generate hashed password on findOneAndUpdate [duplicate] - node.js

Question

I'm trying to update counts on a pre hook. The issue is that for some unknown reason the findOneAndUpdate hook doesn't have access to the document, as far as I can tell.
I would like to do this:
source.pre('findOneAndUpdate', function (next) {
console.log('------------->>>>>> findOneAndUpdate: ');
this.objects = this.objects || [];
this.people = this.people || [];
this.events = this.events || [];
this.objectCount = this.objects.length;
this.peopleCount = this.people.length;
this.eventCount = this.events.length;
next();
});
But for some reason the this in the hook isn't the document, its a Query object which seems about useless.
What am I missing? How do I use a pre hook to update counts on a findOneAndUpdate?

Answer 1

You can do smthng like that ->
source.pre('findOneAndUpdate', function (next) {
console.log('------------->>>>>> findOneAndUpdate: ');
this._update.$set.objects = [];
this._update.$set.people = [];
this._update.$set.events = [];
next();
});
pay attention to _update.$set because in the context "this" will be a query. So you can easily add anything you want!

Answer 2

The documentation states:
Query middleware differs from document middleware in a subtle but important way: in document middleware, this refers to the document being updated. In query middleware, mongoose doesn't necessarily have a reference to the document being updated, so this refers to the query object rather than the document being updated.
An update action generally updates a document that only exists in the database (it tells the MongoDB server: "find document X and set property X to value Z"), so the full document isn't available to Mongoose and, hence, you can't update the counts (which requires access to at least the arrays whose length you want to determine).
As an aside: why do you need separate *Count properties in your schema anyway? If you want to query for arrays matching a certain size, you can use the $size operator on the arrays directly.
If you really do need the count properties, then for each update, you need to track the number of changes you made to each of the arrays (in terms of the number of items added/deleted) and use the $inc operator to adjust the counts.

Answer 3

I had a similar issue when I used the updateOne method and was also going to use the updateOne pre hook to make intermittent update before saving to the database. couldn't find a way for it to work. I ended up using the findOneAndUpdate pre hook and doing the updateOne in it.
schema.pre('findOneAndUpdate', async function(next){
const schema = this;
const { newUpdate } = schema.getUpdate();
const queryConditions = schema._condition
if(newUpdate){
//some mutation magic
await schema.updateOne(queryConditions, {newUpdate:"modified data"});
next()
}
next()
})

Answer 4

Another solution is to use the official MongoDB documentation on middleware. They explain why "this" does not refer to the document itself. You may try something in that sense:
source.pre('findOneAndUpdate', async function(next) {
const docToUpdate = await this.model.findOne(this.getFilter());
//modify the appropriate objects
docToUpdate.save(function(err) {
if(!err) {
console.log("Document Updated");
}
});
console.log(docToUpdate);
// The document that `findOneAndUpdate()` will modify
next();
});

Answer 5

This worked for me
SCHEMA.pre('findOneAndUpdate', function(next){
this._update.yourNestedElement
next();
});

Answer 6

schema.pre(['findOneAndUpdate'], async function(next) {
try {
const type = this.get('type')
const query = this.getQuery()
const doc = await this.findOne(query)
if (type) {
this.set('type', doc.type)
}
next()
} catch (e) {
next(new BaseError(e))
}
})

Answer 7

mongoose Documentation:
You cannot access the document being updated in pre('updateOne') or pre('findOneAndUpdate') query middleware. If you need to access the
document that will be updated, you need to execute an explicit query
for the document.
schema.pre('findOneAndUpdate', async function() {
const docToUpdate = await this.model.findOne(this.getQuery());
console.log(docToUpdate); // The document that `findOneAndUpdate()` will modify
});