byterock

Today in the Moose-pen I am going to play with the very familiar 33_condtions.t and this time I am going to solve another little API problem I know I am going to run into.

Part of my evil plan is to allow end users to add in conditions on the fly and I have made provision for that with the 'rw' 'conditions' attribute found on my DAD Role. Now I have to fix a minor oversight on my part can change the type on 'conditions' to be the same as the original in Accessors, so I changed this

–    isa     => 'ArrayRefofPredicates',

++    isa     => 'ArrayRefofConditions',

 

What I want to be able to do is allow my end users to do something like this

  my $da = Database::Accessor->new($in_hash2);

  $da->DAD->add_condition({left      =>{name =>'country',

                                        view =>'People'},

                           right     =>{value=>'Slyvania'},

                           operator  =>'=',

                           condition =>'AND'});

In this case had in just a single Hash-Ref conditions not an array ref. Now I have learned years of programming that a good chunk of the quires I have done had only a single condition. For example in one project I just completed I have about ninety SQL queries, (excluding the dedicated search part of the site) of these almost half forty-two had only a single param. As I like to make things simple for my end users allowing one to enter an Array-Ref or a singleton Hash-Ref is a real benefit.

Moose makes setting up this type of multi-coercion a simple affair. All I need to do is revisit my Types.pm again and 'extend' the 'ArrayRefofConditions ' coercion by dropping the '};' and replace it with a '},' and then adding the new coercion;

–  };

++ from 'HashRef', via {

++     my $objects = [];

++     push( @{$objects}, Database::Accessor::Condition->new({predicates=>[$_]}) );

++     return $objects;

++ };

This time I am telling Moose what to do when it encounters a HashRef on the 'Conditions' param. Then is is a simple matter to return just one Constion class in an Array.

Now I just add this to my test case

 my $in_hash3 = {

     view     => {name => 'People'},

     elements => [{name => 'first_name',

                   view =>'People' },

                  {name => 'last_name',

                   view => 'People' },

                  {name => 'user_id',

                   view =>'People' } ],

    conditions=>{left =>{name =>'last_name',

                         view =>'People'},

                 right=>{value=>'test'},

                 operator       =>'=',

                 open_parenthes =>1,

                 close_parenthes=>0,

                 condition      =>'AND',

                 }

                     ,

  };

  my $da2 = Database::Accessor->new($in_hash3);

  ok(ref($da2->conditions()->[0]) eq "Database::Accessor::Condition",'DA has a condtion');

  ok(scalar(@{$da2->conditions()}) == 1,'DA has only 1 condtion');

  ok(scalar(@{$da2->conditions()->[0]->predicates}) == 1,'DA has only 1 predicate');

  ok(ref($da2->conditions()->[0]->predicates->[0]) eq "Database::Accessor::Predicate",'DA has a condtion predicate is a predicate');

  

re-run my test case and get;

ok 7 - DA has a condtion

ok 8 - DA has only 1 condtion

ok 9 - DA has only 1 predicate

ok 10 - DA has a condtion predicate is a predicate

Sophisticated no?