bridge-odata

OData JS SDK

Installation

 npm install bridge-odata

Usage

  var bridge = require('bridge-odata')
  // Vendor defaults to `test`
  var bridge = new BridgeAPI(ACCESS_TOKEN, [vendor])
 
  // Fetches a list of Properties, provided by the vendor
  bridge
    .Properties()
    .exec()

Demo

A simple demo of an autocomplete can be seen here, The SDK part of the code looks like:

  var BridgeAPI = require('bridge-odata')
 
  const Bridge = new BridgeAPI('6baca547742c6f96a6ff71b138424f21')
 
  /**
   * @param {string} address - The beginning of an address e.g. `1120 Mi`
   * @returns {Promise} - resolves if the API request is successful.
   */
  function autocomplete (address) {
    let prim = Bridge.Properties()
      .$select('','')
      .$filter({
        left: {
          left: 'UnparsedAddress',
          comparator: 'neq',
          right: 'null'
        },
        comparator: 'and',
        right: {
          left: 'UnparsedAddress',
          comparator: 'startswith',
          right: `'${address}'` // Note: string quotes are not auto inferred.
        }
      })
      .exec()
 
    return prim
  }

API

new BridgeAPI(token, [vendor])

Returns a new instance of BridgeAPI. Requires an API token and optionally set the vendor (the MLS data source), defaults to test.

bridge.Property([ListingKey])

Returns a single property if a ListingKey is specified. Otherwise will return a list of properties that fulfill the criteria. This function has an alias: bridge.Properties

bridge.Member([MemberKey])

bridge.Office([OfficeKey])

bridge.OpenHouse([OpenHouseKey])

Returns a single entity if a key is specified. If a key is not specified all related entities are returned.

bridge.Media()

Returns all media.

bridge.count()

The number of results from the most recent query, set to 0 before and during query execution.

bridge.next()

Paginates to the next page of results.

bridge.prev()

Paginates to the previous page of results.

bridge.exec([cb])

Executes the API query, will return a Promise if no callback is specified, otherwise, calls a the callback cb(err, resp)

OData Specific Params

bridge.$skip(n)

Skips the first n items.

bridge.$select(attributes)

Select items that have the following specific attributes, accepts an array of attributes or a comma seperated string. e.g.

  bridge.$select('StandardStatus,UnparsedAddress')
  // Is the same as:
  bridge.$select(['StandardStatus','UnparsedAddress'])
  // Is the same as:
  bridge.$select('StandardStatus','UnparsedAddress')

bridge.$top(n)

Only returns the top n items.

bridge.$orderby(field, order)

Sets the $orderby parameter based on the field and order params, order must be either ASC or DESC case insensitive.

bridge.$expand(attribute)

Expands the provided attribute, also accepts an array or comma seperated string of attributes.

bridge.$filter(query)

Filtered queries can get complex however they are fairly powerful. One can write a JS object literal as the query that will map to a string query. e.g.

{right: 'a', op: 'eq', left: 'b'} => 'a eq b'
{right: 'a', op: 'intersect', left: 'b'} => 'geo.intersect(a,b)'

Hardcoded operations

The full list of operations can be found in the `src/lib/maps.js' file, but are not limited to:

Name	Operation	Description
eq	'a eq b'	checks if a == b
neq	'a neq b'	checks if a != b
lt	'a lt b'	checks if a < b
gt	'a gt b'	checks if a > b
ge	'a ge b'	checks if a >= b
le	'a le b'	checks if a <= b
and	'a and b'	checks if both a and b are true
or	'a or b'	checks if either a or b are true
startswith	startswith(a,b)	checks if the field a starts with string b
endswith	endswith(a,b)	checks if the field a ends with string b
contains	contains(a,b)	checks if field a contains string b
intersect	geo.intersect(a,b)	checks if geo postiion b intersects geo field a

Modifiers

Modifiers modify a specific response field. The full list of modifiers can be found in the `src/lib/maps.js' file, but are not limited to:

Name	Operation	Description
time	time(a)	Grabs the time of the response date field
year	year(a)	Grabs the year of the response date field
month	month(a)	Grabs the month of the response date field
day	day(a)	Grabs the day of the response date field
hour	hour(a)	Grabs the hour of the response date field
min	min(a)	Grabs the min of the response date field
sec	sec(a)	Grabs the sec of the response date field
upper	upper(a)	Converts the response field to uppercase
lower	lower(a)	Converts the response field to lowercase

When using a modifier, one must move the tradititional syntax to that with a modifier, e.g.

// Traditional syntax
{
  left: "'joe'"
}

to

// Modifier syntax
{
  left: {
    modifier: "upper",
    value: "'joe'"
  }
}

Modifiers only work when the object fields are modifier and value exclusively.

Lambdas

The any and all operations are referred to and act as lambdas in the OData syntax. Lambda based filters require 4 parts, left, variable, operation, and inner. However, inner breaks down into its own simple clause. e.g.

// Select all the properties where all the agents are syndicate to Zillows
{
  left: 'SyndicateTo',
  operation: 'all',
  variable: 'a',
  inner: {
    expr: 'a le 10'
  }
}
// OR, the following is an equivalent statement
{
  left: 'SyndicateTo',
  operation: 'all',
  variable: 'a',
  inner: {
    left: 'a'
    operation: 'le',
    right: '10'
  }
}

Custom operations (unsafe)

In the event that one is aware of an operation that currently doesn't exist within the set of hardcoded operations they can create their own. With this syntax the object literal attributes must have the same name as the operation function parameters.

Example of a valid custom query

// Valid!
{
  right: 'Joe',
  left: '"The greatest person ever"',
  operation: (right, left) => `${right} eq ${left}`
} => 'Joe eq "The greatest person ever"'
 

Example of an invalid custom query

// Invalid! Will throw error
{
  right: 'Joe',
  left: '"The greatest person ever"',
  operation: (a,b) => `${a} eq ${b}`
} => ERROR