I want to automatically add a query option for all queries related for a specific mongoose model without affecting other models
I saw this answer where Mongoose.Query is patched and that will affect all mongoose models.
I was able to do this for my soft deleted items. Haven't tested it extensively yet though.
function findNotDeletedMiddleware(next) {
this.where('deleted').equals(false);
next();
}
MySchema.pre('find', findNotDeletedMiddleware);
MySchema.pre('findOne', findNotDeletedMiddleware);
MySchema.pre('findOneAndUpdate', findNotDeletedMiddleware);
MySchema.pre('count', findNotDeletedMiddleware);
I see two possible easy ways to do this:
Alternative #1
Add a static dict with the options you want to be applied to your specific Mongoose schema:
FooSchema.statics.options = {
...
};
Now, when you query you need to do:
Foo.find({}, null, Foo.options, function(err, foos) {
...
});
Alternative #2
Implement a wrapper to the find method that always uses your specific options:
FooSchema.statics.findWithOptions = function(query, next) {
var options = { ... };
this.find(query, null, options, next);
};
And use this method like so:
Foo.findWithOptions({}, function(err, foos) {
...
})
Reusability
To make these wrapper methods more reusable, you can make a dict with all your wrappers:
var withOptionsWrappers = {
findWithOptions: function(query, next) {
this.find(query, null, this.options, next);
},
findByIdWithOptions: ...
findOneWithOptions: ...
...
};
Since we're referring to this there will be no problem reusing this. And now have this be applied to all your schemas along with your schema specific options:
FooSchema.statics = withOptionsWrappers;
FooSchema.statics.options = {
...
};
BarSchema.statics = withOptionsWrappers;
BarSchema.statics.options = {
...
};
Related
I'm looking to find a way to populate virtuals ( or something similar ) to a mongoose model.
I have a model which I would like to have non persisted properties.
I'm attempting to have the ability to have helping pointers such as 'isFavourited : true' on the model init instead of looping through results and decorating these values.
Cheers
Found the answer
Schema.set("toObject", { virtuals: true });
Schema.set("toJSON", { virtuals: true });
will render the virtuals on the object/s when returned from finds
Virtuals will certainly do this for you out of the box:
someSchema.virtual('isFavourited').get(function() {
return true
})
It would give you a transient isFavorited property that can't be set.
What you might want to get arbitrary transient properties on a model is a plugin that looks something like this:
function IHaveContext(schema, init={}) {
schema.virtual('context')
.get(function () {
return this._context;
})
.set(function (item) {
if (!this._context)
this._context = init;
this._context = Object.assign({}, this._context, item);
});
}
Then you apply this to any model, optionally setting up defaults:
let Game = new Schema({ ... })
Game.plugin(IHaveContext, {'isFavourited': false})
Now you have an api to decorate your model with arbitrary properties:
let item - new Game()
item.set('context', {'isFavourited': true});
item.get('context')('isFavourited');
Been trying to find samples usage for some of the static methods for a persistedModel in Loopback.
https://apidocs.strongloop.com/loopback/#persistedmodel-prototype-updateattribute
it just says:
persistedModel.updateAttributes(data, callback)
But how you I choose the which record I want to update? this is not working for me.
var order = Order.setId('whateverrecordId');
order.updateAttributes({name:'new name'},callback)
Loving loopback.. but their doc, sucks.. :(
You can use those on event listener like AfterSave
example:
Model.observe('after save', function(ctx, next) {
ctx.instance.updateAttribute(fieldname:'new value');
next();
});
1- What you did was right but i do not advise this method it's used for instance methods and generally to update fields like date for all the collection that you have so you don't need an id for it.
But you can try to make an array containing data to update containing also the ids and then make a comparison to fill in data for the ids that you have. (in #dosomething)
order.find().then(function(orders) {
orders.forEach(function(element) {
order.setId(element.id);
#DoSomething
order.updateAttribute({new: data}, function(err, instance) {
console.log(instance);
})
});
})
2- You can use updateAll to update one or many attribute.
PersistedModel.updateAll([where], data, callback)
var Updates = [{id : 1, name: name1}, ...]
Updates.forEach(function(element) {
order.updateAll({id : element.id}, {name :element.name}, function(err, count) {
if (err) {
console.error(err);
}
console.log(count); // number of data updated
})
})
I would like baffle.where({id: 1}).fetch() to always get typeName attribute as a part of baffle model, without fetching it from baffleType explicitly each time.
The following works for me but it seems that withRelated will load relations if baffle model is fetched directly, not by relation:
let baffle = bookshelf.Model.extend({
constructor: function() {
bookshelf.Model.apply(this, arguments);
this.on('fetching', function(model, attrs, options) {
options.withRelated = options.withRelated || [];
options.withRelated.push('type');
});
},
virtuals: {
typeName: {
get: function () {
return this.related('type').attributes.typeName;
}
}
},
type: function () {
return this.belongsTo(baffleType, 'type_id');
}
});
let baffleType = bookshelf.Model.extend({});
What is the proper way to do that?
Issue on repo is related to Fetched event, However Fetching event is working fine (v0.9.2).
So just for example if you have a 3rd model like
var Test = Bookshelf.model.extend({
tableName : 'test',
baffleField : function(){
return this.belongsTo(baffle)
}
})
and then do Test.forge().fetch({ withRelated : ['baffleField']}), fetching event on baffle will fire. However ORM will not include type (sub Related model) unless you specifically tell it to do so by
Test.forge().fetch({ withRelated : ['baffleField.type']})
However I would try to avoid this if it is making N Query for N records.
UPDATE 1
I was talking about same thing that you were doing on fetching event like
fetch: function fetch(options) {
var options = options || {}
options.withRelated = options.withRelated || [];
options.withRelated.push('type');
// Fetch uses all set attributes.
return this._doFetch(this.attributes, options);
}
in model.extend. However as you can see, this might fail on version changes.
This question is super old, but I'm answering anyway.
I solved this by just adding a new function, fetchFull, which keeps things pretty DRY.
let MyBaseModel = bookshelf.Model.extend({
fetchFull: function() {
let args;
if (this.constructor.withRelated) {
args = {withRelated: this.constructor.withRelated};
}
return this.fetch(args);
},
};
let MyModel = MyBaseModel.extend({
tableName: 'whatever',
}, {
withRelated: [
'relation1',
'relation1.related2'
]
}
);
Then whenever you're querying, you can either call Model.fetchFull() to load everything, or in cases where you don't want to take a performance hit, you can still resort to Model.fetch().
I'm trying to update an entries, if they are found in my Mongo DB:
exports.insert = function(project, data) {
data.forEach(function(d){
d.project = project;
var asset = new Asset(d);
Asset.findOne({
project: asset.project,
ip: asset.ip
}, function(err, match) {
if (err) { return next(err); }
if (match) {
console.log('asset found, updating');
match.mac = 'blablah';
match.save();
}
});
});
};
I also tried to update like this:
asset.mac = 'blalah';
match.update(asset);
In both cases my fields don't update in the DB. I see no change.
There may be smarter ways to do this but I need to be able to use save or update to do it for future.
NB: Although findOneAndUpdate may be the preferred way of doing this, I'm really curious to know why save() or update() do not work in my case. I would like to know how to use those methods to update my document.
If you're trying to find one entry and update it, you should use findOneAndUpdate:
Asset.findOneAndUpdate({
project: asset.project,
ip: asset.ip
}, {
mac: 'blablah'
}, function (err, docThatWasUpdated) {
....
})
I have defined several models that use a Datasource "db" (mysql) for my environment.
Is there any way to have several datasources attached to those models, so I would be able to perform REST operations to different databases?
i.e:
GET /api/Things?ds="db"
GET /api/Things?ds="anotherdb"
GET /api/Things (will use default ds)
As #superkhau pointed above, each LoopBack Model can be attached to a single data-source only.
You can create (subclass) a new model for each datasource you want to use. Then you can either expose these per-datasource models via unique REST URLs, or you can implement a wrapper model that will dispatch methods to the correct datasource-specific model.
In my example, I'll show how to expose per-datasource models for a Car model that is attached to db and anotherdb. The Car model is defined in the usual way via common/models/car.json and common/models/car.js.
Now you need to define per-datasource models:
// common/models/car-db.js
{
"name": "Car-db",
"base": "Car",
"http": {
"path": "/cars:db"
}
}
// common/models/car-anotherdb.js
{
"name": "Car-anotherdb",
"base": "Car",
"http": {
"path": "/cars:anotherdb"
}
}
// server/model-config.json
{
"Car": {
"dataSource": "default"
},
"Car-db": {
"dataSource": "db"
},
"Car-anotherdb": {
"dataSource": "anotherdb"
}
}
Now you have the following URLs available:
GET /api/Cars:db
GET /api/Cars:anotherdb
GET /api/Cars
The solution outlined above has two limitations: you have to define a new model for each datasource and the datasource cannot be selected using a query parameter.
To fix that, you need a different approach. I'll again assume there is a Car model already defined.
Now you need to create a "dispatcher".
// common/models/car-dispatcher.json
{
"name": "CarDispatcher",
"base": "Model", //< important!
"http": {
"path": "/cars"
}
}
// common/models/car-dispatcher.js
var loopback = require('loopback').PersistedModel;
module.exports = function(CarDispatcher) {
Car.find = function(ds, filter, cb) {
var model = this.findModelForDataSource(ds);
model.find(filter, cb);
};
// a modified copy of remoting metadata from loopback/lib/persisted-model.js
Car.remoteMethod('find', {
isStatic: true,
description: 'Find all instances of the model matched by filter from the data source',
accessType: 'READ',
accepts: [
{arg: 'ds', type: 'string', description: 'Name of the datasource to use' },
{arg: 'filter', type: 'object', description: 'Filter defining fields, where, orderBy, offset, and limit'}
],
returns: {arg: 'data', type: [typeName], root: true},
http: {verb: 'get', path: '/'}
});
// TODO: repeat the above for all methods you want to expose this way
Car.findModelForDataSource = function(ds) {
var app = this.app;
var ds = ds && app.dataSources[ds] || app.dataSources.default;
var modelName = this.modelName + '-' + ds;
var model = loopback.findModel(modelName);
if (!model) {
model = loopback.createModel(
modelName,
{},
{ base: this.modelName });
}
return model;
};
};
The final bit is to remove Car and use CarDispatcher in the model config:
// server/model-config.json
{
"CarDispatcher": {
dataSource: null,
public: true
}
}
By default, you can only attach data sources on a per-model basis. Meaning you can attach each model to a different data source via datasources.json.
For your use case, you will to add a remote hook to each endpoint you want for multiple data sources. In your remote hook, you will do something like:
...
var ds1 = Model.app.dataSources.ds1;
var ds2 = Model.app.dataSources.ds2;
//some logic to pick a data source
if (context.req.params...
...
See http://docs.strongloop.com/display/LB/Remote+hooks for more info.
For anyone still looking for a working answer to this, the solution for switching databases on the fly was to write a middleware script that examined the request path and then created a new DataSource connector, passing in a variable based on the req.path variable. For example, if the request path is /orders, then "orders" as a string would be saved in a variable, then we attached a new Datasource, passing in that variable for "orders". Here's the complete working code.
'use strict';
const DataSource = require('loopback-datasource-juggler').DataSource;
const app = require('../server.js');
module.exports = function() {
return function datasourceSelector(req, res, next) {
// Check if the API request path contains one of our models.
// We could use app.models() here, but that would also include
// models we don't want.
let $models = ['offers', 'orders', 'prducts'];
// $path expects to be 'offers', 'orders', 'prducts'.
let $path = req.path.toLowerCase().split("/")[1];
// Run our function if the request path is equal to one of
// our models, but not if it also includes 'count'. We don't
// want to run this twice unnecessarily.
if (($models.includes($path, 0)) && !(req.path.includes('count'))) {
// The angular customer-select form adds a true value
// to the selected property of only one customer model.
// So we search the customers for that 'selected' = true.
let customers = app.models.Customer;
// Customers.find() returns a Promise, so we need to get
// our selected customer from the results.
customers.find({"where": {"selected": true}}).then(function(result){
// Called if the operation succeeds.
let customerDb = result[0].name;
// Log the selected customer and the timestamp
// it was selected. Needed for debugging and optimization.
let date = new Date;
console.log(customerDb, $path+req.path, date);
// Use the existing veracore datasource config
// since we can use its environment variables.
let settings = app.dataSources.Veracore.settings;
// Clear out the veracore options array since that
// prevents us from changing databases.
settings.options = null;
// Add the selected customer to the new database value.
settings.database = customerDb;
try {
let dataSource = new DataSource(settings);
// Attach our models to the new database selection.
app.models.Offer.attachTo(dataSource);
app.models.Order.attachTo(dataSource);
app.models.Prduct.attachTo(dataSource);
} catch(err) {
console.error(err);
}
})
// Called if the customers.find() promise fails.
.catch(function(err){
console.error(err);
});
}
else {
// We need a better solution for paths like '/orders/count'.
console.log(req.path + ' was passed to datasourceSelector().');
}
next();
};
};