Object Access Issue

Darren123 has asked for the wisdom of the Perl Monks concerning the following question:

Hello,

I'm writing some code that interacts with a F5 BigIP load balancer using the BigIP::iControl Perl module.

However the .pm file available is very out of date compared to the API now available so I am having to manually update the .pm with the additional functionality I need.

I've used Perl for some time now, but never done anything like this, and I am having some issue with accessing the objects that are being returned to me.

The context of this might be irrelevant, but I wanted to give some background.

I am being given the following object, but I cannot work out how I can access the values inside the second bless:

$VAR1 = bless( [
                 bless( {
                          'availability_status' => 'AVAILABILITY_STATU
+S_RED',
                          'status_description' => 'Pool member has bee
+n marked down by a monitor',
                          'enabled_status' => 'ENABLED_STATUS_ENABLED'
                        }, 'LocalLB::ObjectStatus' ),
                 bless( {
                          'availability_status' => 'AVAILABILITY_STATU
+S_RED',
                          'status_description' => 'Pool member has bee
+n marked down by a monitor',
                          'enabled_status' => 'ENABLED_STATUS_ENABLED'
                        }, 'LocalLB::ObjectStatus' )
               ], 'LocalLB::ObjectStatus[]' );
[download]

It looks a little odd to me as I was not expecting to have a bless inside another bless object.

Here is the API and Method in question https://devcentral.f5.com/wiki/iControl.LocalLB__Pool__get_member_object_status.ashx

Any help with this would be appreciated, let me know if you would like more information.

Thanks,

Darren

Comment on Object Access Issue Download Code

Replies are listed 'Best First'.
Re: Object Access Issue by tobyink (Canon) on Mar 19, 2014 at 10:08 UTC
As robby_dobby said, it's not unusual for blessed objects to have other blessed objects as members. What is unusual is the package name that the outer object is blessed into: `'LocalLB::ObjectStatus[]'`. It's not technically a problem, but quite weird to put square brackets in a package name. `use 5.010; use strict qw(vars subs); use warnings; *{"Foo[]::hello"} = sub { say "Hello" }; my $obj = bless({}, "Foo[]"); $obj->hello;` [download] `use Moops; class Cow :rw { has name => (default => 'Ermintrude') }; say Cow->new->name`	[reply] [d/l] [select]
Re: Object Access Issue by robby_dobby (Hermit) on Mar 19, 2014 at 09:29 UTC
Hello Darren123, No, this is not a "bless inside another bless" as you put it. It's simply an array of `LocalLB::ObjectStatus` objects. So you iterate over this array and gather values out of items as you access them. Here's a PM post talking about arrays of objects in OOPerl.	[reply] [d/l]
Re: Object Access Issue by Bloodnok (Vicar) on Mar 19, 2014 at 11:21 UTC
That looks rather like a representation of the aggregate/composite pattern - a list being an object (which, as tobyink has already pointed out, has an unusual name - `LocalLB::ObjectStatus[]`) which itself contains a number of other objects (of class `LocalLB::ObjectStatus`). In order to access the contained objects, I suggest that you have a look at the containing class (`LocalLB::ObjectStatus[]`) to determine the name(s) of the accessor methods - which will, I would guess, follow the form of the GoF Iterator pattern e.g. `get_next()`, `has_next()` etc. HTH , A user level that continues to overstate my experience :-))	[reply] [d/l] [select]
Re: Object Access Issue by Darren123 (Initiate) on Mar 19, 2014 at 14:22 UTC
Thank you all for your help. It took me a while to digest what you had all posted, but I have now worked it out, and it seems so simple now! In the end all I needed was this: `foreach ($ic->get_ltm_pool_members_status($pool)) { foreach (@{$_}) { print "$_->{enabled_status}\n"; }` [download] Thanks Darren	[reply] [d/l]