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API

TOC

Requesting a resource

To request a resource, you will need to import the address module with the modules:

// using ES6 modules
import { address } from '@zambezi/address'

// using AMD modules
define([
  '@zambezi/address/lib/address'
], function(address) {
  // ...
})

address(uri)

Creates a resource request object, with an optional uri parameter, that is used to:

  • provide additional request options - headers and accept types
  • specify data with the request - parameters, query strings, body
  • register listeners to response events
  • initiate the request once all configuration has been done
address('/price/usd/gbp')
  .on('ok', function(response) {
    // use data from response
  })
  .get()

.uri()

Provides set or get of the resource uri to be requested.

set:

address()
  .uri('/price/usd/gbp')
  .on('ok', function(response) {
    // use data from response
  })
  .get()

get:

var value = address()
  .uri('/price/usd/gbp')
  .uri()
// value === '/price/usd/gbp'

.param()

Provides set or get for path parameters, using key-value arguments or an object of key-value properties, which are interpolated into the path.

set (key-value arguments):

address('/price/{ccy1}/{ccy2}')
  .param('ccy1', 'usd')
  .param('ccy2', 'gbp')
  .get()

// -> /price/usd/gbp

set (object of key-value properties):

address('/price/{ccy1}/{ccy2}')
  .param({ ccy1: 'usd', ccy2: 'gbp' })
  .get()

// -> /price/usd/gbp

get (object of key-value properties):

var value = address('/price/{ccy1}/{ccy2}')
  .param('ccy1', 'usd')
  .param('ccy2', 'gbp')
  .param()

// value === { ccy1: 'usd', ccy2: 'gbp' }

.query()

Provides set or get for query parameters, using key-value arguments or an object of key-value properties, which will be appended to the path.

set (key-value arguments):

address('/price/usd/gbp')
  .query('ccy1', 'usd')
  .query('ccy2', 'gbp')

// -> /price/usd/gbp?ccy1=usd&ccy2=gbp

set (object of key-value properties):

address('/price/usd/gbp')
  .query({ ccy1: 'usd', ccy2: 'gbp' })

// -> /price/usd/gbp?ccy1=usd&ccy2=gbp

get (object of key-value properties):

var value = address('/price/usd/gbp')
  .query('ccy1', 'usd')
  .query('ccy2', 'gbp')
  .query()

// value === { ccy1: 'usd', ccy2: 'gbp' }

.body()

Provides set or get for the body of your request. This can be any object and will be accessible to the resource through the request.body property.

set:

address('/price/usd/gbp')
  .body({ foo: 'bar' })
  .post()

get:

var value = address('/price/usd/gbp')
  .body({ foo: 'bar' })
// value === { foo: 'bar' }

.origin()

To disambiguate the DOM element used as the local root, when navigating or using DOM view resource, it is possible to specify an origin node when building a request.

The origin node provided should be a descendant of the root node in which the request should be resolved. In cases where the running application contains more than one possible root (for instance when running in browser workspaces), specifying an origin node allows address to navigate in the correct window.

example: navigation with origin specified

address('/price/usd/gbp')
  .origin(node)
  .navigate()

example: using DOM view resource with origin specified

address('/price/usd/gbp')
  .origin(node)
  .into()
  .get()

.get()

Invoke the request using the get method.

address('/price/usd/gbp')
  .on('ok', function(response) {
    // use data from response
  })
  .get()

.post()

Invoke the request using the post method.

A payload can be passed in as a parameter, which will be equivalent to passing in a payload through .body().

address('/price/usd/gbp')
  .post({ foo: 'bar' })

.put()

Invoke the request using the put method.

A payload can be passed in as a parameter, which will be equivalent to passing in a payload through .body().

address('/price/usd/gbp')
  .put({ foo: 'bar' })

.remove()

Invoke the request using the remove method.

A payload can be passed in as a parameter, which will be equivalent to passing in a payload through .body().

address('/price/usd/gbp')
  .remove({ foo: 'bar' })

.patch()

Invoke the request using the patch method.

A payload can be passed in as a parameter, which will be equivalent to passing in a payload through .body().

address('/price/usd/gbp')
  .patch({ foo: 'bar' })

.method()

Set method for the request, with invoking the request.

The method chosen should match the semantics found in the standard HTTP verbs):

GET
POST
PUT
REMOVE
PATCH

address('/price/usd/gbp')
  .method('post')
  .body(someData)
  () // invoke request

.header()

Allows headers to be added to a request, so that further information can be conveyed about how the request should be handled.

For example, resources may route requests to different handlers based on the accept type of the request. Specify the accept type header using the .header() api.

address('/price/usd/gbp')
  .header('accept-type', 'application/json')
  .on('ok', function(response) {
    // use data from response
  })
  .get()

Accept types must conform to the HTTP field definition

The default accept type for requests is 'application/x.nap.view' which is the type for a view resource.

.json()

A convenience methods for setting the accept type header to 'application/json':

address('/price/usd/gbp')
  .json()
  .on('ok', function(response) {
    // use data from response
  })
  .get()

.xml()

A convenience methods for setting the accept type header to 'text/xml':

address('/price/usd/gbp')
  .xml()
  .on('ok', function(response) {
    // use data from response
  })
  .get()

.text()

A convenience methods for setting the accept type header to 'text/plain':

address('/price/usd/gbp')
  .text()
  .on('ok', function(response) {
    // use data from response
  })
  .get()

Handling the response

.on(RESPONSE TYPE, cb)

Listen for any response type as specified in the HTTP/1.1 specification:

listen for: successful

address('/price/usd/gbp')
  .on('successful', function(response) {
    // handle response
  })
  .get()

listen for: client-error

address('/price/usd/gbp')
  .on('client-error', function(response) {
    // handle response
  })
  .get()
Status Code Name Status Code
'informational' 1xx
'successful' 2xx
'redirection' 3xx
'client-error' 4xx
'server-error' 5xx

.on(STATUS CODE NAME, cb)

Listen for specific status code, based open the corresponding names as defined in the specification:

listen for: created

address('/price/usd/gbp')
  .on('created', function(response) {
    // use data from response
  })
  .get()

listen for: bad-request

address('/price/usd/gbp')
  .on('bad-request', function(response) {
    // handle error response
  })
  .get()
Example Status Code Name Status Code
'ok' 200
'created' 201
'bad-request' 400
'unauthorized' 401
'service-unavailable' 503

.on('done', cb)

Listen to when a request completes, regardless of status code:

address('/price/usd/gbp')
  .on('done', function(response) {
    // handle error response
  })
  .get()

.on('err', cb)

Listen for the exception to be thrown during the request.

There are some errors that get sent from address:

  • If the requested resource does not support the specified method a 405 error response will be returned.
  • If the requested resource does not support the specified accept type a 415 error response will be returned.
address('/price/usd/gbp')
  .on('err', function(response) {
    // handle error response
  })
  .get()

Building a resource

To build a resource, some of the following exports might need to be imported:

// using ES6 modules
import { ok, error, created, redirect, response } from '@zambezi/address'

export function(req, res) {
  // handle request and call `res` with response
}

// using AMD modules
define([
  '@zambezi/address/lib/ok'
, '@zambezi/address/lib/error'
, '@zambezi/address/lib/created'
, '@zambezi/address/lib/redirect'
, '@zambezi/address/lib/response'
], function(ok, error, created, redirect, response) {
  return function(req, res) {
    // handle request and call `res` with response
  }
})

req.body

The body payload associated with the request - see address.body():

var value = req.headers

// value === { foo: 'bar' }

req.headers

An object of key-value properties for the headers associated with the request - see address.header():

var value = req.headers

// value === { accept: 'application/json' }

req.method

The method associated with the request - see address.method():

var value = req.method

// value === 'get'

req.origin

The origin DOM node associated with the request - see address.origin():

var value = req.origin

// value === <div class="z-app"/>

req.params

An object of key-value properties for the params associated with the request - see address.param():

var value = req.params

// value === { ccy1: 'usd', ccy2: 'gbp' }

req.uri

The uri associated with the request - see address(uri) and address.uri():

var value = req.url

// value === '/price/usd/gbp'

res()

The callback function, for passing back an error or a response object - see response(STATUS CODE, BODY, HEADERS).

An error should only be passed when there is a problem with making a request, where as when there is an error due to some response (such as a network request) should pass a response object.

example: with error

if (/* missing request parameter*/) {
  res('Parameter "ccy1" has not been supplied.')
}

example: with an ok() response object

res(null, ok({ amount: 10000, ccy1: 'usd', ccy2: 'gbp' }))

example: with an error() response object

res(null, error(401, { message: 'User does not have permissions to make request' }))

response(STATUS CODE, BODY, HEADERS)

A response object, which allows the status code, body and headers to be supplied.

A resource function must call the response function with an appropriate response.

res(null, response(201, { amount: 10000, ccy1: 'usd', ccy2: 'gbp' }, { 'location': 'order/1221' }))

ok(BODY)

A convenience method for a http status code 200 response object:

res(null, ok({ amount: 10000, ccy1: 'usd', ccy2: 'gbp' }))

error(ERROR CODE, BODY)

A convenience method for a http status code 4xx or 5xx response object:

res(null, error(401, { message: 'User does not have permissions to make request' }))

created(LOCATION, BODY)

A convenience method for a http status code 201 response object:

res(null, created('order/1221', { amount: 10000, ccy1: 'usd', ccy2: 'gbp' }))

redirect(LOCATION)

A convenience method for a http status code 302 response object:

res(null, redirect('price/usd/gbp/now'))

Listening to a stream resource

address.stream()

A convenience methods for setting the accept type header to 'application/x.zap.stream':

var stream

address('/price/usd/gbp')
  .stream()
  .on('ok', function(response) {
    stream = result.body
    // handle stream object
  })
  .get()

.on('error', cb)

Listen for errors sent on the stream:

var stream

address('/price/usd/gbp')
  .stream()
  .on('ok', function(response) {
    stream = result.body
    stream.on('error.custom-namespace', function (error) {
      // Handle the error
    })
  })
  .get()

.on('message', cb)

Listen for messages sent on the stream:

var stream

address('/price/usd/gbp')
  .stream()
  .on('ok', function(response) {
    stream = result.body
    stream.on('message.custom-namespace', function (message) {
      // Handle the message
    })
  })
  .get()

.on('status', cb)

Listen for status data sent on the stream:

var stream

address('/price/usd/gbp')
  .stream()
  .on('ok', function(response) {
    stream = result.body
    stream.on('status.custom-namespace', function (status) {
      // Handle the status data
    })
  })
  .get()

Building a stream resource

A stream resource is a resource with accept type application/x.zap.stream. Streams resources, when received, expose the on method and can be listened to for different types of messages.

To build a resource, some of the following exports might need to be imported:

// using ES6 modules
import { stream } from '@zambezi/address'

// using AMD modules
define([
  '@zambezi/address/lib/stream'
], function(ok, error, created, redirect, response) {
  // ...
})

stream()

A factory method for producing a stream object.

return function handler(req, res) {
  var resourceStream = stream()

  // ...

  res(null, ok(resourceStream))
}

resourceStream.on('firstsubscribed', cb)

Listen to when the first subscription has been made to the stream.

Typically a stream should not be performing any activity until there has been some subscription to the stream.

return function handler(req, res) {
  var resourceStream = stream()
      .on('firstsubscribed', function() {
        // start up or connect to any network (or other) resources that you will want to stream
      })

  res(null, ok(resourceStream))
}

resourceStream.on('lastunsubscribed', cb)

Listen to when the last subscription has been closed for the stream.

Typically a stream should clean up any connections or scheduled work when there are no longer any subscribers to the stream

return function handler(req, res) {
  var resourceStream = stream()
      .on('lastunsubscribed', function() {
        // clean up any connections or scheduled work
      })

  res(null, ok(resourceStream))
}

resourceStream()

A convenience method to send a message over the stream - see resourceStream.message():

return function handler(req, res) {
  var resourceStream = stream()

  // Send message over stream
  resourceStream({ data: [1, 2, 3], id: 934 })

  res(null, ok(resourceStream))
}

resourceStream.error()

Sends an error over the stream:

return function handler(req, res) {
  var resourceStream = stream()

  // Send error over stream
  resourceStream.error({ message: 'No data found for item 934' })

  res(null, ok(resourceStream))
}

resourceStream.message()

Sends a message over the stream:

return function handler(req, res) {
  var resourceStream = stream()

  // Send message over stream
  resourceStream.message({ data: [1, 2, 3], id: 934 })

  res(null, ok(resourceStream))
}

resourceStream.status()

Sends an status data over the stream:

return function handler(req, res) {
  var resourceStream = stream()

  // Send status data over stream
  resourceStream.status({ message: 'Reconnecting to server' })

  res(null, ok(resourceStream))
}

Requesting DOM view resource

address.view()

A convenience methods for setting the accept type header to 'application/x.nap.view':

address('/price/usd/gbp')
  .view()
  .on('ok', function(response) {
    // handle view function
  })
  .get()

address.app()

A convenience methods for setting the accept type header to 'application/x.am.app':

address('/price/usd/gbp')
  .app()
  .on('ok', function(response) {
    // handle view function
  })
  .get()

address.into()

A convenience method to remove the need for boilerplate whilst also checking for error status codes and validating the content type of the response. Using the into api also triggers an update event on the target node as a hook for existing views.

This method can either takes a DOM node, though a valid CSS selector can also be used in place of a document element reference. If a CSS selector is provided, then the selection will be performed in the context of the document.

If you don't specify a target for the into it will be targeted into the root node (.z-app by default).

example: DOM node

var node = document.getElementsByClassName('.price')[0]

address('/price/usd/gbp')
  .into(node)
  .get()

example: CSS selector

address('/price/usd/gbp')
  .into('.price')
  .get()

example: without .into() call

var node = document.getElementsByClassName('.price')[0]

address('/price/usd/gbp')
  .on('ok', function(response) {
    var view = response.body
    view(node)
  })
  .get()

Building DOM view resource

return function(req, res) {
  res(null, ok(view))

  function view (node) {
    // render and listen to events on the DOM node
  }
}

node.addEventListener('update', cb)

Dispatched before invoking a view function, regardless of the resource addressed into the DOM element of the view.

function view(node) {
  node.addEventListener('update', handleUpdate)

  function handleUpdate(detail) {
    console.log('Updating resource from %s to %s.', deatail.from, detail.to)
  }
}

node.addEventListener('resourcewillchange', cb)

Dispatched before invoking a view function with a new resource.

function view(node) {
  node.addEventListener('resourcewillchange', handleResourceWillChange)

  function handleResourceWillChange() {
    console.log('Resource will change: do you want to clear the DOM?.')
  }
}

Top level navigation

.navigate()

Sometimes it is neccessary to perform a top level navigation by updating the browser address bar.

If a target is specified the request will be opened in the target window.

example: perform top level navigation

address('/price/usd/gbp')
  .navigate()

example: perform navigation into target window

address('/price/usd/gbp')
  .navigate('_blank')

.target()

Provides set or get of the resource navigation target to be requested:

address('/price/usd/gbp')
  .target('_blank')
  .navigate()