"Object Expected" error in MVC JQuery autocomplete

Problem :-


I have been working in MVC and its very interesting to work with it. I just started working on JQuery. I have encountered this problem when implementing autocomplete to Text box in MVC with JQuery. The JavaScript error "Object Expected" will be coming when you reload the page. That means during first time load, there will be no problem. But if you click on paging and try to do autocomplete in text box. You could face this error in autocomplete statement.

Solution :-


Normally  we used to include the Jquery files by dragging to the page. When we drag the files, the following text will be added,

<script src="../../Scripts/jquery-1.4.1.js" type="text/javascript">

The blue color text shows like the Scripts directory is placed inside one folder from the root. But its not like that. Its placed directly under the root.

So change that script include to the below one.

<script src="/Scripts/jquery-1.4.1.js" type="text/javascript">


This will solve your problem.


Conclusion :-


This may be the small issue but kill your time like anything. You won think the problem due to this script include tag. 


Happy Coding.. :)

Assign default text in Html.TextBoxFor

To assign textbox value in MVC view, use the following syntax.

<%= Html.TextBoxFor(x => x.EmployeeName, new { @Value = "Enter Employee Name"}) %>

Here the @Value case is must.

MVC Cascading dropdown, Jquery Grid and Resolving circular references

1. Look at the below link by Stephen Walther to work on Cascading dropdowns

http://stephenwalther.com/blog/archive/2008/09/07/asp-net-mvc-tip-41-creating-cascading-dropdown-lists-with-ajax.aspx

You may face this circular reference error due to referring one class in another class for foreign key relation,

can use the below link to solve that problem

http://blogs.telerik.com/atanaskorchev/posts/10-01-25/resolving_circular_references_when_binding_the_mvc_grid.aspx

2. jquery provides the Grid with paging and sorting. check with the below link

http://haacked.com/archive/2009/04/14/using-jquery-grid-with-asp.net-mvc.aspx

Thanks to respective authors..

Deploy Webparts in Sharepoint Server 2007

Steps to deploy Webpart in Sharepoint Server 2007 


1. Copy themes files to C:\Inetpub\wwwroot\wss\VirtualDirectories\80\_themes if you have it in webpart.


2. Open web.config file under the port 80 C:\Inetpub\wwwroot\wss\VirtualDirectories\80\ 


3. Add assembly information to safecontrol tag 


    Ex. <<SafeControl Assembly="HelloworldWebPart, Version=1.0.0.0, Culture=neutral, PublicKeyToken=9f4da00116c38ec5" Namespace="HelloworldWebPart" TypeName="HelloworldWebPart" Safe="True" />>


4. Move the webpart assembly file(.dll under bin folder) to GAC.


5. Restart IIS using iisreset command


6. Go to webpart Gallery and click New on the top.


7. You could find your webpart, select the webpart and click populate button to load the webpart to Gallery.


8. Eventually create a webpart page and add this webpart to the web page.


9. Hope you could see the result displayed in the webpage in the form of webpart.




Happy Coding...

MVC Basics

Model View Controller [MVC]


MVC is a design pattern which separates the Business Logic, User Interface and Controlling user inputs. It consists of Model, View and Controllers. 


Let we see about each components...


Model


Model represents the data model which contains the all DB related operations including select, insert, delete and update. I have used Entity Data Model(edmx) to build model for my application. We can also have classes to represent the DB operations like DAL.


View


The view describes the user interface which will appears to the user. Normally the page files(.aspx) with html design is called views. It doesn't contain the code behind file. since its not event driven.


Controller  


Controllers are class file which should be derived from the base class Controller. Basically controllers determine which view should be called based on the URL routes. The default route is defined in the Application_Start() event of Global.asax.


Sample Application


I'd like to create one sample application so that you could understand more clearly how the model, view and controllers are interacting each other with real time scenario.


Purpose


To display all the Employees from Northwind database Employees table.


Step 1 : Creating ASP.NET MVC Web Application


Create ASP.NET MVC Web Application under .Net Framework 3.5. Note that we have created MVC Framework 1.0. Refer the below image how the solution looks,

If you look at the project structure, you could find Controllers, Models and Views folder to hold the respective files.

Step 2 : Add Controllers

Right click on the Controllers folder and select Add Controller menu, it will open a popup (see the below image) to give the controller name with suffix of controller.

It also has the check box to Add action methods for create, update and Details scenarios. If you check this box it will create controller action for the Create, update and details action.

Step 3 : SampleController File

After you click that Add button, it will add controller file to Controllers folder. Look at the below image how it looks like.

The Class contains Index method with the type of ActionResult and return View(). The controller is ready now. We have to create Model and View to make this work.

Step 4 : Create Model

Creating model is very easy as we are going to use Entity Data Model(edmx). Right click on the Model folder and select New Item. Select Data from Category then select ADO.NET Entity Data Model. A pop up will open and select Generate From Database. 

Click Next and select the server and database to create Model.You could find the Model1.edmx under Model folder.

Good.. Model is ready to consume the data from Database.

Step 5 : Add Code in Controller file

Add Model Namespace to controller file in order to get the classes from the Model.

public ActionResult Index()

{

NorthwindEntities nw = new NorthwindEntities();

var emp = nw.Employees;

return View("Index",emp);

}

Add the above code into method Index of the controller file created. The first line is creating the instance for the model which we have created from Northwind/any other DB. The Employees is a ObjectQuery which will return all the employees from the database. The var defines the Object which can be bind to the View. The last line return the View with the view name called "Index" and the datasource object.

Note: Here we are calling the view from Controller.

Step 6 : Creating View

Right click on the Above ActionResult Index and click Add View. Now you could see the below image...

The View name will come by default. Check Create a strongly-typed view and  you have to choose the Model from the Model(.edmx) class here am using Employees. In addition with select view content, We are going to display all the employees so select List. Note that the user can select the Master page for the view.

Finally click Add. 

Step 7 : Index View

If you look at the Views Folder, new folder has created with the controller name(Sample). Inside Sample folder, file named Index.aspx created with all the table fields to display the list of employees.

Its really amazing when see it first time. No need to drag and drop any controls or write any html code to build the tables. Simply all the html codes are in the view.If you look in deep you could see the binding has also been included in the html code.

Index View Code

It loop through all the items in the Model(The model selected for this view is Employees) and build the html table. The arrow indicates the loop and how the field has been binded with the table cell. Also note that the Edit/Details/Delete links are created for each row. This will help you to edit the particular row or to see the details about the row. Don worry about this at present. We have to build view to display the details/edit the row.

The Application is ready except one below configuration settings step. 

Step 8 : Configure in Global.asax

The Global.asax is located in the applications root directory and open it.

Global.asax

The Application_Start() call the RegisterRoutes method and pass the RouteTable.Routes as parameter. We are going to add the default route to the routes. The green color bordered area shows how to add MapRoute to the Routes. The "Default" is the route name, next one is format and last on is value for the format. For the above definition, the URL looks like http://localhost:1173/Home/Index. Home is a Controller and Index is a View. 

Step 8 : Run the Application

Run the application and this will display the default page (Home\Index.aspx)

If you want to access our page which we have developed, Change the URL to the below one,

http://localhost:1173/Sample/Index or http://localhost:1173/Sample is enough since Index is a default page.

Here is our First MVC output..

This is really nice to see the output without coding much...

Happy Programming...

Service unavailable error when browse pages in Windows 2003

Getting "Service unavailable" error when you try to access the web pages hosted in Windows 2003 server.

Resolution 1


Right click on website and click Properties menu. you could find "Web Site" tab.


Check for TCP Port Number. Change the port number which is not assigned to any other web site. The other virtual directories(web sites) may access the same port no.

Resolution 2

1. Right click on website and click Properties menu. Click on "Home Directory" tab.

2. Get "Application pool" name and verify whether that application pool service has started.

3. "Application Pools" exists above the websites folder.

Conclusion


I have faced the above said error and rectified using the resolution2.


.

Gridview - Highlight selected row after Postback

Problem:

I have a gridview to display employee information. When user clicks on employee no /name the particular row should be selected and selected row color should be changed. This has to be done after the postback.

Solution:

Since we are doing it after postback, the control losts the data as well selected row. We can do this with linkbutton control to change the color of the selected row very easily.

code snippet:

If you look at the snippet in the first image, I have used the linkbutton inside the itemtemplate. The important thing here is the property CommandName as Select. This property will take care of the selected row color changes. The row selection color will be taken from the SelectedRowStyle styles from the gridview.

Conclusion:

Hope this will be easy for everyone rather than doing it after the binding the grid with some extra code.

Happy coding...

Open a page in the same browser using JavaScript without Postback

Problem:

Had a requirement to open up a page in the same browser window without postback to the existing page.

Solution:

In JavaScript, window.Open(...) is there to open a page in a new window. With the value of _self as a second parameter to the Window.Open, we could open the page in the same browser window.

Code Snippet:

#1 Using Image Button

OnClientClick="Javascript:window.open('Format.aspx','_self',null,false);return false;" />

#2 Using href anchor tag

href="javascript:window.open('Format.aspx','_self');" style="text-decoration:underline" id="A1" >Click...Here

I have opened the page called "Format.aspx" using window.open with the second parameter as "_self" on the OnClientclick of ImageButton. Finally give the return false to not posted back to the existing page.

Reference:

Refer the below Microsoft knowledge base library for more info.

http://msdn.microsoft.com/en-us/library/ms536651(VS.85).aspx

Windows ReportViewer - Change rdlc report files during runtime

Problem

I had faced the problem of assigning different rdlc report files to a single Reportviewer. It always shows the report which opened first.

Solution

1. Clear the datasources of the LocalReport or ServerReport in ReportViewer
2. Reset the ReportViewer control in the beggining of the function.
3. Do assign the datasources Name and Value. The Datasources name from the dataset as string and value.
4. Finally add the datasource to the reportviwer datasource in localreport or serverreport.

Sample c# code snippet to solve this problem

this.reportViewer1.Reset();

this.reportViewer1.LocalReport.DataSources.Clear();

reportDataSource.Name = "DataSet_usp_EmpFoodCouponMonthly";

reportDataSource.Value = this.DataSet.usp_EmpFoodCouponMonthly;

this.reportViewer1.LocalReport.DataSources.Add(reportDataSource);

this.reportViewer1.RefreshReport();

Difference between Postback and Callback

The OnPreRender won't be fired in the Callback event. Whereas in Postback, After the particular event handling, the PreRender will be invoked.

But all the controls will be created again in both Postback and Callback. The viewstate values will be reassigned to the controls again.