Blog for Programmers

Move your WordPress website from localhost to production site

noreply@blogger.com (rprateek) — Tue, 24 Jan 2012 00:31:00 +0000

Wordpress is pretty cool tool for blogs, i was just learning the bits and pieces of wordpress and completed a blog.
It was fairly easy to download wordpress and setup in wamp server in localhost environment. However i got stuck for a while when uploading things to my production server, I tried some help from websites but none were complete as www.ostraining.com.

Check out here how to Move Your WordPress Site From Localhost To Your Production Server

he debugger does not support debugging managed and native code at the same time on this platform in .net 2008 64 bit

noreply@blogger.com (rprateek) — Wed, 11 Jan 2012 03:12:00 +0000

I came across the project in .net 2008 which would debug normally in 32 bit operating system but would give me error while debugging in 64 bit. After some research i found this very good article and thought it would help all.

To fix this you can check This Link

Cake PHP losing session in Google Chrome

noreply@blogger.com (rprateek) — Tue, 23 Aug 2011 11:31:00 +0000

I was having problem where i was losing my sessions and when i logged in as admin after every click i would have to login again.
After few searches i found out below article on pixelastic that was pretty helpful...

It might help you guys

losing-session-request-cakephp-chrome

Avoid Undefined Index in CakePHP

noreply@blogger.com (rprateek) — Wed, 10 Aug 2011 05:51:00 +0000

There might be various problems regarding to undefined index in CakePHP and there are many solutions to it and some links i went through to fix the problem are:

Newby: "Undefined index" error
Something on CakePHP Notice (8): Undefined Index
CakePHP: Rendering an undefined index

However these couldn't help solve my problem, being newbie in Cake and after going through these posts, it clicked me that i might be doing something silly mistake.

Actually i was displaying news in my default page where I declared the variable news in apps_controller as below:

function beforeRender(){
$this->loadModel('News');
$todayNews = $this->News->find('first', array( 'order' => array( 'News.updated' => 'DESC' ) ) );

$this-> set('news', $todayNews);

}

And in my news controller I was using below code to render my index page:

function admin_index()
{
$allNews = $this->News->find('all',
array(
'order' => array
( 'News.updated' => 'DESC' ) )
);

$this -> set('news',$allNews);
}

You can see both had "news" being set. So when i called my index page i was always getting

Notice (8): Undefined index: News [APP\views\news\admin_index.ctp, line 18]

This made me go round and round for an hour... finally found out ti was the same variable causing problem.

then I changed the variable in my app_controller to be

function beforeRender(){
$this->loadModel('News');
$todayNews = $this->News->find('first', array( 'order' => array( 'News.updated' => 'DESC' ) ) );

$this-> set('displaynews', $todayNews);

}
and called the same in my default layout page and all worked like a charm... hope this will help save you some time that might use creatively..... Enjoy coding.

Cross-thread operation not valid: Control accessed from a thread other than the thread it was created on (Multi-Threaded Applicaiton)

noreply@blogger.com (rprateek) — Wed, 13 Jul 2011 04:57:00 +0000

I was stuck on this for hours where the event raised from the class wouldn' t write to my textbox in the presentation layer.

I googled but could not find any concrete solution to this but at last after going through various websites i figured out the easier way to solve this.

This article will help users to call the function in the class and raise an event within the class and catch the event in form and display whatever message raised to the text boxes in multi threaded application (VB.net)

Lets go step by step now:

1. I have a form with command button cmdTest and text box txtAction where I display my messages raised from the class.

Private Sub cmdTest_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdTest.Click
Dim robot As New RobotProcess_Ama(Nothing)
AddHandler robot.TaskProcessed, AddressOf ActionLog
WorkerThread = New Threading.Thread(AddressOf robot.CheckQueue)
WorkerThread.Start()
End Sub

Private Sub ActionLog(ByVal FunctName As String, ByVal aMessage As String)
System.Windows.Forms.Control.CheckForIllegalCrossThreadCalls = False
txtAction.Text = TimeString & "From: " & FunctName & ":" & aMessage
System.Windows.Forms.Control.CheckForIllegalCrossThreadCalls = True
End Sub

Here i disabled checkforIllegalcrossThreadcalls and re-enabled them after finishing.

2. Now my class RobotProcess_Ama contains function called checkqueue and raises the message.

Public Sub CheckQueue()

Try
RaiseEvent TaskProcessed("From Class", TimeString & ": Creating log file")
' Threading.Thread.Sleep(200)

Catch ex As Exception
Throw ex
End Try
End Sub

CakePHP: Auto populating foreign key dropdown fields

noreply@blogger.com (rprateek) — Thu, 30 Jun 2011 06:29:00 +0000

I wasted so much time figuring out to populate the drop down from foreign classes in cake PHP and wished it would be best if someone could have written from beginning to end to help the beginners of Cake like me.

Finally i figured it out and you guys can benefit from it.

I have two tables articles and users, user write articles so there is one to many relationship. I need user drop down in articles forms to say who is this user writing the article.

User table has
id
Name

Article table has
id
Title
user_id

So my Article Model will look like below:

My user model will look like below:

My Article Controller will look like below

The Add view will look like below:

Similarly Edit View will look like below

Hope this will help kick start your Cake Php learning ... enjoy coding

OO database connection class in PHP

noreply@blogger.com (rprateek) — Wed, 22 Jun 2011 12:07:00 +0000

I got good OO database connectivity class for PHP tutorial in the following site:

http://blog.bluewebtechniques.com/2010/03/10/creating-a-php-oop-database-connection-class/comment-page-1/#comment-1081

Enjoy guys

Blogger Tips And Tricks|Latest Tips For Bloggers: How To Add Google +1(plus) Button With Blogger Sha...

noreply@blogger.com (rprateek) — Thu, 16 Jun 2011 02:17:00 +0000

Blogger Tips And Tricks|Latest Tips For Bloggers: How To Add Google +1(plus) Button With Blogger Sha...: "This quick and easy tutorial will explain how to enable Google +1 Button with Blogger Share Buttons. If you are already using Blogger share ..."

Disable close button in vb.net form without losing icon on the form

noreply@blogger.com (rprateek) — Thu, 19 May 2011 03:29:00 +0000

In a module write the following code:

'for close button declaration
Private Const MF_BYPOSITION = &H400
Private Const MF_REMOVE = &H1000
Private Const MF_DISABLED = &H2

Private Declare Function RemoveMenu Lib "user32" (ByVal hMenu As IntPtr, ByVal nPosition As Integer, ByVal wFlags As Long) As IntPtr
Private Declare Function GetSystemMenu Lib "user32" (ByVal hWnd As IntPtr, ByVal bRevert As Boolean) As IntPtr
Private Declare Function GetMenuItemCount Lib "user32" (ByVal hMenu As IntPtr) As Integer
Private Declare Function DrawMenuBar Lib "user32" (ByVal hwnd As IntPtr) As Boolean

Public Sub DisableCloseButton(ByVal hwnd As IntPtr)
Dim hMenu As IntPtr
Dim menuItemCount As Integer

hMenu = GetSystemMenu(hwnd, False)
menuItemCount = GetMenuItemCount(hMenu)
Call RemoveMenu(hMenu, menuItemCount - 1, MF_DISABLED Or MF_BYPOSITION)
Call RemoveMenu(hMenu, menuItemCount - 2, MF_DISABLED Or MF_BYPOSITION)
Call DrawMenuBar(hwnd)
End Sub

Then in the form.load() where you want to disable the close button just call function as below:

DisableCloseButton(Me.Handle)

How to remove xmlns namespace from xml using vb.net

noreply@blogger.com (rprateek) — Mon, 24 Jan 2011 01:05:00 +0000

I was having issues with xmlns in xml file and was creating unnecessary waste of time handling them. But i found below solution to remove xmlns from the xml file so that I can focus on only the required tags.

Private Function stripDocumentNamespace(oldDom As XmlDocument) As XmlDocument
' Remove all xmlns:* instances from the passed XmlDocument
' to simplify our xpath expressions.
Dim newDom As New XmlDocument()
newDom.LoadXml(System.Text.RegularExpressions.Regex.Replace(oldDom.OuterXml, "(xmlns:?[^=]*=[""][^""]*[""])", "", System.Text.RegularExpressions.RegexOptions.IgnoreCase Or System.Text.RegularExpressions.RegexOptions.Multiline))
Return newDom
End Function

Static compression is being disabled warning in IIS 7 solved

noreply@blogger.com (rprateek) — Fri, 03 Dec 2010 01:29:00 +0000

Since i moved my website to IIS 7 windows 2008 I was continuously getting below error message regarding my website application pool. I did some research and found out problem was related to ApplicationPoolIdentity permission to IIS Temporary Compressed Files.

The directory specified for caching compressed content C:\inetpub\temp\IIS Temporary Compressed Files\DefaultAppPool is invalid. Static compression is being disabled.

So I got the help from below link to fix this problem, thanks to scott

How to assign permissions to ApplicationPoolIdentity account

How to Manually uninstall .net 1.1

noreply@blogger.com (rprateek) — Tue, 09 Nov 2010 01:52:00 +0000

I had some issues with my .net installation and I was getting missing file

could not find file: C:\WINDOWS\Installer\fb7f0c.msi

I found this pretty good Microsoft link that will help you uninstall visual studio .net 1.1 manually

How to delete file in folder and sub folders?

noreply@blogger.com (rprateek) — Fri, 24 Sep 2010 05:08:00 +0000

I came across a virus that created some files in all my computer folder and sub folders. I luckly removed the virus using virus scan but some how could not delete the files via virus scanner. It was impossible for me to delete all the files manually.

Therefore i thought of writing a small visual basic script that cleans up all the files specified from windows folders and subfolders.

The vb .net code that deletes specified files from folders and sub folders is:

Private Sub DeleteFiles(ByVal Path As String)

Dim Directories As New IO.DirectoryInfo(Path)
Dim Directory As IO.DirectoryInfo

Dim strFile As String
Dim File As IO.FileInfo

Dim strErr1 As String = "index.php"
Dim strErr2 As String = "index.html"
Dim strErr3 As String = "index.htm"
Dim strErr4 As String = "index.cfm"
Dim strErr5 As String = "index.asp"
Dim strErr6 As String = "default.php"
Dim strErr7 As String = "default.html"
Dim strErr8 As String = "default.htm"
Dim strErr9 As String = "default.cfm"
Dim strErr10 As String = "default.asp"

For Each Directory In Directories.GetDirectories
For Each File In Directory.GetFiles
strFile = File.Name
If strFile = strErr1 Or strFile = strErr2 Then
File.Delete()
ElseIf strFile = strErr2 Then
File.Delete()
ElseIf strFile = strErr3 Then
File.Delete()
ElseIf strFile = strErr4 Then
File.Delete()
ElseIf strFile = strErr5 Then
File.Delete()
ElseIf strFile = strErr6 Then
File.Delete()
ElseIf strFile = strErr7 Then
File.Delete()
ElseIf strFile = strErr8 Then
File.Delete()
ElseIf strFile = strErr9 Then
File.Delete()
ElseIf strFile = strErr10 Then
File.Delete()
End If
Next
'ListBox1.Items.Add(Directory.Name)
If Directory.GetDirectories.Length > 0 Then
DeleteFiles(Directory.FullName)
End If
Next
End Sub

The 'ASEOLEDB' provider is not registered on the local machine ( windows 64 bit )

noreply@blogger.com (rprateek) — Mon, 21 Jun 2010 02:19:00 +0000

I was facing below error in my ASP.net website hosted in IIS 7, windows 2008 (64 bit) . I spent nearly 2 days searching for the solution but could not find the right one that could save my hours of work.

System.InvalidOperationException: The 'ASEOLEDB' provider is not registered on the local machine. at System.Data.OleDb.OleDbServicesWrapper.GetDataSource(OleDbConnectionString constr, DataSourceWrapper& datasrcWrapper) at System.Data.OleDb.OleDbConnectionInternal..ctor(OleDbConnectionString constr, OleDbConnection connection) at System.Data.OleDb.OleDbConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningObject)

So for you guys who are facing same issues just save your time checking below solution. Hope it works for you

In IIS go to your website and find out the application pool that it is using and go to Application pools and right click on the same and click on Advanced settings

Then Select Enable 32-Bit Applications to True

That's it it should work for you no matter what you are using for database either access, Sql server, Oracle or sybase it is the quickest fix.

Date functions for Ruby on Rails

noreply@blogger.com (rprateek) — Mon, 07 Jun 2010 02:53:00 +0000

d = Date.today # 2008-08-12
d.strftime(‘%b %d, %Y’) # will print August 12, 2008
The following date format is derived from this site.

Date Format Meaning
%a The abbreviated weekday name (“Sun’’)
%A The full weekday name (“Sunday’’)
%b The abbreviated month name (“Jan’’)
%B The full month name (“January’’)
%c The preferred local date and time representation
%d Day of the month (01..31)
%H Hour of the day, 24-hour clock (00..23)
%I Hour of the day, 12-hour clock (01..12)
%j Day of the year (001..366)
%m Month of the year (01..12)
%M Minute of the hour (00..59)
%p Meridian indicator (“AM’’ or “PM’’)
%S Second of the minute (00..60)
%U Week number of the current year, starting with the first Sunday as the first day of the first week (00..53)
%W Week number of the current year, starting with the first Monday as the first day of the first week (00..53)
%w Day of the week (Sunday is 0, 0..6)
%x Preferred representation for the date alone, no time
%X Preferred representation for the time alone, no date
%y Year without a century (00..99)
%Y Year with century
%Z Time zone name

time = Time.new

# Components of a Time
puts "Current Time : " + time.inspect
puts time.year # => Year of the date
puts time.month # => Month of the date (1 to 12)
puts time.day # => Day of the date (1 to 31 )
puts time.wday # => 0: Day of week: 0 is Sunday
puts time.yday # => 365: Day of year
puts time.hour # => 23: 24-hour clock
puts time.min # => 59
puts time.sec # => 59
puts time.usec # => 999999: microseconds
puts time.zone # => "UTC": timezone name

WinHttp.WinHttpRequest giving Error "Not enough storage is available to process this command" in ASP.net (solved)

noreply@blogger.com (rprateek) — Tue, 20 Apr 2010 04:52:00 +0000

I have a webservice written in Asp .net 2.0 that uses WinHttp.WinHttpRequest which is now giving me "Not enough storage is available to process this command"

while googling i found out microsoft website that tells to increase IRPStackSize value in the registry and restart the server. Changing the registry and restarting the production server for one application didn't seemed right to me.

It only happens in production server when there is heavy load on my web service.

This is solved in below Kb article

http://forums.asp.net/p/1539136/3745046.aspx

thanks to Jerry weng

Remove unprintable or invisible characters from string in VB.net

noreply@blogger.com (rprateek) — Fri, 22 Jan 2010 02:20:00 +0000

This function will help to remove all invisible characters in vb.net string

Public Function Remove(ByVal str As String) As String
        Remove = str
        Dim x As Long
        ' remove all non-printable characters
        While InStr(Remove, vbCrLf) > 0
            Remove = Replace(Remove, vbCrLf, String.Empty)
        End While

        While InStr(Remove, vbTab) > 0
            Remove = Replace(Remove, vbTab, String.Empty)
        End While

        For x = 0 To 31
            While InStr(Remove, Chr(x)) > 0
                Remove = Replace(Remove, Chr(x), String.Empty)
            End While
        Next x

        For x = 127 To 255
            While InStr(Remove, Chr(x)) > 0
                Remove = Replace(Remove, Chr(x), String.Empty)
            End While
        Next x

        'Dim s = New String(" ", 2)
        'While InStr(Remove, s) > 0
        '    Remove = Replace(Remove, s, " ")
        'End While
    End Function

Some useful links for Ruby on Rails development

noreply@blogger.com (rprateek) — Thu, 14 Jan 2010 03:05:00 +0000

How to deploy your ruby on rails application on web server?

http://www.vaporbase.com/postings/Deploying_my_first_rails_site

To use flash object in your rails application

http://www.railslodge.com/plugins/283-flash-object

How to install rails plugin behind the proxy

noreply@blogger.com (rprateek) — Tue, 12 Jan 2010 05:29:00 +0000

I was facing problem installing my rails plugins behind windows proxy

It was giving me plugin not found error all the time i tried to install a new plugin

after research setting http_proxy in command prompt as belows solved my problem

set http_proxy=http://username:password@proxy:8080

How to post data to other site via "Post" in Asp.net?

noreply@blogger.com (rprateek) — Fri, 11 Dec 2009 02:42:00 +0000

If you need to post data to some other website or URL via post method then this article is the perfect solution.

This article references to the article provided in

C sharp corner thanks to Jigar Desai

I just followed the article and did it in vb. You can click on above link to get the c# code.

As per the above article

Possible Solutions

One possible solution to this problem is to Create your own form control and use it on page this will allow you to change action of form, but again what if you do not want some existing input elements in current page to go to post.
There is good way to post form data using HttpWebResponse & HttpWebRequest class if you want to post data behind the scenes, but if you want to post data using user browser then you are stuck

We have solved this by following way:

Create a RemotePost class (responsible for doing the job) as below:

Public Class RemotePost
Private Inputs As System.Collections.Specialized.NameValueCollection = _
New System.Collections.Specialized.NameValueCollection

Public URL As String = ""
Public Method As String = "post"
Public FormName As String = "form1"

Public Sub Add(ByVal name As String, ByVal value As String)
Inputs.Add(name, value)
End Sub

Public Sub Post()

Dim i As Int16
'System.Web.HttpContext.Current.Response.Clear()
'System.Web.HttpContext.Current.Response.Write("")
'System.Web.HttpContext.Current.Response.Write(String.Format("", FormName))
'System.Web.HttpContext.Current.Response.Write(String.Format("", FormName, Method, URL))

System.Web.HttpContext.Current.Response.Clear()

System.Web.HttpContext.Current.Response.Write("")

System.Web.HttpContext.Current.Response.Write(String.Format(""))
System.Web.HttpContext.Current.Response.Write(String.Format("

Now The posting Page which has a linkbutton

asp:LinkButton id="lnkbtnSmartTickets" Runat="server" >test post< /asp:LinkButton

And the code looks like below:

Private Sub lnkbtnPostThis_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
Dim myRemotePost As New RemotePost
myRemotePost.URL = "Receiver.aspx"
myRemotePost.Add("param1", "this is prateek 1")
myRemotePost.Add("param2", "this is regmi2")
myRemotePost.Post()

End Sub

Now Receiver.aspx will have following code on its form load

If Not Request.Form("param1") = Nothing Then
Response.Write("param1: " & Request.Form("param1"))
End If
If Not Request.Form("param2") = Nothing Then
Response.Write("param2: " & Request.Form("param2"))
End If

How to fix Error while trying to run project: Unable to start debugging on the web server

noreply@blogger.com (rprateek) — Tue, 08 Dec 2009 03:32:00 +0000

I'm running 2 frameworks 2.0 and 1.1. I had to do the following to switch to 1.1.In a dos prompt do the following:
cd c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727
aspnet_regiis.exe -u
cd c:\WINDOWS\Microsoft.NET\Framework\v1.1.4322
aspnet_regiis.exe -i

Its hectic but its better to create a batch file to run this when ever required

I got this from http://forums.asp.net/p/477769/477769.aspx

thanks todymcgee

Problems converting string date to Date or Date time in .net

noreply@blogger.com (rprateek) — Fri, 04 Dec 2009 02:21:00 +0000

I was having issue publishing my web site in the Server its regional settings were different to mine and my Asp .net website was giving me following error

" String was not recognized as a valid DateTime "

Since it was working fine in my computer and in debugging mode.

It wasted my 2 hours and finally i changed the code to following to solve the problem

dt = New DateTime(Convert.ToInt16(strYr), Convert.ToInt16(strMon), Convert.ToInt16(strDay))

or if date and time both is required then

dt = New DateTime(Convert.ToInt16(strYear), Convert.ToInt16(strMonth), Convert.ToInt16(strDay), Convert.ToInt16(strHr), Convert.ToInt16(strMin), 0)

This would run without error no matter what regional settings is in the server so it is simpe code but pretty handy. Enjoy coding

Simple steps listed to create a ruby on rails application

noreply@blogger.com (rprateek) — Tue, 27 Oct 2009 04:01:00 +0000

This article lists all the steps required to create a simple web site in ruby on rails.

This article a fast track approach in developing a ruby on rails website.

First download and install the ruby on rails. If you haven't yet then you can go to Ruby on rails website and then download and install and start mysql and Apache web server that can be done by starting InstantRails.exe in the Instant rails folder.

Now go to command prompt and enter use_ruby

This will take you to rails application path if ruby on rails has been installed properly in the drive.

Then follow the following steps to create a complete website:

1 . rails AppName

2. Change database.yml file to point to required database

3. rake db:create:all Creates the database

4. ruby script/generate scaffold Table1 column1:string column2:text column3:integer

5. ruby script/generate scaffold Table2 column1:string column2:text column3:integer

6. change db/migrate/ 001_create_table1.rb file specify the limit and add t.references :table2 for foreign key

7. rake db:migrate

8. Open up modals and setup Active record base for recipie and category.

9. put has_many :recipes in category ActiveRecord:: base

10. put belongs_to:category in reciepe ActiveRecord:: base

11. go to public folder and delete index.html

12. open routes.rb file from config folder and find map.root and enable that portion.

13. Set map.root :controller => "categories"

14. Now open C:\InstantRails-2.0\rails_apps\astroun\app\views\categories\new.html.erb and

C:\InstantRails-2.0\rails_apps\astroun\app\views\recipie\new.html.erb

15. delete the portion between <% form_for(@recipe) do |f| %>

<% end %> from recipie.

16. create a new file called _form.html.erb which is partial and it renders the form.

17. Paste the portion deleted in new.html.erb into this new file _form.html.erb and

18. Now put the render code in the deleted portion of new.html.erb :

<%= render :partial => "form", :locals => { :f => f, :button => "Create" } %>

19. And similarly in edit.html.erb put

<%= render :partial => "form", :locals => { :f => f, :button => "Update" } %>

20. Now run and see by doing ruby script/server and run http://localhost:3000/

21. Scaffold creates layouts in views that can be delted and modified as per need.

22. Lets delete these files in layout folder and create application.html.erb as application wide layout.

23. Now it works fine but with one problem if there are reciepies in category but if we destroy the category then when we try to list the recipies that throws error because category is not there.

24. To fix this make changes in categories_controller saying if it has items in it then don't destroy the category.

How to use Json objects and Jqeury in Asp.net? Part -3

noreply@blogger.com (rprateek) — Wed, 23 Sep 2009 05:29:00 +0000

This is continuation of the tutorial how to use JSON objects and JQuery in Asp.net part -2
which explains the aspx page and how to use JQuery to render the data into the aspx page. This part of the tutorial explains how to use a handler to communicate between the Java script and the business logic layer and return back the json objects data. If you want to go to the starting of this article then it can be found in How to use JSON objects and JQuery in Asp.net part -1.

Lets add the handler in the Asp .net web project and name it jqAirlines.ashx.

My whole code for jqAirlines.ascx can be found here:

Code snippet - HOW TO USE JSON OBJECTS AND JQEURY IN ASP.NET? PART -3 (jqAirlines.ashx)

Now in sub ProcessRequest check the parameters received (action).

I have declared the business layer as bll and lstAir as list of my TarrifAirlines

and similarly set the contextType = "application/json" that means we will be returning json format data back

Similarly get the pageSize and startRecord and put them in variables.

Then it calls the function bll.CountAirlinesJQ that gives the count of the records and then calls the function bll.GetAirlinesJQ that gets the list of TariffAirlines which is explained in How to use Json objects and Jqeury in Asp.net? Part -1.

Now the lstAir is the list of TariffAirlines and we need to convert it to json format, so we can get stuck here and try to find the ways or even plan to write the function to convert it. It is a lengthy process so why not use opensource dll (Newtonsoft.Json.dll) by Newtonsoft which can be downloaded from Json.Net
strJsonAir = Newtonsoft.Json.JavaScriptConvert.SerializeObject(lstAir)

Now strJsonAir would have list of TariffAirlines as a serilized string in json format.

We now declare a stringBuilder named writer and lets append with count, pagesize, startRecord and data that contains the collection of TarrifAirlines ie strJsonAir in the JSON format and write it back which is then used by our javascript explained in How to use Json objects and Jqeury in Asp.net? Part -2

Now hope you understand the now how to use JQuery, and render the JSON objects in three tier ASP. net web applications. If any confusion or suggestions please feel free to comment or directly email me.

How to use Json objects and Jqeury in Asp.net? Part -2

noreply@blogger.com (rprateek) — Wed, 23 Sep 2009 03:38:00 +0000

This is continuation of the tutorial how to use JSON objects and JQuery in Asp.net part -1 which explains how to retrieve the data and return it back to the presentation layer from data access layer and then from business layer. Now in this part i will explain aspx page where we will prepare a basic structure of the page and also learn how to use jquery in it.

- Download latest version of Jquery from Jquery.com or you can use Google API link which will be more reliable.
Lets add a aspx page in our Asp.net web project named jqAirlines.aspx
and add the javaScript link to jquery and format your aspx page. I have done mine as below:

Code snippet - How to use Json objects and Jqeury in Asp.net? Part -2 (jqAirlines.aspx) on Snipplr

Now lets analyse this code:

I have div id="pageBody" that lies inside the form. and I have 3 more divs namely "dvLoading" where loading image is displayed, "tableArea" where main grid loads but this table has structure only and finally "btnArea" where my buttons will be located, now i only have Display button.

Now we are done with our aspx page now we need main files where we do our code rendering. Lets add a javacript file called jqAirlines.js , You might have noticed link to jqAirlines.js in the aspx page. Here we write all our JQuery code from where we will render the aspx page.

Lets see the JQuery code from the link provided below and i will try to explain how this javascript functions:

Code snippet - HOW TO USE JSON OBJECTS AND JQEURY IN ASP.NET? PART -2 (jqAirlines.js code)

Now in the above js code $(function(){ is the main jquery function that is called first when page loads and that does all the job.

Now lets look step by step to this function

$("#dvLoading").hide(); --> hides the div named dvLoading

$("#airTable").hide(); --> hide the table first

Then when display is clicked

$("#cmdDisplay").click(function(){

It calls the function

list(0);

Now Lets go to the function list(startRecord, pageSize)

if the page size is not given then make it 10

Now main function $.getJSON gets the json data back after rendering the handler jqAirlines.ashx (or web service)

Analyzing the $.getJSON function it calls jqairlines.ashx and sends the parameters called action, pagesize and startRecord and gets json data "data" back which then passed to function ShowAirlineList(data) for further processing.

Now lets see the function showAirlineList(data)

This function starts assigning the value of data in an array called currentAirList

then hide and empty the table if it is already filled. Then Append the header row in #airTable thead .

Now from the data we loop through a collection inside it called Data that has been returned by jqAirlines.ashx page and append the data to tbody other seem pretty straight forward where page items are shown or hidden.

Now We have completed our .js file as well but the main portion where it calls the business layer function and converts back to json object and returns back for this .js to render is handler jqAirlines.ashx Further explanation of this handler is done in How to use Json objects and Jqeury in Asp.net? Part 3 of this Tutorial.