********** * Traditional code block -- exiting all the way out from an inner loop ***** llBigExit = .F. SELECT myTable SCAN FOR lnI = 1 TO 10 IF someTestOnThisData(lnI) llBigExit = .T. WAIT WINDOW "It was found!" EXIT ENDIF NEXT IF llBigExit EXIT ENDIF ENDSCAN IF NOT llBigExit WAIT WINDOW "Sorry, Charlie!" ENDIF ********** * Visual FreePro's ROPE..ENDROPE structured flow for exiting all the way out * with the single SWING OUT command, which continues on after the ENDROPE. * Note also that no EXIT command is needed to exit a ROPE..ENDROPE block. ***** ROPE SELECT myTable SCAN FOR lnI = 1 TO 10 IF someTestOnThisData(lnI) WAIT WINDOW "It was found!" SWING OUT ENDIF NEXT ENDSCAN WAIT WINDOW "Sorry, Charlie!" ENDROPE * Control continues here after SWING OUT command ********** * An extended ability to SWING TO a specific destination, yet in a structured * manner. * * Note: One of the purposes of adding this ability was to document major code * blocks in one specific area (near the end of the ROPE..ENDROPE block), * thereby bringing important algorithms out of interspersed, nested code, * and into more centralized, easily sought after areas. ***** ROPE SELECT myTable SCAN FOR lnI = 1 TO 10 IF someTestOnThisData(lnI) SWING TO foundIt ENDIF NEXT ENDSCAN SWING TO notFound PLATFORM foundIt WAIT WINDOW "It was found!" PLATFORM notFound WAIT WINDOW "Sorry, Charlie!" ENDROPE * Control continues here after each platform code block is run ********** * Adding FUNCTION definitions to a ROPE..ENDROPE block, as you * would any program. These are in addition to ADHOC..ENDADHOC function * blocks, which can also be added anywhere. * * Note: The same note above is added for functions, as this helps with * encapslation, such that related functions are included within the * ROPE..ENDROPE block, also aiding with documentation, debugging, and * code maintenance. ***** ROPE SELECT myTable SCAN FOR lnI = 1 TO 10 IF someTestOnThisData(lnI) SWING TO foundIt ENDIF NEXT ENDSCAN SWING TO notFound FUNCTION showMessage LOBJECT po AS (pcMessage AS Character) WAIT WINDOW pcMessage PLATFORM foundIt showMessage("It was found!") PLATFORM notFound showMessage("Sorry, Charlie!") ENDROPE * Control continues here after each platform code block is run ********** * Adding ERROR handling to a ROPE..ENDROPE block * Note: The new ERROR block at the end is called instead of any * ON ERROR or class Error() events. A future support will * allow for explicit number handling as in "ERROR nCode" * so that multiple ERROR blocks can be added, one for each * type of known error. ***** ROPE SELECT myTable SCAN FOR lnI = 1 TO 10 IF someTestOnThisData(lnI) SWING TO foundIt ENDIF NEXT ENDSCAN SWING TO notFound FUNCTION showMessage LOBJECT po AS (pcMessage AS Character) WAIT WINDOW pcMessage PLATFORM foundIt showMessage("It was found!") PLATFORM notFound showMessage("Sorry, Charlie!") ERRROR thisCodeOfError ERRORMESSAGEBOX(thisCodeOfError) && Show Visual FreePro standard error message handler ENDROPE * Control continues here after each platform code block is run ********** * Adding simple MESSAGE handling to a ROPE..ENDROPE block. In this * example, the called function is used to spawn control flow in this * ROPE..ENDROPE block, and that's based upon its known return results. * This removes the requirement of us testing the result here, as our * program can simply act on it. The new MEMA keyword indicates that * this source code line will respond to the RETURN MESSAGE command * flow control, and automatically SWING TO the MESSAGE code block. * The MESSAGE code block receives as a named parameter the thisCode * object of whatever triggered the MESSAGE. In this case, it would be * the thisCode object pointing to the source code line with MEMA on it. ***** ROPE SELECT myTable SCAN FOR lnI = 1 TO 10 * The following function is shown below. * It uses the new RETURN MESSAGE command. someTestOnThisData(lnI) MEMA NEXT ENDSCAN SWING TO notFound FUNCTION someTestOnThisData LOBJECT po AS (pnCount AS Integer) IF SUBSTR(cName, pnCount, 4) == "rick" RETURN MESSAGE "It was found!" ENDIF FUNCTION showMessage LOBJECT po AS (pcMessage AS Character) WAIT WINDOW pcMessage PLATFORM notFound showMessage("Sorry, Charlie!") MESSAGE msg * Note: The thisCode object has an _m1 member which is the first * parameter of the returned message. _m2 continues on, _m3, * _m4, and so on. Each of these is sticky and persist until * another RETURN MESSAGE command is encountered. showMessage(msg._m1) ENDROPE * Control continues here after each platform code block is run ********** * Adding a more advanced MESSAGE handler to a ROPE..ENDROPE block. In * this example, the called function is able to spawn flow control based * upon its known return results. The MEMA SWING TO command is used to * swing to a specific platform destination by name. In this case we * know the called function will return a message if the item is found. * As such, we trigger off of that condition automatic flow control. ***** ROPE SELECT myTable SCAN FOR lnI = 1 TO 10 * The following function is shown below. * It uses the new RETURN MESSAGE command. someTestOnThisData(lnI) MEMA SWING TO foundIt WITH thisCode._m1 NEXT ENDSCAN SWING TO notFound FUNCTION someTestOnThisData LOBJECT po AS (pnCount AS Integer) IF SUBSTR(cName, pnCount, 4) == "rick" RETURN MESSAGE "It was found!" ENDIF FUNCTION showMessage LOBJECT po AS (pcMessage AS Character) WAIT WINDOW pcMessage * Here we see that the destination PLATFORM can receive parameters like a function. PLATFORM foundIt LOBJECT po AS (pcMessage AS Character) showMessage(pcMessage) PLATFORM notFound showMessage("Sorry, Charlie!") ENDROPE * Control continues here after each platform code block is run ********** * Had I gone with the flow controller, or FLOWER definition, it would * have been like this instead of ROPE..ENDROPE (picture a bee flying * about a flower). * * What do you think? Too girly? :-) I actually like this because it * would be very hard to not be enjoying writing code when in your mind * you're flying around flowers. :-) ***** FLOWER * Normal programming goes here FLY TO cPetalName && Instead of "swing to" the bee would "fly to" PETAL cPetalName LOBJECT po AS (pcParam1 AS Character, pnParam2 AS Integer) FUNCTION cFunctionName LOBJECT po AS (pcParam1 AS Character, pnParam2 AS Integer) RETURNS llResult MESSAGE ERROR ENDFLOWERPlease provide any thoughts or comments.
