Re: [Pyobjc-dev] problem accessing outlet

[<bb...@ma...>]

On Tuesday, October 29, 2002, at 01:42 AM, Steven D. Arnold wrote:
> I appreciate the helpful answers I've gotten so far from Ronald and 
> Bill.  I
> hate to ask so many questions, but I think I'm very close to a working
> Python/Cocoa application.

This is extremely valuable feedback -- every question helps us to 
understand where we need to provide better documentation or better 
examples.

> I've done as I said in a previous post:
>
> 1. Start PB, create Cocoa app
> 2. Open resources, double-click the IB icon
> 3. Create a subclass of NSObject, in my case HelloWorld
> 4. Create an outlet called "text" which is the NSTextField intended to
> display the "Hello World" message
> 5. Create an action called "sayIt" which is wired to a button on the 
> form
> 6. Modify main.m to look exactly as described in Ronald's TableModel2
> project
> 7. Create a file Main.py which is in the "Other Sources" in my project.
> This file looks like this:
>
> import sys
> import os.path
>
> sys.path.insert( 0, os.path.join( sys.path[ 0 ], "pyobjc" ) )
>
> import objc
> import Foundation
> import AppKit
> print "foo"
>
> class HelloWorld(Foundation.NSObject):
>     __slots__ = ( 'text' )

For an outlet, replace the above line with this:

     text = objc.IBOutlet('text')

I wonder if there is a way to remove this requirement?  I'll have to 
investigate the whole IBConnection stuff -- I just did a boat load of 
custom IB work (converting NIB files from NS 3.3 -> OS X) and the APIs 
are still fresh.

>     def __init__( self ):
>         print "hello!"
>         self.text.setStringValue_( "Hello World!" )

This should just be init() and it should return self.  However...

For initialization from a NIB file, implement awakeFromNib() -- there 
are cases where the object might be instantiated before the NIB is 
loaded (NIB loading takes a significant hunk of time -- lazy loading 
the NIB for a piece of UI that the user may not use can increase 
perceived performance).  From the currency example:

         def awakeFromNib(self):
                 print "awakeFromNib"

                 # Provide some defaults for the user...
                 self.dollarField.setFloatValue_(2.0)
                 self.rateField.setFloatValue_(3.0)

>     def sayIt( self ):
>         self.text.setStringValue_( "Hello World, I am here!" )

An action method takes a single argument, the sender of the action.  
So, this should be:

     def sayIt_( self, sender ):
         self.text.setStringValue_( "Hello World, I am here!" )

b.bum