Xml String/DataSet - Need Help

Kung Pao · Apr 28, 2012

Hey all, I read Anthony's article on Xml String/DataSet usage, and actually found a use for it in a Wizard for the site I'm creating. In Step 2, I need to put data into a DataGrid using an Xml String, and allow users to change the information, or add new items, but I don't want the actual database to be updated until the user finishes Step 4. My question is, what is the best way to go about updating the data in/adding new data to the Xml string? Right now I'm attempting to manually modify the string using the string commands, but I'd imagine there is a way to use the DataSet to regenerate the Xml. Am I correct? Thank you, Joe Fiorini Lead Web Developer/Project Manager PanasonicYou are correct. 1. Load the Dataset with the Xml String 2. Bind the Dataset to the Datagrid 3. Process all inserts and updates with the Datagrid/Dataset 4. Commit changes to the datastore (DB) 5. If you need to persist the new XML that describes the Dataset, use the Dataset.getXML() method: Returns the XML representation of the data stored in the DataSet. [Visual Basic] <Serializable> Public Function GetXml() As String [C#] [Serializable] public string GetXml(); [C++] [Serializable] public: String* GetXml(); [JScript] public Serializable function GetXml() : String; Return Value A string that is a representation of the data stored in the DataSet. Remarks Calling this method is identical to calling WriteXml with XmlWriteMode set to IgnoreSchema. Note GetXml returns XML as a string, and therefore, requires more overhead than using WriteXml to write XML to a file. The problem is, I don't want to commit the changes made in Step 2 until Step 4, therefore I need the Xml to persist throughout the rest of the Wizard, until Step 4. Here is an implementation that I came up with, that works for now. If anyone knows a better way, please let me know. Thanks, Joe Fiorini This is in the UpdateCommand method of my DataGrid: Private Sub dgrReviseParts_UpdateCommand(ByVal source As Object, ByVal e As System.Web.UI.WebControls.DataGridCommandEventArgs ) Handles dgrReviseParts.UpdateCommand Dim PartName As String = CType(e.Item.Cell(0).FindControl ("txtPartName"), Web.UI.WebControls.TextBox).Text Dim Status As String = CType(e.Item.Cells(2).FindControl ("cmbStatus"), Web.UI.WebControls.DropDownList).SelectedItem.Valu e Dim PartType As String = CType(e.Item.Cells(1).FindControl ("txtPartType"), Web.UI.WebControls.TextBox).Text Dim ItemNumber As String = CType(e.Item.Cells(3).FindControl ("txtItemNumber"), Web.UI.WebControls.TextBox).Text Dim sXml As String = Session("sXml") Dim ds As New Data.DataSet() Dim rdr As New System.IO.StringReader(sXml) ds.ReadXml(rdr) ds.Tables("Table").Rows(dgrReviseParts.EditItemIndex).BeginEdit() ds.Tables("Table").Rows(dgrReviseParts.EditItemIndex).Item("PartName") = PartName ds.Tables("Table").Rows(dgrReviseParts.EditItemIndex).Item("Status") = Status ds.Tables("Table").Rows(dgrReviseParts.EditItemIndex).Item("PartType") = PartType ds.Tables("Table").Rows(dgrReviseParts.EditItemIndex).Item("ItemNumber") = ItemNumber ds.Tables("Table").Rows(dgrReviseParts.EditItemIndex).EndEdit() sXml = ds.GetXml Session("sXml") = sXml dgrReviseParts.EditItemIndex = -1 BindData() End Function And in my BindData() function: Private Function BindData() Dim sXML As String If Session("sXml") Is Nothing Then sXML = dbActions.GetXmlFromDataSet(dbActions.GetPartsDS(, GetDrawingId)) Session.Add("sXml", sXML) Else sXML = Session("sXml") End If dgrReviseParts.DataSource = dbActions.GetDataSetFromXml(sXML) dgrReviseParts.DataBind() End FunctionSure... you can persist the XML by sticking it in a session variable, or you can persist it to a file, or to a db table... whatever.... you are on the right track!Sweet, thanks for the help! -Joe

Xml String/DataSet - Need Help

Kung Pao

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