I try to create a tkEntry with a tkVariable attached in the class
startupinterface and create a callback to startupinterfacecontroller but
it doesn't work : it says that themember variable supposed to hold a
link to the tkVariable object is nil:nilClass when i try to call the
value member function
code is in attachement
any help appreciated
Attachments:
http://www.ruby-forum.com/attachment/3478/chess_games_helper.rb
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Message-ID: <34100fb324f5193a1b8567f60a34eea0@ruby-forum.com>
it doesn't work : it says that themember variable supposed to hold a
link to the tkVariable object is nil:nilClass when i try to call the
value member function
Hmmm...
You may be misunderstanding about a block given to <widgetclass>.new.
# And, your code has a problem about accessing a TkVariable object.
From: Cristian Achim <cristiach@yahoo.com>
Subject: ruby tkentry tkvariable with class wrappers problem
Date: Tue, 24 Mar 2009 04:43:01 +0900
---------------------------------------------------
@files_lcoation_text=TkVariable.new
@files_location_text=""
@files_location_entry=TkEntry.new(tk_root){
textvariable @files_location_text
}.grid("row"=>0 , "column"=>1)
@files_location_text="tada"
---------------------------------------------------
Such block is evaluated with "instance_eval".
That is, at internal of the block, "self" is the widget created by
"new" method. So, @files_location_text in the block is a instance
variable of the entry widget.
There are two ways to avoid this problem.
The one is to use a local variable.
And another is to use a Hash argument.
-----<case.1>----------------------------------------------
@files_lcoation_text = txt_var = TkVariable.new("")
@files_location_entry=TkEntry.new(tk_root){
textvariable txt_var
}.grid("row"=>0 , "column"=>1)
@files_location_text.value = "tada"
-----------------------------------------------------------
-----<case.2>----------------------------------------------
@files_lcoation_text = TkVariable.new("")
@files_location_entry=TkEntry.new(tk_root, :textvariable=>@files_lcoation_text).grid(:row=>0 , :column=>1)
@files_location_text.value = "tada"
-----------------------------------------------------------
Please take attention to a scope of a variable.
--
Hidetoshi NAGAI (nagai@ai.kyutech.ac.jp)
problem solved ; thanks for the help
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the fix is good but i hit another problem
when I try to change the value of the tkvariable member variable with
the value member function of tkvariable it doesn't work : it says
nil:NilClass when pressing the button change_entry_text
I try to change the value of the initial entry/tkvariable by using the
value of a new one or possibly the value supplied by any external class
that has a reference
new code version is attached
Attachments:
http://www.ruby-forum.com/attachment/3479/chess_games_helper.rb
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Message-ID: <81d191cc09ee5a2117fba8201cbbbfe7@ruby-forum.com>
when I try to change the value of the tkvariable member variable with
the value member function of tkvariable it doesn't work : it says
nil:NilClass when pressing the button change_entry_text
It's a typo.
--- chess_games_helper.rb.orig 2009-03-24 11:38:46.000000000 +0900
+++ chess_games_helper.rb 2009-03-24 11:40:03.000000000 +0900
@@ -51,7 +51,7 @@
files_location_entry_d.insert('end' , "data files location")
files_location_entry_d.state="disabled"
- @files_lcoation_text=txt_var=TkVariable.new
+ @files_location_text=txt_var=TkVariable.new
new_txt=TkVariable.new
files_location_entry=TkEntry.new(tk_root){
From: Cristian Achim <cristiach@yahoo.com>
Subject: Re: ruby tkentry tkvariable with class wrappers problem
Date: Tue, 24 Mar 2009 07:00:24 +0900
--
Hidetoshi NAGAI (nagai@ai.kyutech.ac.jp)
that fixed it again hope i'll be more carefull next time and not post
typo questions
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