mobx-rest
REST conventions for mobx.
Table of Contents
Installation
npm install mobx-rest --save
What is it?
An application state is usually divided into three realms:
- Component state: Each component can have their own state, like a button
being pressed, a text input value, etc.
- Application state: Sometimes we need components to share state between them and
they are too far away to actually make them talk each other through props.
- Resources state: Other times, state is persisted in the server. We synchronize
that state through APIs that consume resources. One way to synchronize this state
is through REST.
MobX is an excellent state management choice to deal with those three realms:
It allows you to represent your state as a graph while other solutions,
like Redux for instance, force you to represent your state as a tree.
With mobx-rest
resources are implemented with all their REST
actions built in (create
, fetch
, save
, destroy
, ...) so instead
of writing, over and over, hundreds of lines of boilerplate we can leverage
REST conventions to minimize the code needed for your API interactions.
Full React example
If you want to see a full example with React you
can check out the mobx-rest-example repo.
The demo is deployed here.
Documentation
mobx-rest
is fairly simple and its source code could be read in 5 minutes.
Model
A Model
represents one resource. It's identified by a primary key (mandatory) and holds
its attributes. You can create, update and destroy models in the client and then sync
them with the server. Apart from its attributes, a Model
also holds the state of
the interactions with the server so you can react to those easily (showing loading states
for instance).
constructor(attributes: Object)
Initialize the model with the given attributes.
defaultAttributes: Object
An object literal that holds the default attributes of the model. {} by default.
attributes: ObservableMap
An ObservableMap
that holds the attributes of the model in the client.
commitedAttributes: ObservableMap
An ObservableMap
that holds the attributes of the model in the server.
collection: ?Collection
A pointer to a Collection
. By having models
"belong to" a collection you can take the most out
of mobx-rest
.
toJS(): Object
Return the object version of the attributes.
primaryKey: string
Implement this abstract method so mobx-rest
knows what to
use as a primary key. It defaults to 'id'
but if you use
something like mongodb you can change it to '_id'
.
urlRoot(): string
Implement this abstract method so mobx-rest
knows where
its API points to. If the model belongs to a Collection
(setting the collection
attribute) this method does
not need to be implemented.
url(): string
Return the url for that given resource. Will leverage the
collection's base url (if any) or urlRoot
. It uses the
primary id since that's REST convention.
Example: tasks.get(34).url() // => "/tasks/34"
changedAttributes: Array
Get an array with the attributes names that have changed.
Example:
model.set({ name: 'Pau'})
model.changedAttributes
changes: { [string]: any }
Gets the current changes.
Example:
model.set({ name: 'Pau'})
model.changes
hasChanges(attribute?: string): boolean
If an attribute is specified, returns true if it has changes.
If no attribute is specified, returns true if any attribute has changes.
Example:
model.set({ name: 'Pau'})
model.hasChanges('name')
model.hasChanges()
commitChanges(): void
Commit attributes to model.
Example:
model.set({ name: 'Pau' })
model.hasChanges
model.commitChanges()
model.hasChanges
discardChanges(): void
This will reset the model attributes to the last committed ones.
Example:
const model = new Model({ name: 'Foo' })
model.set({ name: 'Pau' })
model.get('name')
model.discardChanges()
model.get('name')
isNew: boolean
Return whether that model has been synchronized with the server or not.
Resources created in the client side (optimistically) don't have
an id
attribute yet (that's given by the server)
Example:
const user = new User({ name : 'Pau' })
user.isNew
user.save()
user.isNew
user.get('id')
get(attribute: string): any
Get the given attribute. If the attribute does not exist, it will throw an error.
If different resources have different schemas you can
always use has
to check whether a given attribute exists or not.
Example:
if (user.has('role')) {
return user.get('role')
} else {
return 'basic'
}
has(attribute: string): boolean
Check that the given attribute exists.
set(data: Object): void
Update the attributes in the client.
Example:
const folder = new Folder({ name : 'Trash' })
folder.get('name')
folder.set({ name: 'Rubbish' })
folder.get('name')
fetch(options): Promise
Fetches this resource's data from the server.
Example:
const task = new Task({ id: 3 })
const promise = task.fetch()
await promise
task.get('name')
save(attributes: Object, options: Object): Promise
The opposite of fetch
. It takes the resource from the client and
persists it in the server through the API. It accepts some attributes
as the first argument so you can use it as a set
+ save
.
It tracks the state of the request using the label saving
.
If the model has a collection associated, it will be added into it.
Options:
optimistic = true
Whether we want to update the resource in the client
first or wait for the server's response.patch = true
Whether we want to use the PATCH
verb and semantics, sending
only the changed attributes instead of the whole resource down the wire.keepChanges = false
Whether we want to keep the changes after the response from the API.path
(Optional) Target API path where we want perform the save action. It
has preference over url()
.
Example:
const company = new Company({ name: 'Teambox' })
const promise = company.save({ name: 'Redbooth' }, { optimistic: false })
company.get('name')
await promise
company.get('name')
destroy(options: Object): Promise
Tells the API to destroy this resource.
Options:
optimistic = true
Whether we want to delete the resource in the client
first or wait for the server's response.path
(Optional) Target API path where we want perform the save action. It
has preference over url()
.
rpc(method: 'string', body?: {}, label?: 'fetching'): Promise
When dealing with REST there are always cases when we have some actions beyond
the conventions. Those are represented as rpc
calls and are not opinionated.
Example:
const response = await task.rpc('resolveSubtasks', { all: true })
if (response.ok) {
task.subTasks.fetch()
}
Collection
A Collection
represents a group of resources. Each element of a Collection
is a Model
.
Likewise, a collection tracks also the state of the interactions with the server so you
can react accordingly.
models: ObservableArray
An ObservableArray
that holds the collection of models.
indexes: Array<String>
Indexes allow you to determine which attributes you want to index your collection by.
This allows you to trade-off memory for speed. By default we index all the models by
primaryKey
but you can add more indexes that will be used automatically when using filter
and find
with the object form.
users.find({ id: 123 })
users.find(user => user.get('id') === 123)
You can query your collection by a combination of attributes that are indexed and others
that are not indexed. mobx-rest
will take care to sort your query in order to scan the least
number of models.
constructor(data: Array<Object>)
Initializes the collection with the given resources.
url(): string
Abstract method that must be implemented if you want your collection
and it's models to be able to interact with the API.
model(): Model
Abstract method that tells which kind of Model
objects this collection
holds. This is used, for instance, when doing a collection.create
so
we know which object to instantiate.
toJS(): Array<Object>
Return a plain data structure representing the collection of resources
without all the observable layer.
toArray(): Array<ObservableMap>
Return an array with the observable resources.
isEmpty: boolean
Helper method that asks the collection whether there is any
model in it.
Example:
const promise = usersCollection.fetch()
usersCollection.isEmpty
await promise
usersCollection.isEmpty
usersCollection.models.length
at(index: number): ?Model
Find a model at the given position.
get(id: number, { required?: boolean = false }): ?Model
Find a model (or not) with the given id. If required
it will raise an error if not found.
filter(query: Object | Function): Array<Model>
Helper method that filters the collection by the given conditions represented
as a key value.
Example:
const resolvedTasks = tasksCollection.filter({ resolved: true })
resolvedTasks.length
const resolvedTasks = tasksCollection.filter(model => model.resolved)
resolvedTasks.length
It's important to notice that using the object API we can optimize
the filtering using indexes.
find(query: Object | Function, { required?: boolean = false }): ?Model
Same as filter
but it will halt and return when the first model matches
the conditions. If required
it will raise an error if not found.
Example:
const user = usersCollection.find({ name: 'paco' })
user.get('name')
const user = usersCollection.find(model => model.name === 'paco')
user.get('name')
usersCollection.find({ name: 'foo'})
last(): ?Model
Returns the last model of the collection. If the collection is empty, it returns null
add(data: Array<Object|T>|T|Object): Array<Model>
Adds models with the given array of attributes.
usersCollection.add([{id: 1, name: 'foo'}])
reset(data: Array<Object|T>): Array<Model>
Resets the collection with the given models.
usersCollection.reset([{id: 1, name: 'foo'}])
remove(ids: Array<number|T>|number|T): void
Remove any model with the given ids.
Example:
usersCollection.remove([1, 2, 3])
set(models: Array<Object | Model>, options: Object): void
Merge the given models smartly the current ones in the collection.
It detects what to add, remove and change.
Options:
add = true
Change to disable adding modelschange = true
Change to disable updating modelsremove = true
Change to disable removing models
const companiesCollection = new CompaniesCollection([
{ id: 1, name: 'Teambox' }
{ id: 3, name: 'Zpeaker' }
])
companiesCollection.set([
{ id: 1, name: 'Redbooth' },
{ id: 2, name: 'Factorial' }
])
companiesCollection.get(1).get('name')
companiesCollection.get(2).get('name')
companiesCollection.get(3)
build(attributes: Object|T): Model
Instantiates and links a model to the current collection.
const factorial = companiesCollection.build({ name: 'Factorial' })
factorial.collection === companiesCollection
factorial.get('name')
create(target: Object | Model, options: Object)
Add and save to the server the given model. If attributes are given,
also it builds the model for you. It tracks the state of the request
using the label creating
.
Options:
optimistic = true
Whether we want to create the resource in the client
first or wait for the server's response.path
(Optional) Target API path where we want perform the save action. It
has preference over url()
.
const promise = tasksCollection.create({ name: 'Do laundry' })
await promise
tasksCollection.at(0).get('name')
fetch(options: Object)
Fetch the date from the server and then calls set
to update the current
models. Accepts any option from the set
method.
const promise = tasksCollection.fetch()
tasksCollection.isEmpty
await promise
tasksCollection.isEmpty
rpc(method: 'string', body: {}): Promise
Exactly the same as the model one, but at the collection level.
forEach (callback: (model: T) => void): void
Alias for models.forEach
Example: collection.forEach(model => console.log(model.get('id')))
map
(callback: (model: T) => P): Array
Alias for models.map
Example: collection.map(model => model.get('id')) // => [1,2,3...]
peek (): Array<T: Model>
Returns a shallow array representation of the collection
slice (): Array<T: Model>
Returns a defensive shallow array representation of the collection
apiClient
This is the object that is going to make the xhr
requests to interact with your API.
There are currently three implementations:
Initially you need to configure apiClient()
with an adapter and the apiPath
. You can also set additional options, like headers to send with all requests.
For example, if you're using JWT and need to send it using the Authorization header, it could look like this:
const options = {
apiPath: window.env.apiUrl,
}
if (token) {
options.commonOptions = {
headers: {
Authorization: `Bearer ${token}`
}
}
}
apiClient(adapter, options)
All options:
- apiPath (required): what do prepend for all model and collections URLs
- commonOptions: settings to use for all requests
- headers: Additional request headers, like
Authorization
- tbd.
Simple Example
A collection looks like this:
const apiPath = '/api'
import adapter from 'mobx-rest-fetch-adapter'
import { apiClient, Collection, Model } from 'mobx-rest'
apiClient(adapter, { apiPath })
class Task extends Model { }
class Tasks extends Collection {
url () { return `/tasks` }
model () { return Task }
}
export default new Tasks()
And here an example of how to use React with it:
import tasksCollection from './TasksCollection'
import { computed } from 'mobx'
import { observer } from 'mobx-react'
@observer
class Task extends React.Component {
onClick () {
this.props.task.save({ resolved: true })
}
render () {
return (
<li key={task.id}>
<button onClick={this.onClick.bind(this)}>
resolve
</button>
{this.props.task.get('name')}
</li>
)
}
}
@observer
class Tasks extends React.Component {
componentDidMount () {
tasksCollection.fetch({ data: { all: true } })
}
@computed
get activeTasks () {
return tasksCollection.filter({ resolved: false })
}
render () {
return (
<div>
<span>{this.activeTasks.length} tasks</span>
<ul>{activeTasks.map((task) => <Task task={task} />)}</ul>
</div>
)
}
}
State shape
Your collections and models will have the following state shape:
Collection
models: Array<Model>
Model
attributes: Object
optimisticId: string,
FAQ
How do I create relations between the models?
This is something that mobx makes really easy to achieve:
import users from './UsersCollections'
import comments from './CommentsCollections'
import { computed } from 'mobx'
class Task extends Model {
@computed
author () {
return users.get(this.get('user_id'))
}
@computed
comments () {
return comments.filter({ task_id: this.get('id') })
}
}
Where is it used?
Developed and battle tested in production in Factorial
License
(The MIT License)
Copyright (c) 2022 Pau Ramon masylum@gmail.com
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.