How can I make an array of points created by a for loop in featurescript?

Answers

• NeilCooke Moderator, Onshape Employees Posts: 5,354

  September 2019

  i does not exist once outside the curly braces of the for loop. There are a number of ways you can do this, but it all depends on the rest of the script.
  
  This is the most elegant way but may fall down if you have other similar loops in your code (due to id hierarchy):
  

  for (var i = 0; i < numberOfDowels; i += 1)
  {
      opPoint(context, id + i + "locationPoint", {                        
          "point" : toWorld(cSys, vector((fenceDistance + (dowelSpacing * i)), 0 * inch, 0 * inch))
      });
  }
  
  var locationPoints is array = evaluateQuery(context, qCreatedBy(id + ANY_ID + "locationPoint", EntityType.BODY));

  Senior Director, Technical Services, EMEAI

  0
• NeilCooke Moderator, Onshape Employees Posts: 5,354

  September 2019 edited September 2019 Answer ✓

  Another way (more id compliant) is:
  

  var locationPoints = [];
  for (var i = 0; i < numberOfDowels; i += 1)
  {
      opPoint(context, id + ("locationPoint" ~ i), {&nbsp;
          "point" : toWorld(cSys, vector((fenceDistance + (dowelSpacing * i)), 0 * inch, 0 * inch))
      });
      locationPoints = append(locationPoints, qCreatedBy(id + ("locationPoint" ~ i), EntityType.BODY));
  }
  locationPoints = evaluateQuery(context, qUnion(locationPoints));
  

  There are a few other ways besides.

  Senior Director, Technical Services, EMEAI

  6
• emory_krall Member Posts: 15 PRO

  September 2019

  Is "ANY_ID" meant to be used literally? When I try this I get the error "Typecheck canBeId failed"
  

  0
• NeilCooke Moderator, Onshape Employees Posts: 5,354

  September 2019

  Yes, ANY_ID is a wildcard. Make sure it is spelled out exactly as above. I think you may be safer using the second method.

  Senior Director, Technical Services, EMEAI

  0
• NeilCooke Moderator, Onshape Employees Posts: 5,354

  September 2019

  Id hierarchy is a little difficult to follow: https://cad.onshape.com/FsDoc/library.html#Id

  Senior Director, Technical Services, EMEAI

  0
• emory_krall Member Posts: 15 PRO

  September 2019

  Thanks Neil, your second suggestion appears to work for me!
  

  0
• emory_krall Member Posts: 15 PRO

  September 2019

  There is a typo in the code: "EntityType.Body" should be "EntityType.BODY"
  

  0
• NeilCooke Moderator, Onshape Employees Posts: 5,354

  September 2019 edited September 2019

  Yeah, sorry - I hand-typed it from memory. I've edited the post above for anybody else that might copy it.

  Senior Director, Technical Services, EMEAI

  0
• Jake_Rosenfeld Moderator, Onshape Employees, Developers Posts: 1,646

  September 2019 Answer ✓

  I would do this like this:
  

  const parentId = id + "points";
  for (var i = 0; ...)
  {
      opPoint(context, parentId + toString(i), {...});
  }
  const locationPoints = evauateQuery(context, qCreatedBy(parentId, EntityType.BODY));

  
  Since ids are hierarchical, if you nest a bunch of child ids under a parent, you can just evaluate a query on the entire parent, and the query will be evaluated for the entire group of ids contained by the parent.
  
  Note that:
  

  id + ("points" ~ i)

  creates ids that are like this "rootId > points0" "rootId > points1" "rootId > points2" (where the > is representing the transition of one id component to the next)
  
  but:
  

  (id + "points") + toString(i)
  // which is equivalent to:
  const parentId = id + "points";
  parentId + toString(i)

  creates ids that are like this "rootId > points > 0" "rootId > points > 1" "rootId > points > 2".  Then, because the ids are structured in a nice way, you can just do evaluations on parentId ("rootId > points"), and it will capture all of the ids which are children of that.

  Jake Rosenfeld - Modeling Team

  6