A PHP class that makes it trivial to pop up a RESTful, JSON-emitting API from a single JSON file. Intended for retrieving individual records from a JSON file that is comprised of many records. It indexes records by a specified field, which functions as the unique ID.

It caches API data as a single serialized object, in APC, in Memcached, or as individual JSON files on the filesystem.

If you'd prefer this in Python, @jbradforddillon ported it and made some improvements.

1. Install index.php and class.InstantAPI.php in a public directory on a web server.
2. If you want to cache data on the filesystem, create a directory called cache, and give the web server permission to write to it and read from it.
3. Edit the configuration options in settings.inc.php:
   • Specify the path to the JSON file as JSON_FILE. (You can just drop it in the same directory as index.php etc.)
   • Specify the name of the field in each JSON record that will function as the unique ID for each request as INDEXED_FIELD.
   • Specify the type of caching that you want to use.
   • If caching in Memcached, provide the server name (MEMCACHED_SERVER) and port (MEMCACHED_PORT).

Requests must be in the format of http://example.com/?id=[unique_id]. Of course, the directory need not be named instantapi, and mod_rewrite can be used to eliminate ?id= from the public URL, so the URL could read http://example.com/person/jsmith.json, or http://example.com/zipcode/90210.json.

The first request will prime the cache and then deliver the requested result; subsequent requests will be served from the cache. To force a refresh of the filesystem cache, such as after updating the master JSON file, simply delete all of the files in cache/.

To create an API for this JSON file, committees.json, with CommitteeCode as the unique ID:

{
  "0": {
    "AccountId": "a1f8792b-3e82-e111-9bed-984be103f032",
    "CommitteeCode": "PP-12-00458",
    "CommitteeName": "10th District Republican Congressional Committee"
  },
  "1": {
    "AccountId": "92b38bad-2583-e111-9bed-984be103f032",
    "CommitteeCode": "PP-12-00366",
    "CommitteeName": "11th Congressional District Democratic Committee"
  },
  "2": {
    "AccountId": "69376bae-3e82-e111-9bed-984be103f032",
    "CommitteeCode": "PP-12-00457",
    "CommitteeName": "11th Congressional District of VA Republican Committee"
  },
  "3": {
    "AccountId": "341646c1-4082-e111-9bed-984be103f032",
    "CommitteeCode": "PP-12-00450",
    "CommitteeName": "1st District Republican Committee"
  },
  "4": {
    "AccountId": "2b5f88f6-aa7d-e111-9bed-984be103f032",
    "CommitteeCode": "PAC-12-00377",
    "CommitteeName": "2007 Conservative Victory Committee"
  }
}

Copy committees.json into the Instant API directory, set JSON_FILE to committees.json, and set INDEXED_FIELD to CommitteeCode. If CACHE_TYPE is kept at the default value of json, then loading http://example.com/?id=PP-12-00458 will create five JSON files in cache, and then pass the contents of /cache/PP-12-00458.json directly to the browser. (The cache directory could be to say, records, and the URL http://example.com/records/PP-12-00458.json could be queried directly, loading that static file and eliminating the need to invoke Instant API at all.)

• PHP v5.2 or later.