TraceHandler Interface (PRIM_APP.ITraceHandler)
Trace Handler Interface for user defined tracing
Ancestors - None

Details

The iTraceHandler interface is a low overhead tracing mechanism that can be built in to applications to provide feedback for developer without the need to provide replacement runtime objects.
Tracing statements can be written in the RDMLX using the TraceMessageText and TraceMessageData methods and left in place. Unless a Trace Handler is implemented at runtime, they are effectively ignored.

Example

The sample below is a simple web tracehandler.
When this reusable part is created in the runtime and Trace=True added as a parameter on the querystring, tracing output is sent to the browser console.
Function Options(*DIRECT)
Begin_Com Role(*EXTENDS #PRIM_OBJT *implements #Prim_App.iTraceHandler)

• Include a Define_Com for this reusable part in your web page
• It will install itself as the TraceHandler if "trace=true" is included as a parameter on the URL
• You can then embed #sys_appln.TraceMessageText( aaa bbb ccc ddd ) whereever you want to send trace data to the console.
• Each parameter equates to a single trace statement
  Evtroutine Handling(#Com_Owner.CreateInstance)
  For Each(#Parameter) In(#sys_web.UrlParameters)
  Continue If(#Parameter.Name.UpperCase <> Trace)
  Continue If(#Parameter.Value.uppercase <> True)
  #Sys_appln.TraceHandler <= #Com_owner /* Set this to be the trace handler for the application */
  Leave
  Endfor
  Endroutine
  Mthroutine Name(TraceMessage) Help('Request to trace data received') Options(*redefine)
  #Com_owner.WriteToConsole( #ComponentName #Description #LineNumber #MessageText )
  Endroutine
  Mthroutine Name(WriteToConsole) Help('Write an entry to the browser console') Access(*private)
  Define_Map For(*Input) Class(#prim_alph) Name(#ComponentName)
  Define_Map For(*Input) Class(#prim_alph) Name(#Description)
  Define_Map For(*Input) Class(#prim_nmbr) Name(#LineNumber)
  Define_Map For(*Input) Class(#prim_alph) Name(#Message)
  Define_Com Class(#prim_Dat) Name(#Now)
  #Message := #Now.now.AsLocalizedDateTime.AsString.Righttrim( "0" ) + " " + #ComponentName + " " + #Description + " " + #LineNumber.asstring + " " + #Message
  #sys_web.Console.Log( #Message )
  Endroutine
  Mthroutine Name(TracingState) Options(*redefine)
  #MessageTracingActive := True
  Endroutine
  End_Com
  

  Methods

  Name	Description
  Initialize	Executed when user tracing starts
  Terminate	Executed when user tracing ends
  TraceMessage	Executed whenever a trace message is issued ComponentName, Description, LineNumber, MessageText
  TracingState	Is Tracing active? MessageTracingActive

  See also

  All Component Classes
  Technical Reference