Blog moved

Guys,

I have moved my blog from wordpress to http://blog.nishanthnair.com . please do visit my own site!!

Cool feature in Google Chrome – Drag out tabs to create new window

I was experimenting with Google chrome and accidnely foud a cool new feature which I liked a lot. Suppose you have 10 tabs opened in your chrome browser and you want to move out one tab to a new window, hust drag the tab out of the main window….. There you are… you get a new chrome window witht the same page opened. If you do the same in Firefox 3, you get a short cut added to the desktop and you cant do this in IE 7 . 

Note: Google chrome tabs are seperate windows process and as a result if one tab crashes, it wont affect other tabs!!

The screen shot is provided below. 

File / Folder properties not showing security tab

Today I was trying to configure a website as virtual directory on my newly setup XP professional machine. I wanted to to give permissions to .NET accounts to access the website directory, but was not able to see the security tab when I right clicked on the folder. It was quite surprising as I was experiencing this situation for the first time. After doing dome research  I found out the way out .

Go to Explorer -> tools -> folder options -> View-> navigate to the last check box in the list “USE SIMPLE FILE SHARING” . Uncheck this checkbox and click OK. Now you will be bale to see the security tab in file properties.

Hope this helps!!

New Look Gmail – Better Gmail 2

Today I installed Firefox 3 on my machine and was browisng for some cool Add-ons and found this amazing add on “Better Gmail 2″ (  https://addons.mozilla.org/en-US/firefox/addon/6076 ).  it has got 174,670 weekly downloads and 1,086,159 total downloads. It adds useful extra features and skins to Gmail, like hierarchical labels, macros, signatures, file attachment icons, and more.

Below given is the new look of my gmail after installing Better Gmail 2. Hats off to the author Gina Trapani .

Download the Better-Gmail 2 add-on here.

To install other recommended add ons browse this link: https://addons.mozilla.org/en-US/firefox/recommended .

Windows 2008/2003 IE7 nagging “Your current security settings put your computer at risk ” message

I recently installed Windows 2008 server on my laptop . Fully excited to learn the new features I logged in to the machine and started to browse the net with Internet explorer. Then I noticed a nagging “Your current security settings put your computer at risk ” message below the IE address bar. it was so irritating that i stopped browsing with Win2008 server. Another problem I faced is that the IE was displaying  ”Security Settings at risk ” page on IE startup than my predefined homepage ion IE options. I dont understand why microsoft wants to irritate people like this. WHo ever using Windows 2008 server will have a minimum amount of knowledge about security and its only required show them a warning once. Why are they showing this idiotic message everytime ?? And they dont have a button/link to disable this feature which makes us hate the OS/IE the very first time.  

Image of Security settigns at risk page:

 

 

After cursing the the MS team. I found a way to disable these irritating  features.

The steps are  as follows:

Start -> Run – Gpedit.msc (MS group policy editor)
Navigate to User Configuration -> Administrative Templates -> Windows Components -> Internet Explorer -> Security Features -> Information Bar.

Change “All processes” to “Disable”.

Now go to Start – Run – regedit
Navigate to HKLM -> Software -> Microsoft -> Internet Explorer -> Main 

 

 

Change the “Security Risk Page” to your home page link.

 

A common SQL Query

This is a very simple SQL query for finding the 2nd highest salary from an employee table.

A very common question in .NET interviews. The query is pretty self explanatory.

select  top(1)[Name],Salary from Employee

where  salary  not in (select top (1) salary from employee order by salary desc) ORDER BY SALARY DESC 

– Change the top parameter to (nth highest salary – 1)

Article on why not to use * in SQL Queries

Today I got to read a very good article on SqlCentral.com. This about a simple example(one of many scenarios ) why developers should not use ‘*’ when writing SQL queries. I felt all developers should read this article as the issue addressed is something that may occur frequently in daily development.

Interesting things that you will learn about this article are:

1. One main difference between User defined functions and SPs(how table structure is stored in system tables in case of UDF and this is updated only when Create function is called which is not the case in Stored procedures)

2. How to easily get a list of columns in a table as comma separated values which will be helpful while writing column names of tables having lots of columns(Especially for people like me who are Excel illiterates J )

Link to the article: http://www.sqlservercentral.com/articles/UDF/62730/

Validating an XML File using XSD in .NET .20

Below given is the.NET 1.1 code for validating an XML File using an XSD File.

.NET 1.1 Code

//.NET1.1 code
///
/// Methode to validate XML File
///
///

This method expects input XML as string
///
Path to schema file
/// true if xml is validated else false
private bool ValidateXmlUsingXsd(string XmlData,String SchemaPath)
{
XmlValidatingReader v = new XmlValidatingReader(XmlData, XmlNodeType.Document, null);
v.ValidationType = ValidationType.Schema;
v.ValidationEventHandler +=
new ValidationEventHandler(MyValidationEventHandler); 

while (v.Read())
{
// Can add code here to process the content.
}
v.Close();

return isValid;

}

///

public static void MyValidationEventHandler(object sender,
ValidationEventArgs args)
{
//these two variables should be initialized as class level variables
isValid = false;
errorMessage = “Validation event\n” + args.Message;///
/// Method to get XML in a string from an XML file
///
///

}

///
private string GetStringFromXML(string fileName)
{
StreamReader rd = new StreamReader(fileName);
string str = rd.ReadToEnd();
rd.Close();
return str;
}

Calling the method :
bool valid = ValidateXmlUsingXsd(str, txtXSD.Text);

There are some changes in the .NET 2.0 code for XML Validation .
XmlValidatingReader is marked as obsolete. Need to use XMLReader.Create() using XmlReaderSettngs instead

There are some behavioral changes between validation using the XmlReaderSettings and XmlSchemaSet classes and validation using the XmlValidatingReader class.

The XmlReaderSettings and XmlSchemaSet classes do not support XML-Data Reduced (XDR) schema validation.

The most important difference I found out is that to do XML data validation using a schema, settings.ValidationFlags = XmlSchemaValidationFlags.ReportValidationWarnings;
Flag must be enabled. Otherwise the Schema check error will not be displayed.

//.NET2.0 code
private bool ValidateXmlUsingXsd2(string XmlData,String SchemaPath)
{
XmlReaderSettings settings = new XmlReaderSettings();
settings.ValidationType = ValidationType.Schema;
settings.Schemas.Add(null, SchemaPath);
settings.ValidationFlags = XmlSchemaValidationFlags.ReportValidationWarnings;
settings.ValidationEventHandler += new ValidationEventHandler(ValidationCallBack);
More about XmlSchemaValidationFlags Enumeration

StringReader xmlStream = new StringReader(XmlData);
XmlReader reader = XmlReader.Create(xmlStream, settings);
while (reader.Read()) ;

return isValid;
}

private static void ValidationCallBack(object sender, ValidationEventArgs e)
{
isValid = false;
errorMessage = “Validation Error: ” + e.Message;
}

 

Member name
Description
AllowXmlAttributes
Allow xml:* attributes even if they are not defined in the schema. The attributes will be validated based on their data type.
None
Do not process identity constraints, inline schemas, schema location hints, or report schema validation warnings.
ProcessIdentityConstraints
Process identity constraints (xs:ID, xs:IDREF, xs:key, xs:keyref, xs:unique) encountered during validation.
ProcessInlineSchema
Process inline schemas encountered during validation.
ProcessSchemaLocation
Process schema location hints (xsi:schemaLocation, xsi:noNamespaceSchemaLocation) encountered during validation.
ReportValidationWarnings
Report schema validation warnings encountered during validation.

In a nutshell, Always set settings.ValidationFlags = XmlSchemaValidationFlags.ReportValidationWarnings; when a schema validation is required for the XML in .NET 2.0

///
/// This event handler is called only when a validation error occurs
///
///

Truncation of fields when CSV file is read using ADO.NET

I encountered a major problem with ADO.NET CSV reader in one of the projects where CSV File Import played a major role.
When a field in the CSV file with a “–“(hyphen) is read, the characters before the “–“are discarded. For example the model F-150 is read as –150 and T-Bird in the model field is not being read. And some of the values were missing in some of the fields.
Given below is the code I used :string strConnString = “Provider=Microsoft.Jet.OLEDB.4.0;Data Source=” + folderName + “;Extended Properties=\”text;HDR=Yes; FMT=Delimited; IMEX=1\””;
string sqlSelect = “select * from [" + fileName + "]“;
System.Data.OleDb.OleDbConnection conn = new System.Data.OleDb.OleDbConnection(strConnString.Trim());
conn.Open();
System.Data.OleDb.OleDbDataAdapter adapter = new System.Data.OleDb.OleDbDataAdapter(sqlSelect, conn);
DataSet ds = new DataSet();ds.ReadXmlSchema(Server.MapPath(”xmlschema.xsd”));
ds.EnforceConstraints = false;
F-100 reads as -100
K-100 reads as -100
S-100 reads as -100
100-F reads as -100
100-K reads as -100
100-S reads as -100
100$F reads as 100
100$K reads as 100
100$S reads as 100
F100 reads as 100
K100 reads as 100
S100 reads as 100
F\100 reads as 100
K\100 reads as 100
S\100 reads as 100
F.100 reads as .1
K.100 reads as .1
S.100 reads as .1
K-.\\$$$.\\1 reads as -0.1
K\\-22..$$\\21 reads as -22.221
-$\.FSK1 reads as -0.1
This happens only wen there is only one row in the csv file or more than half the values in a column is having the avove specified values

string strConnString = “Provider=Microsoft.Jet.OLEDB.4.0;Data Source=” + folderName + “;Extended Properties=\”text;HDR=Yes; FMT=Delimited\””;
string sqlSelect = “select * from [" + fileName + "]“;
System.Data.OleDb.OleDbConnection conn = new System.Data.OleDb.OleDbConnection(
strConnString.Trim());
conn.Open();
System.Data.OleDb.OleDbDataAdapter adapter = new System.Data.OleDb.OleDbDataAdapter(sqlSelect, conn);
DataSet ds = new DataSet();
adapter.Fill(ds, “Inventory”);
return ds.Tables[0];

Samir found a solution, to add a schema file which identifies all fields in the csv file as string values.
And call DataSet.ReadXMLSchema() method to attach the schema to the DataSet. Also the schema constraints are not enforced .

modified code looks like this..

 

 

adapter.Fill(ds, “Inventory”);
return ds.Tables[0];

Even after using this code values like “F-150″ was read as -150 if there is only one row in the csv file.

May be because ADO.NET does some internal calculation to treat F as floating point or something.. The fun part is that f-150 is read correctly.. problem is with capital letters .
So we ended up using a custom third party csv reader .
Moral of the story… never use ADO.NET csv reader… Always go for a custom CSV parser or a third party library.

Method to sort an array of strings in descending order of number of words in each array element

Just adding a method which i wrote for an application for which the requirement was scrapped.
Hope someone can refer to this silly method.

///
/// Method to sort an array of strings in descending order of number of words in each array element
///
///

Array to be sorted
/// Array sorted in descending order of number of words in each array element 

private static string[] SortArrayWithDescendingWordCount(string[] strArray)
{
//Array to store the number of words in each string of the array to be sorted
int[] wordLengths = new int[strArray.Length];
//variable to keep track of array index of wordLengths array.
int arrayIndex = 0;
foreach (string str in strArray)
{
//split the string in to an array of words and store the word count in wordLengths array.
wordLengths[arrayIndex] = str.Split(’ ‘).Length; ;
arrayIndex++;
}
//Sort arrays(ascending order) by taking wordLenths array as key and strArray as value
Array.Sort(wordLengths, strArray);
//now reverse strArray array to sort the array in descending order of number of words in each array element
Array.Reverse(strArray);
return strArray;
}