[gentoo-dev] Re: Progress on Universal Select Tool

[Sérgio Almeida]

Hello,

This has been a very productive week regarding uselect.

I'm still not doing any commits as uselect can still break your python
environment while testing and i don't have the time to learn how to
handle branches in git.

Status:

* Fully Converted all action types to new module syntax
* Infinite symlinking dependency fully working
* Runnable Actions now support dynamic usage showing

An example fully commented module follows

### Start of Module

#!/usr/bin/env python
# Copyright 1999-2009 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# python.py mephx.x@×××××.com 
# (will explain .py instead of .uselect below)
# still lacking vim/emacs python line

from umodule import * 

# We Create The Module
module = Module(name = "python", description = "Python Version
Switcher", version = "0.1", author ="mephx.x@×××××.com")

# We Create a Linking Action
action_bin = Action (name = 'bin', description = "Change Python's
Version", type = "sym")

# We Create a Link
link_python = Link(alias = "python", target = "/usr/bin/python", prefix
= "/usr/bin/", regexp = "python([0-9]+\.[0-9]+$)")

# We Create Another Link
link_python_config = Link(alias = "python-config", target =
"/usr/bin/python-config", prefix = "/usr/bin/", regexp =
"python([0-9]+\.[0-9]+)-config$")

# Make the link "python_config" depend of "link_python"
link_python.add_link(link_python_config)

# Add the link to the action
action_bin.add_link(python)

# Add the action to the module
module.add_action(action_bin)


# We create a simple runnable action that "tests" python environment
test = Action (name = 'test', description = 'Test Python Environment',
type = 'runnable')

# We add the parameters/arguments

test.add_parameter('<times>')
test.add_parameter('[<what>]')

# We add the usage code

test.add_usage("""#!/usr/bin/python
print "Python Test will echo <times> * <what>"
print "Usage can be multi-line Yay!"
print ""
for i in range(5):
	print "Usage can have dynamic options! " + str(i)
""")

# We add the action code
test.add_code("""#!/usr/bin/python
import sys

def is_number(s):
    try:
        int(s)
        return True
    except ValueError:
        return False
		
argv = sys.argv[1:]
times = sys.argv[1:][0]
if is_number(times):
	times = int(times)	
	if len(argv) >= 2:
		what = sys.argv[1:][1]
	else: 
		what = 'Hello World...'
	print str(what) * times
else:
	print 'Invalid Option(s)'
	exit(1)
exit(0)
""")

# We add the action to the module
module.add_action(test)

### End of Module


So... what's the output of this?

### Start Examples

* uselect 

Usage: uselect <options> <module> <action> 

 Options:
    -v  		(*) Verbose Mode
    -nc 		(*) No Colors
    -version    	(*) Version Information

Modules:
    python      	(*) Python Version Switcher
    gcc 		(*) Python GCC Version Switcher

* uselect python

Usage: uselect <options> python <action> 

Module python:
Author: mephx.x@×××××.com Version: 0.1

Actions:
    bin 		Change Python's Version
    test		Test Python Environment


* uselect python bin

Usage: uselect <options> python bin <target> ... <target> 

    Change Python's Version

      0 - /usr/bin/python2.6 - (>)
          1 - /usr/bin/python2.6-config - (>)
          2 - /usr/bin/python2.5-config - (!)
      3 - /usr/bin/python2.5 - (!)
          4 - /usr/bin/python2.6-config - (>)
          5 - /usr/bin/python2.5-config - (!)

* uselect python bin 2

Setting /usr/bin/python2.5-config success!
Setting /usr/bin/python2.6 success

* uselect python bin (again)

Usage: uselect <options> python bin <target> ... <target> 

    Change Python's Version

      0 - /usr/bin/python2.6 - (>)
          1 - /usr/bin/python2.6-config - (!)
          2 - /usr/bin/python2.5-config - (>)
      3 - /usr/bin/python2.5 - (!)
          4 - /usr/bin/python2.6-config - (>)
          5 - /usr/bin/python2.5-config - (!)

* uselect python test

Usage: uselect <options> python test <times> [<what>] 

    Test Python Environment

    Python Test will echo <times> * <what>
    Usage can be multi-line Yay!
        		
    Usage can have dynamic options! 0
    Usage can have dynamic options! 1
    Usage can have dynamic options! 2
    Usage can have dynamic options! 3
    Usage can have dynamic options! 4

* uselect python test 10 "yeah! "

yeahyeahyeahyeahyeahyeahyeahyeahyeahyeah

I guess this is all for the past week. Symlinking dependency really
cranked my brain and almost got me stuck.

Next steps:

* add the --system option for system-wide changes
* Implement env actions
* Structure folders ".uselect/" (probabily will have a bin folder and a
env.d folder)
* Start structuring uprofile application and api
* Profiles will be xml/json (and will use this part of code to uselect
too)


* Call for ideas

        * Python gurus: Atm i'm retrieving the module from .uselect
        files this way:
        
        def get_modules(self):
        	self.modules = []
        	for module in filesystem.list_dir(modules_dir):
        		if re.match('__init__.py$', module):
        			continue
        		match = re.match('(.*).py$', module)
        		if match:
        			import modules
        			modname = match.group(1)
        			modpath = 'modules.'+ modname
        			__import__(modpath)
        			module = eval(modpath + '.module')
        			self.modules.append(module)		
        
        This is a bit ugly. Should there be a better way? I can't seem
        to achieve one. This is the reason why new modules are still
        called module.py and not module.uselect as should be.
        

        * If you are a developer of any eselect modules or
        something-config please reply with suggestions. All ideas are
        welcome.

    * Everyone else: 
        User profiles will stand in ~/.uselect
        Folder Profiles will stand in $FOLDER/.uselect
        What about group profiles?
        
        Modules like bash-completion work in a "env.d" style. Should an
        action type be created for actions like these (I believe they
        are very common).
        
        Well, all ideas are welcome again.

P.S: I have successfully passed the first midterm evaluation. Thanks to
everyone that has contributed to this new project, especially my mentor
Sébastien Fabbro (bicatali).

Cheers,
Sérgio
        
-- 
Sérgio Almeida - mephx.x@×××××.com
mephx @ freenode