MooseX::Types 强制转换和 $self

发布于 2024-10-07 19:56:30 字数 1260 浏览 7 评论 0原文

无论如何，有没有办法让 $self 进入 MooseX::Types 强制转换？我在对象中有其他数据，我想用它们来将 String 强制转换为 Object。或者，是否有类似 Class::MOP 的 initializer 的东西可以允许我执行此操作 - 它必须在之前触发类型检查。

请求的伪代码：

with 'DBHandle';
has 'database' => ( isa => 'Str', is => 'ro', default => 'Db' );
has 'schema' => ( isa => 'Str', is => 'ro', default => 'schema' );
has 'table' => ( isa => 'Str', is => 'ro', default => 'column );

has 'columns' => ( isa => DBCols, is => 'ro', default => sub {[qw/foo bar baz/]} );

在这里，我希望“列”强制转换为 DBCols —— DBCols（对象）的 ArrayRef —— 需要使用 catalog、在类中找到 schema 和 col 属性，并使用 DBHandle 提供的 dbh/singleton。

为了减少这种虚假性，实际情况只是稍微复杂一些。我能够使用 around 完成上述任务，现在我想做的是创建一个允许此语法的属性特征：

has 'column_id' => (
  isa => Int
  , is => 'ro'
  , traits => ['DBKey']
  , default => 5
  , column => 'foo'
);

其中属性特征 column 由 < 提供code>DBKey，以与上述列相同的方式强制转换为DBCol：这需要能够访问类数据库 >、schema、table 以及 dbh 的单例。

原文

Is there anyway to get $self into a MooseX::Types coercion? I have other data in the object that I want to use to seed my coercion from a String to an Object. Alternatively, is there anything like Class::MOP's initializer that will permit me to do this -- it would have to fire before the type checks.

Requested pseudo code:

with 'DBHandle';
has 'database' => ( isa => 'Str', is => 'ro', default => 'Db' );
has 'schema' => ( isa => 'Str', is => 'ro', default => 'schema' );
has 'table' => ( isa => 'Str', is => 'ro', default => 'column );

has 'columns' => ( isa => DBCols, is => 'ro', default => sub {[qw/foo bar baz/]} );

Here, I want "columns" to coerce to a DBCols -- an ArrayRef of DBCol's (objects) -- requiring the use of catalog, schema, and col attributes found in the class, and with a dbh/singleton provided by DBHandle.

To make this less-pseudo, the actually situation is only slightly more complex. I was able to accomplish the above with around, now what I want I to do is create an attribute trait that would permit this syntax:

has 'column_id' => (
  isa => Int
  , is => 'ro'
  , traits => ['DBKey']
  , default => 5
  , column => 'foo'
);

Where the attribute trait column provided by DBKey, coerces to DBCol the same way that the above columns would: this would require the ability to access the classes database, schema, table, and again the singleton for the dbh.