The MiniALV Trace (SAP Library - ALV Grid Control (BC-SRV-ALV))

The MiniALV Trace

Use

If you receive the error message that the RFC did not return data , this means that the MiniALV service has not received any data and is therefore unable to display the table. Possible reasons may be that the report does not output any data at all or that the RFC contains errors.

The MiniALV Trace helps you to find out the cause of the error more precisely (see also: MiniALV Architecture).

Prerequisites

To be able to use the MiniALV Trace, you must set the service parameter ma_trace to 'on' .

Features

To track down the error, the system writes entries to a database table for the MiniALV Trace at several times. The system then returns a table with these entries for the MiniALV service as the result of the trace run. The table contains the following information:

Column	Meaning
Report name	Name of the report passed with the service parameter report
Variant	Name of the variant passed with the service parameter variant
Name	User who logged on to the system to execute the report
Date/time	Time at which the corresponding MiniALV component was called
Trace time	Trace times sorted in ascending order
Text	Specifies the component in which the trace entry was generated (see below)

The trace result is returned even if the MiniALV has been displayed correctly. In this case, two tables are shown in the Web browser.

Note

The MiniALV Trace is also displayed if error messages other than RFC did not return data occur (for example, if the variant specified does not exist).

Trace Times

The trace times allow you to determine where the processing of the MiniALV output was interrupted (below see the output for the AddOn MiniALV):

Number	Text
1	FLOW_LOGIC_MINIALV_CALL(START)
2	FLOW_LOGIC_MINIALV_CALL(BEFORE SUBMIT REPORT)
3	REUSE_MINIALV_LIST_DISPLAY(START)
4	MINI_TABLE_FOR_DISPLAY(END)
5	FLOW_LOGIC_MINIALV_CALL(AFTER_SUBMIT_REPORT)
6	FLOW_LOGIC_MINIALV_CALL(END)

The text specifies the component (function module) of the MiniALV for which the system generated a trace entry. This tells you the following:

If no trace is output and the error message RFC did not return data has been issued, either the proxy report or the function module FLOW_LOGIC_MINIALV_CALL has not been released for the Internet.

If only the first trace time is output, in most cases either the proxy report or the variant specified contains errors or does not exist.

If only the first three trace times are output in the trace, the error in most cases is due to the fact that the proxy report generates frontend objects, the function module ITS_PING has been used or the proxy report creates an endless loop.

Activities

Activating the Trace

For your own MiniApps that use the MiniALV and are still under development, you can activate the MiniALV Trace simply by setting the service parameter ma_trace to on .

Note

There is the Internet service BCMINIALV_S_01 for the Standard MiniALV which you can use to test if a proxy report is displayed in the browser. This service also allows you to enable or disable the MiniALV Trace using a checkbox.

If you want to temporarily activate the MiniALV Trace for an existing MiniApp, proceeed as follows:

Click the right mouse button to call the context menu of the Internet Explorer in the MiniApp frame and choose Create Shortcut . The Internet Explorer then creates a shortcut to the MiniApp on your desktop.

Click the right mouse button on this shortcut and choose Properties . Under Web Document you can edit the hyperlink that points to the MiniApp.

For a MiniApp that uses the MiniALV service directly but does not include the service in another service, you can add ma_trace=on (separated by an ampersand from the other service parameters) to the URL.

Note

For stateful MiniApps, the ITS adds characters for the user session to the URL. So that you can start the service with ma_trace=on added to the URL, you must delete these characters. For information on the URL structure, see Calling the Internet Service in the standard documentation.

Restart the Internet service using the modified URL.

The Web browser should now display the MiniApp in the entire output area and contain the trace (if not, the following exceptions apply: the MiniALV service is included in a MiniApp frame that has disabled the trace explicitly with ma_trace="off" ; the MiniApp does not use the MiniALV; the URL is not correct).

Correcting the Error

Try to correct the error. To do this, first check whether the prerequisites for display have been met and then correct the problem.

Note

See also RFC Did not Return Data in the standard documentation.

You can use the report bcalv_minialv_trace (AddOn MiniALV) or bcalv_minialv_trace_evaluate (Standard MiniALV) to display or delete existing trace runs.