combining two textbox values - asp.net

Question

i called a field from mysql into a readonly textarea and i made another textbox to allow users to add fields into the textarea. how do I combine the values from the textbox into the textarea?
an example of what i want to do is:
textarea
15/12: Nothing special today
16/12: another day
17/12: and so on
textbox
this is a new input
Result
15/12: Nothing special today
16/12: another day
17/12: and so on
18/12: this is a new input
The textarea is "log1" and the textbox is "txb1". I'm currently using
log = trim(request.form("log1"))
how do I do something like
log = trim(request.form("log1")) <br> date ": " trim(request.form("txb1"))

Answer 1

assuming date is a string variable, You would want to do the following:
log = trim(request.form("log1")) & "<br>" & [date] & ": " & trim(request.form("txb1"))
also, if date is a DateTime variable, you would want to use date.ToShortDateString() and instead of <br/> i would recommend using Environment.NewLine
and even better, you should use StringBuilder:
Dim SB As New StringBuilder()
SB.AppendLine(trim(request.form("log1")))
SB.AppendLine([date] & ": " & trim(request.form("txb1")))
log = SB.ToString()
UPDATE:
if you want to store the entire log in one record rather than a separate table, you better off saving it as a list of logs into a varbinary(MAX) column.
here is a full example of how to do it:
1. we start by creating a <div> element that will hold our pretty logs and will be handled by the server, and a text box for new logs:
<asp:TextBox ID="txb1" runat="server"></asp:TextBox>
<div id="Text_Div1" runat="server"></div>
2. now in the code behind, we create a class to hold 1 single line of log:
'create a log class and state that it serializable
<Serializable> _
Public Class MyLogRecord
Public Sub New(_msg As String)
[Date] = DateTime.Now
Message = _msg
End Sub
Public Property [Date]() As DateTime
Get
Return m_Date
End Get
Set
m_Date = Value
End Set
End Property
Private m_Date As DateTime
Public Property Message() As [String]
Get
Return m_Message
End Get
Set
m_Message = Value
End Set
End Property
Private m_Message As [String]
Public Function ToText() As String
Return [Date].ToShortDateString() & ": " & Convert.ToString(Message)
End Function
End Class
3. wherever you update the logs, whether its button_click or textbox_keydown, you do the following:
' create a list of logs
Dim MyLogs As List(Of MyLogRecord)
'check if we stored the logs already in the session,
'if yes, retrieve it from the session var,
'if not then create a new one.
If Session("MyLogs") IsNot Nothing Then
MyLogs = DirectCast(Session("MyLogs"), List(Of MyLogRecord))
Else
MyLogs = New List(Of MyLogRecord)()
End If
' create a new log record from the new textbox value
Dim _tempLog As New MyLogRecord(txb1.Text)
'add the new log to the list
MyLogs.Add(_tempLog)
'save it back in a session var:
Session("MyLogs") = MyLogs
4. in the part where you save the logs to the mysql db, you do it this way: first convert the list to a byte array and store it in a varbinary(MAX) column
'create a new binary formatter, include System.Runtime.Serialization.Formatters.Binary;
Dim formatter As New BinaryFormatter()
'create a byte array to store our logs list
Dim _logsBinary As Byte()
'create a memory stream to write the logs list into
Using _logStream As New MemoryStream()
'use the formatter to serialize the list in to an array of bytes
'directly into the memory stream
formatter.Serialize(_logStream, MyLogs)
'dump the memory stream into the byte array
_logsBinary = _logStream.ToArray()
End Using
' ... save the _logsBinary into mysql as a 'varbinary(max)' ...
5. in the place where you retrieve the logs from the mysql db, you de-serialize the byte array back to a logs list:
Dim MyLogs As New List(Of MyLogRecord)()
Dim formatter As New BinaryFormatter()
Using _logStream As New MemoryStream()
_logStream.Write(_logsBinary, 0, _logsBinary.Length)
_logStream.Position = 0
' de-serialize the byte array back into a logs list
MyLogs = DirectCast(formatter.Deserialize(_logStream), List(Of MyLogRecord))
End Using
6. in the place where you write the logs in your page, you do it this way:
Dim SB As New StringBuilder()
' create a temp date to compare against all the records,
' and initialize it with the first value or else you will have
' a orizontal line before the first row
Dim _prevDate As DateTime = MyLogs.First().[Date]
For Each _logRec As MyLogRecord In MyLogs
'take the date of the currently iterrated item and
'compare against the temp date, note that comparing months is not enough,
'month might be same/earlier but year can be higher
Dim _currentDate As DateTime = _logRec.[Date]
If _currentDate.Month > _prevDate.Month OrElse _currentDate.Year > _prevDate.Year Then
'append horizontal line
SB.AppendLine("<hr/>")
'update temp value
_prevDate = _currentDate
End If
'finally append the log: ToText() is the class custom
'function that we created above
SB.AppendLine(_logRec.ToText())
Next
'dump the logs into the server managed div:
Text_Div1.InnerHtml = SB.ToString()