on the two object
    ''' </summary>
    ''' <param name="sourceObject">Oject from which fields values will be copied</param>
    ''' <param name="targetObject">Object which will have copied property values</param>
    ''' <param name="sameValueTypesOnly">If true, only property having the same type of value (ex: String, CustomClassType, etc) will be cloned</param>
    ''' <remarks></remarks>
    Public Shared Sub CopyPropertiesToTargetObject(ByVal sourceObject As Object, ByVal targetObject As Object, ByVal sameValueTypesOnly As Boolean)
        '''' getting all properties from two objects
        Dim sourceFields As FieldInfo() = sourceObject.[GetType]().GetFields(flags)
        Dim targetFields As FieldInfo() = targetObject.[GetType]().GetFields(flags)

        Dim tempValue As Object
        For Each sourceField As FieldInfo In sourceFields
            For Each targetField As FieldInfo In targetFields
                If sourceField.Name = targetField.Name Then
                    '' Same property name => value to copy?
                    tempValue = sourceField.GetValue(sourceObject)
                    ' If same value type between object, or not strict copy asked
                    If tempValue.GetType() Is targetField.GetValue(targetObject).GetType() Or Not sameValueTypesOnly Then
                        Try
                            targetField.SetValue(targetObject, tempValue)
                        Catch ex As Exception
                            If sameValueTypesOnly Then Throw
                            System.Diagnostics.Debug.WriteLine(ex.ToString())
                        End Try
                    End If
                End If
            Next
        Next
    End Sub
#End Region

#Region " To copy object fields values "
    ''' <summary>
    ''' Copy all fields values from sourceObject to targetObject
    ''' Private and public field values will be cloned from sourceObject to targetObject when fields name exists on the two object
    ''' </summary>
    ''' <param name="sourceObject">Oject from which fields values will be copied</param>
    ''' <param name="targetObject">Object which will have copied values</param>
    ''' <remarks>
    ''' By default, only fields having same value types are cloneed
    ''' </remarks>
    Public Shared Sub CopyFieldsToTargetObject(ByVal sourceObject As Object, ByVal targetObject As Object)
        CopyFieldsToTargetObject(sourceObject, targetObject, False)

    End Sub
    ''' <summary>
    ''' Copy all fields values from sourceObject to targetObject
    ''' Private and public field values will be cloned from sourceObject to targetObject when fields name exists on the two object
    ''' </summary>
    ''' <param name="sourceObject">Oject from which fields values will be copied</param>
    ''' <param name="targetObject">Object which will have copied values</param>
    ''' <param name="sameValueTypesOnly">If true, only fields having the same type of value (ex: String, CustomClassType, etc) will be cloned</param>
    ''' <remarks></remarks>
    Public Shared Sub CopyFieldsToTargetObject(ByVal sourceObject As Object, ByVal targetObject As Object, ByVal sameValueTypesOnly As Boolean)
        '''' Getting fields from source & target objects
        Dim sourceFields As PropertyInfo() = sourceObject.[GetType]().GetProperties(flags)
        Dim targetFields As PropertyInfo() = targetObject.[GetType]().GetProperties(flags)
        Dim tempValue As Object

        '''' Searching match between objects property names
        For Each sourceField As PropertyInfo In sourceFields
            For Each targetField As PropertyInfo In targetFields
                If sourceField.Name = targetField.Name Then
                    '' Same field name => value to copy?
                    tempValue = sourceField.GetValue(sourceObject, Nothing)

                    ' If same value type between object, or not strict copy asked
                    If tempValue.GetType() Is targetField.GetValue(targetObject, Nothing).GetType() Or Not sameValueTypesOnly Then
                        Try
                            targetField.SetValue(targetObject, tempValue, Nothing)
                        Catch ex As Exception
                            If sameValueTypesOnly Then Throw
                            System.Diagnostics.Debug.WriteLine(ex.ToString())
                        End Try
                    End If

                End If
            Next
        Next
    End Sub
 
#End Region


End Class

SQL transaction & error handling template

2008-01-25T10:38:00.000-08:00

Here is a small template to execute a SQL statement in a transaction scope, with a rollback if an error occured.


BEGIN TRAN
/*
( SQL CODE TO EXECUTE HERE)
*/
GO
IF (@@ERROR = 0)
BEGIN
   COMMIT
   PRINT 'EXECUTION COMPLETED WITH SUCCESS'
END
ELSE
BEGIN
   ROLLBACK
   PRINT 'ERROR HAS OCCURED'
END

Some tools

2007-11-29T09:31:00.000-08:00

Here are somme useful tools I use:

Pure text (copy-paste in windows)
magic iso (virtual drive like)
win diff (file & folder comparer, comes with VS)
ndepend (profiler .net?)
web development helper

Expresso (regular expression ide)
Notepad ++
SQL Prompt (Intellisense in sql editors)
slick run
Gadwin System Print Screen (free & easy screen shot tool)

VS Plug-in:
Smart Paster (paste as comment, as stringbuilder, etc)
Resharper

Binding a Windows form to a TableAdapter through a Web Service

2007-09-04T11:45:00.001-07:00

How can I use a TableAdapter object in a Windows Form aplication, when this TableAdapter object is returned from a Web Service? It's simple, but...

I wanted a simple thing:
1- define a TableAdapter in a Web Service project, to get a typed DataSet from the BD
2- return this TableAdater in a WebMethod
3- use the TableAdapter returned by the web service from a DataGridView in a Windows form application (referencing the web service, of course).

I tried many combinations before getting this worked, playing with objects and properties, and googling, and playing again... There is finally a recipe that works:

On the web service side:

Create a TableAdapter (by dragging adatabase table from the werver explorer and settinga select method). This create a DataSet (name of the *.xsd file), a DataTable (name in the top of the box) and a TableAdapter (with a "TableAdapter" suffix after the DataTable name).
Create a web method returning an instance of the new DataTable.

On the windows application side:

In the Windows client project, add a Web Reference to the class of the web service (like the default name "Service1").
Next, go on the design view of the web form. On the toolbox pane, some items are automatically added. There should be an item with the DataSet used in the web service; the name will be the "*.xsd" file name, not the DataTable or the TableAdapter name (default will be "DataSet1"). This should be in a section of the toolbox labeled with the web service namespace ("MyWebService components"). Drag this component on the web form. A DataSet object will be created.
Drag a BindingSource on the web form
In the properties of the new BindingSource object, set the datasource to the new DataSet objet. In the DataMember drop down list, you can now choose the name of the DataTable (similar to the TableAdapter name) within the DataSet.
In the DataGridView control properties, set the DataSource to the new DataBindingSource object.
All properties shoud now be ok.

To get the data populating the DataGridView on load, there is a line to write.In the Load() event of the form, add something like
Me.BindingSource1.DataSource = New [WebReferenceAliasName].[ServiceName]().[WebMethodName]()

It works fine this way.

Upcasting an object "for real"

2007-08-31T08:01:00.000-07:00

This week, I had a problem with serialization in a web service. Theorically, any serializable object or object collection can be send or received by a web service. The problem occured when the web service's tried to send a object collection including objects of type A and objects of type B inherited from A. While it tried to serialize the collection (an array or a typed list) as a collection of type A, the runtime throwed this exception:

System.InvalidOperationException: The type [inheritedType] was not expected. Use the XmlInclude or SoapInclude attribute to specify types that are not known statically.

Here is what happened (as I undersand): The SOAP protocol defines a strict serialisation format constructed with the declared type in the [WebMethod] functions, and this format is in the web service's contract. That's why the formatter refuses to serialise inherited types. For example, if type A have a Name and a Id attributes, the web service returning a A object defines theese two attributes it it's SOAP contract. But if the service tries to send a B object, inherited from A but having a added Employer attribute, the formatter will normally want to serialize it with this Employer attribute, whitch is not in the SOAP contract. That is why the exception is throwned.

Normally, upcasting objects is about upcasting reference, not instances. In other words, the program can use an object of type B as if it was an object of type A, but the .net runtime kows it is a object of type B. If you observe an upcasted or downcasted object with the compiler, you will see that the runtime can tell the original type.

Thas is why a object of type B can be upcasted to its parent class type A, then downcasted to type B and still preserve it's properties restricted to class B.

Now, how can I face my web service serialization problem without touching the serialisation process itself ? The serialization can be customized, but that's not what I wanted. I needed a process to handle this particular casting problem in a generic way. That's why I made a class to transform an object of type b in a new object of it's parent type and still preserve it's values. The class uses generic and reflection to convert an object B to a new object A having it's original field values. Note that by reflection, we can access objects private fields and set their values.

Here is the class:


/// <summary>
/// Helper class to Upcast an object to it's parent type in a definitive way.
/// To get an objet with a runtime type of the target parent type.
/// 
/// By reflection, it gets child instance fields values (event privates) 
/// and assign them to a new instance of the given parent class.
/// </summary>
/// <typeparam name="ParentClass">Class to upcast object to</typeparam>
public class InstanceUpCaster<ParentType>
    where ParentType : new()
{
    /// parent class fields
    FieldInfo[] fParents;

    /// flags to get all instance fields, even privates
    BindingFlags flags = BindingFlags.NonPublic |
            BindingFlags.Public | BindingFlags.Instance;
  
    /// <summary>
    /// Getting target class fields
    /// </summary>
    public InstanceUpCaster()
    {            
         fParents = typeof(ParentType).GetFields(flags);           
    }

    /// <summary>
    /// Convert the object to a new object of the parent class.
    /// Assign field values of the child instance to the new instance, 
    /// if theese fiels exists in the parent type.
    /// (public and private fields can be set by reflection)
    /// </summary>
    /// <param name="instance">Object to upcast to ParentType</param>
    /// <returns>New object with same values (where possible in this type)</returns>
    public ParentType ToParentClassInstance(ParentType childTypeObject)
    {
        /// Object already of the wright type (not derived) ?
        if (childTypeObject.GetType() == typeof(ParentType)) return childTypeObject;

        // No -> new object to upcast to
        ParentType newObject = new ParentType();                       
        
        /// transfering child field values to new object
        FieldInfo[] fChilds = childTypeObject.GetType().GetFields(flags);
        object tempValue;
        foreach (FieldInfo fParent in fParents)
        {
            foreach (FieldInfo fChild in fChilds)
            {
                if (fParent.Name == fChild.Name)
                {
                    tempValue = fChild.GetValue(childTypeObject);
                    if (tempValue != null)
                        fParent.SetValue(newObject, tempValue);
                }
            }
        }

        return newObject;
    }
}

Creating a HTTP POST from in C#

2007-07-04T10:52:00.000-07:00

Here is a way to make a HTTP request to a web page with the POST method.
Use this method with parameters formatted like in GET method.

Example : result = PostPage("www.mypage.aspx", "id=2&name=Paul&amp;age=33");

public string PostPage(string url, string params)
      {
          byte[] dataToPost = new ASCIIEncoding().GetBytes(params);
 

          HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create(url);
          myRequest.Method = "POST";

          //Request properties 
          myRequest.ContentType = "application/x-www-form-urlencoded";
          myRequest.ContentLength = dataToPost.Length;

          //Writing data in stream
          Stream myStream = myRequest.GetRequestStream();
          myStream.Write(dataToPost, 0, dataToPost.Length);
          myStream.Close();

          //Getting response 
          WebResponse myResponse = myRequest.GetResponse();

          //Reading it
          Stream responseStream = myResponse.GetResponseStream();                
          StreamReader streamReader = new StreamReader(responseStream);
          string result = streamReader.ReadToEnd();
        

          //closing all
          streamReader.Close();
          responseStream.Close();
          myResponse.Close();
          myStream.Close();

          return result;
      }

Simple HTTP request and response

2007-07-04T10:45:00.000-07:00

For getting programmatically the HTML content of a web page:


using System.Net;
        
public string GetPage(string pageToGet)
        {
            HttpWebRequest request= (HttpWebRequest)HttpWebRequest.Create(pageToGet);            
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();

            return new streamReader(response.GetResponseStream()).ReadToEnd();
            
        }

Class for storing QUERY STRING in XML files and manage query parameters collection

2007-07-04T10:21:00.001-07:00

I recently needed to reuse HTTP query for a web robot, and I did'nt want to use a complex string like this one: "title=Using%20the%20Web%20Client%20Software%20Development%20Package&referringTitle=Getting%20Started"

I wanted to use a readable and reusable representation of a HTTP query that could be easilly serializable in files, easy to generate from a query string, easy to change in code or in files.

A simple StringDictionary would have been perfect, but unfortunately, dictionary collections are not serializable in .NET. I made a class that extends StringDictionary whitch write itself in simple XML format. The format is like this:

<MyQueryName>
<myfirsparamname>myFirsParamValue</myfirsparamname>
<postid>33</postid>
....

Two methods helps work with GET queries: ones (LoadValuesFromQueryString) loads the inner collection with name-values parameters frow a standard query string, and the other one, ToQueryString(), converts the object to a standard query string representation.

This class can be use to reuse, save, adapt and modify query strings.

Note: comments are in french, but method names are in english and should be self-describing enough.


using System;
using System.Collections.Generic;
using System.Text;
using System.Xml;


/// <summary>    
/// Objet représentant les champs d'un formulaire html (pour POST ou GET)
/// qui contient essentiellement une collection de clés/valeurs
/// 
/// À utiliser pour représenter, sauvegarder et produire des requêtes HTTP.
/// On peut ainsi sauvegarder les requêtes HTTP en fichier xml, les modifier, puis les réutiliser.
/// 
/// Des méthodes de sauvegarde en fichier en format XML ont été mise pour contourner
/// le manque de possibilité de sérialiser les collections telle que le StringDictionary
/// </summary>
public class FormDefinition : System.Collections.Specialized.StringDictionary
{

    string _nom = "";
    public FormDefinition(string nom)
    {
        this._nom = nom;
    }
    /// <summary>
    /// Convertit la collection de paramètres/valeurs en query string normal
    /// </summary>
    /// <returns></returns>
    public string ToQueryString()
    {
        StringBuilder sb = new StringBuilder();
        foreach (string k in this.Keys)
        {
            sb.Append(k + "=" + System.Web.HttpUtility.UrlEncode(this[k]) + "&");
        }
        return sb.ToString();
    }
    /// <summary>
    /// Initialise la collection de paramètres/valeurs à partir d'un query string
    /// </summary>
    /// <param name="query"></param>
    public void LoadValuesFromQueryString(string query)
    {
        if (query.IndexOf("?") > -1)
            query = query.Substring(query.IndexOf("?"));
        string[] queryParams = query.Split('&');

        string[] cleValeur;
        foreach (string parmametre in queryParams)
        {
            cleValeur = parmametre.Split('=');
            this.Add(cleValeur[0], System.Web.HttpUtility.UrlDecode(cleValeur[1]));
        }

    }
    /// <summary>
    /// Charge un objet FormDefinition à partir de sa représentation XML en fichier
    /// </summary>
    /// <param name="nomFichier"></param>
    /// <returns></returns>
    public static FormDefinition LoadFromFile(string nomFichier)
    {
        FormDefinition formulaire;
        XmlDocument doc = new XmlDocument();

        doc.Load(nomFichier);
        formulaire = FormDefinition.FromXmlDocument(doc);

        return formulaire;
    }
    /// <summary>
    /// Sauvegarde l'objet dans un fichier en représentation XML
    /// </summary>
    /// <param name="nomFichier"></param>
    public void SaveToFile(string nomFichier)
    {
        XmlDocument doc = this.ToXmlDocument();
        doc.Save(nomFichier);

    }
    /// <summary>
    /// Formatte l'objet (le StringDictionnary) en xml 
    /// </summary>
    /// <returns>xml avec balises nommées d'après les paramètres, contenant les valeurs</returns>
    protected XmlDocument ToXmlDocument()
    {
        XmlDocument doc = new XmlDocument();
        XmlElement root = doc.CreateElement(this._nom);
        doc.AppendChild(root);
        foreach (string k in this.Keys)
        {
            XmlElement nod = doc.CreateElement(k);
            nod.InnerText = this[k];
            root.AppendChild(nod);

        }
        return doc;
    }

    /// <summary>
    /// Construit l'objet à partir de la représentation xml
    /// </summary>
    /// <param name="doc"></param>
    /// <returns>Objet initialisé</returns>
    protected static FormDefinition FromXmlDocument(XmlDocument doc)
    {
        FormDefinition formulaire = new FormDefinition(doc.FirstChild.Name);

        foreach (XmlNode enfant in doc.FirstChild.ChildNodes)
        {
            formulaire.Add(enfant.Name, enfant.InnerText);
        }

        return formulaire;
    }



}

Unable to start debugging on the Web server

2007-05-29T12:02:00.000-07:00

Got this message?

Here is a complete troubleshooting page from MDSN:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dv_vstechart/html/vsdebug.asp

If you use the framework 1.1 , you may have to reinstall asp.net:
C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322\aspnet_regiis -i

If the probleme persist, you may have to reinstall Visual Studio, or even the framework...

Reading an Excel file as a DataTable

2007-03-26T12:22:00.000-07:00

This method open a Excel file and retun it as a datatable.
It uses oleDB, wich is very powerful.

If your columns contains headers, they will be read as datacolumn names. This way, you can access datarows with theese names as indexers, ex: value = myRow("myColumnName").


Protected Function GetDatatableFromExcel(ByVal fileName As String, ByVal sheetName As String) As DataTable
  Dim conn As System.data.oledb.OleDbConnection
  Dim dataResult As New DataTable
  Try
  conn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" _
  + fileName + ";Extended Properties=Excel 8.0;")
  conn.Open()

  Dim command As New System.Data.OleDb.OleDbCommand(" SELECT * FROM [" + sheetName + "$]")
  command.Connection = conn
  Dim adaperForExcelBook As New OleDbDataAdapter
  adaperForExcelBook.SelectCommand = command
  adaperForExcelBook.Fill(dataResult)
  conn.Close()

  Catch err As Exception
  Throw New Exception("Error reading file: " + fileName)
  End Try

  Return dataResult
End Function

Converting a DataRow to a string

2007-03-26T11:58:00.000-07:00

This can help to show a datarow content. Il shows the column name and values for all the column in the row in this format:
ColumnName=value; ColumnName2=value2;


Protected Function DataRowToString(ByVal dr As DataRow) As String
    ''''
    ''' For debugging purpose, per example : convert a datarow to a string 
    ''' represantation with all columns contents
    Dim result As String = ""
    result += Environment.NewLine
    For Each col As DataColumn In dr.Table.Columns
    result += col.ColumnName + "=" + dr(col.ColumnName).ToString() + " ;"
    Next
    Return result
End Function

Checking if a column is a foreing key with system tables in SQL

2007-03-23T08:47:00.001-07:00

With this request, we can see if a column of a given table is a foreign key. If it is the case, we get the parent table and the primary key associated with this column.

Replace MY_COLUMN_NAME and MY_TABLE_NAME with the real table and column values.


SELECT     dbo.sysobjects.name as CHILD_TABLE,
     dbo.syscolumns.name AS CHILD_COLUMN,
        sysobjects_1.name AS PARENT_TABLE,
     syscolumns_1.name AS PARENT_COLUMN
FROM         dbo.syscolumns syscolumns_1 INNER JOIN
           dbo.syscolumns
     INNER JOIN
           dbo.sysobjects
     INNER JOIN
           dbo.sysforeignkeys
     ON dbo.sysobjects.id = dbo.sysforeignkeys.fkeyid
     INNER JOIN
           dbo.sysobjects sysobjects_1
     ON dbo.sysforeignkeys.rkeyid = sysobjects_1.id
     ON dbo.syscolumns.id = dbo.sysforeignkeys.fkeyid AND
            dbo.syscolumns.colid = dbo.sysforeignkeys.fkey
     ON syscolumns_1.id = dbo.sysforeignkeys.rkeyid AND
           syscolumns_1.colid = dbo.sysforeignkeys.rkey
     where dbo.sysobjects.name = 'MY_COLUMN_NAME'
     and dbo.syscolumns.name = 'MY_TABLE_NAME

Works with SQL Server 2000

Checking if a culomn is a primary key with System Tables

2007-03-22T13:56:00.000-07:00

This will return 1 if the column specified is a primary key. Works with SQL Server 2000.

You just have to replace MY_TABLE_NAME and CULOMN_NAME in whe query


select
count(*)
from sysindexes ind,
    sysindexkeys indkey,
    sysobjects obj,
    sysobjects obj2,
    syscolumns col
 where indkey.id + indkey.indid = ind.id + ind.indid and
       ind.name = obj.name and
       ind.id = obj.parent_obj and
       col.id = indkey.id and
       obj.parent_obj = col.id and
       obj.parent_obj = obj2.id and
       col.colid = indkey.colid and
       obj.xtype = 'PK' and
       obj2.name = 'MY_TABLE_NAME' and
       col.name = 'CULOMN_NAME'

Free stylesheets from W3C

2007-02-16T04:17:00.000-08:00

We can find here a web public free stylewheets from the W3C consortium.

http://www.w3.org/StyleSheets/Core/

MCTS Links

2007-01-19T09:14:00.000-08:00

Here are some links for Microsoft Certified Technology Specialist certification.

Microsoft Preparation Guide
http://www.microsoft.com/learning/exams/70-536.asp

Microsoft free Skills Assessments
http://assessment.learning.microsoft.com/test/home.asp

Measure UP
http://www.measureup.com/Site/display_article.aspx?id=955

SelfTest Software
http://www.selftestsoftware.com/dept.aspx?dept_id=1000

Transcender
http://www.transcender.com/gen.aspx?pf=page&sn=TraNewEngine

Passing parameter to Crystal Report in VB.NET

2006-11-30T10:46:00.000-08:00

Here is how to pass a parameter value to a Crystal Report objet at runtime. There are two methods, depending if the report is to be exported as a file or opened with a viewer.
Required namespace:


Imports System.Collections.Generic
Imports CrystalDecisions.CrystalReports.Engine
Imports CrystalDecisions.Shared

EXAMPLE 1: parameter to a report exported as a file


'loading the report with dynamic data 
myCrystalReport.Load()
myCrystalReport.SetDataSource(myDataSet)
myCrystalReport.Refresh()
'Passing the parameter
Dim param As New ParameterDiscreteValue
param.Value = "my value"
myCrystalReport.ParameterFields("parameterName").CurrentValues.Add(param)

'exporting as .PDF

myCrystalReport.ExportToDisk(ExportFormatType.PortableDocFormat, strFileName)

EXAMPLE 2 : parameter to a report opened with a crystal viewer:


   'Loading the report with dynamic data 
 myCrystalReport.SetDataSource(myDataSet)
 myCrystalReport.Refresh()

   'Creating and binding the report viewer
 Dim frmViewer As New CrystalDecisions.Windows.Forms.CrystalReportViewer()
 frmViewer.ReportSource = myCrystalReport


   'Passing the parameter
 Dim oField As New ParameterField()
 Dim oVal As New ParameterDiscreteValue()
 oField.ParameterFieldName = "parameterName"
 oVal.Value = " my parameter value "
 oField.CurrentValues.Add(oVal)
 frmViewer.ParameterFieldInfo.Add(oField)

 'Showing the viewer
 frmViewer.Show()

It works with Crystal Report 10.

Simple function for converting a .NET DataTable to CSV format.

2006-11-22T11:11:00.000-08:00

Need to convert a datatable directly to CSV string, write the datatable in a CSV file, or export it in a Excel compatible format?

This method can be used for creating a .csv string or file that can be opened with Excel.
Excel can import CSV, Excel parses automatically CSV data when the CSV file have a ".xls" extension.


''' Exporting a datatable to an Excel file
Public Sub WriteDataTableToCsvFile(ByVal dtTowrite As DataTable, ByVal strFileName As String)
Dim sw As New System.IO.StreamWriter(strFileName, False, System.Text.Encoding.Unicode)
' see function below
dim strContent as string = ConvertDataTableToCSV(dtTowrite, ControlChars.Tab)
sw.Write(strContent)
sw.Close()
End Sub

'''  Converting a datatable to as comma separated value string format, compatible for Excel.
''' This method dynamically create columns headers.
''' The method ensures thant the separator value will be removed from 
''' the datatable fields if it is already there, for consistency purpose.
Public Function ConvertDataTableToCSV(ByVal dtTowrite As DataTable, _
 ByVal strColSeparator As String) As String
 ' Line breaks are reserved for separating rows
 If (strColSeparator = Environment.NewLine) Then
  Throw New Exception("A new line cannot be used for a csv columns separator.")

 Dim sb As New System.Text.StringBuilder
 Dim intNbCols As Integer = dtTowrite.Columns.Count

 'Write headers
 For i As Integer = 0 To intNbCols - 1
     sb.Append(dtTowrite.Columns(i).ColumnName.Replace(strColSeparator, " ") _
     + strColSeparator)
 Next
 sb.Append(Environment.NewLine)

 'write data
 For Each line As DataRow In dtTowrite.Rows
     For i As Integer = 0 To intNbCols - 1
         sb.Append(line(i).ToString().Replace(strColSeparator, " ") + _
         strColSeparator)
     Next
     sb.Append(Environment.NewLine)
 Next

 Return sb.ToString()
End Function

That's all. It can be tested with the following code:


Dim dt As New DataTable()
dt.Columns.Add(New DataColumn("date", GetType(System.DateTime)))
GetType(System.DateTime)))
dt.Columns.Add(New DataColumn("name", GetType(System.String)))
dt.Columns.Add(New DataColumn("id", GetType(System.Int32)))


Dim line As DataRow = dt.NewRow()
line("date") = Now()
line("name") = "Albert Einstein"
line("id") = 28847
line("test") = "sdfiom " + ControlChars.Tab + " pok po"
dt.Rows.Add(line)

line = dt.NewRow()
line("date") = Now().AddYears(99)
line("name") = "Charles Darwin"
line("id") = 28847
line("test") = "sdfsdfsdfsdfsdf"
dt.Rows.Add(line)

line = dt.NewRow()
line("date") = Now().AddDays(2)
line("name") = "Sigmund Freud"
line("id") = 23423423
' ligne("test") = EMPTY ROW
dt.Rows.Add(line)

Dim strTest As String = ConvertDataTableToCSV(dt, ControlChars.Tab)
Dim sw As New System.IO.StreamWriter("C:\Test.xls")
sw.Write(strTest)
sw.Close()

sql server french format date

2006-11-02T06:24:00.000-08:00

Here is how we can get a YYYY-MM-DD date format, without the hours and minutes.

select CONVERT(VARCHAR(10), GetDate(), 120) as [myFrenchDate]

Great free addIn for Visual Studio 2005

2006-10-20T09:39:00.000-07:00

Smart Paster
The most practical addin: enabled multiple line pasting of string into Visual Studio from other applications. I use smart paster to paste SQL strings without headaches!
You can paste text as comment, string, stringbuilder or region. To be used with the right mouse button.

Cool command
Interresting contextual menu addin for project: collapse all, open container folder, reference manager

Dev Express SQL prompt
Enable intellisense style edition in SQL Query Analyzer and SQL Server Management Studio.
You just have to register to use it freely.

CokeKeep
Code snippet storing and sharing website. Can be used with a Visual Studio addin

REFERENCES
Ten tools for VS 2005

Listing of 10 smart plug-ins.

Visual studio Hacks
By the author of the book "Visual Studio Hacks"

.NET assembly binding order

2006-10-19T13:35:00.000-07:00

Excellent article explainig how referenced assemblies are loaded from the IDE (visual studio) or at runtime.

http://plans.thefrankes.com/tutorials/Assemblies/

Sql Server add culumn if not exist

2006-10-17T08:07:00.000-07:00

Generic script for adding a column if not already existing in database.


IF NOT EXISTS ( SELECT * 
  FROM [dbo].syscolumns 
   ID = OBJECT_ID(N'[dbo].tableName') 
    AND   NAME = N'culumnName') 
BEGIN
ALTER TABLE dbo.tableName
  ADD 
 culumnName decimal NULL
END

Changing cursor (mouse pointer) in javascript

2006-10-11T13:52:00.000-07:00

// for a hourglass cursor
window.document.body.style.cursor = "wait";

// for a normal cursor
window.document.body.style.cursor = "default";

Adding global validation before submit (javascript)

2006-10-11T13:46:00.000-07:00

Context: need for validation or special javascript behaviour before POST.

Since the asp.net postback mecanism occurs with html POST method, it is possible to add an javascript event that replace the normal post event to force a special behaviour or validation.

This function define a pointer to the normal post event of the form, than it define a behaviour that will occur when the post event will fire. This behaviour decides if the form will really submit (ie firing a asp.net postback event).


// setting the handler of the main form:
SetSubmitHandler(document.forms[0]);

// handler definition to personalize
function SetSubmitHandler(form)
{
 // setting a pointer to the original submit function
 // to really post the form to the server
 form.orginalSubmit = form.submit;
 
 // function that replaces the normal post function
 form.newSubmit = function()
 {
  // special behaviour
  // .....  
  if (1==1)// validation goes here..
  {
  // validation is ok --> post to the server
   form.orginalSubmit();
  }    
 }
 // replacing the standard handler (posting to the server)
 // with the new handler
 form.submit = form.newSubmit;
}

Changing url between frames in a frameset

2006-10-10T13:23:00.000-07:00

Need a javascript than can, from a frame, relaod another frame with a new url -- or a url with new parameters?

// by frame id (in the parent frameset)
parent.frames["OtherFrameId"].window.location = "http://...."

// or by index
parent.frames[2].window.location = "http://..."

Cursor in SQL Server

2006-10-10T13:16:00.000-07:00

Example of a simple cursor, SQL Server.


DECLARE @id integer
DECLARE @name  varchar(500)

    DECLARE myCursor CURSOR FOR
    SELECT   cursomerId, [name]
    FROM   CUSTOMER

    OPEN myCursor

    FETCH NEXT FROM myCursor
    INTO @id, @name

    WHILE @@FETCH_STATUS = 0
    BEGIN
    -- do something (updates, insert into other tables, etc)
    print @name

        FETCH NEXT FROM myCursor
        INTO @id, @name

    END

CLOSE myCursor
DEALLOCATE myCursor

Setting and retrieving cookies in javascript

2006-10-06T09:25:00.000-07:00

Here are two function to use cookies directly from javascript. The firt one stock a pair of key/value in the cookie collection. The second one retrieve the value for a key.


function setCookie(idCookie,value)
{
  var cookie_date = new Date ();  // current date & time
  var milli = cookie_date.getMilliseconds()+5*60*1000; // == cokie valid for 5 minutes
  cookie_date.setMilliseconds(milli);
  cookie_date.setTime ( cookie_date.getTime());
  document.cookie = idCookie += "=" + value +"; expires=" + cookie_date.toGMTString();
}

function getCookie ( idCookie )
{

var results = document.cookie.match ( idCookie + '=(.*?)(;|$)' );

if ( results )
   return ( unescape ( results[1] ) );
else
   return null;
}

Loading class by name from another asp.net application

2006-10-04T08:05:00.000-07:00

What if you need to load a class, a webcontrol or a user control that is not in the current web application and the .dll of the other application is not used in the current application?

Remoting can help to do that. The control to load will be created with remoting using the class name given as string.

'Vb example, loading a web control from another application

Dim dllPhysicalPath as String = "C:\...\...\myOtherApplication.dll"
Dim ClassName as String = "MyNamespace.MyClassName"
Dim controlHandle As Runtime.Remoting.ObjectHandle
controlHandle = Activator.CreateInstanceFrom(dllPath , ClassName )
' converting to webcontrol
dim myCtr as WebControl = CType(controlHandle .Unwrap, WebControl)
Page.Controls.Add(myCtr )