Global Variables - Feature Script

3D

Can anyone offer advise on the possibility / components for / method of making a global variable using FeatureScript?

lemon1324

What scope are you actually thinking of? The two things that pop to mind are getting/setting a variable in the context and using a box to pass by reference.

In my thoughts on programming, there's very very few cases in which the best way to implement something is with an actual global variable; usually it's cleaner to pass by reference or use getters/setters.

3D

How do you make a variable in a Part Studio available / reference-able in an Assembly?

lemon1324

Not with FeatureScript; for security (and probably other) reasons, FS scripts are sandboxed to only affect the Part Studio they're used in.  It will probably be possible to use the full API to access variables in Assembly, but I haven't had time to look at what's available there.

lougallo

A workaround would be to create variables that drive a sketch and then snap a version and derive it in other documents. Many docs can use that sketch and by changing it and snapping a new version you can give the feeling of a global variable. 

FS could be done in a similar way but it would be a workaround leveraging linked documents. 

ilya_baran

There is currently no way to reference variables in assemblies (FS or otherwise) -- this is on our todo list.  For variables global to multiple part studios, like Arul suggests, having a single custom feature set all your variables and then using that feature at the beginning of every part studio is the workaround I would recommend.  We do plan on allowing true global variables (within a document) in the future.

axel_svensson

ilya_baran said:

There is currently no way to reference variables in assemblies (FS or otherwise) -- this is on our todo list.  For variables global to multiple part studios, like Arul suggests, having a single custom feature set all your variables and then using that feature at the beginning of every part studio is the workaround I would recommend.  We do plan on allowing true global variables (within a document) in the future.

It will require some thought to make this play nicely with assemblies that use parts with configurations.
With part studio configurations, part variables become scoped to the part instance in the assembly. If other parts in the assembly depend on such a variable, I don't see how simple global variables would be a solution. (For example, with two instances of the same part with different configurations in the same assembly, two values for the same variable can be at play in the same assembly context.)

Maybe the assembly "Insert" functionality could somehow be extended to import variables, as well as sketches and parts?

shawn_updegraff

Any progress on this? It looks like closing in on 3 years on the last comment, 4-5 years on the original question.

john_mcclary

I believe they are working on a solution to this, at least many Onshape staff have agreed they want it too, but they can't tell us where it is on the priority list or give any indication on when new features will be available, as is the norm. They would hate to promise a  feature on a date, then find there are crippling bugs associated with it. It's better to just be surprised one day with a well thought out plan, rather than a band-aid feature that barely works. I mean look at configurations, that took a while, once it was released for assemblies also, it became the best configurator in the business.

I'd love to have variables in asm, mostly for defining patterns. But today there enough work arounds to get 80% there.
If you have a particular need, you should post it. We'll see if there is an elegant work around available.

Alex_Kempen

As I've stated in a recent thread, I actually have an advanced FeatureScript for this currently in the works, which uses setAttributes to read off attributes set with a custom built FS in another part studio. I plan on releasing it sometime in the next week or so. You can find more info about it in this forum thread.

jeffrey_hawkins

Unsure where to report this, but there is an odd bug in using a FeatureScript as a method of having globals... global variables (even if names are unique) cannot be combined with local variables.

I have a FeatureScript with parameters for the tolerance needed for a tight fit vs. a loose fit for example. If I put all variables in (i.e. #diameter here), I can have one tube outside diameter specified as something like "#diameter - #gapLoose". But if I make a one-off tube where the variable is declared locally as #mountTube, I cannot set anything to be (#mountTube - #gapLoose). No error is displayed, but it turns red and fails.. 

ilya_baran

@jeffrey_hawkins I'd start by checking that the units on mountTube and gapLoose match.