Need to refresh record stored in Mapper::identityMap

[pokmot]

I am using the new Symfony Flex bundle. I have a long running process. I am creating a new row in a table, then waiting for a semaphore, and reading the row again as it has changed in the meantime.

Similarly, I want to be able to create a new row and then re-read it as MySQL executes a trigger that amends values. I am not able to retrieve the updated row values.

It seems the row is stored in Mapper::identityMap so I am getting back the original array passed through; not the updated row from the database.

I cannot see a way to force a refresh so the row is actually read from the database.

Thoughts?

[pokmot]

Also, the row stored in ::identityMap is not updated on Mapper::update or removed in Mapper::delete.

This code therefore returns the original array that was stored:

$data = [
  'contact_id' => null,
  'first_name' => 'Firstname',
];
$r = $atlas->newRecord(Contact::class, $data);
$atlas->insert($r);
$atlas->delete($r);
var_export($atlas->fetchRecord(Contact::class, $r->contact_id)->getArrayCopy());

outputs (with primary key in 'contact_id'):

array (
  'contact_id' => '1',
  'firstname' => 'Firstname',
)

[pmjones]

I cannot see a way to force a refresh so the row is actually read from the database.

There isn't one. Obviously there needs to be. Will see what I can do. Thanks for the report!

[pmjones]

@pokmot here are some functionality expectations; let me know what you think.

• There should be a refresh() or similar method on each Mapper, that does a bulk query against all rows in the relevant IdentityMap, and re-initializes those rows with the newly-selected data.

• There should be a corollary method in MapperLocator that calls refresh() on each of its mapper instances.

The tricky bits come with deleted rows:

• If you have a Record with a deleted Row, nothing else in the system can remove it from that Record. You would need to unset it yourself after delete. (I have considered a "detachDeleted()" or "unsetDeleted()" method on Records and RecordSets that could do that for you.)

• Should a deleted row be removed from the IdentityMap? That will still leave the Row in memory, attached to one or more Records; it won't look like it still exists from the IdentityMap point of view, but it might be weird to have it "in hand" while not actually existing in the IdentityMap or at the database. Alternatively, perhaps the IdentityMap should check the Row status, and not return it if it is marked as deleted.

What do you think? What have I missed?

[pine3ree]

Hello @pmjones @pokmot
Maybe instead of reloading an object that already in the identity map we should just re-hydrated it on update with the new property values. This would preserve the object hash as well so that $original === $updated evaluates to true. (this is what I usually do in my tiny mappers)
kind regards