loopback/README.md

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# asteroid
v0.8.0
## Install
slnode install asteroid -g
## Server API
- [App](#app)
- [Model](#model)
- [DataSource](#data-source)
- [Connectors](#connectors)
- [GeoPoint](#geo-point)
- [Asteroid Types](#asteroid-types)
- [REST Router](#rest-router)
## Client API
_TODO_
### App
Create an asteroid application.
var asteroid = require('asteroid');
var app = asteroid();
app.get('/', function(req, res){
res.send('hello world');
});
app.listen(3000);
**Notes:**
- extends [express](http://expressjs.com/api.html#express)
- see [express docs](http://expressjs.com/api.html) for details
- supports [express / connect middleware](http://expressjs.com/api.html#middleware)
#### app.model(Model)
Expose a `Model` to remote clients.
var memory = asteroid.createDataSource({connector: asteroid.Memory});
var Color = memory.createModel('color', {name: String});
app.model(Color);
app.use(asteroid.rest());
**Note:** this will expose all [shared methods](#shared-methods) on the model.
#### app.models()
Get the app's exposed models.
var models = app.models();
models.forEach(function (Model) {
console.log(Model.modelName); // color
});
### Model
An Asteroid `Model` is a vanilla JavaScript class constructor with an attached set of properties and options. A `Model` instance is created by passing a data object containing properties to the `Model` constructor. A `Model` constructor will clean the object passed to it and only set the values matching the properties you define.
// valid color
var Color = asteroid.createModel('color', {name: String});
var red = new Color({name: 'red'});
console.log(red.name); // red
// invalid color
var foo = new Color({bar: 'bat baz'});
console.log(foo.bar); // undefined
**Properties**
A model defines a list of property names, types and other validation metadata. A [DataSource](#data-source) uses this definition to validate a `Model` during operations such as `save()`.
**Options**
Some [DataSources](#data-source) may support additional `Model` options.
Define an asteroid model.
var User = asteroid.createModel('user', {
first: String,
last: String,
age: Number
});
### Validation (expiremental)
#### Model.validatesPresenceOf(properties...)
Require a model to include a property to be considered valid.
User.validatesPresenceOf('first', 'last', 'age');
#### Model.validatesLengthOf(property, options)
Require a property length to be within a specified range.
User.validatesLengthOf('password', {min: 5, message: {min: 'Password is too short'}});
#### Model.validatesInclusionOf(property, options)
Require a value for `property` to be in the specified array.
User.validatesInclusionOf('gender', {in: ['male', 'female']});
#### Model.validatesExclusionOf(property, options)
Require a value for `property` to not exist in the specified array.
User.validatesExclusionOf('domain', {in: ['www', 'billing', 'admin']});
#### Model.validatesNumericalityOf(property, options)
Require a value for `property` to be a specific type of `Number`.
User.validatesNumericalityOf('age', {int: true});
#### Model.validatesUniquenessOf(property, options)
Ensure the value for `property` is unique.
User.validatesUniquenessOf('email', {message: 'email is not unique'});
**Note:** not available for all [connectors](#connectors).
#### myModel.isValid()
Validate the model instance.
user.isValid(function (valid) {
if (!valid) {
user.errors // hash of errors {attr: [errmessage, errmessage, ...], attr: ...}
}
});
#### Model.attachTo(dataSource)
Attach a model to a [DataSource](#data-source). Attaching a [DataSource](#data-source) updates the model with additional methods and behaviors.
var oracle = asteroid.createDataSource({
connector: require('asteroid-connector-oracle'),
host: '111.22.333.44',
database: 'MYDB',
username: 'username',
password: 'password'
});
User.attachTo(oracle);
**Note:** until a model is attached to a data source it will **not** have any **attached methods**.
#### CRUD and Query Mixins
Mixins are added by attaching a vanilla model to a data source with a connector. Each [connector](#connectors) enables its own set of operations that are attached to a `Model` as methods. To see available methods for a data source with a connector call `dataSource.operations()`.
#### Static Methods
##### Model.create(data, [callback])
Create an instance of Model with given data and save to the attached data source. Callback is optional.
User.create({first: 'Joe', last: 'Bob'}, function(err, user) {
console.log(user instanceof User); // true
});
**Note:** You must include a callback and use the created model provided in the callback if your code depends on your model being saved or having an `id`.
##### Model.count([query], callback)
Query count of Model instances in data source. Optional query param allows to count filtered set of Model instances.
User.count({approved: true}, function(err, count) {
console.log(count); // 2081
});
##### Model.find(filter, callback)
Find all instances of Model, matched by query. Fields used for filter and sort should be declared with `{index: true}` in model definition.
**filter**
- **where** `Object` { key: val, key2: {gt: 'val2'}}
- **include** `String`, `Object` or `Array`.
- **order** `String`
- **limit** `Number`
- **skip** `Number`
Find the second page of 10 users over age 21 in descending order.
User.find({where: {age: {gt: 21}}, order: 'age DESC', limit: 10, skip: 10})
**Note:** See the specific connector's [docs](#connectors) for more info.
##### Model.destroyAll(callback)
Delete all Model instances from data source. **Note:** destroyAll method does not perform destroy hooks.
##### Model.findById(id, callback)
Find instance by id.
User.findById(23, function(err, user) {
console.info(user.id); // 23
});
##### Model.findOne(where, callback)
Find a single instance that matches the given where expression.
User.findOne({id: 23}, function(err, user) {
console.info(user.id); // 23
});
##### Model.upsert(data, callback)
Update when record with id=data.id found, insert otherwise. **Note:** no setters, validations or hooks applied when using upsert.
##### Custom Static Methods
Define a static model method.
User.login = function (username, password, fn) {
var passwordHash = hashPassword(password);
this.findOne({username: username}, function (err, user) {
var failErr = new Error('login failed');
if(err) {
fn(err);
} else if(!user) {
fn(failErr);
} else if(user.password === passwordHash) {
MySessionModel.create({userId: user.id}, function (err, session) {
fn(null, session.id);
});
} else {
fn(failErr);
}
});
}
Setup the static model method to be exposed to clients as a [remote method](#remote-method).
asteroid.remoteMethod(
User.login,
{
accepts: [
{arg: 'username', type: 'string', required: true},
{arg: 'password', type: 'string', required: true}
],
returns: {arg: 'sessionId', type: 'any'},
http: {path: '/sign-in'}
}
);
#### Instance Methods
##### model.save([options], [callback])
Save an instance of a Model to the attached data source.
var joe = new User({first: 'Joe', last: 'Bob'});
joe.save(function(err, user) {
if(user.errors) {
console.log(user.errors);
} else {
console.log(user.id);
}
});
##### model.updateAttributes(data, [callback])
Save specified attributes to the attached data source.
user.updateAttributes({
first: 'updatedFirst',
name: 'updatedLast'
}, fn);
##### model.destroy([callback])
Remove a model from the attached data source.
model.destroy(function(err) {
// model instance destroyed
});
##### Custom Instance Methods
Define an instance method.
User.prototype.logout = function (fn) {
MySessionModel.destroyAll({userId: this.id}, fn);
}
Define a remote model instance method.
asteroid.remoteMethod(User.prototype.logout);
#### Remote Methods
Both instance and static methods can be exposed to clients. A remote method must accept a callback with the conventional `fn(err, result, ...)` signature.
##### asteroid.remoteMethod(fn, [options]);
Expose a remote method.
Product.stats = function(fn) {
myApi.getStats('products', fn);
}
asteroid.remoteMethod(
Product.stats,
{
returns: {arg: 'stats', type: 'array'},
http: {path: '/info', verb: 'get'}
}
);
**Options**
- **accepts** - (optional) an arguments description specifying the remote method's arguments. A
- **returns** - (optional) an arguments description specifying the remote methods callback arguments.
- **http** - (advanced / optional, object) http routing info
- **http.path** - the path relative to the model the method will be exposed at. May be a path fragment (eg. '/:myArg') which will be populated by an arg of the same name in the accepts description. For example the stats method above will be at the whole path `/products/stats`.
- **http.verb** - (get, post, put, del, all) - the route verb the method will be available from.
**Argument Description**
An arguments description defines either a single argument as an object or an ordered set of arguments as an array.
// examples
{arg: 'myArg', type: 'number'}
[
{arg: 'arg1', type: 'number', required: true},
{arg: 'arg2', type: 'array'}
]
**Types**
Each argument may define any of the [asteroid types](#asteroid-types).
**Notes:**
- The callback is an assumed argument and does not need to be specified in the accepts array.
- The err argument is also assumed and does not need to be specified in the returns array.
#### Remote Hooks
Run a function before or after a remote method is called by a client.
// *.save === prototype.save
User.beforeRemote('*.save', function(ctx, user, next) {
if(ctx.user) {
next();
} else {
next(new Error('must be logged in to update'))
}
});
User.afterRemote('*.save', function(ctx, user, next) {
console.log('user has been saved', user);
next();
});
Remote hooks also support wildcards. Run a function before any remote method is called.
// ** will match both prototype.* and *.*
User.beforeRemote('**', function(ctx, user, next) {
console.log(ctx.methodString, 'was invoked remotely'); // users.prototype.save was invoked remotely
next();
});
Other wildcard examples
// run before any static method eg. User.find
User.beforeRemote('*', ...);
// run before any instance method eg. User.prototype.save
User.beforeRemote('prototype.*', ...);
// prevent password hashes from being sent to clients
User.afterRemote('**', function (ctx, user, next) {
if(ctx.result) {
if(Array.isArray(ctx.result)) {
ctx.result.forEach(function (result) {
result.password = undefined;
});
} else {
ctx.result.password = undefined;
}
}
next();
});
#### Context
Remote hooks are provided with a Context `ctx` object which contains transport specific data (eg. for http: `req` and `res`). The `ctx` object also has a set of consistent apis across transports.
##### ctx.user
A `Model` representing the user calling the method remotely. **Note:** this is undefined if the remote method is not invoked by a logged in user.
##### ctx.result
During `afterRemote` hooks, `ctx.result` will contain the data about to be sent to a client. Modify this object to transform data before it is sent.
##### Rest
When [asteroid.rest](#asteroidrest) is used the following `ctx` properties are available.
###### ctx.req
The express ServerRequest object. [See full documentation](http://expressjs.com/api.html#req).
###### ctx.res
The express ServerResponse object. [See full documentation](http://expressjs.com/api.html#res).
Access the raw `req` object for the remote method call.
#### Relationships
##### Model.hasMany(Model)
Define a "one to many" relationship.
// by referencing model
Book.hasMany(Chapter);
// specify the name
Book.hasMany('chapters', {model: Chapter});
Query and create the related models.
Book.create(function(err, book) {
// create a chapter instance
// ready to be saved in the data source
var chapter = book.chapters.build({name: 'Chapter 1'});
// save the new chapter
chapter.save();
// you can also call the Chapter.create method with
// the `chapters` property which will build a chapter
// instance and save the it in the data source
book.chapters.create({name: 'Chapter 2'}, function(err, savedChapter) {
// this callback is optional
});
// query chapters for the book using the
book.chapters(function(err, chapters) {
// all chapters with bookId = book.id
console.log(chapters);
});
book.chapters({where: {name: 'test'}, function(err, chapters) {
// all chapters with bookId = book.id and name = 'test'
console.log(chapters);
});
});
##### Model.hasAndBelongsToMany()
TODO: implement / document
#### Shared Methods
Any static or instance method can be decorated as `shared`. These methods are exposed over the provided transport (eg. [asteroid.rest](#rest)).
### Data Source
An Asteroid `DataSource` provides [Models](#model) with the ability to manipulate data. Attaching a `DataSource` to a `Model` adds [instance methods](#instance-methods) and [static methods](#static-methods) to the `Model`. The added methods may be [remote methods](#remote-methods).
Define a data source for persisting models.
var oracle = asteroid.createDataSource({
connector: 'oracle',
host: '111.22.333.44',
database: 'MYDB',
username: 'username',
password: 'password'
});
#### dataSource.createModel(name, properties, options)
Define a model and attach it to a `DataSource`.
var Color = oracle.createModel('color', {name: String});
#### dataSource.discoverModelDefinitions([username], fn)
Discover a set of model definitions (table or collection names) based on tables or collections in a data source.
oracle.discoverModelDefinitions(function (err, models) {
models.forEach(function (def) {
// def.name ~ the model name
oracle.discoverSchema(null, def.name, function (err, schema) {
console.log(schema);
});
});
});
#### dataSource.discoverSchema([owner], name, fn)
Discover the schema of a specific table or collection.
**Example schema from oracle connector:**
{
"name": "Product",
"options": {
"idInjection": false,
"oracle": {
"schema": "BLACKPOOL",
"table": "PRODUCT"
}
},
"properties": {
"id": {
"type": "String",
"required": true,
"length": 20,
"id": 1,
"oracle": {
"columnName": "ID",
"dataType": "VARCHAR2",
"dataLength": 20,
"nullable": "N"
}
},
"name": {
"type": "String",
"required": false,
"length": 64,
"oracle": {
"columnName": "NAME",
"dataType": "VARCHAR2",
"dataLength": 64,
"nullable": "Y"
}
},
"audibleRange": {
"type": "Number",
"required": false,
"length": 22,
"oracle": {
"columnName": "AUDIBLE_RANGE",
"dataType": "NUMBER",
"dataLength": 22,
"nullable": "Y"
}
},
"effectiveRange": {
"type": "Number",
"required": false,
"length": 22,
"oracle": {
"columnName": "EFFECTIVE_RANGE",
"dataType": "NUMBER",
"dataLength": 22,
"nullable": "Y"
}
},
"rounds": {
"type": "Number",
"required": false,
"length": 22,
"oracle": {
"columnName": "ROUNDS",
"dataType": "NUMBER",
"dataLength": 22,
"nullable": "Y"
}
},
"extras": {
"type": "String",
"required": false,
"length": 64,
"oracle": {
"columnName": "EXTRAS",
"dataType": "VARCHAR2",
"dataLength": 64,
"nullable": "Y"
}
},
"fireModes": {
"type": "String",
"required": false,
"length": 64,
"oracle": {
"columnName": "FIRE_MODES",
"dataType": "VARCHAR2",
"dataLength": 64,
"nullable": "Y"
}
}
}
}
#### dataSource.enableRemote(operation)
Enable remote access to a data source operation. Each [connector](#connector) has its own set of set remotely enabled and disabled operations. You can always list these by calling `dataSource.operations()`.
#### dataSource.disableRemote(operation)
Disable remote access to a data source operation. Each [connector](#connector) has its own set of set enabled and disabled operations. You can always list these by calling `dataSource.operations()`.
// all rest data source operations are
// disabled by default
var oracle = asteroid.createDataSource({
connector: require('asteroid-connector-oracle'),
host: '...',
...
});
// or only disable it as a remote method
oracle.disableRemote('destroyAll');
**Notes:**
- disabled operations will not be added to attached models
- disabling the remoting for a method only affects client access (it will still be available from server models)
- data sources must enable / disable operations before attaching or creating models
#### dataSource.operations()
List the enabled and disabled operations.
console.log(oracle.operations());
Output:
{
find: {
remoteEnabled: true,
accepts: [...],
returns: [...]
enabled: true
},
save: {
remoteEnabled: true,
prototype: true,
accepts: [...],
returns: [...],
enabled: true
},
...
}
#### Connectors
Create a data source with a specific connector. See **available connectors** for specific connector documentation.
var memory = asteroid.createDataSource({
connector: asteroid.Memory
});
**Available Connectors**
- [Oracle](http://github.com/strongloop/asteroid-connectors/oracle)
- [In Memory](http://github.com/strongloop/asteroid-connectors/memory)
- TODO - [REST](http://github.com/strongloop/asteroid-connectors/rest)
- TODO - [MySQL](http://github.com/strongloop/asteroid-connectors/mysql)
- TODO - [SQLite3](http://github.com/strongloop/asteroid-connectors/sqlite)
- TODO - [Postgres](http://github.com/strongloop/asteroid-connectors/postgres)
- TODO - [Redis](http://github.com/strongloop/asteroid-connectors/redis)
- TODO - [MongoDB](http://github.com/strongloop/asteroid-connectors/mongo)
- TODO - [CouchDB](http://github.com/strongloop/asteroid-connectors/couch)
- TODO - [Firebird](http://github.com/strongloop/asteroid-connectors/firebird)
**Installing Connectors**
Include the connector in your package.json dependencies and run `npm install`.
{
"dependencies": {
"asteroid-connector-oracle": "latest"
}
}
### GeoPoint TODO
Embed a latitude / longitude point in a [Model](#model).
var CoffeeShop = asteroid.createModel('coffee-shop', {
location: 'GeoPoint'
});
Asteroid Model's with a GeoPoint property and an attached DataSource may be queried using geo spatial filters and sorting.
Find the 3 nearest coffee shops.
CoffeeShop.attachTo(oracle);
var here = new GeoPoint({lat: 10.32424, long: 5.84978});
CoffeeShop.find({where: {location: {near: here}}}, function(err, nearbyShops) {
console.info(nearbyShops); // [CoffeeShop, ...]
});
#### geoPoint.distanceTo(geoPoint, options)
Get the distance to another `GeoPoint`.
var here = new GeoPoint({lat: 10, long: 10});
var there = new GeoPoint({lat: 5, long: 5});
console.log(here.distanceTo(there, {type: 'miles'})); // 438
#### GeoPoint.distanceBetween(a, b, options)
Get the distance between two points.
GeoPoint.distanceBetween(here, there, {type: 'miles'}) // 438
#### Distance Types
- `miles`
- `radians`
- `kilometers`
#### geoPoint.lat
The latitude point in degrees. Range: -90 to 90.
#### geoPoint.long
The longitude point in degrees. Range: -180 to 180.
### Asteroid Types
Various APIs in Asteroid accept type descriptions (eg. [remote methods](#remote-methods), [asteroid.createModel()](#model)). The following is a list of supported types.
- `null` - JSON null
- `Boolean` - JSON boolean
- `Number` - JSON number
- `String` - JSON string
- `Object` - JSON object
- `Array` - JSON array
- `Date` - a JavaScript date object
- `Buffer` - a node.js Buffer object
- [GeoPoint](#geopoint) - an asteroid GeoPoint object. TODO
### REST Router
Expose models over rest using the `asteroid.rest` router.
app.use(asteroid.rest());
**REST Documentation**
View generated REST documentation by visiting: [http://localhost:3000/_docs](http://localhost:3000/_docs).
### SocketIO Middleware **Not Available**
**Coming Soon** - Expose models over socket.io using the `asteroid.sio()` middleware.
app.use(asteroid.sio);