[libpc] property tree / options

[Michael P. Gerlek]

Sorry, I don't quite understand... Here's a start, can you flesh it out a
bit for me?


class libpc::Stage
{
public:

  Stage()      // default ctor doesn't take a ptree
  { ... }

  Stage(ptree& tree)  // alternate ctor, which uses the ptree system
  { 
    Initialize(tree)
    ...
  }
  
protected:
  virtual Initialize(ptree& tree) {}    // user can implement
};
  
class MyStage : Stage
{
public:
  MyStage(ptree& tree) :
     Stage(tree)
  {...}

private:
  Initialize(ptree& tree)
  {
     // do something with the options
    }
};



> -----Original Message-----
> From: Howard Butler [mailto:hobu.inc at gmail.com]
> Sent: Friday, March 25, 2011 6:14 AM
> To: mpg at flaxen.com
> Cc: libpc at lists.osgeo.org
> Subject: Re: [libpc] property tree / options
> 
> 
> On Mar 24, 2011, at 11:07 PM, Michael P. Gerlek wrote:
> 
> > At the sprint, we came up with a plan for using property trees to pass
> > options to Stages -- or something like that.  I can't make heads or
> > tails of my notes.  Can someone pls summarize the plan we made?
> 
> I believe the plan was something like:
> 
> * Give each stage a public Initialize(boost::property_tree::ptree& tree)
> method that each stage's constructor can choose to call or not in its
ctors
> * Give each stage a public ValidateOptions() method that throws
> libpc::validation_errors if something isn't right.
> * Give each stage a public boost::property_tree::ptree GetDefaultOptions()
> that fills out a default tree that the user can then tweak values of and
set on
> Initialize
> 
> I'm not sure this is the way to go even though I lean this way...
> 
> Howard=