till yesterday i had never used T4 for a real problem solving. i knew what it is but i did not know how great and easy it is.

in my current scenario i have a database table which contains options available for each property of 30 available properties of items to be added to the system. the table has almost 500 records.  in the item registration page i had to create a structure like this for each property:

<div id="div1" runat="server" class="row">
<asp:Label ID="SmartLabel13" runat="server" AssociatedControlID="" Text="Title of the property"></asp:Label>
<asp:DropDown ID="SmartDropDown1" runat="server">
<asp:ListItem Selected="True" Text="-----------" Value="">
<asp:ListItem Selected="True" Text="option 1" Value="option 1 value">
<asp:ListItem Selected="True" Text="option 2" Value="option 2 value">
.
.
.
.
<asp:ListItem Selected="True" Text="option n" Value="option n value">
</asp:ListItem>
</asp:DropDown>
</div>

creating 50 of these snippet and adding almost 12 list item for each of them along with setting the control names and property title and also AssociatedControlID of each would have taken me at least a day. i thought i could benefit from T4(Text Template Transformation Toolkit which is used for code generation) to save myself some time. so i started creating a T4 file to do this and vala… 15 minutes later i had it done. i have to say that, it was the first time that i actually was using T4. i cannot believe how easy it is to use it. the following few lines of code saved me at least a day by generating around 1000 lines of code:

<#@ template language="C#" debug="True" #>
<#@ output extension="txt" #>
<#@ assembly name="System.Core" #>
<#@ assembly name="System.Data" #>
<#@ import namespace="System" #>
<#@ import namespace="System.IO" #>
<#@ import namespace="System.Diagnostics" #>
<#@ import namespace="System.Linq" #>
<#@ import namespace="System.Collections" #>
<#@ import namespace="System.Collections.Generic" #> 
<#@ import namespace="System.Data.SqlClient" #>
<#
string catName=string.Empty;
int i=50;
System.Data.SqlClient.SqlConnection cn=new  System.Data.SqlClient.SqlConnection("data source=.\\sqlexpress;integrated security=true;database=Irizzle");
SqlCommand cmd=new SqlCommand("select * from IRZ.Lookupvalues order by Category",cn);
cn.Open();
SqlDataReader dr=cmd.ExecuteReader();
while(dr.Read())
{    
if(catName==dr["Category"].ToString())
{#>
<asp:ListItem Text="<#= dr["Name"].ToString()#>" Value="<#= dr["Code"].ToString()#>" />
<#}
else
{
if(catName!=string.Empty){#>
</Irizzle:SmartDropDown>
</div>
<#}#>
<div id="div<#= dr["Category"].ToString()#>" runat="server" class="row">
<label for="drp<#= dr["Category"].ToString()#>"><#= dr["Title"].ToString()#></label>
<Irizzle:SmartDropDown ID="drp<#= dr["Category"].ToString()#>" runat="server">
<asp:ListItem Selected="True" Text="-----------" Value=""/>
<asp:ListItem Text="<#= dr["Name"].ToString()#>" Value="<#= dr["Code"].ToString()#>" />
<#}
catName=dr["Category"].ToString();
#>        
<#    i++;}
dr.Close();
cn.Close();
#>
</Irizzle:SmartDropDown>
</div>

i am sure T4 can save you and your companies hell lot of time. what i am wondering about is why not so many people talk about this great feature.

If you are also involved in web development as part of your day to day job(sure most of us are), you know that dealing with css is inevitable. css is so important that everybody has to consider it; from the application architects to graphic designers.

Recently in the following blog post i read about .LESS library which was totally new but interesting for me. 

".LESS is a free, open-source port of Ruby's LESS library. LESS (and .LESS, by extension) is a parser that allows web developers to create style sheets using new and improved language features, including variables, operations, mixins, and nested rules. Behind the scenes, .LESS converts the enhanced CSS rules into standard CSS rules. This conversion can happen automatically and on-demand through the use of an HTTP Handler, or done manually as part of the build process. Moreover, .LESS can be configured to automatically minify the resulting CSS, saving bandwidth and making the end user's experience a snappier one. "  

If you want to know about .LESS for css, you can go through the same blog post which I went through:

http://www.4guysfromrolla.com/articles/030310-1.aspx

i have found a perfect blog post from mr. tim heuer on new features in silverlight 4.0. it's definitely worth going through his post.

http://timheuer.com/blog/archive/2009/11/18/whats-new-in-silverlight-4-complete-guide-new-features.aspx

 it has been always a question for me that  what the maximum number of table in a sql server database is. searching for an answer to this question, i came across the following table in msdn. i found it very usefull and thought of sharing it with you.

recently in our project we had a requirement to export html to PDF in asp.net. there are so many components around which we can use to do this but the restriction for us was that we had to do it without spending money means we had to go for an open source component. doing so much I&D on this, we came to know about itextSharp which is a powerful open source component to create PDF files in .net. first it seemed good to us but spending sometimes on it we came to know it was not what we were looking for. two reason for that:

1. it requires a big learning curve
2. it’s not at all easy to work with

then the idea of using crystal report came to our mind. we could build the report in crystal report, load it through code without showing anything to user and through it’s API calling the export to pdf function. but it did not work since we had to run some setup components on the live server which we are not allowed to do.

meantime i just remembered we have rdlc reports in .net framework and also Microsoft report viewer. since these are .net component we don't have to install anything on the production server and Xcopy of the required assemblies will work for us. normally you can deploy the .net report files (.rdlc) using xcopy but in order to be able to use the reports you need to install Microsoft report viewer redistributable package which is freely available to download and distribute. this is fine when you have the rights to install components on the server. anyways spending sometime on this technology i found the files required to make the functionality up and running. if you don't want to install report viewer component you need to put these four dll in your bin folder:

Microsoft.ReportViewer.Common.dll
Microsoft.ReportViewer.ProcessingObjectModel.dll
Microsoft.ReportViewer.WebForms.dll
Microsoft.ReportViewer.WinForms.dll

you can download the files from here:
http://cid-c1dc0bf06aa2e3a6.skydrive.live.com/self.aspx/BlogFiles/ReportViewerFiles.zip

then you need the following lines of code to export:

string[] streamids;
string mimeType;
string encoding;
string extension;
string fileFormat = "PDF";//can also be "Excel" or "Image";
Microsoft.Reporting.WebForms.LocalReport localReport = 
new Microsoft.Reporting.WebForms.LocalReport();
localReport.ReportPath = Server.MapPath("Report1.rdlc");
Microsoft.Reporting.WebForms.Warning[] warnings;
byte[] bytes = localReport.Render(
fileFormat, null, out mimeType, out encoding,
out extension,
out streamids, out warnings);
System.IO.FileStream fs = 
new System.IO.FileStream(Server.MapPath("output.pdf"),
System.IO.FileMode.Create);
fs.Write(bytes, 0, bytes.Length);
fs.Close();
Response.Redirect("output.pdf");

remember you can export to PDF, Excel and Image

you can use this method both for asp.net applications and windows application.

hope this comes handy for you.

ever wanted to connect to an oracle database in your .net application (asp.net, windows client ect) but tnsnames.ora file was missing? ok,i just found a solution for this in connectionstrings.com. you can use the following connection strings to connect to an oracle database using both microsoft .net provider for oracle database and odp.net:

SERVER=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=yourHost)(PORT=yourPort))(CONNECT_DATA=(SERVICE_NAME=yourOracleSID)));uid=yourUsername;pwd=yourPassword;

All of us have already dealt with the problem of promoting configuration files in different application life cycles. this problem can be as simple as managing different connection strings for different databases in each environment to managing the other complicated settings in each environment.

so many times it happens that we forget to update the configuration file (web.config or app.config) before promotes. what we had already done was to keep one configuration file for each environment (development, testing, staging …) and after promote before build overwrite the the existing configuration file. but even in this case we used to miss to update the configuration file with the latest information. anyway i came across the very good solution in Scott Hanselman's blog. ok here is the solution.

1. In your project Click the configuration management dropdown and select "Configuration Manager."

You'll probably have Debug and Release configurations, but you can also make custom ones and base them on existing configuration. In this dialog I've made a new "Deploy" and I'll base it on the "Release" configuration.

Make sure to create a Solution Configuration AND a Project Configuration, as they are different. Here I've made one called Deploy for the Project also. If you get an error message, be aware of the "Create new project configurations" checkbox. You might get a warning if you are making a new configuration and the dialog tries to make another configuration with the same name; uncheck the checkbox if that happens. Of course, you can have as many Configurations as you'd like.

2. Add some custom configuration stuff in web.config, like connectionStrings:

	   1: <connectionStrings>
	

	   2:     <add name="Foo"
	

	   3:          connectionString="Data Source=localhost;Initial Catalog=DatabaseName;
	
	   4:                            User Id=sa;Password=debug;"
	
	
	

	   5:          providerName="System.Data.SqlClient" />
	

	   6: </connectionStrings>
	

See now I've made the password in my nonsense connectionString = "debug"? Now, create three new web.config's by CTRL-dragging the web.config on top of the project. Name them web.config.debug, web.config.deploy, and web.config.release. Make the password equal to "deploy" and "release" respectively.

3. Ok,  now we've got different configuration and different configuration files. Let's create a batch file called "copyifnewer.bat" and here's the contents:

	   1: @echo off
	

	   2: echo Comparing two files: %1 with %2
	

	   3:  
	

	   4: if not exist %1 goto File1NotFound
	

	   5: if not exist %2 goto File2NotFound
	

	   6:  
	

	   7: fc %1 %2 
	

	   8: if %ERRORLEVEL%==0 GOTO NoCopy
	

	   9:  
	

	  10: echo Files are not the same.  Copying %1 over %2
	

	  11: copy %1 %2 /y & goto END
	

	  12:  
	

	  13: :NoCopy
	

	  14: echo Files are the same.  Did nothing
	

	  15: goto END
	

	  16:  
	

	  17: :File1NotFound
	

	  18: echo %1 not found.
	

	  19: goto END
	

	  20:  
	

	  21: :File2NotFound
	

	  22: copy %1 %2 /y
	

	  23: goto END
	

	  24:  
	

	  25: :END
	

	  26: echo Done.
	

Basically this batch file will copy a file over another if the files don't match. It's not strictly "copyifnewer" (like, not at all) but it does the job.

Why bother with a batch file to check for changes and not just copy over the file every time? Well, each time you copy over a web.config it restarts all the designers and running AppDomains that are watching that file. No need to copy over a file if it hasn't changed...everything will churn less.

Put this copyifnewer.bat file in the root of your project.

4. Create a Pre-build Event. Right-click on your Project and select Properties. Click Build Events and in the "Pre-build event command line" and enter this value:

	"$(ProjectDir)copyifnewer.bat" "$(ProjectDir)web.config.$(ConfigurationName)" "$(ProjectDir)web.config"
	

Notice the magic dust, the $(ConfigurationName) project variable, that contains "Debug" or "Release" or "Deploy."

5. Build. Now if you build, you'll see in the Build Output the batch file being run and the files being copied. Because it's a Pre-Build Event it'll be seen in both the Build Output in Visual Studio .NET.

When you build within Visual Studio the currently selected item in the drop-down list is the current configuration.  now you have different configuration file for each build

there is catch here and that is we have to remember that we've got to keep web.config's in sync if there's lots of settings, but we could totally break it apart via "include files."

Here are some key differences between JavaScript Object Notation (or JSON), an open and text-based data exchange format, that provides a standardized data exchange format better suited for Ajax-style web applications and XML.

Although Both JSON and XML can be used to represent native, in-memory objects in a text-based, human-readable, data exchange format, but the two data exchange formats are isomorphic—given text in one format, an equivalent one is conceivable in the other.

following tables is a high level comparision between JSON and XML.

Key Characteristic Differences between XML and JSON

JSON is a relatively new data exchange format and does not have the years of adoption or vendor support that XML enjoys today (although JSON is catching up quickly). The following table highlights the current state of affairs in the XML and JSON spaces.

Support Differences between XML and JSON

  if you work with XML and xpath for sure the reference seems to be a trivial one for you. but if you stop working with xml and xpath for a while you’ll find the reference pretty handy. i personally keep it with me always. hope it also helps you.

the reference xpath expression is for this xml content:

   1: <?xml version="1.0" encoding="utf-8" ?>

   2: <Albums>

   3:   <Album country="USA">

   4:     <title>Empire Burlesque</title>

   5:     <artist>Bob Dylan</artist>

   6:     <price>10.90</price>

   7:   </Album>

   8:   <Album country="UK">

   9:     <title>Hide your heart</title>

  10:     <artist>Bonnie Tyler</artist>

  11:     <price>10.0</price>

  12:   </Album>

  13:   <Album country="USA">

  14:     <title>Greatest Hits</title>

  15:     <artist>Dolly Parton</artist>

  16:     <price>9.90</price>

  17:   </Album>

  18: </Albums>

and here is the quick reference