How to access the created/updated sub-document?

[mtvs]

I noticed when you save a parent document, the save middleware of its sub-document`s schema is called for all of the sub-documents.

Is there a way that you can access the created/updated sub-document?

subDocSchema.post('save'. function (doc) {
    console.log(doc);
}

then

parent.subDocs.push({note: 'new doc'});
parent.save();

results

// {note: 'new doc'}
// {note: 'old doc'}
// ...

[vkarpov15]

I'm sorry, I don't understand the question, can you please clarify? In my mind it looks like you've got the answer to your question in your code samples.

[mtvs]

@vkarpov15 Normally when a document is saved the pre/post save middleware of its schema are called with the newly created/updated doc but when a sub-doc is created/updated by changing the document-array inside its parent document and then saving the parent document then the pre/post save middleware of the sub-document schema are called for all the sub-docs not just the newly created/updated one.

So how are you supposed to detect the new one to for example emit an event with that?

[vkarpov15]

Documents, including subdocs, have an isNew property that tells you whether the doc has been saved to the db or not.

subDocSchema.post('save'. function (doc) {
  if (doc.isNew) {
    console.log('new doc', doc);
  }
});

[mtvs]

@vkarpov15 Inside post save middleware of the sub document schema, isNew is false for all the sub documents.

I think this behavior (execution of save middleware for all sub docs) is something against the expectation and also a development obstacle.

[vkarpov15]

Yeah because after you save, isNew will always be false. Take a look at #1474 for a workaround.

And IMO it's the correct behavior - save middleware happens for parent docs regardless of whether or not there's anything to save, so makes sense that the child docs get the same behavior too.

[mtvs]

@vkarpov15 Ok, thanks for your help.