Fetching report data from an XML file

You can get the report data from an XML file instead of getting it directly from a database.

The XML file can be a ProcessLevelData file created by a Genero report ( Output to an XML File) which has a special format, or it may be an arbitrary XML file.

From a process level data file

This XML file has a special format, and is created using the Report Writer API function fgl_report_createProcessLevelData File().

The MAIN block of SimpleReport.4gl would change as follows:

Provides the name of the data file to be used for the report
Use the fgl_report_runReportFromProcessLevelDataFile() function to run a report using a data file. The parameters are:
- The report handler object
- A String containing the name of the XML file that contains the data
This function will replay the report from the file thereby replacing the running of the report (START REPORT, OUTPUT TO REPORT, FINISH REPORT statements).

MAIN

   DEFINE handler om.SaxDocumentHandler, -- report handler 
          data_file String,              -- XML file containing data 
          report_ok boolean              -- return value from function 

    --call the mandatory functions that configure the report  
  IF fgl_report_loadCurrentSettings("myreport.4rp") THEN -- if  the file
                                                         --  loaded OK
    LET handler = fgl_report_commitCurrentSettings()     -- commit the file 
                                                         -- settings
  END IF

  --call the report driver to run the report
  IF handler IS NOT NULL THEN  
    LET data_file = "./OrderReportData.xml"
    LET report_ok = 
           fgl_report_RunReportFromProcessLevelDataFile(handler, data_file) 
  ELSE
    EXIT PROGRAM
  END IF

END MAIN

From other XML files

XML files that were not created by the Reporting API function fgl_report_createProcessLevelData File() can be used as the data source for a Genero report. The file OrderData.xml in the demo sample files of the Reports project is an example of this type of file.

The function fgl_report_runFromXML() is used to specify the data source:

This function sets up the report engine based on the current settings that have previously been loaded by a call to fgl_report_loadCurrentSettings(), and may have been modified by calls to fgl_report_selectDevice() or fgl_report_selectPreview(). The function automatically calls fgl_report_commitCurrentSettings().
This function replays the report from the file, thereby replacing the running of the report (START REPORT, OUTPUT TO REPORT, FINISH REPORT statements).

This example is from the OrderReportXML.4gl demo program in the Reports project:

MAIN

  IF NOT fgl_report_loadCurrentSettings("Table.4rp") THEN
    EXIT PROGRAM
  END IF

  IF NOT fgl_report_runFromXML("OrderData.xml") THEN
    DISPLAY "RUN FAILED"
    EXIT PROGRAM
  END IF

END MAIN