# Data Modeling with Model Classes

Feathers-Vuex 1.0 introduced some lightweight data modeling. Every service had its own, internal FeathersVuexModel. In version 2.0 this FeathersVuexModel is now called the BaseModel and is extendable, so you can add your own functionality.

# Extending the BaseModel Class

While setting up Feathers-Vuex, we exported the BaseModel class so that we could extend it. The below example shows how to import and extend the BaseModel. Each service must now have its own unique Model class.

import feathersClient, { makeServicePlugin, BaseModel } from '../feathers-client'

class User extends BaseModel {
  // Required for $FeathersVuex plugin to work after production transpile.
  static modelName = 'User'
  // Define default properties here
  static instanceDefaults() {
    return {
      email: '',
      password: ''
    }
  }
}

const servicePath = 'users'
const servicePlugin = makeServicePlugin({
  Model: User,
  service: feathersClient.service(servicePath),
  servicePath
})

In case you're wondering, the modelName property is used to get around transpilation errors when using Babel with ES3 or ES5. Babel is still installed by default in most projects and generators. The modelName is used instead of the name property to provide a reliable name AFTER transpilation.

If you're working in an environment that doesn't support static properties on classes, you can always specify the static properties using the dot operator:

class User extends BaseModel {}

User.modelName = 'User'
User.instanceDefaults = function() {
  return {
    email: '',
    password: ''
  }
}

# Model attributes

The following attributes are available on each model:

  • servicePath {String} - Model.servicePath is the path passed to create the FeathersClient service.
  • namespace {String} - Model.namespace holds the value that was used to register the module with Vuex. This will match the servicePath unless you've provided a custom namespace in the Service Module options.
  • store {Vuex Store} - Use Model.store to access the Vuex store. example

# Model Methods

# find(params)

Model classes have a find method, which is a proxy to the find action. 1.7.0+

// In your Vue component
created () {
  const { Todo } = this.$FeathersVuex.api
  Todo.find({ query: {} }).then(/* ... */)
}

# findInStore(params)

Model classes have a findInStore method, which is a proxy to the find getter. 1.7.0+

// In your Vue component
created () {
  const { Todo } = this.$FeathersVuex.api
  const todos = Todo.findInStore({ query: {} })
}

# get(id, params)

Model classes have a get method, which is a proxy to the get action. 1.7.0+ Notice that the signature is more Feathers-like, and doesn't require using an array to passing both id and params.

// In your Vue component
created () {
  const { Todo } = this.$FeathersVuex.api
  Todo.get(this.id).then(/* ... */)
}

# getFromStore(id, params)

Model classes have a getFromStore method, which is a proxy to the get getter. 1.7.0+ Notice that the signature is more Feathers-like, and doesn't require using an array to passing both id and params.

// In your Vue component
created () {
  const { Todo } = this.$FeathersVuex.api
  const todo = Todo.getFromStore(this.id)
}

# instanceDefaults 1.7.0+

instanceDefaults(data, { store, models })

The instanceDefaults API was created in version 1.7 to prevent requiring to specify data for new instances created throughout the app. Depending on the complexity of the service's "business logic", it can save a lot of boilerplate. Notice that it is similar to the setupInstance method added in 2.0. The instanceDefaults method should ONLY be used to return default values for a new instance. Use setupInstance to handle other transformations on the data.

Starting with version 2.0, instanceDefaults must be provided as a function. The function will be called with the following arguments and should return an object of default properties for new instances.

  • data {Object} - The instance data
  • An utils object containing these props:
    • store - The vuex store
    • models {Object} The globalModels object, which is the same as you'll find inside a component at this.$FeathersVuex.

As an example, a User model class might look like this:

instanceDefaults(data, { store, models }) {
  return {
    firstName: '',
    lastName: '',
    email: '',
    password: '',
    isAdmin: false
  }
}

With the above attributes in place, you no longer have to manually specify any of the listed attributes. You can, however, provided data to replace them. Calling new User({ firstName: 'Marshall' }) will create the instance with the firstName filled in, already.

One important note, the isAdmin attribute is specified in the above example in order to allow immediate binding in a form. You would pretty much NEVER allow specifying isAdmin from the client and storing it on the server. Attributes related to roles and app security should pretty much ALWAYS be written in hooks on the API server.

# setupInstance 2.0.0+

setupInstance(data, { store, models })

A new setupinstance class method is now available in version 2.0. This method allows you to transform the data and setup the final instance based on incoming data. For example, you can access the models object to reference other service Model classes and create data associations.

The function will be called during model instance construction with the following arguments and should return an object containing properties that'll be merged into the new instance.

  • data {Object} - The instance data
  • A utils object containing these props:
    • store - The vuex store
    • models {Object} The globalModels object, which is the same as you'll find inside a component at this.$FeathersVuex.

For an example of how you might use setupInstance, suppose we have two services: Users and Posts. Assume that the API request to get a user includes their posts, already populated on the data. The instanceDefaults allows us to convert the array of posts into an array of Post instances.

// The setupInstance method on an imaginary User model.
setupInstance(data, { store, models }) {
  if (data.posts) {
    // Turn posts into an array of Post instances
    data.posts = data.posts.map(post => new models.Post(post))
  }
  return data
}

With the above setupInstance method in place, each User instance now stores a direct reference to the Post records in the store.

# on 2.3.0+

Register event handlers to listen to events.

# once 2.3.0+

Register an event handler that only occurs once.

# off 2.3.0+

Remove an event handler.

# Model Events 2.3.0+

Model classes are EventEmitter instances which emit service events when received (technically, EventEmitter methods are mixed onto each Model class). All FeathersJS events are supported. Oh, and one more thing: it works with feathers-rest (you won't receive socket events, but you can listen for when instances are created in other parts of the app.)

Here’s an example of how to use it in a component:

export default {
   created() {
      this.$FeathersVuex.api.Todo.on(‘created’, this.handleTodoCreated)
   },
   destroyed() {
      this.$FeathersVuex.api.Todo.off(‘created’, this.handleTodoCreated)
   },
   methods: {
      handleTodoCreated(todo) {
         console.log(todo)
      }
   }
}

Since they have all of the EventEmitter methods, Model classes can be used as a data-layer Event Bus. You can even use custom event names:

const { Todo } = this.$FeathersVuex.api

Todo.on('custom-event', data => {
  console.log(data) // { test: true }
})

Todo.emit('custom-event', { test: true })

# Creating instances

The FeathersVuex plugin for Vue allow convenient access to all Model constructors. You can create a Model instance by getting a reference to a Model class from the $FeathersVuex object:

// In your Vue component
created () {
  const { Todo } = this.$FeathersVuex.api
  const todo = new Todo({ description: 'Do something!' })
}

You can also reference this directly from the Vue module:

import Vue from 'vue'

const { Todo } = Vue.$FeathersVuex.api
const todo = new Todo({ description: 'Do something!' })

The examples above show instantiating a new Model instance without an id field. In this case, the record is not added to the Vuex store. If you instantiate a record with an id field, it will get added to the Vuex store. Note: This field is customizable using the idField option for this service.

Now that we have Model instances, let's take a look at the functionality they provide. Each instance will include the following methods:

  • .save()
  • .create()
  • .patch()
  • .update()
  • .clone()
  • .commit()
  • .reset()

Remember, if a record already has an attribute with any of these method names, it will be overwritten with the method.

These methods give access to many of the store actions and mutations. Using Model instances, you no longer have to use mapActions for create, patch, update, or remove. You also no longer have to use mapMutations for createCopy, commitCopy, or resetCopy.

store.dispatch('todos/find', { query: {} })
  .then(response => {
    const { data } = response
    const todo = data[0]

    todo.description = 'Read Nuxt.js docs'
    todo.save() // Calls store.dispatch('todos/patch', [item.id, item, {}])
  })

# Instance Methods

# instance.save(params)

The save method is a convenience wrapper for the create/patch methods, by default. If the records has no _id, the instance.create() method will be used. The params argument will be used in the Feathers client request. See the Feathers Service docs, for reference on where params are used in each method.

// In your Vue component
created () {
  const { Todo } = this.$FeathersVuex.api
  const todo = new Todo({ description: 'Do something!' })

  todo.save() // --> Creates the todo on the server.
}

Once the create response returns, the record will have an _id. If you call instance.save() again, it will call instance.patch(). Which method is used depends soletly on the data having an id (that matches the options.idfield for this service).

As mentioned, save performs either create or patch, but you can use the preferUpdate option to change the behavior to create/update.

# instance.create(params)

The create method calls the create action (service method) using the instance data. The params argument will be used in the Feathers client request. See the Feathers Service docs, for reference.

You might not ever need to use .create(), but can instead use the .save() method. Let feathers-vuex call create or patch.

const { Todo } = this.$FeathersVuex.api
const data = { description: 'Do something!' }
const todo = new Todo(data)

todo.create() // --> Creates the todo on the server using the instance data

# instance.patch(params)

The patch method calls the patch action (service method) using the instance data. The instance's id field is used for the patch id. The params argument will be used in the Feathers client request. See the Feathers Service docs, for reference.

Similar to the .create() method, you might not ever need to use .patch() if you just use .save() and let feathers-vuex figure out how to handle it.

const { Todo } = this.$FeathersVuex.api
const todo = new Todo({ id: 1, description: 'Do something!' })

todo.description = 'Do something else'

todo.patch() // --> Sends a `patch` request the with the id and description.
3.9.0+ As of version 3.9.0, you can provide an object as `params.data`, and Feathers-Vuex will use `params.data` as the patch data. This allows patching with partial data:
import { models } from 'feathers-vuex'
const { Todo } = models.api

const todo = new Todo({ description: 'Do Something', isComplete: false })

todo.patch({ data: { isComplete: true } })

# instance.update(params)

The update method calls the update action (service method) using the instance data. The instance's id field is used for the update id. The params argument will be used in the Feathers client request. See the Feathers Service docs, for reference.

Use .update() whenever you want to completely replace the data on the server with the instance data. You can also set the preferUpdate option to true to make .save() call .update() when an id field is present on the instance.

const { Todo } = this.$FeathersVuex.api
const todo = new Todo({ id: 1, description: 'Do something!' })

todo.description = 'Do something else'

todo.update() // --> Sends a `update` request the with all instance data.

# instance.remove(params)

The remove method calls the remove action (service method) using the instance data. The instance's id field is used for the remove id. The params argument will be used in the Feathers client request. See the Feathers Service docs, for reference.

const { Todo } = this.$FeathersVuex.api
const todo = new Todo({ id: 1, description: 'Do something!' })

todo.save()
  .then(todo => {
    todo.remove() // --> Deletes the record from the server
  })

# instance.clone()

The .clone() method creates a deep copy of the record and stores it on Model.copiesById. This allows you to make changes to the clone and not update visible data until you commit or save the data.

const { Todo } = this.$FeathersVuex.api
const todo = new Todo({ id: 1, description: 'Do something!' })
const todoCopy = todo.clone()

todoCopy.description = 'Do something else!'
todoCopy.commit() // --> Update the data in the store.

console.log(todo.description) // --> 'Do something else!'
console.log(todoCopy.description) // --> 'Do something else!'

There's another use case for using .clone(). Vuex has a strict mode that's really useful in development. It throws errors if any changes occur in the Vuex store state outside of mutations. Clone really comes in handy here, because you can make changes to the clone without having to write custom Vuex mutations. When you're finished making changes, call .commit() to update the store. This gives you strict mode compliance with little effort!

Note: You could previously use the keepCopiesInStoredeprecated option to keep copies in state.copiesById. In 2.0, this feature is deprecated and will be removed from the next release.

# instance.commit()

const { Todo } = this.$FeathersVuex.api
const todo = new Todo({ id: 1, description: 'Do something!' })
const todoCopy = todo.clone()

todoCopy.description = 'Do something else!'
todoCopy.commit() // --> Update the data in the store.

console.log(todo.description) // --> 'Do something else!'
console.log(todoCopy.description) // --> 'Do something else!'

# instance.reset()

const { Todo } = this.$FeathersVuex.api
const todo = new Todo({ id: 1, description: 'Do something!' })
const todoCopy = todo.clone()

todoCopy.description = 'Do something else!'
todoCopy.reset() // --> Resets the record to match the one in the store.

console.log(todo.description) // --> 'Do something!'
console.log(todoCopy.description) // --> 'Do something!'