Response.Redirect

dstreeter · November 30th, 2010, 05:11 PM

Hi Imar,

I'm still having a great time reading the book and trying to develop my golf club web application. The exercise in Chapter 14 that creates new PhotoAlbums then allows adding Pictures makes use of passing a newly created ID of the PhotoAlbum to the next page (ref Chap 14, p 502 in the how it works discussion).

The VB.NET code is:
Dim myPhotoAlbum As PhotoAlbum = CType(e.Entity, PhotoAlbum)
Response.Redirect(String.Format("ManagePhotoAlbum. aspx?PhotoAlbumId={0}", myPhotoAlbum.Id.ToString()))

In my application, I want to pass the Id as well as the Name to the next page. I've been trying to make this work, but apparently have not used correct syntax for passing both of these parameters. Am I missing something in order to send myPhotoAlbum.Name (in addition to the Id already shown in the example)?

Thanks.

Imar · November 30th, 2010, 06:08 PM

Hi there,

You can separate parameters with an &:

String.Format("ManagePhotoAlbum.aspx?PhotoAlbumId= {0}&Name={1}", someId, someName)

Hope this helps,

Imar

dstreeter · November 30th, 2010, 06:23 PM

Imar,

Thank you - it works great. Seems like I was using every wrong variation of this syntax.

I searched the web last night to try and get this right, but never found a great example that I understood.

Thanks again.

Old Pedant · November 30th, 2010, 09:51 PM

But there's a *BIG* caution about doing this!

String.Format("ManagePhotoAlbum.aspx?PhotoAlbumId= {0}&Name={1}", someId, someName)

If, for example, the value of someName contains various special characters (e.g., & or = or ? or % or even space), then the value may welll *NOT* be passed correctly to the target page. And you are somewhat dependent on browser vagaries here.

So you should probably always play it safe and use Server.URLEncode with non-numeric variables/values.

Code:

String.Format("ManagePhotoAlbum.aspx?PhotoAlbumId={0}&Name={1}", _
    someId, _
    Server.UrlEncode(someName)  _
    )

I assume that someId is a number, and you would never need to UrlEncode a number.

http://msdn.microsoft.com/en-us/library/zttxte6w.aspx

Imar · December 1st, 2010, 03:41 AM

Yes, good suggestion from Old Pedant that will help you prevent a lot of potential problems.

In addition, you may not have to pass the name to the target page. Since the ID is unique, you could get the associated object (a PhotoAlbum in this case) based on the ID passed to the target page and then retrieve its name. Whether that is preferable depends. If you are already working with the PhotoAlbum it's any easy way to avoid cluttering the query string. However, if it means hitting the database just to get the name, it may be better to pass it through the query string. Also, depending on your site, it may also be good for search engine optimization purposes to pass the name to the target page as it provides more context about the otherwise anonymous ID. But I guess that's a topic for another day....

Cheers,

Imar

dstreeter · December 1st, 2010, 08:18 AM

Thanks to Old Pendant and Imar for the additional caution on passing the "Name" information with the redirect. Although my application would not normally call for special characters in the Golf Course name, a user could enter one by mistake.

I appreciate the quick response and great advice.