Picking up a few interesting threads from the Revit API discussion forum and AI news:
Weight of a heart versus feather of truth in Book of the Dead
Revit Add-In Code Signing YAML
Peter Hirn's YAML file for automating the code signing of the continuous integration build of RevitLookup helps solve the Revit API discussion forum thread on Revit 2018 Code Signing:
Question: I am attempting to code sign my Revit add-in and I cannot seem to get Revit to recognise it. I have a self-signed certificate which I have manually installed into my trusted root authorities, I have built out the add-in in Visual Studio and copied all DLL's and addin file to the addins folder. I have then run the sign tool command:
signtool sign /f "Path/To/codesign.pfx" /t \
http://timestamp.comodoca.com/authenticode \
/p "MyPassword" "Path/To/Addins//2018/AppName.dll"
This command executes successfully and I can see a digital signatures tab containing the information I added for my self-signed certificate in the DLL properties. Yet, When I start Revit, it still says it is unsigned... Where did I go wrong?
I have tried various other combinations of this command including passing in the .addin file which errors out saying unrecognized file and signing all dlls in my addins folder.
Answer: Peter Hirn added an automatic signing step to the RevitLookup continuous integration on GitLab.
The YAML file executing the add-in signing is available in the RevitLookup GitHub repository.
The pertinent bits are
the lines 53-79 in .gitlab-ci.yml:
script:
- apt-get update && apt-get install -y --no-install-recommends osslsigncode
- mkdir -p .secrets && mount -t ramfs -o size=1M ramfs .secrets/
- echo "${CODESIGN_CERTIFICATE}" | base64 --decode > .secrets/authenticode.spc
- echo "${CODESIGN_KEY}" | base64 --decode > .secrets/authenticode.key
- osslsigncode -h sha1 -spc .secrets/authenticode.spc -key .secrets/authenticode.key -t ${TIMESERVER} -in "${ASSEMBLY}" -out "${ASSEMBLY}-sha1"
- osslsigncode -nest -h sha2 -spc .secrets/authenticode.spc -key .secrets/authenticode.key -t ${TIMESERVER} -in "${ASSEMBLY}-sha1" -out "${ASSEMBLY}"
- rm "${ASSEMBLY}-sha1"
Response: This is great! I am going to utilize that in my own Repos. Ok, I finally got windows to recognize my cert; Let me track through what I did and how I got it to work.
Originally, I was using openssl on a linux server to generate the certs and private keys.
I then used openssl to convert those to a pfx file and was using that to sign stuff;
Looks like that does not work too well.
I followed the post in this thread and that worked...
To rehash what I did to make this work:
Notes before you begin: MakeCert.exe, pvk2pfx.exe, and signtool.exe are all located in *C:\Program Files (x86)\Windows Kits\8.1\bin\x64*.
I have already added this to my environment variables; make sure you do so too, otherwise you will have to specify in your command where to find these exes.
MakeCert.exe -r -sv AVT_CodeSign.pvk -n "CN=AVT" AVTCodeSign.cer -b 01/01/2020 -e 12/31/2020
NOTE: MakeCert is deprecated according to official Microsoft sources, but at the time of this writing that command still works. They have an alternative PowerShell commandlet that does the same thing though I did not try that since MakeCert worked for me.
pvk2pfx.exe -pvk codesign.pvk -pi MySecurePassword -spc codesign.cer -pfx codesign.pfx -po MyOtherSecurePassword
NOTE: The passwords can be the same here; The password I'm using here is from a prompt from Step 1. That prompt will ask you to supply a password for the private key or give you the option to press "none". Whichever you choose, supply that password in step 2.
Step 3: Use CertMgr.msc to install your codesign.pfx file NOT the certificate.
Install it Trusted Publishers, then in Trusted Root Certification Authorities
NOTE: It's important here to click your .pfx file as when I did this step, the default was choosing the cert file.
I'm unsure if this way is better than simply right clicking and hitting "install cert" but it seems both will get you to the same spot.
signtool sign /f "Path\To\codesign.pfx" /t http://timestamp.verisign.com/scripts/timstamp.dll /p "MySecurePassword" "Path\To\RevitAddin.dll"
Following this process, I was able to get a valid digital signature.
I'm not sure why generating it using openssl on linux was causing an issue but there may be something to this method that works better.
Many thanks to ShinyKey for testing and confirming this, and thanks again to Peter Hirn for the smooth RevitLookup CI and code signing workflow.
Preview Control Rotates Model
Scott Ehrenworth of Microdesk Inc. pointed out a few interesting aspects of using and interacting with the Revit API PreviewControl class in the Revit API discussion forum thread on using PreviewControl ElementHost and PickPoint:
Firstly, The PreviewControl is not a pure preview control, providing read-only access and no user interaction with the model.
Proof: When changing the orientation or rotation of a 3D view inside of a PreviewControl window, the model's 3D view will rotate as well:
Zoom and Pan do not have this effect.
Secondly, even though the preview control modifies the model's current view settings, it does not require a transaction to do so. However, it does require the manual transaction option, presumably so that it can start and commit its own transaction internally.
This could be like the PromptForFamilyInstancePlacement method that has a transaction control built in.
The PreviewControl class is full of Event Handlers, so maybe this is the case?
Here's the very basic sample of the external command I used to test this for 3D views.
[Transaction( TransactionMode.Manual )] class PreviewControlTest : IExternalCommand { public Result Execute( ExternalCommandData commandData, ref string message, ElementSet elements ) { UIApplication uiapp = commandData.Application; UIDocument uidoc = uiapp.ActiveUIDocument; Document doc = uidoc.Document; WPF_GridContainer newGrid = new WPF_GridContainer(); newGrid.theGrid.Children.Add( new PreviewControl( doc, new FilteredElementCollector( doc ) .OfClass( typeof( View3D ) ) .FirstElementId() ) ); newGrid.ShowDialog(); return Result.Succeeded; } }
I assume it will refuse to run in read-only transaction mode, then...
Yes, I can confirm:
Switching the TransactionMode to ReadOnly is now just hanging the command (never opens the window for the PreviewControl).
Funky stuff, but good to know!
Many thanks to Scott for this useful information and research.
For pointers to several previous discussions of various aspects of the PreviewControl, check out the post
on zooming in a preview control.
Element Type Predicates
Here are a bunch of ways to check and filter for Revit element types making use of both .NET generics and the Revit API filtering functionality suggested in the question on how
to determine if element is ElementType:
Question: I'm listening to the Application DocumentChanged event and would like to see if the element modified is an Instance or an ElementType.
I'm currently doing the following but it doesn't quite satisfy all the conditions:
static bool IsElementType( Element element ) { var typeId = element?.GetTypeId(); if( typeId == null || typeId == ElementId.InvalidElementId ) { if( !(element is Room) && !(element is PipeSegment) ) { return true; } } return false; }
I'm not native to Revit sorry if my terminology is off.
How does the FilterCollector.WhereElementIsElementType() determine it's an ElementType?
Answer: This will return false if type is ElementType but true if is derived from ElementType:
bool Bl = element.GetType().IsSubclassOf( typeof( ElementType ) );
This will return true if type is ElementType or is derived from ElementType:
bool B2 = typeof( ElementType ).IsAssignableFrom( element.GetType() );
Here's a more Revit orientated approach in VB: you asked how a collector determines an ElementType, but you can always pass a list of a single element into a collector and filter that:
Dim FEC As New FilteredElementCollector(element.Document, {element.Id}.ToList)
Dim B3 As Boolean = FEC.WhereElementIsElementType.ToElementIds.Count > 0
You can't do it in C# in this abbreviated fashion due to the need to use ICollection<T> directly (option Strict off in VB), but you can do similar.
Answer 2: Here's a simpler way of putting it:
static bool IsElementType( Element element ) { return element is ElementType; }
I'd suggest not even making a method for this and just using the is expression.
Answer 3: I use the is operator quite often in my work.
Here is an online method which will use a type pattern to give you the EType as a variable:
if( element is ElementType EType ) { TaskDialog.Show( "Type Name", EType.Name ); }
Interesting to note that in VB the is statement only returns true if the exact same type is compared.
Since is is used to check if two things are the same object instance.
The equivalent to the way it is used in C# seems to be:
Dim B1 As Boolean = TypeOf Element Is ElementType
AI Ethics
A very interesting and promising first stab at creating 'good' AI and NLP that conforms with common human ethical judgement and behaviour is presented in the research paper on Aligning AI With Shared Human Values.
