Getting handle to symbol in symbol definition

[David Poiron]

I have a script where I am am trying to change record format values of a symbol that is inside a symbol definition but I cannot seem to get a handle on it (pun intended). I was using the following to traverse the symbol definition list:

 

ForEachObjectInList(SetFieldsSD,0,2,FSymDef);

 

I thought this would do a deep traversal but it does not seem to do that in this case. This works for individual symbols with the record format attached, but not those that are within another symbol definition. The parent symbol definitions are of the "blue" type (symbol to group). Anyone have any tips that can get me to the nested symbol?

[Pat Stanford]

What you have SHOULD (I have not tested this) run the SetFiledSD function once on each symbol definition. 

 

What do you have in SetFieldSD?  I think you will need to use FInSymDef(Handle) to get the first object in the symbol definition. Then step through the objects in the symbol definition and set any that are symbols to attach the record.

 

But you say they are Symbol to Group.  Is there actually another symbol defined inside the blue symbol? Because if not, then you will need to assign the record to something other than the symbol definition because that object goes away when it is converted to the group.

 

If you want to share more info on what you are trying to do be glad to try and help more.

[David Poiron]

The script runs fine on symbol definitions with the appropriate record format attached - I am changing the value of the fields in the record format using SetRField. The problem is for symbols that are within the symbol definition. For example, I have symbol A by itself and the record format updates fine. But if the same symbol definition A is inside another symbol (say symbol definition B), the version of symbol A inside symbol B will not update. I would have thought that ForEachObjectInList(SetFieldsSD,0,2,FSymDef); would traverse the symbol B to get to symbol A.

 

This is SetFieldSD

 

FUNCTION SetFieldsSD(h :HANDLE) :BOOLEAN; {set symbol fields for objects}

BEGIN
    
    IF (GetRField(h, cpaRF, cpaRF4) = RF4) THEN BEGIN {for symbols with correct serial record field}
        
        SetRField(h, cpaRF, cpaRF1, RF1);
        SetRField(h, cpaRF, cpaRF2, RF2);
        SetRField(h, cpaRF, cpaRF3, RF3);
        
    END; {If}
END; {SetFieldsSD}

 

Thanks Pat.

 

Edited June 20, 2022 by David Poiron

[Pat Stanford]

I think what is happening, is that the "included" symbol is not a symbol definition, but rather a symbol instance. And since in symbol instances there is not link between the record attached to the definition, only the data that was attached to the definition when it was instantiated.

 

As I said, I think you are going to have to walk the contents of the symbol definition and see if each object is a symbol and if you want to attach the record or update the record values if it already exists.  You could probably do this with a nested ForEachObjectIn List, but I think a simple loop with Next Object is probably easier.  Pseudocode below

 

FUNCTION SetFieldsSD(h :HANDLE) :BOOLEAN; {set symbol fields for objects}
BEGIN
    
    IF (GetRField(h, cpaRF, cpaRF4) = RF4) THEN BEGIN {for symbols with correct serial record field}
        
        SetRField(h, cpaRF, cpaRF1, RF1);
        SetRField(h, cpaRF, cpaRF2, RF2);
        SetRField(h, cpaRF, cpaRF3, RF3);
        
    END; {If}

	H2:=FInSymDef(h);

	While H2 <> Nil do
		Begin
			If GetTypeN(H2)=15 then		{Check is symbol}
				Begin
					{Code goes here to check if proper record is attached and update the values}
				End;
			H2:=NextObject(H2);
		End;

END; {SetFieldsSD}

 

HTH. Ask again if you need more info.

[Jiajing]

@Pat Stanford  What if there are multiple layers of nested symbols, what's the best way to traverse through all of them. That happens when I import CAD file, or on few lighting symbols (light devise is a symbol and inside light devise, clamp is another symbol, the bolt nested in clamp is another symbol)

 

[Pat Stanford]

It depends a lot on what you are trying to do and what outcome you want.

 

Vectorscript supports recusion, so you could probably write a custom procedure/function that would enter a symbol and then if it found another symbol in the definition call itself with the new symbol definition.

 

More information on what you are actually trying to do would help.

[Jiajing]

@Pat Stanford Thanks Pat.

 

Here is what I am thinking

 

h2 = vs.FInGroup(objecth)

def todo(h2):
	while h2 !=0:
		if vs.GetTypeN(h2) != 15:
			* do one thing*
		elif vs.GetTypeN(h2) == 15:
			h2= vs.FinGroup(h2)
			todo(h2)
		h2 = vs. NextObj(h2)

todo(h2)

I think I mess up with traverse into nested symbol. 

[MullinRJ]

@Jiajing,

   To get a handle to objects inside a Symbol Instance, you have to take a more circuitous route. First, symbol instances are not container objects. The real container is the Symbol Definition. To get a handle to a Symbol Definition when you start with a handle to a Symbol Instance try this:

 

# return a handle to the first object inside a symbol definition where H points to a symbol instance
if (vs.GetTypeN(H) == 15):
	SymDefName = vs.GetSymName(H)
	SDefHnd = vs.GetObject(SymDefName)
	InsideH = vs.FIn3D(SDefHnd)
	

vs.Message(InsideH, '  ', vs.GetTypeN(InsideH))

 

or you can express it in one line:

 

# return a handle to the first object inside a symbol definition where H points to a symbol instance
InsideH = vs.FIn3D(vs.GetObject(vs.GetSymName(H)))

Raymond

[Jiajing]

@MullinRJ Thank you.

 

I thought 

FIn3D(h)

only get handle of 3D objects, actually it also works for 2D.

[MullinRJ]

Hi @Jiajing,

   It seems to work on all container objects, as best I can tell. As you can see, it even works on symbol definitions. I think I saw @Julian Carr use it once in an unexpected way a couple of decades ago, and I've been using it ubiquitously ever since. It's never caused a problem, so I keep using it. It's my magic can opener.

 

Raymond

 

PS - Thanks, Julian.