Array problem codeigniter with mongoDB

[eluser]zacksyah[/eluser]
Please help me, i have a case that must be solve immediately due to strict deadline.. I have an idea using preg_match or preg_split to solve this, and had tried so many way to use it but still not understand how to use it. Maybe someone could guide me, about this case so i could get more understanding about how to use preg_match or preg_split.
from this string

Code:

$temp = "{foo:bar,bar:foo},{_id:1,nama:1,nim:1}";

how to assign it to array so the result will be like this

Code:

Array
(
[0]=>foo:bar,bar:foo
[1]=>_id:1,nama:1,nim:1
)

also the second string

Code:

$temp2 = "_id:1,nama:1,nim:1";

how to assign it to array so the result will be like this

Code:

Array
(
[0] => _id
[1] => nama
[2] => nim
)

Thank you for your guidance and the help..