Backendless Request


Simple Node.js and Browser REST client
```
backendless.js => ~ 28 KB
backendless.min.js => ~ 11 KB
``

- How to use
- Install
- Require it as a module
- Include it as a single file
- As a part of the JS-SDK
- In the UI Builder and JS Cloud Code environment

- Request Methods
- GET
- POST
- PUT
- DELETE
- PATCH

- Query Params

- Request Body
- Form
- ContentType Header

- Request Events

- Caching Requests
- Cache Tags
- Reset Cache

- Own XMLHttpRequest

- Logging

How to use

$3


for installation just execute the following command:
``
npm i backendless-request -S
``

$3

``js
import BackendlessRequest from 'backendless-request';

//or

const BackendlessRequest = require('backendless-request');
``

$3

Inside the installed package you can find a dist directory, where are two js files backendless-request.js and backendless-request.min.js
``
-|
- dist
|-backendless.js
|-backendless.min.js

``

Get one of the js files into your project
``html

``

you can use minimized file as well
``html

``

After that you can use BackendlessRequest from the global scope

``js
BackendlessRequest.get('http://foo.bar/')
``

$3

Since the JS-SDK already uses the module for API requests, therefor if you use the SDK in your code you can use the Request module as well in your code without additional require, see the example below:

``js
import Backendless from 'backendless';

Backendless.Request.get('https://foo.bar/')
.then(result => console.log(result))
.catch(error => console.error(error))
``

$3

The Backendless UI Builder and JS Cloud Code include the Backendless JS-SDK in the global scope, therefor the Request module is also available there, see the example below:

``js

Backendless.Request.get('https://foo.bar/')
.then(result => console.log(result))
.catch(error => console.error(error))
``

$3

#### GET

``js
BackendlessRequest.get('https://foo.bar/')
.then(result => console.log(result))
.catch(error => console.error(error))
``

#### POST

``js
BackendlessRequest.post('https://foo.bar/', { foo: 'bar', bool: true, num: 1 })
.then(result => console.log(result))
.catch(error => console.error(error))
``

#### PUT

``js
BackendlessRequest.put('https://foo.bar/', { num: 123 })
.then(result => console.log(result))
.catch(error => console.error(error))
``

#### DELETE

``js
BackendlessRequest.delete('https://foo.bar/foo')
.then(result => console.log(result))
.catch(error => console.error(error))
``

#### PATCH

``js
BackendlessRequest.patch('https://foo.bar/foo', { bool: false })
.then(result => console.log(result))
.catch(error => console.error(error))
``

$3


You can set up a request query through .query(query) method
and the library will automatically add the query to request url

``js
// RequestUrl: https://foo.bar/some-path?str=some-string&num=123&bool=true&arr=1&arr=2&arr=3&arr=4
BackendlessRequest.get('https://foo.bar/some-path')
.query({ str: 'some-string', num: 123, bool: true, list: [1, 2, 3, 4] })
.then(result => console.log(result))
.catch(error => console.error(error))
``

$3

You can send request body through the .send(body) method,
but if you don't do that, the method will be called with the second argument when you call then or catch method.

``js
BackendlessRequest.post('https://foo.bar/some-path')
.send({ str: 'some-string', num: 123, bool: true, list: [1, 2, 3, 4] })
.then(result => console.log(result))
.catch(error => console.error(error))
``

``js
BackendlessRequest.post('https://foo.bar/some-path', { str: 'some-string', num: 123, bool: true, list: [1, 2, 3, 4] })
.then(result => console.log(result))
.catch(error => console.error(error))
``

#### Form
For sending a form you should use .form(form) method

``js
BackendlessRequest.post('http://foo.bar/')
.form(form)
.then(result => console.log(result))
.catch(error => console.error(error))
``

#### ContentType Header
To manually set up the Content-Type header, you can use the .type(contentTypeHeader) method or set it via .set('Content-Type', value) method.
If you pass an object as a request body the Content-Type header will be automatically specified as application/json

``js
BackendlessRequest.get('https://foo.bar/')
.set('x-header-key', 'x-header-value')
.set({ 'y-header-key': 'y-header-value', 'z-header-key': 'z-header-value' })
.then(result => console.log(result))
.catch(error => console.error(error))
``

$3

A request instance might fire events to notify about changing request state:

for subscribing use method .on(, callback)

``js
BackendlessRequest.post('https://foo.bar/some-path')
.on('request', req => req.set('my-x-header-key', 'my-x-header-value'))
.on('response', result => console.log('result', result))
.on('error', error => console.log('error', error))
.on('done', (error, result) => console.log('done', { error, result }))
.send({ str: 'some-string', num: 123, bool: true, list: [1, 2, 3, 4] })
.then(result => console.log(result))
.catch(error => console.error(error))
``

- request - it will be fired before sending a request to the server
- response - it will be fired when a request is successfully completed
- error - it will be fired when a request is failed
- done - it will be fired when a request is done, it's a shortcut for response and error




$3

The feature allows you to have some responses cached and reset the cache by the next requests.

#### Cache Tags
Cache tags help you to keep your cache up-to-date

For example, you have a route to retrieve a list of Persons and you want to cache the result for the same requests,
for this, you need to specify a cache tag and set TTL via useCache method,
after that when you do the request again the response will be retrieved from the cache store.

``js
// get list of persons
BackendlessRequest.get('https://your-domain.com/persons')
.cacheTags(['persons'])
.useCache(30 * 1000) // cache time to live is 30 seconds, by default it's 15 seconds
.then(result => console.log(result))
.catch(error => console.error(error))
``

You can use as many tags as you need

``js
// get list of persons
BackendlessRequest.get('https://your-domain.com/persons')
.cacheTags(['persons', 'friends', 'posts'])
.useCache()
.then(result => console.log(result))
.catch(error => console.error(error))
``

#### Reset Cache
In many cases you want to reset the cache when doing some requests that can change values on the server

``js
// create a new person
BackendlessRequest.post('https://your-domain.com/persons', { name: 'Bob' })
.cacheTags(['persons'])
.resetCache(true)
.then(result => console.log(result))
.catch(error => console.error(error))
``

``js
// create a new person
BackendlessRequest.delete('https://your-domain.com/persons/personId')
.cacheTags(['persons'])
.resetCache(true)
.then(result => console.log(result))
.catch(error => console.error(error))
``

$3


You can use your own XMLHttpRequest, just replace it in BackendlessRequest namespace.

See Example

``js

class MySupperXMLHttpRequest {

open(){

}

...

send(){

}
}

BackendlessRequest.XMLHttpRequest = MySupperXMLHttpRequest
``

$3


If you want to log all the requests just set true for verbose

``js
BackendlessRequest.verbose = true
```