A little module add-on (For scripters)

Started by Zeriab, January 08, 2008, 06:51:41 am

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Zeriab

January 08, 2008, 06:51:41 am Last Edit: December 05, 2010, 05:21:12 am by Blizzard
Here's a litte addition to the module I have made ^^
class Module
 def attr_secure_accessor(sym, *args, &block)
   if block.nil? # default actions
     args = [0] if args.size == 0 #default = 0
     if args.size < 2 # One pair
       attr_writer sym
       attr_secure_reader sym, *args
     else # loads of methods followed by a default value.
       default = args[-1]
       syms = [sym].concat(args)
       syms.pop
       for sym in syms
         attr_writer sym
         attr_secure_reader sym, default
       end
     end
   else # when a block is given
     # currently just pair sematics
     args.unshift(sym)
     i = 0
     while i < args.size
       attr_writer args[i]
       attr_secure_reader args[i], args[i+1]
       i += 2
     end
   end
 end
 
 def attr_secure_reader(sym, default = 0)
   sym = sym.id2name
   string = "def #{sym};" +
            "  @#{sym} = #{default}  if @#{sym}.nil?;" +
            "  @#{sym};" +
            "end;"
   module_eval(string)
 end
end


Simple Version
class Module
 def attr_secure_accessor(sym, default = 0)
   attr_writer sym
   attr_secure_reader sym, default
 end
 
 def attr_secure_reader(sym, default = 0)
   sym = sym.id2name
   string = "def #{sym};" +
            "  @#{sym} = #{default}  if @#{sym}.nil?;" +
            "  @#{sym};" +
            "end;"
   module_eval(string)
 end
end


You can use it like this:
attr_secure_accessor :method, default

It works pretty much like the attr_accessor except that you can only do method creation per call.
method is the method name.
default is the default value the method returns. (If it has not been written to yet.)

An usage example:
class Foo
 attr_secure_accessor :visible, false
 attr_secure_accessor :data, 'Data_Foo.new'
end


This way you'll have that the default variable of visible is false.
If it is called before you write to the variable you will get 'false' rather than 'nil'
One thing to note is that lazy instantiation is used.
Let us assume that Data_Foo is a heavy object. It is only created if you try to read what the data attribute contains before you have written to it. More specifically. If the value of data attribute is nil then it is change to be what the default value is.

The code in the example is converted to this:

class Foo
 def visible=(value)
   @visible = value
 end
 def visible
   @visible = false  if @visible.nil?
   @visible
 end
 
 def data=(value)
   @data = value
 end
 def data
   @data = Data_Foo.new  if @data.nil?
   @data
 end
end

One thing to notice is that you must put '' around Data_Foo.new to make it a string. Otherwise you will get an error in almost all cases.

The greatest use will probably be if you want to add information to hidden classes. Let's for an example take RPG::Actor.
You can use its initialize method to set the default value by default because it won't be called automatically.
Other than that it will hopefully make the coder shorter and easier to understand.

Naturally. Only use this functionality where it is needed or where it can have a positive use ^_^

*hugs*
~ Zeriab

Fantasist

This went into my 'Default Script Enhancement' project :)
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Zeriab

'Default Script Enhancement' project.
That sounds interesting. I would love to hear more about it.

I'm glad you found this useful ^_^

Fantasist

Don't expect too much, just slight modding and adding features into default scripts, that's all. I used other scripts a lot efore, but right now, I only use Bliz's debugger.

About this nifty addon, I think I'll name it something shorter, like simply attr or attribute :)
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Zeriab

Sounds fun ^^

Don't call it attr. There is already a module method called attr. You shouldn't overwrite it ;)
I don't know about attribute though... I don't think that has been used. Still. I suggest you name them after what they do. I would have named the method attr_secure_accessor and attr_secure_reader, but since there is not auto-completion in the script editor I shortened the name a little despite it being bad style. In fact, now that I think about it *changes*

Sally


Zeriab

Sorry for the bump.
Can anyone test whether this works also works on RMVX?
I see no reason why it shouldn't, but better safe than sorry ^_^

Blizzard

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