Difference between LinqDataSource_inserting and DetailsView_ItemInserting?

robbaralla · January 27th, 2010, 10:53 AM

Hello Imar,

Could you explain why in AddEditReviews you use

Code:

protected void DetailsView1_ItemInserting(object sender, DetailsViewInsertEventArgs e)
    {
        e.Values["UpdateDateTime"] = DateTime.Now;
    }

and in NewPhotoAlbum you use

Code:

protected void LinqDataSource1_Inserting(object sender, LinqDataSourceInsertEventArgs e)
    {
        PhotoAlbum myPhotoAlbum = (PhotoAlbum)e.NewObject;
        myPhotoAlbum.UserName = User.Identity.Name;
    }

couldn't you in the last case just as well have used

Code:

protected void DetailsView1_ItemInserting(object sender, DetailsViewInsertEventArgs e)
    {
        e.Values["UserName"] = User.Identity.Name;
    }

The thing is that I am a bit confused when to use which eventhandler.

Here in both cases the LinqDs is connected to a DetailsView, and I noticed that in ManagePhotoAlbum, that you prefer to use LinqDataSource_inserting for inserting the imageUrl.

So what's the rule here?

Best regards, Robin

Imar · January 27th, 2010, 11:42 AM

Hi Robin,

Yes, that would certainly work as well.

Personally, I prefer LinqDataSource1_Inserting over DetailsView1_Inserting as I get strongly typed access to my object. The DetailsView doesn't support it, so you need to use string literals which can easily break things. For example, what if you accidentally typed:

Code:

e.Values["UsrName"] = User.Identity.Name;

Or what if you renamed the UserName property to just User? With a string literal you wouldn't notice it until run-time. By accessing a strongly typed property of PhotoAlbum you can catch these kind of errors at development time.

In AddEditReview.aspx you can't do this and need to use the DetailsView1_Inserting as that pages uses a (weakly typed) SqlDataSource.

Hope this clarifies things a bit.

Cheers,

Imar
---------------------------------------------------------------------------------------------------------------------
Imar Spaanjaars
Web: Imar.Spaanjaars.Com Twitter: ImarSpaanjaars

Author of Beginning ASP.NET 4 : in C# and VB | Beginning ASP.NET 3.5 : in C# and VB | ASP.NET 2.0 Instant Results.
While typing this post, I was listening to: Loose Fit by Happy Mondays (Track 5 from the album: Pills 'N' Thrills And Bellyaches) What's This?

barakros · January 27th, 2010, 12:02 PM

hi
is it right to say that when using Linq we can use the LinqDataSource1_Inserting or other events since we have stronly typed access
and when using sqldatasource we better use the data bounding object (i.e. gridview, detailsview etc...) ing functions (i.e. inserting,updating ,deleteing)
and use

Quote:

e.Values["UpdateDateTime"] =someValue

or we can use this syntax in the sqldatasource "ing" functions as well:

Quote:

Protected Sub SqlDataSource1_Inserting(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.SqlDataSourceCommandEven tArgs) Handles SqlDataSource1.Inserting
'do soething with e
'like e.Command.Parameters("somefield") or something?
End Sub

thanks
Barak

Imar · January 27th, 2010, 12:08 PM

Yes, that's correct. And yes, you could use the Inserting event of the SqlDataSource using something like this:

Code:

e.Command.Parameters["@UpdateDateTime"].Value = DateTime.Now;

Personally, I find indexing the Parameters collection and using the @ symbol a bit verbose and prefer the simpler

Code:

 e.NewValues["UpdateDateTime"] = DateTime.Now;

instead, but I guess that's a matter of personal taste...

Imar
---------------------------------------------------------------------------------------------------------------------
Imar Spaanjaars
Web: Imar.Spaanjaars.Com Twitter: ImarSpaanjaars

Author of Beginning ASP.NET 4 : in C# and VB | Beginning ASP.NET 3.5 : in C# and VB | ASP.NET 2.0 Instant Results.
While typing this post, I was listening to: Michael by Franz Ferdinand (Track 9 from the album: Franz Ferdinand) What's This?