Ashraf's Blog

Auto Growing TextArea

ashraf — Sat, 11 Jul 2009 19:38:01 +0000

Ehsan was telling me about the litte, simple and useful control. All of us already seen that control in facebook chatting window. that textboox automatically bacome bigger according to the text written in the textbox.

Here is the demo of that JQuery http://www.aclevercookie.com/demos/autogrow_textarea.html

I have tested that in asp.net TextBox it works. Here is my code in asp.net for auto growing textbox.

You should download JQuery and JQuery Auto Grow to use it.

|]*>)[^>]*>”,”", RegexOptions.IgnoreCase | RegexOptions.Singleline) ;

I was working fine but i found that for some pages these are making problem specially problems are coming to remove javascript and styles from html data and data was not coming in a good format.

Finally I have got a very nice tool to do that . name of the tool is Html Agility .

this is a very nice features in html agility , it has libraires to convert html to xml, html to rss and html to text. I used html to text yo convert my httpresponse data to text.

in html agility you will find a class HTMLDocument.cs If you want to convert your webresponses then just add these codes in Load method, bacuase in load method this is reading html file from a local drive so to read webresponse use that code.

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
StreamReader sr = new StreamReader(response.GetResponseStream(), OptionDefaultStreamEncoding);

Posted in C#.NET

ASP.NET Caching with Cache Dependency on a File

ashraf — Fri, 17 Oct 2008 07:41:57 +0000

Caching is a very important concept in programming . caching is a very nice technique to speed up processing. To increase performance of application caching is a great enhance.

One of my buddy razwan has written a very nice article on asp.net caching using cache dependency on file. You can follow this article to implement that in your applicaiton to speed it up.

here is the link ASP.NET Caching with Cache Dependency on a File

Posted in C#.NET

Wrapping text

ashraf — Thu, 16 Oct 2008 13:01:42 +0000

Sometime we face problen to wrap text. this is a very easy solution to solve wrapping problem .

public string GetFormattedText(string str)
{
string[] parts = str.Split(new char[] { ‘ ‘ });
StringBuilder sb = new StringBuilder();
foreach (string s in parts)
{
sb.Append(Server.HtmlEncode(s));
sb.Append(” ”);
}
return sb.ToString();
}

In case of firefox its is more easier, just use white-space: -moz-pre-wrap in css style.

Posted in CSS Tagged: Programming

Singleton – instantiate just ONE OBJECT

ashraf — Wed, 13 Aug 2008 12:43:34 +0000

i was reading a book head first design pattern, actually read that book many times, an excellent book. Sharing my details idea singleton design patter.

class diagram of Singleton design pattern

a singleton class is look like that
public class Singleton
{
private static Singleton UniqueInstance; //variable to hold one instance of the class Singleton
private Singleton(){}
public static Singleton getInstance()
{
if(UniqueInstance==null)UniqueInstance=new Singleton();
return UniqueInstance;
}
}
here the Singleton class constructor is private and it has only one static method to get it, that ensures that this class has only one instance, and provide a global point to access it.

Now think for multi threading…
what will happen??? suppose you have 2 threads, so 2 different instance of the object will be created.
WHATS THE SOLUTION ???
add keyword to getInstance(), so it will ensure that 2 threads will not enter in the method at the same time. So solution codes looks like that.
public class Singleton
{
private static Singleton UniqueInstance;

private Singleton(){}
public static synchronized Singleton getInstance()
{
if(UniqueInstance==null)UniqueInstance=new Singleton();
return UniqueInstance;
}
}

but Remember that Synchronization is EXPENSIVE.
lets use “double-checked locking” to reduce the use of Synchronization in getInstance()
public class Singleton
{
private volatile static Singleton UniqueInstance;
private Singleton(){}
public static Singleton getInstance()
{
if(UniqueInstance==null)
{
synchronized (Singleton.class)
{
if(UniqueInstance==null)
UniqueInstance=new Singleton();
}
return UniqueInstance;
}
so this check for an instance and if there in not one, enter a synchronized block.
and volatile keyword ensures that multiple threads handle the uniqueInstance variable perfectly.

so hope that now you can perfectly implement Singleton design pattern in you application.

fun with Javascript

ashraf — Thu, 07 Aug 2008 09:07:13 +0000

I faced a problem to call 2 methods at the same time from body. and the solution is very simple. I wrote a script block at the end of the page look like that.