Lazy Loading and Updates?

[garyrichardson]

Hi,

I think I've found an issue with lazy loading. I have the following code:

#!/usr/bin/php
<?

require_once 'mongodb-php-odm/classes/json.php';
require_once 'mongodb-php-odm/classes/mongo/database.php';
require_once 'mongodb-php-odm/classes/mongo/collection.php';
require_once 'mongodb-php-odm/classes/mongo/document.php';

/*
 * Extension classes
 */

class Model_Example_Collection extends Mongo_Collection
{
    protected $name = 'examples';
    protected $db   = 'exampledb';
}

class Model_Example extends Mongo_Document
{
    protected function before_save($state)
    {
        error_log("**** At start of before_save");
        var_dump($this->_changed);

        $this->modifiedTime = time();

        error_log("**** After adding modifiedTime");
        var_dump($this->_changed);

        if(null == $this->createTime)
        {

            $this->createTime = time();
        }

        error_log("**** After checking createTime");
        var_dump($this->_changed);
    }
}

/*
 * test code
 */
$db = Mongo_Database::instance('exampledb', Array('database' => 'exampledb'));

// create a new object
error_log("*** Creating");
$newObj = new Model_Example();
$newObj->exampleName = "FooBar";
$newObj->save();
$objId = $newObj->id;
$newObj = null;

// reload it
error_log("*** Reloading with lazy load");
$reloadedObj = new Model_Example($objId);
$reloadedObj->exampleName = "Modified!";
$reloadedObj->save();
$reloadedObj = null;

// reload it
error_log("*** Reloading with forced load");
$reloadedObj = new Model_Example($objId);
$reloadedObj->load();
$reloadedObj->exampleName = "Modified! Forced Load!";
$reloadedObj->save();

And I get the following output:

*** Creating
**** At start of before_save
array(1) {
  ["exampleName"]=>
  bool(true)
}
**** After adding modifiedTime
array(2) {
  ["exampleName"]=>
  bool(true)
  ["modifiedTime"]=>
  bool(true)
}
**** After checking createTime
array(3) {
  ["exampleName"]=>
  bool(true)
  ["modifiedTime"]=>
  bool(true)
  ["createTime"]=>
  bool(true)
}
*** Reloading with lazy load
**** At start of before_save
array(1) {
  ["exampleName"]=>
  bool(true)
}
**** After adding modifiedTime
array(2) {
  ["exampleName"]=>
  bool(true)
  ["modifiedTime"]=>
  bool(true)
}
**** After checking createTime
array(0) {
}
*** Reloading with forced load
**** At start of before_save
array(1) {
  ["exampleName"]=>
  bool(true)
}
**** After adding modifiedTime
array(1) {
  ["exampleName"]=>
  bool(true)
}
**** After checking createTime
array(1) {
  ["exampleName"]=>
  bool(true)
}

So to recap:

• if I call ->load() on an object and do an update, everything works
• if I don't call ->load(), but check for the presence of a value in a before_save() function, all of my changes get wiped out

Thanks!

[colinmollenhour]

I see the dilemma. However, loading an object after changes have been made without wiping out those changes could cause other problems. If you changed your before_save code to use if('insert' == $state) rather than if(null == $this->createTime) then everything should work as you intended. I don't really see a better solution, perhaps an exception should be thrown if lazy loading is triggered while unsaved changes exist to prevent this kind of confusion? Thanks for the issue report.

[colinmollenhour]

Closing