如何覆盖 Perl 的 Class::DBI 中自动生成的访问器？

发布于 2024-07-12 22:28:37 字数 977 浏览 7 评论 0原文

我按照 http://wiki.class-dbi.com/wiki/Overriding_autogenerate_accessors

我想在将 URL 插入数据库之前修改它：

package Hosting::Company;
use base 'Class::DBI';

 my $class = __PACKAGE__;

$class->table('Companies');
$class->columns(Primary => 'CompanyId');
$class->columns(Others => qw/Name Url Comment/);

sub Url {
my $self = shift;

    # modify URL.
    if (@_) {
        $_[0] = 'aaaaaaaaaaaa';
        # return $self->_Url_accessor('aaaaaaaaaaaa'); - doesn't work either
    }

    # Back to normal Class::DBI 
    return $self->_Url_accessor(@_);
}

但它不起作用：

my $company = Hosting::Company->insert({ Name => 'Test', Url => 'http://http://url' });
print $company->Url, "\n";

显示：

http://http://url

我希望 Class:DBI 邮件列表仍然存在！

原文

I followed the example at http://wiki.class-dbi.com/wiki/Overriding_autogenerated_accessors

I want to modify the URL before it is inserted to the database:

package Hosting::Company;
use base 'Class::DBI';

 my $class = __PACKAGE__;

$class->table('Companies');
$class->columns(Primary => 'CompanyId');
$class->columns(Others => qw/Name Url Comment/);

sub Url {
my $self = shift;

    # modify URL.
    if (@_) {
        $_[0] = 'aaaaaaaaaaaa';
        # return $self->_Url_accessor('aaaaaaaaaaaa'); - doesn't work either
    }

    # Back to normal Class::DBI 
    return $self->_Url_accessor(@_);
}

But it doesn't work:

my $company = Hosting::Company->insert({ Name => 'Test', Url => 'http://http://url' });
print $company->Url, "\n";

Shows:

http://http://url

I wish the Class:DBI mailing list were still alive!

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我为君王 2024-07-19 22:28:37

在 URL 访问器中，您检查参数是否传递给该方法。但是您没有传递任何内容，因此访问器除了调用 _Url_accessor() 之外什么也不做。您可能应该首先调用 _Url_accessor，然后修改结果：

sub Url {
    my $self = shift;

    # Was there a param passed in?
    if ( @_ ) {
         # Do you really want to modify it here?
         return $self->_Url_accessor(@_);
    }
    else {
        my $url = $self->_Url_accessor();
        # mangle result here:
        $url = 'aaaaaaaaa';
        return $url;
     }
}

如果您想在 URL 进入数据库之前更改 URL，我想您必须在您的类中提供 normalize_column_values，并且每次插入时都会调用它。

In you URL accessor, you check whether a parameter was passed to that method. But you aren't passing anyhting in so the accessor will do nothing but call _Url_accessor(). You should probably call _Url_accessor first and then modify the result:

sub Url {
    my $self = shift;

    # Was there a param passed in?
    if ( @_ ) {
         # Do you really want to modify it here?
         return $self->_Url_accessor(@_);
    }
    else {
        my $url = $self->_Url_accessor();
        # mangle result here:
        $url = 'aaaaaaaaa';
        return $url;
     }
}

If you want to change the URL before it even goes in the database, I guess you must provide a normalize_column_values in your class and this will be called each time an insert is made.

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