Loopback issues when adding relations - json

Question

I have a Loopback API in which I have a container and I'm trying to add some relations to my models (using this) but when it comes to adding relations to container.js, it does not work anymore and I get this error :
/home/mowso/Documents/loopback-examples/test/node_modules/loopback-datasource-juggler/lib/datasource.js:434
modelClass[relation.type].call(modelClass, name, params);
^
TypeError: Cannot read property 'call' of undefined
at EventEmitter.<anonymous> (/home/mowso/Documents/loopback-examples/test/node_modules/loopback-datasource-juggler/lib/datasource.js:434:36)
at EventEmitter.g (events.js:260:16)
at emitOne (events.js:77:13)
at EventEmitter.emit (events.js:169:7)
at DataSource.setupDataAccess (/home/mowso/Documents/loopback-examples/test/node_modules/loopback-datasource-juggler/lib/datasource.js:540:14)
at DataSource.attach (/home/mowso/Documents/loopback-examples/test/node_modules/loopback-datasource-juggler/lib/datasource.js:752:8)
at Function.ModelClass.attachTo (/home/mowso/Documents/loopback-examples/test/node_modules/loopback-datasource-juggler/lib/model-builder.js:336:16)
at Registry.configureModel (/home/mowso/Documents/loopback-examples/test/node_modules/loopback/lib/registry.js:238:15)
at configureModel (/home/mowso/Documents/loopback-examples/test/node_modules/loopback/lib/application.js:441:16)
at EventEmitter.app.model (/home/mowso/Documents/loopback-examples/test/node_modules/loopback/lib/application.js:133:5)
I have three models like in the example I link above, they basically just have different names. Here is my container.json :
{
"name": "Container",
"base": "PersistedModel",
"properties": {
"name": {
"type": "string"
}
},
"validations": [],
"relations": {
"user": {
"type": "belongsTo",
"model": "user",
"foreignKey": "ownerId"
}
},
"acls": [],
"methods": {}
}
and my user.json :
{
"name": "user",
"base": "User",
"idInjection": true,
"options": {
"validateUpsert": true
},
"properties": {},
"validations": [],
"relations": {
"containers": {
"type": "hasOne",
"model": "Container",
"foreignKey": "ownerId"
},
"companies": {
"type": "hasOne",
"model": "company",
"foreignKey": "ownerId"
}
},
"acls": [],
"methods": {}
}
Here is the model-config.json :
{
"_meta": {
"sources": [
"loopback/common/models",
"loopback/server/models",
"../common/models",
"./models"
],
"mixins": [
"loopback/common/mixins",
"loopback/server/mixins",
"../common/mixins",
"./mixins"
]
},
"User": {
"dataSource": "db"
},
"AccessToken": {
"dataSource": "db",
"public": false
},
"ACL": {
"dataSource": "db",
"public": false
},
"RoleMapping": {
"dataSource": "db",
"public": false
},
"Role": {
"dataSource": "db",
"public": false
},
"Container": {
"dataSource": "myfile",
"public": true
},
"user": {
"dataSource": "db",
"public": false
},
"company": {
"dataSource": "db",
"public": false
}
}
and finally my datasource.json, notice that I have a storage folder at the root of my project :
{
"db": {
"name": "db",
"connector": "mongodb"
},
"myfile": {
"name": "myfile",
"connector": "loopback-component-storage",
"provider": "filesystem",
"root": "storage"
}
}

Answer 1

Your foreign key is not correct, as per the documentation it should be,
Relation name: Camel case of the model name, for example, for the "supplier" model the relation is "supplier".
Foreign key: The relation name appended with ‘Id’, for example, for relation name "supplier" the default foreign key is "supplierId".
So in your case it should be
"foreignKey": "userId"
https://docs.strongloop.com/display/public/LB/HasOne+relations
And you should use the slc relations instead of editing the json files.

Answer 2

I believe Container should inherit Model, not PersistedModel. By default, a Container is a folder inside a filesystem, so there is no choice of persisting it or not.
{
"name": "Container",
"base": "Model",