Get Google Search Results in RSS Format

Here is my attempt to transform Google Search Results into a RSS feed. This functionality is missing from Google. Test it out and provide some feedback. I have published the feed as a web service at

http://www.ecubicle.net/gsearch_rss.asmx

There is a single function called GetSearchResults with the following signature

GetSearchResults(byval searchPage As string, byval gQuery As String, byval numOfResults As String)

• searchPage provides the google search page that runs in multiples of 10 with 10 results each page (default on Google). The value for first page is 0


• gQuery is google query. You can use any set of Google operators here to tune the query


• numOfResults is the number of results to return per page. Default is 15.

The returned XML is RSS 2.0 compliant. As such, any feed reader can also read the returned XML document.

 

Using in a Feed Reader

To call this in a feedreader, here is the GET syntax for the web service

http://www.ecubicle.net/gsearch_rss.asmx/GetSearchResults?searchPage=0&gQuery=tutorial+asp+net&numOfResults=15

In the above, replace the parameter values shown in red with the your query values.

Read Google Maps KML using LINQ in ASP .NET to Show Driving Directions

We can use LINQ to query the Google Maps KML File. The magic piece is the Google Maps URL to retrieve KML.

http://maps.google.ca/?q=From 25 King St. West, Toronto, ON to Niagara Falls, Ontario&output=kml

Dim fromAddress = "25 King St. West, Toronto, ON"
Dim toAddress = "Niagara Falls, ON"
Dim urlString As String = "http://maps.google.ca/?q=From " & fromAddress & " to " & toAddress & "&output=kml&view=text"
Dim xmlDataSource2 As New XmlDataSource()
xmlDataSource2.DataFile = urlString

Dim xdoc As XDocument = XDocument.Parse(xmlDataSource2.GetXmlDocument().InnerXml)
Dim ns As XNamespace = XNamespace.Get("http://earth.google.com/kml/2.0")
Dim ele = xdoc.Element(ns + "kml").Element(ns + "Document").Elements(ns + "Placemark").Elements(ns + "name")


GridView1.DataSource = ele.Take(ele.Count - 1)
GridView1.DataBind()

Youtube Downloading - Web Service

Here is an interesting web service that allows applications to download youtube videos. Applications that require interaction with youtube can obviously use the YouTube API's to provide exhaustive youtube functionality right from their web sites. However, the only API function that is missed is the ability to download from Youtube.

The Youtube web service provides this missing functionality.

The service is located at http://www.ecubicle.net/youtubedownloader.asmx

What the service does is provide the download URL for any video on Youtube. .NET applications can then use any method to access the download URL and download the file. For example, WebClient.DownloadFile() method can be used to download the file directly if the returned URL is passed to DownloadFile.

Very interesting.

Command Window in Visual Studio 2008

As we develop applications in a particular IDE, it becomes imperative that we come to terms with the technical details of the IDE itself. Features like shortcuts can prove big time saves when working in huge projects. In this post, I want to discover the command window feature in Visual Studio 2005 and 2008.

Command window allows working with the IDE using commands, instead of using the mouse and the IDE menu. Some times it is just quicker to pop open the command window and perform routine tasks, such as opening and saving files, creating aliases for other windows, reading and setting the value of a variable during debugging.

Once in a while my IDE would get messed up and I would lose my solution explorer. By having an alias for it, I simply open up the command window and get straight to any window that I need. Now, solution explorer does have its shortcut (Ctrl-Alt-L), but I am not very keen about these "3keyed shortcuts". For those of us that are used to the more traditional Dos Prompt Style, command window makes us feel right at home with its command features.

Command window can be accessed using the shortcut Ctrl-Alt-A.

Lets get down and dirty and see some useful features that have helped me. I am sure you would find them useful as well.

Creating Aliases

Aliases allow us to define a shorter name for a command. So, for example, we can define an alias to open up Server Explorer using the alias syntax like this:

alias se View.ServerExplorer

Now, lets have a look at our created alias. Simply type alias and press Enter to see a list of all aliases defined in the environment.

The alias command gives us a list as show in the image above. Notice our newly created alias highlighted.

To run this alias, simply type se on an empty line in the command window and the Server Explorer opens up for us.

To delete an alias, type in: alias se /delete as shown below.

Command window has other useful uses as well. I will leave those for another post.

FTPing with ASP .NET

The framework provides us with various techniques to connect with FTP servers and interact with them. In this post, I will go over some of the ways and we will see how to add functionality to a FTP client.

Here is a limited class for our FTP. It has three methods: listFiles, makeDirectory and deleteDirectory.

 1 Imports Microsoft.VisualBasic
 2 Imports System.IO
 3 Imports System.Net
 4 
 5 
 6 Public Class ftpclientcode
 7     Protected myftprequest As FtpWebRequest
 8     Protected myftpresponse As FtpWebResponse
 9     Private _myserver As String
10     Private _myuser As String
11     Private _mypw As String
12 
13     Public Sub New(ByVal myserver As String, ByVal myuser As String, ByVal mypw As String)
14         _myserver = myserver
15         _myuser = myuser
16         _mypw = mypw
17         myftprequest = WebRequest.Create(_myserver)
18         myftprequest.Credentials = New NetworkCredential(_myuser, _mypw)
19 
20     End Sub
21 
22 
23     Public Function ListFiles() As Stream
24         myftprequest.Method = WebRequestMethods.Ftp.ListDirectory
25         myftpresponse = myftprequest.GetResponse()
26         Return myftpresponse.GetResponseStream()
27 
28     End Function
29 
30     Public Sub MakeDirectory(ByVal mydirname As String)
31 
32         myftprequest.Method = WebRequestMethods.Ftp.MakeDirectory
33         myftpresponse = myftprequest.GetResponse()
34 
35     End Sub
36 
37     Public Shared Sub Close()
38         ' myftpresponse.Close()
39 
40     End Sub
41 
42     Public Sub DeleteDirectory(ByVal mydirname As String)
43         myftprequest.Method = WebRequestMethods.Ftp.RemoveDirectory
44         myftpresponse = myftprequest.GetResponse()
45 
46     End Sub
47 
48 
49 End Class

And here is the Default.aspx page to work with our class

 1 Imports System.Net
 2 Imports System.IO
 3 
 4 Partial Class _Default
 5     Inherits System.Web.UI.Page
 6 
 7     Private servername As String = "localhost"
 8     Private myusername As String = "rafayali"
 9     Private mypassword As String = "******"
10 
11 
12     Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
13         Dim myftp As New ftpclientcode("ftp://" & servername, myusername, mypassword)
14         Label1.Text = ""
15         Dim datastream As Stream = myftp.ListFiles()
16         Dim reader As New StreamReader(datastream)
17         While Not reader.EndOfStream
18             'Response.Write(reader.ReadLine() & "<br/>")
19             Label1.Text = Label1.Text & "&nbsp;&nbsp;?&nbsp;&nbsp;&nbsp;" & reader.ReadLine() & "<br/>"
20         End While
21         'myftp.Close()
22     End Sub
23 
24     Protected Sub createdir_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles createdir.Click
25         Panel1.Visible = False
26         Panel2.Visible = False
27         Panel3.Visible = True
28         TextBox1.Focus()
29     End Sub
30 
31     Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles createbutton.Click
32         Panel3.Visible = False
33         Panel1.Visible = True
34         Panel2.Visible = True
35         Dim myftp As New ftpclientcode("ftp://" & servername & "/" & TextBox1.Text, myusername, mypassword)
36         Try
37             myftp.MakeDirectory(TextBox1.Text)
38             Page_Load(sender, e)
39         Catch ex As Exception
40             Response.Write(ex.Message.ToString())
41         Finally
42             'myftp.Close()
43         End Try
44     End Sub
45 
46     Protected Sub cancelbutton_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles cancelbutton.Click, Button2.Click
47         Panel1.Visible = True
48         Panel2.Visible = True
49         Panel3.Visible = False
50         Panel4.Visible = False
51     End Sub
52 
53     Protected Sub removedir_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles removedir.Click
54         Panel1.Visible = False
55         Panel2.Visible = False
56         Panel4.Visible = True
57         TextBox2.Focus()
58     End Sub
59 
60     Protected Sub Button1_Click1(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
61         Panel4.Visible = False
62         Panel1.Visible = True
63         Panel2.Visible = True
64 
65         Dim myftp As New ftpclientcode("ftp://" & servername & "/" & TextBox2.Text, myusername, mypassword)
66         Try
67             myftp.DeleteDirectory(TextBox2.Text)
68 
69         Catch ex As Exception
70             Response.Write(ex.Message.ToString())
71 
72         End Try
73         Page_Load(sender, e)
74     End Sub
75 
76     Protected Sub Page_Unload(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Unload
77 
78 
79     End Sub
80 End Class
81 

Web.Config Code Snippets

I was going through some old projects yesterday and came across some interesting web.config settings that I thought would be a good read. So, without further ado, here are some useful code snippets.

 

Set The Upload File Size to 128KB for a Particular Page

1 <configuration>
2   <location path="myFileUploadPage.aspx">
3     <system.web>
4       <httpRuntime maxRequestLength="128"/>
5     </system.web>
6   </location>
7 </configuration>

Bringing an Application Offline

1 <configuration>
2 <system.web>
3  <httpRuntime enable="false" />
4 </system.web>
5 </configuration>

Encrypting Database Passwords using MD5

Today, I will show you a very basic technique to encrypt database passwords for storage using MD5 algorithm. MD5 is a one-way algorithm; decrypting is almost next to impossible. One very important characteristic of this algorithm is that a particular text value would always result in the same encrypted value. Therefore, even though the encrypted value cannot be decrypted directly, we do have a way to verify such passwords.

Let us get down straight to code and see for ourselves:

 1 Dim connectionString As String = "Data Source=.\SQLEXPRESS;AttachDbFilename=D:\rafay\projects\certification\encrypt\App_Data\members.mdf;Integrated Security=True;User Instance=True"
 2 
 3         Dim sqlStatement As String = "INSERT INTO users VALUES(@myuser,@mypassword)"
 4         Using objConn As SqlConnection = New SqlConnection(connectionString)
 5             Using objComm As SqlCommand = New SqlCommand(sqlStatement, objConn)
 6                 Dim userNameParameter As New SqlParameter("@myuser", Data.SqlDbType.NVarChar, 15)
 7                 userNameParameter.Value = "Test"
 8 
 9                 Dim passwordParameter As New SqlParameter("@mypassword", Data.SqlDbType.Binary, 16)
10                 passwordParameter.Value = encryptPasswordWithMD5("TestAccountPassword")
11 
12                 Dim objCommParameterArray() As SqlParameter = {userNameParameter, passwordParameter}
13                 objComm.Parameters.AddRange(objCommParameterArray)
14 
15                 objConn.Open()
16                 Dim result As Integer = objComm.ExecuteNonQuery()
17             End Using
18         End Using
19 

This is our very basic example of connecting to SQL Server Express database file called members.mdf. We set up a sql statement and two parameters for username and password. The important part to look at is that the password is first encrypted using our helper function called encryptPasswordWithMD5. Another thing to note is that the database field for password is defined as a binary type of length 16. Once the parameters are defined and their values set, a parameter array is formed and then added to the SQLCommand object. The record is finally inserted with a call to ExecuteNonQuery.

Let us now have a look at our encryptPasswordWithMD5 function.

 1 Private Function encryptPasswordWithMD5(ByVal stringToEncrypt As String) As Byte()
 2         Dim MD5Encrypter As New MD5CryptoServiceProvider()
 3         Dim stringBytes() As Byte = convertStringToBytes(stringToEncrypt)
 4         Dim bufferToHoldEncryptedData() As Byte = Nothing
 5 
 6         bufferToHoldEncryptedData = MD5Encrypter.ComputeHash(stringBytes)
 7 
 8         Return bufferToHoldEncryptedData
 9     End Function
10 
11     Private Function convertStringToBytes(ByVal stringToConvert As String) As Byte()
12         Return Text.Encoding.UTF8.GetBytes(stringToConvert)
13     End Function

Line 3 of the code above is of particular interest. Since the ComputeHash method of MD5CryptoServiceProvider class takes in a byte value, our very first task is to convert the password string into a byte. This is accomplished using our second helper function convertStringToBytes (also defined in the listing above). What convertStringToBytes does is to take a string value and return the bytes using GetBytes method of the Encoding class in System.Text namespace. Once this is done, we calculate the hash and store in a buffer and return this buffer.

So, how do we actually verify the credentials since there is no way to decrypt? Well, since MD5 always results in the same hash for the same text, we can encode the text again and compare this against the value in the database. Code sample follows:

 1 Public Function checkPassword(ByVal userName As String, ByVal myPassword As String) As Boolean
 2         Dim connectionString As String = "Data Source=.\SQLEXPRESS;AttachDbFilename=D:\rafay\projects\certification\encrypt\App_Data\members.mdf;Integrated Security=True;User Instance=True"
 3         Dim result As Integer = 0
 4         Dim sqlStatement As String = "SELECT count(*) from users Where myuser=@myuser AND mypassword=@mypassword"
 5         Using objConn As SqlConnection = New SqlConnection(connectionString)
 6             Using objComm As SqlCommand = New SqlCommand(sqlStatement, objConn)
 7                 Dim userNameParameter As New SqlParameter("@myuser", Data.SqlDbType.NVarChar, 15)
 8                 userNameParameter.Value = userName
 9 
10                 Dim passwordParameter As New SqlParameter("@mypassword", Data.SqlDbType.Binary, 16)
11                 passwordParameter.Value = encryptPasswordWithMD5(myPassword)
12 
13                 Dim objCommParameterArray() As SqlParameter = {userNameParameter, passwordParameter}
14                 objComm.Parameters.AddRange(objCommParameterArray)
15 
16                 objConn.Open()
17                 result = CInt(objComm.ExecuteScalar())
18             End Using
19         End Using
20         If result > 0 Then
21             Return True
22         Else
23             Return False
24         End If
25     End Function
26 End Class

In the first code above, I have hardcoded the username and password values. These would naturally need to be changed and the source of input would be probably be a CreateUserWizard or another composite control with various textboxes. The values were hardcoded for simplicity.