117 lines
5.0 KiB
Markdown
117 lines
5.0 KiB
Markdown
##Concepts
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###SDKs
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**PLACEHOLDER FOR SDK INTRO**
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###Model
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LoopBack is centered around models. A model is an object that encapsulates
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data. A model is usually named after its real life counterpart. Like its real
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life counterpart, a model has some properties. Each property has a name, a type,
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and other attributes. For example,
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model: Person
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properties:
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- a Person model has properties such as First Name, Last Name and Birthday.
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- First Name and Last Name are strings while Birthday is date.
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A model can also do things as actions and behaviors. Some actions are common to
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all instances of the same model while others are specific to a given instance.
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For example,
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model: Person
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actions:
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- a Person model can say his/her Full Name (relying on a given instance)
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- a Person model can find people by Last Name (independent of instances)
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Models are the vehicle for data exchange and data representation across
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different layers in LoopBack. For example, the Person model is available as
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database tables, Node.js classes, REST resources, and mobile SDK objects.
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When developing your mobile applications, think of models being the "M" in your
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MVC framework. Models in LoopBack have backend connectivity built in already,
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so that you can save data back to your backend and call actions or functions run
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on the backend seamlessly from your mobile application.
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###LoopBack Definition Language (LDL)
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All models in LoopBack can be described as JSON objects. LoopBack has utilized
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and extended JSON to define a model's properties and structure. The JSON that is
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utilized to help define a model's properties and structure or schema is called
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LoopBack Definition Language (LDL). LDL is simple DSL to define data models in
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JavaScript or plain JSON. The model definitions establish common knowledge of
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data in LoopBack. For example,
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model: Person
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definition in LDL:
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{
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"firstName" : "string",
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"lastName" : "string",
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"birthday": "date"
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}
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For more information, please read [LoopBack Definition Language Guide](/loopback-datasource-juggler/#loopback-definition-language-guide).
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###Datasources and Connectors
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LoopBack allows you to connect to many sources of data and services in the cloud
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and on premise in your data center. These sources of data and services are
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called DataSources. DataSources are accessed through a plugin called a Connector
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in LoopBack. Plugins are highly customizable and extensible. Unlike other
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mobile backend, LoopBack can leverage your existing data and organize them in
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the form of models.
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The concept of DataSource is introduced to encapsulate business logic to
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exchange data between models and various data sources. Data sources are
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typically databases that provide create, retrieve, update, and delete (CRUD)
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functions. LoopBack also generalize other backend services, such as REST APIs,
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SOAP Web Services, and Storage Services, as data sources.
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Data sources are backed by connectors which implement the data exchange logic
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using database drivers or other client APIs. In general, connectors are not used
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directly by application code. The DataSource class provides APIs to configure
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the underlying connector and exposes functions via DataSource or model classes.
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#### LoopBack Connector Modules
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| Type | Package Name |
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| --------- |:--------------------------------------------------------------------------------------:|
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| Memory | [Built-in](https://github.com/strongloop/loopback-datasource-juggler) |
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| MongoDB | [loopback-connector-mongodb](https://github.com/strongloop/loopback-connector-mongodb) |
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| Oracle | [loopback-connector-oracle](https://github.com/strongloop/loopback-connector-oracle) |
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| REST | [loopback-connector-rest](https://github.com/strongloop/loopback-connector-rest) |
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For more information, please read [LoopBack DataSource and Connector Guide](/loopback-datasource-juggler/#loopback-datasource-and-connector-guide).
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### REST
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Everything defined in LoopBack is available to you as a REST endpoint. For
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every model that is created in LoopBack, a REST endpoint is automatically
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created for you. You can see and experiment with your REST api using the
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[LoopBack API Explorer](http://localhost:3000/explorer/).
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LoopBack also supports other protocols for your API as well. Socket.io is
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another protocol that is currently being developed.
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For more information, please read [Model REST APIs](#model-rest-api).
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### Remoting
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With LoopBack you can add whatever functionality you like either
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by yourself or leveraging functionality from other open source
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modules from the community. The ability to "mix in" behaviors are
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available through the inherent power of Javascript's less resrictive
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inheritance model.
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LoopBack takes this one step further by allowing you to seamlessly
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invoke server side code running in LoopBack in the backend from the
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your client on the front end.
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For more information, please read the [Remoting Guide](/strong-remoting).
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---
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