Track the last imported time for migrations

1. +++ b/core/modules/migrate/src/Entity/Migration.php
   @@ -350,6 +350,10 @@ public function checkRequirements() {
   +        $this->setLastImported();
   

   Here you're setting it where another migration is checking to see if this migration has completed at some time in the past. The place to set it would be at the point the migration actually finished running. The return points in MigrateExecutable::import() would be the place to do that.

2. +++ b/core/modules/migrate/src/Entity/Migration.php
   @@ -477,6 +481,24 @@ public function setTrackLastImported($track_last_imported) {
   +    $key = 'migrate_last_imported:' . $this->id;
   

   We're saving other similar information using keyvalue rather that state - see https://www.drupal.org/node/2429085#comment-9829053 - I think this should be consistent with the others.

3. +++ b/core/modules/migrate/src/Entity/Migration.php
   @@ -477,6 +481,24 @@ public function setTrackLastImported($track_last_imported) {
   +    return date('Y-m-d H:i:s', $last_imported/1000);
   

   I don't think the API should do the formatting, that should be left to the caller (just return the timestamp).

4. +++ b/core/modules/migrate/src/Entity/MigrationInterface.php
   @@ -273,6 +273,21 @@ public function isTrackLastImported();
   +   *   The current system of record of the migration.
   

   A little too much pasted here.

1. +++ b/core/modules/migrate/src/Entity/Migration.php
   @@ -477,6 +477,24 @@ public function setTrackLastImported($track_last_imported) {
   +    $last_imported = \Drupal::state()->get($key, FALSE);
   

   Still looking for that change from state to keyvalue - see the previously-linked issue and the current patch using keyvalue: https://www.drupal.org/files/issues/track_current_state_of-2429085-13.patch

2. +++ b/core/modules/migrate/src/MigrateExecutable.php
   @@ -345,6 +345,7 @@ public function import() {
   +    $this->migration->setLastImported();
   

   There are a couple of error returns in this function, I think we should track the time there as well.

Looking good - I've got a migrate_plus patch using this at #2429107: Display last imported time with drush migrate-status:

$ drush ms
 Group: default  Total  Imported  Unprocessed  Last imported       
 beer_term       3      3         0            2015-04-20 09:45:34 
 beer_user       4      0         4                                
 beer_node       3      0         3                                
 beer_comment    5      0         5

Did you enable migrate_example? That's what provides the migrations for testing.

Also note that for now you need to add

$databases['migrate'] = $databases['default'];

to your settings.php (pending group support getting committed).

+++ b/core/modules/migrate/src/Entity/Migration.php
@@ -477,6 +477,23 @@ public function setTrackLastImported($track_last_imported) {
+    return $migrate_last_imported_store;

Oops - you're returning the keyvalue store rather than the value returned by get().

+++ b/core/modules/migrate/src/MigrateExecutable.php
@@ -242,6 +242,7 @@ public function import() {
+      $this->migration->setLastImported();

OK, my previous statement was a little broad - since the requirements exception is preventing import from happening at all, I would say we should not set the last imported time here.

With the removal of that line, I'll be ready to declare this rtbc. Thanks!

At the moment, the plan is for this to be accomplished by #2535458: Dispatch events at key points during migration.

Contrib can do this itself now: https://www.drupal.org/node/2544874