Freshen your debugging with ASSERTS (FAQ candidate)

[foxdev]

If you're like most of us, you're used to putting in numerous <FONT FACE=monospace>WAIT WINDOW</font> and <FONT FACE=monospace>? MYVAR</font> statements throughout your code to try to track down problems.<br><br>Now that we have a decent debug/trace ability in VFP, you can set breakpoints and <FONT FACE=monospace>SET STEP ON</font> in various places.&nbsp;&nbsp;But sometimes the problem occurs infrequently, and you hate stepping through hundreds of lines of code.<br><br>Enter ASSERT.&nbsp;&nbsp;An ASSERT allows you to test an expression at runtime, and only notify you if the expression evaluates to false.&nbsp;&nbsp;As a bonus, it not only notifies you, but allows you to invoke the debugger at that point.<br><br>And as an extra special bonus:&nbsp;&nbsp;raise your hand if you've ever accidently left debugging code (like a <FONT FACE=monospace>WAIT WINDOW</font>) in an application that went into production.&nbsp;&nbsp;I've done it dozens of times, and its darn embarrassing.&nbsp;&nbsp;Fortunately, if you issue the command <FONT FACE=monospace>SET ASSERTS OFF</font> then ASSERT statements aren't executed at runtime.<br><br>Note that ASSERTS are OFF by default, so you'll have to turn them on by issuing the command <FONT FACE=monospace>SET ASSERTS ON</font>.<br><br>Some examples of using Asserts:<br><br><FONT FACE=monospace>nConnHandle = sqlconnect('myconnection')<br>assert nConnHandle&gt;0 message &quot;connection failed&quot;<br><br>select * from users where userid='FRED' into cursor curUsers<br>assert reccount('curUsers') &gt; 0 message &quot;no users found&quot;<br></font> <p>Robert Bradley<br><a href=mailto: > </a><br><a href=

http://www.foxdev.com/>FoxDev

- Visual FoxPro Development</a><br>

 

[JDurbin]

On the SQL SELECT a frequent expression used is _TALLY.&nbsp;&nbsp;i suppose ASSERT is good here when it should and must return a cursor set?&nbsp;&nbsp;Robert, do you have any good info on the various aspects of the debug environment?&nbsp;&nbsp;watch, locals, event viewer, etc?&nbsp;&nbsp;I for one am way under speed on what all it provides.&nbsp;&nbsp;Do you use a DEFINE in your code or config file like #DEFINE DEBUGMODE .T.&nbsp;&nbsp;&& switch .T.¦.F.?<br>Thanks <p>John Durbin<br><a href=mailto: > </a><br><a href=

http://www.brainbench.com/transcript.jsp?pid=699842>Brainbench

Certified Professional VFP Programmer</a><br>ICQ VFP ActiveList #73897253

 

[foxdev]

<FONT FACE=monospace>ASSERT _TALLY &gt; 0</font><br>would certainly be valid and often useful.<br><br>John, many of the tips-and-tricks of using the various debugging tools are visual in nature, so it is much easier to show someone than to explain it (&quot;click on the little bar to the right&quot.&nbsp;&nbsp;Oh, if only we had some way of recording screen activity... <p>Robert Bradley<br><a href=mailto: > </a><br><a href=

http://www.foxdev.com/>FoxDev

- Visual FoxPro Development</a><br>

 

[JDurbin]

Yes I've been searching for one.&nbsp;&nbsp;Found HyperCam but it like doubles my screen when played.&nbsp;&nbsp;Check it out at download.com.&nbsp;&nbsp;I just today downloaded Camtasia and SnagIt!&nbsp;&nbsp;Camtasia works!&nbsp;&nbsp;I'll try SnagIt next.&nbsp;&nbsp;Of course the co$t factor is an issue too&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I'm looking <p>John Durbin<br><a href=mailto: > </a><br><a href=

http://www.brainbench.com/transcript.jsp?pid=699842>Brainbench

Certified Professional VFP Programmer</a><br>ICQ VFP ActiveList #73897253