Entities Edge color apply

krisjaniszakis

Can some one say why this is working: (where 's2' is Sketchup::Edge entity)

material_name=e2.material
if mat
cname=material_name.name
else
cname="<Default>"
end#if

but this is not working:

material_name=e2.material.name

After this code Ruby returns this error:
Error: #<NoMethodError: undefined method `name' for nil:NilClass>

Why i cannot strait forward access material name.

Dan Rathbun

Because the material() method returns a Sketchup::Material object, not a String object, But ONLY IF the entity has been assigned a material. If the entity has no material, then the material() method returns nil.

This is standard operating procedure in Ruby. It is common to test using if, because in Ruby only false and nil evaluate logically false. Everything else, including 0, an empty Array and empty Strings, evaluate as logically true.

So you do:

if mat = e2.material()
  mat_name = mat.name()
else
  mat_name = "<Default>"
end

You cannot call .name() on the singleton NilClass object ( nil,) because it does NOT have a instance method called ' name'.)

krisjaniszakis

Thanks it helped

TIG

mat=e2.material
if mat
  cname=mat.name ### OR .display_name ?
else ### NO MATERIAL
  cname="<Default>"
end#if

test for the existence of the material and then get it's name if it exists, if the material is ' nil'then there's no ' name' to get.

Dan Rathbun

Late to the party

krisjaniszakis

Thanks TIG there can be made changes in my code even more later

thomthom

@tig said:

mat=e2.material
> if mat
>   cname=mat.name ### OR .display_name ?
> else ### NO MATERIAL
>   cname="<Default>"
> end#if

test for the existence of the material and then get it's name if it exists, if the material is ' nil'then there's no ' name' to get.

#display_name should only be used to output the name of a material to the UI - not as an id.
http://www.thomthom.net/thoughts/2012/03/the-secrets-of-sketchups-materials/#speaking-of-names8230