Combine mongo $push and $currentDate to include time in new array element - mongodb

Question

I am trying to add a new document to a mongo array and I require one of the fields to be the current timestamp. This is for field level versioning but I can't figure out how to combine $push and $currentDate to get the result I would like.
Can someone point me in the right direction?
db.tmp.adviceReportingJourney.update(
{ _id : "5525f99be4b041151d51386e5525f99be4b041151d513870" },
{
$push: {
"$currentDate": {
"Conversation1MeetingCreated" : {
"vid" : 4,
"ts" : {"$type": "timestamp"},
"data" : 1428552213559
}
}
}
}
)

Answer 1

You can use your coding language date.Now to add the current time ;-)
Like (i asume java;-)):
db.tmp.adviceReportingJourney.update(
{ _id : "5525f99be4b041151d51386e5525f99be4b041151d513870" },
{
$push: {
"$currentDate": {
"Conversation1MeetingCreated" : {
"vid" : 4,
"ts" : {"$type": "timestamp"},
"data" : Date.now()
}
}
}
}
)
UPDATE: When running mongo > 3.0 you could use $currentDate. From the documentation $currentDate it shows that $currentDate only works on db.collection.update(), db.collection.findAndModify().
See the example below to update the embedded document "Conversation1MeetingCreated" (where you update the timestamp) use:
{
$currentDate: {
"Conversation1MeetingCreated.ts": { $type: "timestamp" }
},
$set: {
"Conversation1MeetingCreated.vid" : 4,
"Conversation1MeetingCreated.data": 1428552213559
}
}
Hope it helps.