View Issue Details
|ID||Project||Category||View Status||Date Submitted||Last Update|
|0003696||Expressions||[All Projects] General||public||2018-11-16 19:01||2018-11-27 14:28|
|Product Version||[FreeCAD] 0.18|
|Target Version||[FreeCAD] 0.19||Fixed in Version|
|Summary||0003696: Constraints lose values upon reloading file.|
|Description||When you use the "formula button" when typing in a constraint, it works only if you don't reload the file! When reloading, the constraint reverts to the value that was saved. It doesn't follow the formula anymore, so if you change a parameter, the linked constraint does not get updated.|
|Steps To Reproduce||Open the attached file. Open the Sketcher window.|
Notice the 44mm dimention to the VERY right. it has the label "Global".
Notice the 44 mm dimension next to it (just left). We'll call this "LinkedVersion". I saved it's formula's constraint as "Constraints.Global" but when you load the program, it gets set to the 44mm value.
You can repeat the bug by updating the "LinkedVersion" constraint by clicking the blue formula icon and typing "Constraints.Global".
Now change the "Global" value (the length constraint to the VERY right).
The "LinkedVersion" will update as it should.
Now save the file. Close. And reload the file.
Now change the "Global" value (the length constraint to the Very right).
Notice that the "LinkedVersion" will not get updated!!
This bug can hide itself and ruin CNC paths if one is not aware of the problem.
|Additional Information||OS: Windows 8.1|
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.15214 (Git)
Build type: Release
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/UnitedStates (en_US)
|Tags||No tags attached.|
BugLinkedConstraintsDontSurviveASave.FCStd (347,917 bytes)
Can somebody from the CAD experts check this case to confirm?
IMO this should have been discussed in the forum first before a report was created; just as is already explained in the GIGANTIC yellow banner at the top.
This file document has multiple user errors. One not pertaining to this issue is starting a sketch in a Body then going to Part to create an Extrude. This produces the following warning in the Report view after a recompute:
One other thing hinting at an error is that at load time, the Report view prints the error "Failed to parse expression".
Notice the 44 mm dimension next to it (just left). We'll call this "LinkedVersion".
It is NOT called "LinkedVersion" in your file, its label is "Edge Vert 1 of 2". I highly doubt that spaces are allowed in contraint names. When I try to refer through it in an expression, it fails with "Failed to parse expression".
This file is a very poor case for a bug, and should have been simplified to only contain the elements to reproduce the issue. The whole Path job is irrelevant here. BTW it is completely inefficient to create such a sketch with >225 constraints and repeated circles. Posting on the forum before creating this bug, you would have received this advice.
I recommend that the next steps should be for the reporter to:
As per comment above, please post on the forum for advice. There may be usage errors that are actually resulting in the issue.
||Thank you very much Normand. It saves me time when things are streamlined :)|
I added a simple file and started a discussion at:
Thank you everybody for taking the time to streamline this.
I have moved this ticket to "Expressions", as the problem lies in the Expression Engine. It is not specific to the Sketcher.
Almost 40 years after the boom of the personal computer, spaces keep being a problem...
|2018-11-16 19:01||TheRainHarvester||New Issue|
|2018-11-16 19:01||TheRainHarvester||File Added: BugLinkedConstraintsDontSurviveASave.FCStd|
|2018-11-16 19:08||abdullah||Target Version||=> 0.19|
|2018-11-16 19:08||abdullah||Steps to Reproduce Updated||View Revisions|
|2018-11-16 19:08||abdullah||Additional Information Updated||View Revisions|
|2018-11-16 19:09||abdullah||Note Added: 0012202|
|2018-11-17 16:40||normandc||Note Added: 0012205|
|2018-11-17 16:41||normandc||Status||new => feedback|
|2018-11-17 16:41||normandc||Note Added: 0012206|
|2018-11-17 16:42||normandc||Note Edited: 0012206||View Revisions|
|2018-11-17 19:46||abdullah||Note Added: 0012207|
|2018-11-26 15:20||TheRainHarvester||Note Added: 0012224|
|2018-11-26 15:20||TheRainHarvester||Status||feedback => new|
|2018-11-27 14:23||abdullah||Project||Sketcher => Expressions|
|2018-11-27 14:23||abdullah||Category||Bug => General|
|2018-11-27 14:28||abdullah||Note Added: 0012226|