The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘Delphi 2’ Category

The StackOverflow Pascal/DelphiSyntax Highlighter

Posted by jpluimers on 2014/07/22

Found out where the StackOverflow Pascal has its origins: What happened to comments in syntax highlighter? – Meta Stack Overflow.

Like any syntax highlighter, it is not perfect (only a Delphi compiler driven highlighter would have a chance to be perfect), but it does a pretty good job and gets better over time.

–jeroen

Posted in Borland Pascal, Delphi, Delphi 1, Delphi 2, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 3, Delphi 4, Delphi 5, Delphi 6, Delphi 7, Delphi x64, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Development, FreePascal, Pascal, Software Development, Turbo Pascal | Leave a Comment »

Delphi `with` post and discussion revisited (via: wiert.me and LinkedIn)

Posted by jpluimers on 2014/06/11

A bit more than a year ago, I wrote about Delphi: you should avoid the with statement as it makes your code less future proof. That caused some nice comments on the blog, and some more on LinkedIn where Paul Foster mentioned it in a thread ‘Jeroen Pluimers makes a case against “with” statements.‘ Both interesting reads, especially the reasons that people use or avoid with, or keep its use in balance. There is one set of comments I want to emphasize: refactoring multiple with statements into a one function and a call per former with. Read the rest of this entry »

Posted in Borland Pascal, Delphi, Delphi 1, Delphi 2, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 3, Delphi 4, Delphi 5, Delphi 6, Delphi 7, Delphi 8, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Development, Pascal, Software Development, Turbo Pascal, With statement | 19 Comments »

Delphi multithreading and DLL exports: watch your exceptions (via: Stack Overflow)

Posted by jpluimers on 2014/06/03

Talking about Danny Thorpe: he also posted a nice hint on threading methods for ancient Delphi versions that equally applies to DLL exports in any Delphi version, even any programming environment.

Recently, I had to do some surgery in such a Pre-Delphi 6 application, and I was really happy to remember this answer: it instantly solved some process crashes, and the added logging allowed for investigating the actual cause.

Note that this tip isn’t just a good advice for old Delphi versions.

Even in younger Delphi versions, you have to watch methods that can be called from outside a regular Delphi context, for instance exported methods.

Heck, it applies to virtually any development environment: exceptions usually are very specific to that environment and should never cross a process boundary.

Summary

Take the approach below

  • for Execute methods in your own thread classes in Delphi 5 or earlier
  • for any method that can be called externally (like DLL exports) Read the rest of this entry »

Posted in Delphi, Delphi 1, Delphi 2, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 3, Delphi 4, Delphi 5, Delphi 6, Delphi 7, Delphi 8, Delphi x64, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Development, Software Development | Leave a Comment »

Delphi: Design-Time Component Name Limited to 63 characters (via: Vin Colgin – Google+)

Posted by jpluimers on 2014/05/05

I learned something new today (thanks Vin Colgin) the Delphi Design-Time Component Name is Limited to 63 characters.

Uwe Raabe found out that this an Object Inspector thing due to this constant in DesignIntf.pas:

const
  MaxIdentLength = 63;

It has been probably there since Delphi 1 and has been documented on-line since at least Delphi 2007.

I remember having had long (like 100+ character) identifiers in source code, but not in the Object Inspector.

Now I know you can’t (:

–jeroen

via: Vin Colgin – Google+ – Delphi: Design-Time Component Name Limited to 63 characters….

Posted in Delphi, Delphi 1, Delphi 2, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 3, Delphi 4, Delphi 5, Delphi 6, Delphi 7, Delphi 8, Delphi x64, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Delphi XE5, Delphi XE6, Development, Software Development | 4 Comments »

delphi: idioms for building strings (via: my answer on Stack Overflow)

Posted by jpluimers on 2014/04/16

Once every while, one of your StackOverflow answers gets an edit suggestion that is really valuable.

This case it was Edwin Yip who suggested to emphasize the difference between TStringBuilder and TStringList (adding characters versus lines).

Too bad that freshly 10k user Makoto showed he hates bold emphasis, intentional property casing and post signatures by removing the added value (there is so much emphasis he could remove on other answers to warrant at least a day time job).

I know that not all emphasis is welcomed at StackOverflow, but in this case I think it added real value.

So I edited my own answer to add even more value: showing the idioms I use for building strings, and now it is time to quote it: Read the rest of this entry »

Posted in Delphi, Delphi 1, Delphi 2, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 3, Delphi 4, Delphi 5, Delphi 6, Delphi 7, Delphi 8, Delphi x64, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Development, Software Development | Leave a Comment »

Delphi `TParser` links

Posted by jpluimers on 2014/03/25

I needed to modify some code that had been amended from the Delphi TParser class (which parses DFM files, but can be amended to other sources as well), so here are some links I found during my research:

Oh and it is on the Delphi VCL Hierarchy poster too (:

–jeroen

Posted in Delphi, Delphi 1, Delphi 2, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 3, Delphi 4, Delphi 5, Delphi 6, Delphi 7, Delphi 8, Delphi x64, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Delphi XE5, Development, Software Development | Tagged: | 2 Comments »

Delphi: make sure you show the `ExceptAddr` and `ClassName` if you display in exception in DEBUG mode.

Posted by jpluimers on 2014/03/21

When handling `Application.OnException` add the `ExceptAddr` to in Delphi the menu `Search` -> `Goto address` has a chance of working, and the `ClassName` so you know what happened.

You might want to always do this, depending on how scared your users get from HEX values in error messages.

This works in about every Delphi version I ever used: Read the rest of this entry »

Posted in Delphi, Delphi 1, Delphi 2, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 3, Delphi 4, Delphi 5, Delphi 6, Delphi 7, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Delphi XE5, Development, Software Development | 2 Comments »

[FOSDEM 2014] Visualizing Delphi with Moose – YouTube

Posted by jpluimers on 2014/03/20

Jus finished watching this very interesting talk from the last FOSDEM 2014 conference: [FOSDEM 2014] Visualizing Delphi with Moose – YouTube.

It is based on MOOSE (an open-source platform for software and data analysis) and PHARO (a free and open-source Smalltalk environment).

This is how to get started (it is in Dutch, we have great developers and researchers around here).

Be sure to watch the presenter Stefan Eggermont (StackOverflow, Twitter, LinkedIn, GitHub, FOSDEM, website www.legacycode.nl) as this kind of analysis (that is also possible for other languages and tools) can highly speedup your work.

You can download the webm version of the talk from the FOSDEV14 devroom.

–jeroen

Posted in Delphi, Delphi 1, Delphi 2, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 3, Delphi 4, Delphi 5, Delphi 6, Delphi 7, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Delphi XE5, Development, Software Development | 4 Comments »

WITH IS EVIL! (via: Paul Foster – Google+)

Posted by jpluimers on 2014/03/13

Yet another example of somehow who got bitten hard by using the with statement (I decided to give with its own category on my blog).

This time it got shared by Paul Foster on G+ and comes down to this:

Even in unsuspiciously looking code, the wit statement can bite you, especially if you need to do refactoring and (because of that) introduce two names in the same scope.

Or in Paul‘s words:

Whilst upgrading the code to remove the Containers unit (its not supported on NextGen platforms, so I have to make things work with Generics.Collections instead, (bye bye D7 support for this code) and refactor a couple stupidities in my original design (they always creep in, don’t they) I ended up with two class members of the same name.  The with block then looked OK but I was in fact not access the member I thought I was. 

–jeroen

via: Paul Foster – Google+ – WITH IS EVIL! God damn it, I know it makes code easier to….

Posted in Borland Pascal, Delphi, Delphi 1, Delphi 2, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 3, Delphi 4, Delphi 5, Delphi 6, Delphi 7, Delphi 8, Delphi x64, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Delphi XE5, Development, Pascal, Software Development, Turbo Pascal, With statement | 18 Comments »

Delphi/Turbo Pascal: AppendWithRetry for text files to retry Append

Posted by jpluimers on 2014/03/10

Every once in a while you have multiple threads or processes wanting to write a short message to the same log file. Append then will give you an I/O error 32 (ERROR_SHARING_VIOLATION), but the below small routine will sleep a bit while retrying a couple of times.

It uses these Delphi aspects around the $I or $IOCHECKS compiler directive:

  • in $I+ mode, you get exceptions when certain “classic” Pascal style I/O operations fail.
  • in $I- mode, you access the IOResult to obtain the results of those I/O operations
  • IOResult gets the result of the last failed operation (if any) or zero if none failed
  • IOResult clears the underlying storage to zero
  • $IFOPT checks for a certain state of a compiler flag
  • You can store the state of $OPT in a temporary conditional define

Note there are a few tables of codes you can get back through IOResult as basically you can get many GetLastError results in IOResult as well: Read the rest of this entry »

Posted in Delphi, Delphi 1, Delphi 2, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 3, Delphi 4, Delphi 5, Delphi 6, Delphi 7, Delphi 8, Delphi x64, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Delphi XE5, Development, Software Development | 2 Comments »