$ versus @
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@didier bur said:
Hi,
But it is a lazy way of retaining values for your dialog boxes for instance, so user get the last values used.
One can avoid globals when using classes and methods, classes variables (@@) and objects variables (@).I'm sorry but I cant let this topic die just yet. I have carefully reread all the
comments. Does this quote offer a solution to retaining values in Dialog Boxes? -
For a dialog's default values that you want keeping from session to session within a particular model, I write them as attributes to the model itself: when the dialog initialises it looks for their values, if they are not there it takes defaults - otherwise you have them saved on a model by model basis... For an example see my TextTag.rb.
.
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So, there you have it - three solutions that avoid globals:
- Sketchup.read_default and Sketchup.write_default (persistent across SketchUp sessions and models)
- Attributes (persistent within a given model, between sessions)
- Class variables (@@variable) (persistent only within a SketchUp session)
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For persistent data for Dialog Boxes, you should use Sketchup.write_default and Sketchup.read_default. The keys and values are stored in the registry (Windows) and the plist (Mac).
Todd
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@rickw said:
So, there you have it - three solutions that avoid globals:
- Sketchup.read_default and Sketchup.write_default (persistent across SketchUp sessions and models)
- Attributes (persistent within a given model, between sessions)
- Class variables (@@variable) (persistent only within a SketchUp session)
Thanks everyone; I took a quick look at TIG's, TextTag.rb. It appears to take a little bit more understanding of Ruby then just simply banging out a mass replacement of @ to $ or vise versa. Nevertheless I will try to implement
these attributes on an exisitng Ruby of mine. -
Hi all !
Just one question : How can you do when you have that :
class ToolsObsTest < Sketchup;;ToolsObserver def onActiveToolChanged (tools_object, toolname, toolid) [b]@t[/b] = toolid end end
and this variable @t is used here :
module def [b]@t[/b] end end
So the variable is not used inside the first class section, but inside the instance of a module section ???
To find variable, I use $....How can I preserve variable value ????
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Just define your Observer class in the scope of your Module
module Foo class ToolsObsTest < Sketchup;;ToolsObserver def onActiveToolChanged (tools_object, toolname, toolid) @t = toolid end end end instance = Foo;;ToolsObsTest.new
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Hi AdamB !
Thak you for your answer...I tried it but it didn't work for me... @toolID (variable name in the code) always returns nil....
here is the real "tree" of the code (including your advice)module Toto class ToolsObsTest < Sketchup;;ToolsObserver def onActiveToolChanged (tools_object, toolname, toolid) @toolID = toolid end end ### def self.act model.tools.add_observer(Toto;;ToolsObsTest.new) end ### def self.obs(id) @toolID end end
Do you know why your method doesn't work ?
Thank you ! -
Matt,
The two @toolid are different. One is a Class instance variable, the other a Module variable.
If you want to track the toolid in module Toto, then use a method to set its value, which you can call from the class.
Note that normally, you might use a Module variable, with @@, (since module instance variables do not really have real application)def Toto.set_toolid(toolid) @@toolid = toolid end def Toto.get_toolid() @@toolid end
Fredo
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Hello Fredo6 !
Thank you for your answer ! It works great ! get_toolid & set_toolid are perfect !
Just one thing, @@variable doesn't work. Just @variable...Thank you Fredo !
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