Alzabo::Runtime::RowCursor(3pm) User Contributed Perl Documentation Alzabo::Runtime::RowCursor(3pm)NAME
Alzabo::Runtime::RowCursor - Cursor that returns "Alzabo::Runtime::Row" objects
SYNOPSIS
use Alzabo::Runtime::RowCursor;
my $cursor = $schema->table('foo')->all_rows;
while ( my $row = $cursor->next )
{
print $row->select('foo'), "
";
}
DESCRIPTION
Objects in this class are used to return "Alzabo::Runtime::Row" objects for queries. The cursor does not preload objects but creates them
on demand, which is much more efficient. For more details on the rational please see the RATIONALE FOR CURSORS section in Alzabo::Design.
INHERITS FROM
"Alzabo::Runtime::Cursor"
METHODS
next
Returns the next "Alzabo::Runtime::Row" object or undef if no more are available.
all_rows
Returns all the rows available from the current point onwards. This means that if there are five rows that will be returned when the
object is created and you call "next" twice, calling all_rows after it will only return three.
reset
Resets the cursor so that the next "next" call will return the first row of the set.
count
Returns the number of rows returned by the cursor so far.
next_as_hash
Return the next row in a hash, where the hash key is the table name and the hash value is the row object.
AUTHOR
Dave Rolsky, <autarch@urth.org>
perl v5.8.8 2007-12-23 Alzabo::Runtime::RowCursor(3pm)
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Alzabo::Runtime::UniqueRowCache(3pm) User Contributed Perl Documentation Alzabo::Runtime::UniqueRowCache(3pm)NAME
Alzabo::Runtime::UniqueRowCache - Implements a row cache for Alzabo
SYNOPSIS
use Alzabo::Runtime::UniqueRowCache;
Alzabo::Runtime::UniqueRowCache->clear();
DESCRIPTION
This is a very simple caching mechanism for "Alzabo::Runtime::Row" objects that tries to ensure that for there is never more than one row
object in memory for a given database row.
To use it, simply load it.
It can be foiled through the use of "Storable" or other "deep magic" cloning code, like in the "Clone" module.
The cache is a simple hash kept in memory. If you use this module, you are responsible for clearing the cache as needed. The only time it
is cleared automatically is when a table update or delete is performed, in which case all cached rows for that table are cleared.
In a persistent environment like mod_perl, you should clear the cache on a regular basis in order to prevent the cache from getting out of
sync with the database. A good way to do this is to clear it at the start of every request.
METHODS
All methods provided are class methods.
* clear
This clears the entire cache
* clear_table( $table_object )
Given a table object, this method clears all the cached rows from that table.
* row_in_cache( $table_name, $row_id )
Given a table name and a row id, as returned by the "Alzabo::Runtime::Row->id_as_string" method, this method returns the matching row
from the cache, if it exists. Otherwise it returns undef.
* delete_from_cache( $table_name, $row_id )
Given a table name and a row id, as returned by the "Alzabo::Runtime::Row->id_as_string" method, this method returns the matching row
from the cache.
* write_to_cache( $row_object )
Given a row object, this method stores it in the cache.
AVOIDING THE CACHE
If you want to not cache a row, then you can pass the "no_cache" parameter to any table or schema method that creates a new row object or a
cursor, such as "Alzabo::Runtime::Table->insert()", "Alzabo::Runtime::Table->rows_where()".
AUTHOR
Dave Rolsky, <autarch@urth.org>
perl v5.8.8 2007-12-23 Alzabo::Runtime::UniqueRowCache(3pm)