Tracking DataGrid changes

[Glenn Owens]

I have a DataGrid web control which I've dynamically populated with
template columns to be used for bulk-editting. Generally, all of the
columns are textbox and/or dropdownlist child controls.

Currently everything is working. I can find the updated rows/columns
by parsing the posted data collection against the DataGrid DataSource.
However, when there is a large amount of DataGridItems (rows) the
update processing can take a while.

What I'd like to do is to be able to, as changes are made, mark the
row as modified (in an invisible temaplate column which I'll add to
the DataGrid). That would provide a faster way to find modified rows
without the parsing.

My question:
Has anyone done this? What are some options? Because of viewstate size
concerns I'd prefer to go with a client-side (JavaScript) solution.

TIA
Glenn

 

[Bassel Tabbara [MSFT]]

Hello Glenn,
If you are using Dataset, this functionality is already implemented. What
you can do is to use the method, DataSet.GetChanges.
This method will get a copy of the Dataset containing all changes made to
it since it was last loaded, or since AcceptChanges
was called. The you will loop through every row and mark accordingly the
rows in the DataGrid. Another method to show
the modified information, is to have a new DataGrid of the updated
information.

For more information on GetChanges method refers to:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/
frlrfsystemdatadatasetclassgetchangestopic.asp

Please let me know if you need more help on this.

Thanks,
Bassel Tabbara
Microsoft, ASP.NET

This posting is provided "AS IS", with no warranties, and confers no rights.



--------------------
| From: (e-mail address removed) (Glenn Owens)
| Newsgroups: microsoft.public.dotnet.framework.aspnet
| Subject: Tracking DataGrid changes
| Date: 2 Jul 2003 08:31:18 -0700
| Organization: http://groups.google.com/
| Lines: 20
| Message-ID: <[email protected]>
| NNTP-Posting-Host: 165.170.128.66
| Content-Type: text/plain; charset=ISO-8859-1
| Content-Transfer-Encoding: 8bit
| X-Trace: posting.google.com 1057159878 25886 127.0.0.1 (2 Jul 2003
15:31:18 GMT)
| X-Complaints-To: (e-mail address removed)
| NNTP-Posting-Date: 2 Jul 2003 15:31:18 GMT
| Path:
cpmsftngxa09.phx.gbl!TK2MSFTNGP08.phx.gbl!newsfeed00.sul.t-online.de!newsfee
d01.sul.t-online.de!t-online.de!newspeer1-gui.server.ntli.net!ntli.net!sn-xi
t-02!sn-xit-06!sn-xit-09!supernews.com!postnews1.google.com!not-for-mail
| Xref: cpmsftngxa09.phx.gbl microsoft.public.dotnet.framework.aspnet:31751
| X-Tomcat-NG: microsoft.public.dotnet.framework.aspnet
|
| I have a DataGrid web control which I've dynamically populated with
| template columns to be used for bulk-editting. Generally, all of the
| columns are textbox and/or dropdownlist child controls.
|
| Currently everything is working. I can find the updated rows/columns
| by parsing the posted data collection against the DataGrid DataSource.
| However, when there is a large amount of DataGridItems (rows) the
| update processing can take a while.
|
| What I'd like to do is to be able to, as changes are made, mark the
| row as modified (in an invisible temaplate column which I'll add to
| the DataGrid). That would provide a faster way to find modified rows
| without the parsing.
|
| My question:
| Has anyone done this? What are some options? Because of viewstate size
| concerns I'd prefer to go with a client-side (JavaScript) solution.
|
| TIA
| Glenn
|

 

[Glenn Owens]

Bassel thanks for the reply.

The problem is not with the update. Once I can get the DataGrid changes
reflected in the DataTable (I'm currently using a DataView as the
DataGrid source) then updating the database is no issue. I'm using the
DataTable.GetChanges to pull the modifed/inserted/deleted DataTable rows
for update.

Perhaps I wasn't clear enough...

For the bulk-edit, the DataGrid template columns are defined as the
ItemTemplate (not the EditTemplate) - this makes the DataGrid look like
a "spreadsheet". The User will update 1 or more columns on 1 or more
rows and will then click the Save button. At that point the Save
processing needs to extract the DataGrid data changes and place them
into the corresponding rows/columns of the Datatable (followed by an
Update/commit to the database).

Again, while this all works currently I'm looking for a quicker way to
migrate the DataGrid changes to the DataTable. I was assuming that some
client-side coding would be faster than parsing the post data collection
against the DataGrid data source (DataTable) on the server-side.

Bassel, if I'm missing soming fundamental (wouldn't be the first time)
please help me understand.

Thanks again!
Glenn

 

[Bassel Tabbara [MSFT]]

Hello Glenn,
I am not sure I totally understand the problem/scenario that you are
running into. I am not sure
what you are looking for exactly. If you are trying to get the changes on
the client side, this is
a totally different route and you might have something custom to build it.
If on the server, are you still looking to get changes?
Please can you illustrate with a sample code or be more specific?
I appreciate your cooperation so I can better help you.

Thanks,
Bassel Tabbara
Microsoft, ASP.NET

This posting is provided "AS IS", with no warranties, and confers no rights.



--------------------
| From: Glenn Owens <[email protected]>
| References: <[email protected]>
| X-Newsreader: AspNNTP 1.50 (ActionJackson.com)
| Subject: RE: Tracking DataGrid changes
| Mime-Version: 1.0
| Content-Type: multipart/mixed; boundary="----=_NextPart_000_44774108"
| Message-ID: <#[email protected]>
| Newsgroups: microsoft.public.dotnet.framework.aspnet
| Date: Wed, 02 Jul 2003 15:15:18 -0700
| NNTP-Posting-Host: actionjackson133.dsl.frii.net 216.17.147.133
| Lines: 1
| Path: cpmsftngxa09.phx.gbl!TK2MSFTNGP08.phx.gbl!TK2MSFTNGP12.phx.gbl
| Xref: cpmsftngxa09.phx.gbl microsoft.public.dotnet.framework.aspnet:31867
| X-Tomcat-NG: microsoft.public.dotnet.framework.aspnet
|
|
| Bassel thanks for the reply.
|
| The problem is not with the update. Once I can get the DataGrid changes
| reflected in the DataTable (I'm currently using a DataView as the
| DataGrid source) then updating the database is no issue. I'm using the
| DataTable.GetChanges to pull the modifed/inserted/deleted DataTable rows
| for update.
|
| Perhaps I wasn't clear enough...
|
| For the bulk-edit, the DataGrid template columns are defined as the
| ItemTemplate (not the EditTemplate) - this makes the DataGrid look like
| a "spreadsheet". The User will update 1 or more columns on 1 or more
| rows and will then click the Save button. At that point the Save
| processing needs to extract the DataGrid data changes and place them
| into the corresponding rows/columns of the Datatable (followed by an
| Update/commit to the database).
|
| Again, while this all works currently I'm looking for a quicker way to
| migrate the DataGrid changes to the DataTable. I was assuming that some
| client-side coding would be faster than parsing the post data collection
| against the DataGrid data source (DataTable) on the server-side.
|
| Bassel, if I'm missing soming fundamental (wouldn't be the first time)
| please help me understand.
|
| Thanks again!
| Glenn
|
|
|
| Don't just participate in USENET...get rewarded for it!
|
|

 

[Glenn Owens]

Yes, I'm looking for an alternative to the server-side code that I
currently have working. The code works (albeit not very fast) to
perform multi-column, multi-row updates within an edittable DataGrid.
My hope is that someone might suggest a JavaScript solution, with
example, (as I'm still coming up-to-speed with JavaScript) that will
identify modified rows in the DataGrid.

My thoughts around the client-side sollution:

o As the User modifies a column, in the DataGrid, a hidden column
(added by my server control) would be marked (i.e. a DataGrid
rowstatus column)

o When the User clicks the Save button for the DataGrid the code can
quickly find each modified DataGrid row and migrate the changes to the
DataTable for update.

The following is the server-side method that I'm currently using.

'===============================================================================
' Author: Glenn W. Owens
' Date: 7/7/2003
'
' Description:
' This method uses the PostBack data for the Fluid control to
populate,
' and update, any/all DDO data records which have been modified.
'
' Parameters:
' postCollection - when the user clicks the "Save" control button
the page
' collects the user-entered data into the Postback
data
' collection. This data collection becomes the
data source
' to update the existing DDO data record.
'
'===============================================================================

Private Sub ExecuteDataGridUpdate(ByVal postCollection As
NameValueCollection)
Me.SetDefaultSelect(ListSelectKey)

Ddo.Retrieve(ListWhere) 'Re-retrieve the DDO data to update

Dim dc As DataColumn
Dim idx As Integer
Dim key As String
Dim newval As String
Dim oldval As String
Dim ctlOffset As Integer
Dim target As String = ":FluidListControl:_ctl"

'----------------------------------------------------------------------------
' Determine the control offset to use when referencing items from
the
' postCollection. The postCollection entries that we're
interested in look
' like:
'
' UniqueId:FluidListControl:_ctl[offset]:_....
'
' We need the offset number from the first postCollection entry
that
' matches the pattern. The offset will be used to sychronize the
post data
' collection with the DataGrid items (rows).
'----------------------------------------------------------------------------

For idx = 0 To postCollection.Count - 1
key = postCollection.Keys(idx)

If key.IndexOf(target) > 0 Then
Dim start As Integer = key.IndexOf(":_ctl")
Dim finish As Integer = key.LastIndexOf(":_")

If (start > 0) And (finish > start) Then
start += 5

ctlOffset = CInt(key.Substring(start, finish - start))

Exit For
End If
End If
Next

'----------------------------------------------------------------------------
' Parse through the DataGrid items (rows). Each modified table
cell
' DataGrid value will be subsequently set to the DDO DataTable.
When we're
' done parsing the DataGrid the updated DataTable rows will be
processed
' via the DDO Update method.
'----------------------------------------------------------------------------

For idx = 0 To Ddo.DataViewCount - 1
Dim items As New SetItemCollection()
Dim modified As Boolean = False

'-------------------------------------------------------------------------
' For each modified data item, for this Fluid control, add the
item to
' the Ddo SetItemCollection
'-------------------------------------------------------------------------

For Each dc In Ddo.ColumnCollection
If (Not dc.ReadOnly) And _
(Ddo.DdoColumnProperties.Visible(dc.ColumnName)) And _
(Ddo.DdoColumnProperties.EditEnabled(dc.ColumnName)) Then
key = UniqueID + _
":FluidListControl:_ctl" + (idx + ctlOffset).ToString()
+ ":_"

If Ddo.IsDropDownColumn(dc.ColumnName) Then
Dim ctlidx As Integer = 0
Dim ddldc As DataColumn

'----------------------------------------------------------------
' Due to the way in which DropDownList controls (in
Table
' cells) are identified we need to find the
dropdownlist
' columns and count the ordinal position of the
control
' relative to preceeding dropdownlist, and invisible,
' controls. This ordinal index will be appended to
the static
' key (which references the postCollection data).
'----------------------------------------------------------------

For Each ddldc In Ddo.ColumnCollection
If (Ddo.IsDropDownColumn(ddldc.ColumnName)) Or _
(Not
Ddo.DdoColumnProperties.Visible(ddldc.ColumnName)) Then
ctlidx += 1

If ddldc.ColumnName = dc.ColumnName Then
Exit For
End If
End If
Next

key += "ctl" + ctlidx.ToString()
Else
key += dc.ColumnName
End If

Try
'----------------------------------------------------------------
' If the current value in the post data collection
differs
' from the data retrieved by the DDO then the
row/data item
' has been modified. The Data item will be added to
the update
' collection.
'----------------------------------------------------------------

newval = postCollection(key).ToString()
oldval = Ddo.GetDataRow(idx)(dc.ColumnName).ToString()

If newval <> oldval Then
modified = True

items.Add(newval, dc.ColumnName)
End If

Catch ex As System.Exception

End Try
End If
Next

If modified Then
'----------------------------------------------------------------------
' Data item(s) were changed for this DataGrid row. Add the
changes
' to the DDO DataTable.
'----------------------------------------------------------------------

Ddo.SetItems(items, idx)

modified = False
End If
Next

'----------------------------------------------------------------------------
' Populate the new data record and add it to the DDO DataTable
'----------------------------------------------------------------------------

Try
Dim parms() As String = {Ddo.Update().ToString()}

Message = GetLocalizedText("FluidRecordUpdated", parms, parms(0)
+ _
" Record(s) Updated.")

Catch ex As System.Exception
Dim parms() As String = {ex.Message}

ErrorMessage = GetLocalizedText("FluidUpdateError", parms, _
"Error Updating Record: " + ex.Message)
End Try
End Sub