Loopback: Question - How to use Mongodb GridFS with loopback?

[veekungx]

LB currently provide storage service to store any file.

But if I want to use MongoDB gridfs to store files(pdf,excel,word etc..) and photos instead.
There are some question.

1. How to do that?
1.1 Do I have to dedicated to new instance and provide API with mongo native driver then connect with REST connector?
1.2 Can I use "loopback connector" to access Mongo native driver gridFS and aggregate?

something like this

collection.aggregate([
          { $project : {
            author : 1,
            tags : 1
          }},
          { $unwind : "$tags" },
          { $group : {
            _id : {tags : "$tags"},
            authors : { $addToSet : "$author" }
          }}
        ], function(err, result) {
          console.dir(result);
          db.close();
      });

[veekungx]

I found it.

app.dataSources.mongo.connect(function(err,db){
        db.collection('parent').findOne({},function(err,doc){
            console.log(doc)
        })
    })

[esco]

:+1:

[thiagobrunoms]

Hi guys, I've tried such solution, but I get "err" and "db" parameters as undefined. Is it still the right solution for working with native mongodb queries?

Thanks in advance!

[sureshkoduri]

Hi, How to get all the collection names in mongo database using Strongloop?

[mariohmol]

I'm having same problem here. With mongodb "in" operator when using filter is not working.. i'm trying to execute native query in mongodb and err,db is undefined.

[mariohmol]

Here is how I did in a MyCollection.js

var ds = MyCollection.app.dataSources.mydb;
ds.connector.collection('MyCollection').find({address: {$in: cities }}).toArray(function(err,cursor){
console.log(err,cursor);
});

[AndersonZacharyT]

@mariohmol but do you have to have 'MyCollection' defined as a model within LoopBack? what if you don't want to do that, and don't want to open another connection to Mongo?

[mariohmol]

sorry.. was testing and do not have this project anymore

[bitmage]

For anyone else looking at this, you want MyCollection.app.dataSource.connector.connect or alternatively MyCollection.app.dataSource.adapter.connect. The connect method on the dataSource is a generic one and returns the empty params that @mariohmol and @thiagobrunoms encountered.

[akvaliya]

I am using this

app.dataSources.mongoConnector.connect(function (errconnect, mdb) {
});

I am getting connected but it returns mdb undefined.
My datasource is
"mongoConnector": { "url": "${CONNECTION_STRING}", "name": "mongoConnector", "connector": "mongodb" }
Anyone can tell me what am i missing here.

[aravindatcts]

I am getting error message - " Cannot read property 'connect' of undefined".
Is there any way to add a hook when datasource is connected to trigger any event ?
app.dataSources.mongods.connect(function(err,db) {

mongods is datasource name.

[uds214125]

app.dataSources.hmsDs.connector.connect(function(err,db){
console.log(db);
db.collection('mastercounters').findOne({},function(err,doc){
console.log(doc)
});
});
it is working example : hmsDs is datasource name defined in datasource.json

[akvaliya]

I am using the same method but i am getting "db" object undefined.

[akvaliya]

@uds214125 Thanks. I was missing connector after ds name. Working now.