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yelp

Introduction

This egg provides an interface to the Yelp API. Yelp is a social database of customer reviews of restaurants and businesses. It also provides generalized lookup by phone number, geocode, or address across the United States, Canada, and Great Britain. All six Yelp APIs are supported along with a simple query mechanism for traversing the JSON query result. A valid Yelp YWSID is required to use this API. There is no charge for a YWSID, though each YWSID has a daily query limit (1000) and use is subject to Yelp's API Terms of Use.

Examples

 
#;1> (use yelp)
#;2> (set-ywsid! "qvGjCuKXg8adMmACm7haqw")     ;; example only
#;3> (define y (by-phone "4154376800"))
#;4> (display-info y)
Categories: Pizza
Neighborhood: Mission
Pizzeria Delfina
3611 18th Street
San Francisco, CA 94110
(415)437-6800
37.761398 -122.424003
#;5> (decode y)
message:
  text: OK
  code: 0
  version: 1.1.1
businesses: (1)
  country_code: US
  id: bai6umLcCNy9cXql0Js2RQ
  is_closed: #f
  city: San Francisco
  mobile_url: http://mobile.yelp.com/biz/bai6umLcCNy9cXql0Js2RQ
  review_count: 836
  zip: 94110
  state: CA
  ...
#;6> (find y "businesses.phone")
"4154376800"
#;7> (find y "businesses.categories.name")
"Pizza"
#;8> (find y "businesses.neighborhoods.name")
"Mission"

Authors

Derrell Piper

License

<blockquote> Copyright (c) 2009 Derrell Piper.

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

A full copy of the GPL license can be found at <http://www.gnu.org/licenses/>. </blockquote>

Requirements

Requires the json egg.

In addition, the chicken-install tests require the test egg. -test also requires a valid YWSID exist in ../ywsid above the egg's temporary install directory. When fetched with chicken-install -r, simply creating a file named ywsid in the parent directory (i.e., the one in which you did the chicken-install -r) with the following content:

(set-ywsid! "<your-personal-ywsid-goes-here>")

...and then doing a chicken-install -test in the yelp subdirectory, should work.

None of this matters if you don't care about regression tests or if you do not specify -test to chicken-install.

API

Authorization and Introspection

[procedure] (set-ywsid! YWSID)

Sets the Yelp web service ID to the value of YWSID. This must be done before calling any other function in this egg.

[procedure] (valid? OBJECT)

Is the OBJECT a valid Yelp response? There's no need to check valid? if you check for 'yelp-success.

All Yelp responses include this structure:

message:
  text: OK
  code: 0
  version: 1.1.1

valid? checks for both "OK" and 0.

Error Handling

The Yelp API consists of the following functions:

Each of these functions returns two values. The first value is a RESPONSE object if successful or a string representing an error code (either from Yelp or internally generated). The second value is a symbolic return status. These values are defined in this egg:

Other values represent the translation of "message.code" in the Yelp response. 'yelp-succes implies valid?.

Yelp Phone API

See Yelp Phone API.

[procedure] (by-phone NUMBER)

Look up a business by its phone number, NUMBER.

Yelp Neighborhood API

See Yelp Neighborhood API.

[procedure] (hood-for-address LOCATION #:CC)

Returns the neighborhood name associated with a street address, LOCATION.

[procedure] (hood-for-geocode LAT LON)

Returns the neighborhood name associated with a geocode location, LAT and LON.

Yelp Review Search API

See Yelp Review Search API

[procedure] (near-address TERM LOCATION #:NUMBER #:CC #:CATEGORY)

Returns a list of NUMBER reviews for businesses containing TERM and located near the address LOCATION. The CATEGORY keyword may be used to limit the search to a particular Yelp category name, e.g., "vietnamese".

[procedure] (near-geocode TERM LAT LON #:NUMBER #:RADIUS #:CATEGORY)

Returns a list of NUMBER reviews for businesses containing TERM and located in a circle around the geocode location LAT and LON for a radius of RADIUS. The Yelp API fails to specify the units. The CATEGORY keyword may be used to limit the search to a particular Yelp category name, e.g., "pizza".

[procedure] (near-geobox TERM TL-LAT TL-LON BR-LAT BR-LON #:NUMBER #:CATEGORY)

Returns a list of NUMBER reviews for businesses containing TERM and located in a box with the upper left geocode of TL-LAT and TL-LON and a bottom-right geocode of BR-LAT and BR-LON. The CATEGORY keyword may be used to limit the search to a particular Yelp category name, e.g., "lounges".

Display and Query

[procedure] (display-info RESPONSE [PORT])

Display basic information for a Yelp RESPONSE on PORT. For example:

#;1> (display-info (by-phone "415.673.3163"))
Categories: Vietnamese
Neighborhood: Civic Center/Tenderloin
Pho Tan Hoa
431 Jones St
San Francisco, CA 94102
(415)673-3163
37.785377 -122.412916
[procedure] (decode RESPONSE [PORT])

Walks the JSON tree and decodes the response to PORT. Primarily useful during development to determine the path to the information you're interested in.

[procedure] (find RESPONSE PATH)

Walks the JSON tree and searches for the JSON key specified by PATH. find uses simple dotted notation to describe the path, for example: businesses.phone or message.code.

Implementation Notes

The Yelp routines alway return an outermost JSON structure which the JSON egg maps to a vector. find may return a list or a vector (or a simple value), depending on what's being queried. Either may be passed to decode or find. For example:

#;1> (define y (by-phone "(415)864-2288"))
#;2> (define c (find y "businesses.categories"))
#;3> (find c "name")
"Sushi Bars"
#;4> (find (list-ref c 0) "name")
"Sushi Bars"
#;5> (for-each (lambda (c) (let ((n (find c "name"))) (print n))) c)
Sushi Bars
Japanese

#;6> (define m (find y "message"))
#;7> (decode m)
text: OK
code: 0
version: 1.1.1
#;8> (find m "text")
"OK"

The Yelp API defines the following elements as JSON arrays:

Note that find stops on first match, so regular iteration must be used to access second and subsequent elements, as in the first example above (i.e., categories by "name").

Limitations

The Yelp servers sometime return spurious HTML 301 redirects (on a good day) for no apparent reason. There's also quite a lot of information returned by default for the "near-" queries, so it makes sense to limit your queries using #:number or #:category when you can.

The egg currently only understands the North American Numbering Plan syntax (US and Canada).

Version History