MissingSchemaError while using mongoose-observer library

Question

I have a typical Node.js, express, mongoDB and mongoose application.

I'm trying to implement the mongoose-observer library to listen for changes on my mongodb. See site: https://www.npmjs.com/package/mongoose-observer

When adding this code (almost exactly like the provided example):

mongooseObserver.register('MessageModel', 'create', function(newMessage) {
    console.log("New Message!");
    console.log(newMessage);
});

I get the following error:

    node_1     | /home/app/chat/node_modules/mongoose/lib/index.js:362
    node_1     |       throw new mongoose.Error.MissingSchemaError(name);
    node_1     |       ^
    nodered_1  | 28 Mar 07:32:11 - [info] Starting flows
    mongo_1    | 2017-03-28T07:32:04.562+0000 I NETWORK  [thread1] waiting for connections on port 27017
    node_1     | MissingSchemaError: Schema hasn't been registered for model "MessageModel".
    node_1     | Use mongoose.model(name, schema)
    node_1     |     at Mongoose.model (/home/app/chat/node_modules/mongoose/lib/index.js:362:13)
    node_1     |     at registerPre (/home/app/chat/node_modules/mongoose-observer/index.js:9:27)
    node_1     |     at Object.register (/home/app/chat/node_modules/mongoose-observer/index.js:38:9)
    node_1     |     at module.exports (/home/app/chat/app/routes.js:35:22)
    node_1     |     at Object.<anonymous> (/home/app/chat/server.js:83:24)
    node_1     |     at Module._compile (module.js:409:26)
    node_1     |     at Object.Module._extensions..js (module.js:416:10)
    node_1     |     at Module.load (module.js:343:32)
    node_1     |     at Function.Module._load (module.js:300:12)
    node_1     |     at Function.Module.runMain (module.js:441:10)
    node_1     |     at startup (node.js:134:18)
    node_1     |     at node.js:962:3
    mongo_1    | 2017-03-28T07:32:11.604+0000 I NETWORK  [thread1] connection accepted from 172.25.0.1:51800 #1 (1 connection now open)

This error only happens when adding the mongoose-observer code, without that is works just fine.

Other code that might be relevant

var mongooseObserver = require('mongoose-observer');
var mongoose         = require('mongoose');
var bcrypt           = require('bcrypt'),
    SALT_WORK_FACTOR = 10;

mongoose.connect('mongodb://mongo:27017/LoRaMessages'); //database name

var messageSchema = mongoose.Schema({
    DevEUI: String,
    LoRaPayload: String,
    Header: String,
    Longitude: Number,
    Latitude: Number,
    PDOP: Number,
    TMG: Number,
    SOG: Number,
    Temparature: Number,
    Time: String,
    ServerTime: Number,
    type: String,
    deviceType: String,
    batteryLevel: String,
    JoinedAndBeeperStatus: String,
    EnabledFlags: Number,
    AlarmFlags: Number,
    T_Temp: Number,
    H_Humi: Number,
    One_Temp: Number, 
    Two_Temp: Number,
    _msgid: String        
});

var MessageModel = mongoose.model('loramessages', messageSchema);  //collection name

mongooseObserver.register('MessageModel', 'create', function(newMessage) { //it fails on this line
    console.log("New Message!");
    console.log(newMessage);
});

I know this library is not used by a lot of people but maybe i'm missing something obvious.

I have seen the other post containing this error but there seems to be another problem since this only happens when implementing the specific library code.

Any help is appreciated.

EDIT: While @Love-Kesh 's answer was correct. I found out this library is only for listening for changes from within Node.js, externally added data is not detected.

Make sure your Observer.register function executing after schema defined means schema file is running before this function. — Love-Kesh, Mar 28 '17 at 08:25
@Love-Kesh Thanks for your comment. But what do you mean by 'running'? I've defined the schema and model before defining the observer function. — Jan, Mar 28 '17 at 08:30
yes you did. Pass 'loramessages' instead 'MessageModel' in Observer.register — Love-Kesh, Mar 28 '17 at 08:34
@Love-Kesh that solved the error, thanks! Next problem: it doesn't do what it should do. When adding a new message to the database, the observer function is not fired. Should this be a new SO question? — Jan, Mar 28 '17 at 08:45

Love-Kesh · Accepted Answer · 2017-03-28T08:58:59.660

1

Pass 'loramessages' instead 'MessageModel' in Observer.register

If you are using save to create new item , it won't fire , please use Model.create({}) to create new record.

//Try if Save event listener available there

Observer.register('loramessages', 'save', function(createdUser){
    // this callback will be executed when a new user is created
    // Do something here, for example, send a email to the created user
  });

edited Mar 28 '17 at 08:58

answered Mar 28 '17 at 08:49

Love-Kesh

777
7
17

is save listener available there or you created using Model.create() @Jan – Love-Kesh Mar 28 '17 at 09:04
There is no 'save' listener available, but 'create' fires when a new document is saved. This library does not solve my initial problem because my data is added externally (not from within node.js). – Jan Mar 28 '17 at 11:39
Could you change "save" to "create" since "save" is not an option provided by the library? – Jan Mar 28 '17 at 11:40

MissingSchemaError while using mongoose-observer library

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