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How to: Extend or Replace the Report Builder

Although Visual FoxPro ships with a default Report Builder application, complete with a framework of Report Designer event handlers, you may choose to replace or augment this application with your own implementation.

See Understanding Report Builder Events for more information on how to write a program that complies with the report builder API.

Using an alternate builder application by default

To set the default report builder application

  • Add a line to CONFIG.FPW that sets the _REPORTBUILDER system variable:

    _REPORTBUILDER = mybuilder.prg

Replacing reportbuilder.app "on the fly"

To change report builders in code

  1. Use code like this to switch to an alternate report builder application:

    cOriginalBuilderApp = _REPORTBUILDER

    _REPORTBUILDER = "mybuilder.prg"

  2. To restore the default:

    _REPORTBUILDER = m.cOriginalBuilderApp

Calling back to ReportBuilder.App

To call back to Reportbuilder.app

  • Use code like this to switch to an alternate report builder application:

    parameters returnFlags, eventType, cmdClauses, sessionID

    :

    do (HOME(1)+"ReportBuilder.App") with returnFlags, eventType,

    cmdClauses, sessionID

See the example below for a builder application that calls back to Reportbuilder.app to augment the default behavior.

Example

This example program wraps ReportBuilder.App to provide custom behavior for the CREATE REPORT - Quick Report Command.

The functionality includes:

  • Adding a "Company letterhead" to the layout.

  • Updating the header and footer controls.

To use, set _REPORTBUILDER = FULLPATH("quickreportbuilder.prg").

*-----------------------------
* QUICKREPORTBUILDER.PRG
*-----------------------------
#DEFINE QUERY_TITLE_LOC "Creating a Quick Report"
#DEFINE HEADER_QUERY_LOC "Company-standard name will be included. "+ ;
                         "Would you like to add something?"
#DEFINE FINISH_QUERY_LOC "Finished! "+CHR(13)+ ;
                         "Would you like to adjust the contents?"
#DEFINE COMPANY_HEADER_LOC  "ABC Company"

* Return value flags:---------
#DEFINE EVENT_PASSED_TO_VFP       0
#DEFINE EVENT_HANDLED_BY_BUILDER  1
#DEFINE FRX_DISCARD_CHANGES       0
#DEFINE FRX_RELOAD_CHANGES        2

* Hook event types:-----------
#DEFINE EVENTTYPE_REPORTOPEN      7
#DEFINE EVENTTYPE_OBJECTCREATE    2
#DEFINE EVENTTYPE_REPORTSAVE      6
#DEFINE EVENTTYPE_REPORTCLOSE     8
#DEFINE EVENTTYPE_PROPERTIES      1

* ReportBuilder.App Handle Modes:
#DEFINE MODE_HANDLE_CLASS         1
#DEFINE MODE_FORCE_DEBUG          2
#DEFINE MODE_FORCE_NATIVE         3

* standard FRX stuff 
#DEFINE OBJTYPE_TEXT              5
#DEFINE OBJTYPE_FIELD             8
#DEFINE OBJTYPE_FONTRES          23
* ----------------------------

#DEFINE MB_YESNO                  4
#DEFINE MB_ICONQUESTION          32
#DEFINE IDYES                     6
#DEFINE IDNO                      7
* ----------------------------

LPARAMETERS returnFlags, eventType, commandClauses, designerSessionId

* This builder only takes action on a quick report.
* Criteria:  - Must be a REPORT and not a LABEL layout
*            - Must be a CREATE REPORT FROM... command

LOCAL BuilderModule
BuilderModule = HOME()+"ReportBuilder.App"

IF commandClauses.IsReport AND NOT EMPTY(commandClauses.FROM)

    LOCAL oFrxHelper
    oFrxHelper = NEWOBJECT("frxCursor", HOME()+"FFC\_frxcursor.vcx")

    DO CASE
    CASE m.eventType = EVENTTYPE_REPORTOPEN
        * This is the first event in a quick report. 
        * First, replace default font resource and font 
        * info in header to match our requirements, because 
        * there are some hardcoded metrics for heights in this 
        * simple example.
        * The FRX cursor is in the current workarea:
        REPLACE frx.fontface WITH "Courier New" ;
            FOR RECNO() = 1 OR frx.objtype = OBJTYPE_FONTRES
        LOCATE FOR frx.objtype = OBJTYPE_FONTRES

        * Now, add a font resource record for our 
        * "designed" expression:
        SCATTER MEMVAR MEMO
        m.penred = 255
        m.fontface = "Tahoma"
        m.fontstyle = 1
        INSERT INTO frx FROM MEMVAR

        * Now, reuse the memvars, changing their values, to set up 
        * the designed expression's record:
        m.uniqueid   = SYS(2015)
        m.objtype    = OBJTYPE_TEXT
        m.objcode    = 0
        m.timestamp  = oFrxHelper.getFrxTimeStamp()
        m.vpos       = 20
        m.hpos       = 20
        m.height     = 3000
        m.width      =  50000
        m.fillchar   = "C"
        m.penred     = 255
        STORE -1 TO m.fillred, m.fillgreen, m.fillblue
        m.mode       = 1
        m.stretch    = .T.
        m.top        = .T.
        m.spacing    = 2
        m.offset     = 2
        m.resettotal = 1
        m.supalways  = .T.
        m.suprpcol   = 3
        m.supgroup   = 0
        m.totaltype  = 0
        m.expr       = INPUTBOX(HEADER_QUERY_LOC, ;
                                QUERY_TITLE_LOC, ;
                                COMPANY_HEADER_LOC)

        DO CASE
        CASE EMPTY(m.expr)
            m.expr = COMPANY_HEADER_LOC

        CASE ATC(COMPANY_HEADER_LOC,m.expr) = 0
            m.expr = COMPANY_HEADER_LOC + " " + ALLTR(m.expr)

        ENDCASE   
        m.expr = ["]+m.expr+["]

        INSERT INTO frx FROM MEMVAR

        * Finally, tell the Designer to consume our edit:
        returnFlags = FRX_RELOAD_CHANGES

    CASE  m.eventType = EVENTTYPE_REPORTSAVE
        * This is the last event in a quick report.

        IF NOT EMPTY(m.BuilderModule) AND ;
            MESSAGEBOX(FINISH_QUERY_LOC,;
                       MB_YESNO +MB_ICONQUESTION,;
                       QUERY_TITLE_LOC) = IDYES

            * Give the user a chance to adjust or eliminate 
            * objects of certain types:
            SCAN ALL FOR INLIST(frx.objtype, ;
                       OBJTYPE_FIELD, OBJTYPE_TEXT)
                * Mark the object as "selected" so that the 
                * builder will act on it:
                REPLACE frx.curpos WITH .T.
                * Call the builder application, ;
                * faking a regular Report Designer event:
                do (BuilderModule) with ;
                        -1, EVENTTYPE_PROPERTIES, ;
                        m.commandClauses, ;
                        m.designerSessionId
                REPLACE frx.curpos WITH .F.
            ENDSCAN
            m.returnFlags = FRX_RELOAD_CHANGES
        ENDIF

        * Find the DATE() expression control created by the 
        * Quick Report process and convert it into a DATETIME():
        LOCATE FOR frx.objtype = OBJTYPE_FIELD AND ;
                        UPPER(ALLTRIM(frx.expr)) == "DATE()"
        LOCAL liWidth
        liWidth = oFrxHelper.GetFruTextWidth( ;
                                TRANSFORM(DATETIME()),;
                                frx.fontface, frx.fontsize )
        REPLACE frx.expr  WITH "DATETIME()", ;
                                frx.width WITH m.liWidth

        * Find the _pageno controls and spiff them up a bit:
        LOCATE FOR frx.objtype = OBJTYPE_TEXT ;
            AND ATC(["PAGE],frx.expr) > 0
        IF FOUND()
            REPLACE frx.expr WITH ["Page "+TRANSFORM(_PAGENO)],;
                    frx.objtype WITH OBJTYPE_FIELD, ;
                    frx.hpos WITH (frx.hpos - (frx.width*2)), ;
                    frx.width WITH frx.width*3 
            SKIP
            * Remove the other _pageno object that 
            * follows the "Page" one in a normal quick report:
            DELETE
        ENDIF

        * We need to instruct the Designer to respect our changes:
        returnFlags = FRX_RELOAD_CHANGES

    OTHERWISE
        returnFlags = EVENT_PASSED_TO_VFP

    ENDCASE

ELSE
    * Parameters are passed by reference:
    do (BuilderModule) with m.returnFlags, ;
                            m.eventType, ;
                            m.commandClauses, ;
                            m.designerSessionId
ENDIF
RETURN

See Also

Tasks

How to: Add Your Own Handler to the Report Builder's Registry

Reference

Report Builder Event Handler Registry Table

Concepts

Understanding Report Builder Events

Other Resources

Extending Reports at Design Time