Search Function and User Controls

hpox · December 22nd, 2006, 03:55 PM

Hi, I posted the same question in the ASP.NET 2.0 Professional forum but thought that this forum might be more appropriate since we're following this book.

I implemented a search functionality to a website. That website was developed using a 3-layers architecture as described in Bellinaso's Problem - Design - Solution.

I use a custom control ProductListings.ascx to show the results. Basically, the Recherche class take a string and return a List<Product>. Then the GridView use that List<Product> to show all the results found by the search.

Code:

<asp:ObjectDataSource 
    ID="objRecherche"
    runat="server"
    SelectMethod="SmartSearch" 
    TypeName="SiteWeb.BLL.Services.Recherche">
    ...

<asp:GridView 
    ID="GridView1" runat="server"
    DataSourceID="objRecherche"
    ...

What we want to add is a way to add more information than only the results via a GridView. For example, we want to print the keywords that were used to search for these products, the time taken to process the search, a special message when there is no product.

The Recherche class does more than just pass the search string to the DAL. It will take a string such as "le ski de fond", cut it into 4 words and remove "le" and "de" because they're article. So it will pass ["ski", "fond"]. I want to print that on the result page so the user knows "le" and "de" were not taken into account.

My idea was to add properties (keywords, timeTaken) inside the Recherche object that can be set during the algorithms. Then inside the control, get those properties and print whatever I want before the GridView using either another control or just a Literal.

So, my question is "how do I do this?" and if it's not possible, "what should be done instead?" I tried to do this in the control but it didn't work:

Code:

<asp:Literal runat="server" Text='<%# Test() %>' />

protected string Test()
{
  return ((Recherche)objRecherche).MyProperty;
}

Thanks

englere · December 24th, 2006, 01:42 AM

Did you try this with a label control?

Did you view the page source at runtime to see what was rendered?

Try it like this first to see if that works:

protected string Test()
{
return "test";
}

Eric

hpox · December 24th, 2006, 03:38 PM

Thank you Eric. Of course that would work. What doesn't work is we cannot cast an ObjectDataSource to our BLL object.

Our problem is that there is no way to get the Recherche object that was used as an ObjectDataSource because it was instanciated declaratively in the ASCX file.

hpox · January 8th, 2007, 11:00 AM

I'm posting this message in case it can be of help to anybody searching for a similar solution.

Our solution was to 1) Instanciate our object in the code-behind file of the aspx page. 2) Get the GridView of our control by using the FindControl() method. 3) Bind the instanciated object as the DataSource of the GridView. Doing that permit us to have our BLL object with the necessary info. The drawback is that the Control is not self-contained. Everyone that wants to use the control must use a similar procedure to bind the DataSource.

Note that since the DataSourceId of the control is not set, we had to manually implement the page change method into the code-behind of the control because it would throw an exception about PAGE INDEX CHANGING everytime we clicked on the 1 2 3 4 5 ... links.

Code:

protected void gridView_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
   gridView.PageIndex = e.NewPageIndex;
   gridView.DataBind();
}