Re: How to DRY code to prompt for parameters

Symbol? Even better.

Mixing some ideas from the Josh code we have...

Remember... as Josh said you shouldn't rely on Hash items order. (this
code does this :/ )
Hashes are not ordered by nature.

http://www.pastie.org/1400695

On Thu, Dec 23, 2010 at 11:10 AM, RichardOnRails
<[e-mail]> wrote:
> On Dec 22, 11:55=A0pm, Josh Cheek <[e-mail]> wrote:
>> [Note: =A0parts of this message were removed to make it a legal post.]
>>
>> On Wed, Dec 22, 2010 at 10:10 PM, RichardOnRails <
>>
>>
>>
>> [e-mail]> wrote:
>> > I pasted code to prompt for a couple of parameter-values at
>> >http://www.pastie.org/1399710.
>>
>> > Running this code under SciTE produces, for example:
>> > Getting parms
>> > =A0 =A0 =A0 =A0Account Number: 123
>> > =A0 =A0 =A0 =A0Report =A0Period: 456
>> > Showing parms
>> > =A0 =A0 =A0 =A0@acct_num =3D 123
>> > =A0 =A0 =A0 =A0@acct_period =3D 456
>>
>> > It is excessively verbose because I couldn't figure out how to use
>> > meta-language to specify the parameter target names. =A0That led me to
>> > using case statements to accept input values and then populate the
>> > instance variables.
>>
>> > Can anyone suggest how I can use the instance variables as targets in
>> > lieu of the case statements? =A0BTW, I want to get this working with
>> > meta-programming. =A0I don't want to use some other approach, such as =
a
>> > plug-in for getting arguments.
>>
>> > Thanks in Advance,
>> > Richard
>>
>> I think you are looking for instance_variable_set and instance_variable_=
get.
>> I don't really understand all the decisions you made, such as the array =
of
>> hashes, to me that implies you want ordered hashes, but are on 1.8 (If y=
ou
>> are in Rails, you have ActiveSupport loaded, and it provides an OrderedH=
ash
>> class that you can use) since they are ordered in 1.9. To get around tha=
t, I
>> just made it an Array of Structs. Anyway, hopefully you can get out of t=
his
>> whatever you're trying to do.
>>
>> class X
>>
>> =A0 def initialize
>> =A0 =A0 param =3D Struct.new :human_readable , :ivar
>> =A0 =A0 @rpt_parms =3D [
>> =A0 =A0 =A0 param.new( "Account Number" , "@acct_num" =A0 =A0),
>> =A0 =A0 =A0 param.new( "Report =A0Period" , "@acct_period" ),
>> =A0 =A0 ]
>> =A0 end
>>
>> =A0 def get_parms
>> =A0 =A0 @rpt_parms.each do |param|
>> =A0 =A0 =A0 print "\t#{param.human_readable}: "
>> =A0 =A0 =A0 instance_variable_set( param.ivar , gets.to_i ) # don't need=
 to chomp,
>> to_i will ignore the newline
>> =A0 =A0 end
>> =A0 end
>>
>> =A0 def show_parms
>> =A0 =A0 @rpt_parms.each do |param|
>> =A0 =A0 =A0 value =3D instance_variable_get(param.ivar)
>> =A0 =A0 =A0 puts "\t#{param.human_readable} =3D #{value}"
>> =A0 =A0 end
>> =A0 end
>>
>> =A0 def run
>> =A0 =A0 puts "Getting parms"
>> =A0 =A0 get_parms
>> =A0 =A0 puts "Showing parms"
>> =A0 =A0 show_parms
>> =A0 end
>>
>> end
>>
>> X.new.run
>
>> I think you are looking for instance_variable_set and instance_variable_=
get.
> That's also exactly the thing I needed! =A0Excellent!!
>
>> To get around that, I just made it an Array of Structs.
> Another responder did what I really wanted but was too stupid to do
> is:
> =A0@parms =3D { =A0"Account Name" =3D> :acct_name,
> =A0 =A0 =A0 =A0 =A0 =A0 =A0"Account Number" =3D> :acct_num
> =A0 =A0 =A0 =A0 =A0 } =A0 # etc.
>
> Thanks very much for your insights.
> Best wishes,
> Richard
>
>