differences between code command file and the code in a command button on a form

[leufj]

Re: differences between code command file and the code in a command button on a form

It can also be solved by calling u_sql2pav5f("",1,1) at the end of FIRST append operation in u_sql2pav5 function. And the SECOND append operation and the following browse in u_sql2pav5 function is deleted (moved to u_sql2pav5f).
In this case, the command button contains only script_play_local("v_wl").

[CALocklin]

Re: differences between code command file and the code in a command button on a form

I'll go a step further than Stan did. I have no idea why the use of Script_play_local() has become so popular but I see no reason to use it EXCEPT in very specific situations.

IF script "B" is called from script "A" and script "B" needs to use a variable that was set in script "A", then one solution is to use Script_play_local(). HOWEVER, this should be a very rare occurrence for most user created scripts. It's not unheard of; just not very common.

I can't help getting the feeling that the word "local" in this function makes people somehow feel more "comfortable" about using it. If so, you are being mislead because it could actually be more susceptible to problems if you aren't careful.

I think the only place the use of this function might be common - and probably the reason this command was created - is in events created within Action Scripts. (This is just a guess because I don't us A/S at all.)

The more conventional way to pass variables to another "script" is to create a function because functions are designed to have variables passed to them.

Personally, I would recommend using Script_play() unless you know of a specific reason that Script_play_local() is needed.

FWIW, I don't recall ever using Script_play_local() and I've been writing nothing but xbasic since somewhere in the early 90's.

[csda1]

Re: differences between code command file and the code in a command button on a form

Hi Cal,

I have no idea why the use of Script_play_local() has become so popular

It is basically laziness. The local variables created in the calling script do not need to be passed with Script_Play_Local(). The entire local variable space is identical in both the calling and called scripts. But, this is a really bad thing for writing reliable code, and makes debugging much harder, as, you need to do it for all the code, rather than isolating each code piece into it's own "island of stability".

I checked my code and found the only two reasons I use it are to call an Alpha Five built-in script (seldom needed, but the only way in certain cases of utilities, otherwise the entire code needs to be duplicated and supported) or when calling other user script code not of my making (for utilities) where I need to allow them access to certain variables I created (again for utilities). Come to think of it, it's really the same reason for both!

Some people make everything a shared or global variable, which amounts to the same as sharing a local space, and again makes it hard to debug individual portions.

You should always use a function with passed arguments, and possibly a WITH - END WITH region (keep it as small as possible so the as not to mix spaces for long periods), for passed variable space pointers. This is covered in my tips

but I see no reason to use it EXCEPT in very specific situations.

The only other exception I've seen is where Alpha forces you to do it, e.g. in older ListView object event handling for some ListView Events, and this is just the way Alpha implemented it, not the way it needed to be.

The more conventional way to pass variables to another "script" is to create a function because functions are designed to have variables passed to them.

And a function can be used identically to Script_Play(), and doesn't have issues (especially if a pure function). Again, see my tips.

Personally, I would recommend using Script_play() unless you know of a specific reason that Script_play_local() is needed.

And I'd go a step further and say Script_Play() and Script_Play_Local() are never needed for any typical code, and only slows things down, creates debugging issues, and timing issues.

[leufj]

Re: differences between code command file and the code in a command button on a form

Thanks a lot for your advices and suggestions. However, after converting my sample script to a function, it still shows the same problem. The problem was solved by including the SECOND append as a called function.

[MikeC]

Re: differences between code command file and the code in a command button on a form

Ira,

It is basically laziness.

If you intended to use this to indicate people just have not taken the many hours to learn what is required to understand how the function script_play_local() works and the difference between that, the script_play(), and/or using a function instead, then I agree....otherwise not. :)

I distinctly remember using script_play_local() many times in the past because I was unsure of how variables in Alpha worked (especially dimensioning)....and not knowing, the info provided about how script_play_local() will be able to use variables, made the novice (me!) use it.

My point is that once many of the aspects of Alpha are understood, it seems many users forget the mindset of a novice and how hard it was (is) at times to grasp all the nuances of xbasic and such. I do not think laziness has all that much to do with it....being overwhelmed by the amount of knowledge it takes to understand Alpha, even on a fairly basic level, is more likely IMO.

rant over!!
:)

[csda1]

Re: differences between code command file and the code in a command button on a form

Hi Mike,

I can understand many people not understanding Dimensioning, but I've seen way too many cases where other people write code and use script_play_local() and do understand the dimensioning.

It's easier/faster than writing a function, passing parameters and isolating the code. They write the code quick and "dirty" that way, but end up never revisiting the code to do it the maintainable way. It's a technique that is not maintainable in a debuggable way as your code grows. It's like having all global variables. In Alpha Four, that was always the case, but in Alpha Five, it's not.

But it's just like the automotive parts commercial, "You can pay me now (for the $5 part), or pay me later! (for the $1000 repair)"

[DaveM]

Re: differences between code command file and the code in a command button on a form

"You can pay me now (for the $5 part), or pay me later! (for the $1000 repair)"

There are VERY few 5.00 parts and also few 1000.00 repairs anymore. LOL

53 years in the industry here.