Ruby Plugin Help

AlexS

Hello,

I've made a a plugin for Ruby before, but I'm writing another one and it requires something a bit tougher...

I want to gather all the groups that have the name that starts with "SPECIAL". In reality these groups will contain no faces, but simply curves. I want to get each "point" in the group and write it to a file (I know how to do that).

Now question is, how do I get the points for a line segment?

If I need to clarify more simply ask,

Thanks,

Alex

TIG

verts=[]
group.entities.each{|e| verts << e.vertices if e.class==Sketchup::Edge }
verts.flatten!

each e.vertices returns a two element array, flatten explodes these

inner arrays so that verts is then one array...

verts.uniq!

this removes duplicate vertices from verts, i.e. because in a curve

most vertices get listed twice because they will have two edges...

points=[]
verts.each{|v| points << v.position }

points is now a list of all points represented by

all of the edges' vertices inside the given group...

AlexS

Thanks, TIG!

How can I separate the groups whos names start with SPECIAL and the ones that don't, though? Thanks for your help,

Alex

EDIT: And also, I'm trying to use the 'puts' function, but when I'm doing this: file.puts "<model/>", it thinks that when I use the < & > symbols that I'm trying to define a constant or something. This is the same for the 'print' function. How can I add the < > characters? Thanks for your patience with me.

Dan Rathbun

Well since you use the group.name= method to set the group's name, you will use the group.name method to retrieve it. Use a comparison expression:

verts=[

Sketchup.active_model.entities.each {|ent|
if ent.kind_of?(Sketchup::Group) && ent.name == 'SPECIAL']

... then iterate the group's entites ...

... then flatten and uniqify the verts array,
... which can be done in one line:
%(#BF0000)[verts.flatten!.uniq!

end # if SPECIAL group
}
points=[]]
... rest of code as shown above.

AlexS

Sorry I wasn't clear enough... I mean to retrieve whatever groups whos name STARTS with SPECIAL... Is there is an equivalent to C's "StartsWith" in Ruby?

Dan Rathbun

You test for substrings using .include?

if ent.kind_of?(Sketchup::Group) && ent.name.include?('_SPECIAL_')

If you wish to really use starts with, then you can test a subrange of a string:

if ent.kind_of?(Sketchup::Group) && ent.name[0..8] == '_SPECIAL_'

or:
if ent.kind_of?(Sketchup::Group) && ent.name[0,9] == '_SPECIAL_'

You can look up Core methods online:
http://www.ruby-doc.org/core-1.8.6/index.html

.. or download the CHM for offline use, from my post here:
http://forums.sketchucation.com/viewtopic.php?f=180&t=10142&p=266725#p266725

thomthom

@alexs said:

Sorry I wasn't clear enough... I mean to retrieve whatever groups whos name STARTS with SPECIAL... Is there is an equivalent to C's "StartsWith" in Ruby?

You can use RegEx:
my_string.test(/^_SPECIAL_/)

Or simple text operation:
my_string[0,9] == '_SPECIAL_'

TIG

To explain a little more about 'patterns'...
/^_SPECIAL_/
The ^ at the start says 'starts_with'
A $ at the end says 'ends_with'
/_SPECIAL_$/
Using both is equivalent to 'is_equal_to'.
Using neither says 'contains_this_text_anywhere' in the string...

Note that the my_string.test(//) method is equivalent to my_string =~ // that you might also come across...

The whole pattern thing can be quite complex - e.g.
/^[^a-z0-9]/
says starts with any character (^ inside the [] reverses the match) that is NOT a lowercase letter or number.
With gsub you can use something like it to 'squeeze' everything out of say a file-name so it only uses letters, numbers, '-' or '_' - e.g. as used in OBJ-file naming conventions, thus:
filename.gsub!(/[^-_A-Za-z0-8]/, '_')

There are several websites that cover this in considerable detail.......

AlexS

Thank you guys, you've been a great help.

Now... just one LAST question. I'm trying to use the 'print' and 'puts' function, and I'm trying to put in these characters: < >

But when I load Sketchup, it gives me an error. I guess it thinks I'm trying to do something within the string when I put a < or >.

How can I fix this?

Dan Rathbun

Those characters are both Ruby operators and instance method names.

Use the String concate method + to add those chars (which must be quoted.)

my_string = 'Some special string' + ' > ' + 'the last part of the string.'

or you can use replacement within double-quoted string:

my_string = "The value: #{biggernum.to_s} > #{smallernum.to_s}"
where biggernum and smallernum are numeric references.

The 3rd way is to use the Integer instance method chr if you know the character's ordinal within the UTF-8 set.
Since decimal 60 is the ordinal for "less than" ...
60.chr returns the single char string "<"