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Will Parsons

2010-Feb-27 01:39 UTC

[fxruby-users] Accessing SQLite database in FXRuby application

I''m trying to develop an application that accesses an SQLite database
and
am running into problems related to using getApp (probably because of some
simple misunderstanding of how FXRuby works on my part).  The following is
a stripped-down version of my (non-functioning) program:

=======================================================================#!/usr/bin/env
ruby

require ''fox16''
require ''sqlite3''

include Fox

class TestApp < FXApp
   def initialize
      super(''Test'', ''Test'')
      @db = SQLite3::Database.new(''test.db3'')
      @db || raise("can''t connect to database")
   end

   def db
      @db
   end
end

class TestTable < FXTable
   def initialize(p)
      super(p, :opts => LAYOUT_FILL|PACK_UNIFORM_WIDTH|TABLE_COL_SIZABLE)

      db = getApp.db
      db || raise("can''t access DB")      # <---- this
condition is raised

      setTableSize(3, 3)
      # fill table with data from database...
   end
end

class TopLevelWindow < FXMainWindow
   def initialize(app)
      super(app, ''Test'', :width => 400, :height => 100)
      TestTable.new(self)
   end

   def create
      super
      show(PLACEMENT_SCREEN)
   end
end

TestApp.new do |app|
   TopLevelWindow.new(app)
   app.create
   app.run
end

=======================================================================
When run, the condition "can''t access DB" is raised.  This is
probably simple,
but I can''t seem to figure out what I''m doing wrong.

-- 
Will

Nataraj S Narayan

2010-Feb-27 10:39 UTC

head link

[fxruby-users] Accessing SQLite database in FXRuby application

Hi

Should''nt it be like this?


class TestApp < FXApp
  def initialize
     super(''Test'', ''Test'')


  end

  def db
    @db = SQLite3::Database.new(''test.db3'')
 @db || raise("can''t connect to database")
  end
end

regards

Nataraj


On Sat, Feb 27, 2010 at 7:09 AM, Will Parsons <wbparsons at cshore.com>
wrote:> I''m trying to develop an application that accesses an SQLite
database and
> am running into problems related to using getApp (probably because of some
> simple misunderstanding of how FXRuby works on my part).  The following is
> a stripped-down version of my (non-functioning) program:
>
> =======================================================================>
#!/usr/bin/env ruby
>
> require ''fox16''
> require ''sqlite3''
>
> include Fox
>
> class TestApp < FXApp
>   def initialize
>      super(''Test'', ''Test'')
>      @db = SQLite3::Database.new(''test.db3'')
>      @db || raise("can''t connect to database")
>   end
>
>   def db
>      @db
>   end
> end
>
> class TestTable < FXTable
>   def initialize(p)
>      super(p, :opts => LAYOUT_FILL|PACK_UNIFORM_WIDTH|TABLE_COL_SIZABLE)
>
>      db = getApp.db
>      db || raise("can''t access DB")      # <---- this
condition is raised
>
>      setTableSize(3, 3)
>      # fill table with data from database...
>   end
> end
>
> class TopLevelWindow < FXMainWindow
>   def initialize(app)
>      super(app, ''Test'', :width => 400, :height =>
100)
>      TestTable.new(self)
>   end
>
>   def create
>      super
>      show(PLACEMENT_SCREEN)
>   end
> end
>
> TestApp.new do |app|
>   TopLevelWindow.new(app)
>   app.create
>   app.run
> end
>
> =======================================================================>
> When run, the condition "can''t access DB" is raised. 
This is probably simple,
> but I can''t seem to figure out what I''m doing wrong.
>
> --
> Will
> _______________________________________________
> fxruby-users mailing list
> fxruby-users at rubyforge.org
> http://rubyforge.org/mailman/listinfo/fxruby-users
>

Joey Kinsella

2010-Feb-27 14:34 UTC

head link

[fxruby-users] Accessing SQLite database in FXRuby application

Try changing the following block:

TestApp.new do |app|
  TopLevelWindow.new(app)
  app.create
  app.run
end

to:

app = TestApp.new
TopLevelWindow.new(app)
app.create
app.run

I think (but I could be mistaken) when you pass a block to FXApp.new
it''s
more like this:

if block_given?
  yield(FXApp.new(name, vendor))
else
  # ....
end

If this is the case, then @db would never get initialized, since the
overloaded initialized method would never be called.

On Fri, Feb 26, 2010 at 8:39 PM, Will Parsons <wbparsons at cshore.com>
wrote:
> I''m trying to develop an application that accesses an SQLite
database and
> am running into problems related to using getApp (probably because of some
> simple misunderstanding of how FXRuby works on my part).  The following is
> a stripped-down version of my (non-functioning) program:
>
> =======================================================================>
#!/usr/bin/env ruby
>
> require ''fox16''
> require ''sqlite3''
>
> include Fox
>
> class TestApp < FXApp
>   def initialize
>      super(''Test'', ''Test'')
>      @db = SQLite3::Database.new(''test.db3'')
>      @db || raise("can''t connect to database")
>   end
>
>   def db
>      @db
>   end
> end
>
> class TestTable < FXTable
>   def initialize(p)
>      super(p, :opts => LAYOUT_FILL|PACK_UNIFORM_WIDTH|TABLE_COL_SIZABLE)
>
>      db = getApp.db
>      db || raise("can''t access DB")      # <---- this
condition is raised
>
>      setTableSize(3, 3)
>      # fill table with data from database...
>   end
> end
>
> class TopLevelWindow < FXMainWindow
>   def initialize(app)
>      super(app, ''Test'', :width => 400, :height =>
100)
>      TestTable.new(self)
>   end
>
>   def create
>      super
>      show(PLACEMENT_SCREEN)
>   end
> end
>
> TestApp.new do |app|
>   TopLevelWindow.new(app)
>   app.create
>   app.run
> end
>
> =======================================================================>
> When run, the condition "can''t access DB" is raised. 
This is probably
> simple,
> but I can''t seem to figure out what I''m doing wrong.
>
> --
> Will
> _______________________________________________
> fxruby-users mailing list
> fxruby-users at rubyforge.org
> http://rubyforge.org/mailman/listinfo/fxruby-users
>
--
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Will Parsons

2010-Feb-27 15:21 UTC

head link

[fxruby-users] Accessing SQLite database in FXRuby application

From: Nataraj S Narayan <natarajsn at gmail.com>
Subject: Re: [fxruby-users] Accessing SQLite database in FXRuby application
Date: Sat, 27 Feb 2010 16:09:22 +0530
> Hi
> 
> Should''nt it be like this?
> 
> 
> class TestApp < FXApp
>   def initialize
>      super(''Test'', ''Test'')
> 
> 
>   end
> 
>   def db
>     @db = SQLite3::Database.new(''test.db3'')
>  @db || raise("can''t connect to database")
>   end
> end
I don''t think so, since that would give me a different database
connexion
each time I invoke getApp.db, but that gave me the idea that a slight
variation might work:

class TestApp < FXApp
   #...
   def db
      @db ||= SQLite3::Database.new(''test.db3'')
      @db || raise("can''t connect to database")
   end
end

It looks like that should defer opening the database until it is actually
needed and keep the handle for later invocations.  Still, it seems less
straightforward than opening the database as part of the application
initialization.  Thanks for the suggestion.> 
> On Sat, Feb 27, 2010 at 7:09 AM, Will Parsons <wbparsons at
cshore.com> wrote:
> > I''m trying to develop an application that accesses an SQLite
database and
> > am running into problems related to using getApp (probably because of
some
> > simple misunderstanding of how FXRuby works on my part).  The
following is
> > a stripped-down version of my (non-functioning) program:
> >
> >
=======================================================================> >
#!/usr/bin/env ruby
> >
> > require ''fox16''
> > require ''sqlite3''
> >
> > include Fox
> >
> > class TestApp < FXApp
> >   def initialize
> >      super(''Test'', ''Test'')
> >      @db = SQLite3::Database.new(''test.db3'')
> >      @db || raise("can''t connect to database")
> >   end
> >
> >   def db
> >      @db
> >   end
> > end
> >
> > class TestTable < FXTable
> >   def initialize(p)
> >      super(p, :opts =>
LAYOUT_FILL|PACK_UNIFORM_WIDTH|TABLE_COL_SIZABLE)
> >
> >      db = getApp.db
> >      db || raise("can''t access DB")      # <----
this condition is raised
> >
> >      setTableSize(3, 3)
> >      # fill table with data from database...
> >   end
> > end
> >
> > class TopLevelWindow < FXMainWindow
> >   def initialize(app)
> >      super(app, ''Test'', :width => 400, :height
=> 100)
> >      TestTable.new(self)
> >   end
> >
> >   def create
> >      super
> >      show(PLACEMENT_SCREEN)
> >   end
> > end
> >
> > TestApp.new do |app|
> >   TopLevelWindow.new(app)
> >   app.create
> >   app.run
> > end
> >
> >
=======================================================================> >
> > When run, the condition "can''t access DB" is
raised.  This is probably simple,
> > but I can''t seem to figure out what I''m doing wrong.

William B. Parsons

2010-Feb-27 15:37 UTC

head link

[fxruby-users] Accessing SQLite database in FXRuby application

On Sat, 27 Feb 2010 09:34:04 -0500
Joey Kinsella <jkinsella at ancillaryservices.com> wrote:
> Try changing the following block:
> 
> TestApp.new do |app|
>   TopLevelWindow.new(app)
>   app.create
>   app.run
> end
> 
> to:
> 
> app = TestApp.new
> TopLevelWindow.new(app)
> app.create
> app.run
> 
> I think (but I could be mistaken) when you pass a block to FXApp.new
it''s
> more like this:
> 
> if block_given?
>   yield(FXApp.new(name, vendor))
> else
>   # ....
> end
> 
> If this is the case, then @db would never get initialized, since the
> overloaded initialized method would never be called.
Thanks!  That does indeed seem to be the case, so it looks like I have
a solution.

-- 
Will

fxruby users - Feb 2010 - Accessing SQLite database in FXRuby application

[fxruby-users] Accessing SQLite database in FXRuby application

[fxruby-users] Accessing SQLite database in FXRuby application

[fxruby-users] Accessing SQLite database in FXRuby application

[fxruby-users] Accessing SQLite database in FXRuby application

[fxruby-users] Accessing SQLite database in FXRuby application