API

api.py

# -*- coding: utf-8 -*-
"""
    Router
    ~~~~~~~~~~~~~~

    Routing API requests and errors handling
"""

from flask import Flask, jsonify, request
from api_versions import *
from config import *

app = Flask(__name__)

@app.route('/call/<int:api_version>/<method>', methods=['GET', 'POST'])
def router(api_version, method):
    """ Basic routing function for extracting API request parameters and calling method of corresponding API version 

        Every API method call returns JSON data
            * response - error or success
            * reason - the caller of API method
            * response_type - type of returned data
            * data - returned data
    """

    API = None

    try:
        API = __import__("api_versions.api%i" % api_version, globals(), locals(), ['API'], -1).API()
    except:
    	return jsonify(response='error', reason='api_import_error', response_type="str", data="wrong api version %i" % api_version)

    if not api_version == API.get_version(None):
    	return jsonify(response='error', reason='api_versions_mismatch', response_type="str", data="API version mismatch between %i and %i" % (api_version, API.get_version(None)))

    if not hasattr(API, method) or not callable(getattr(API, method)):
    	return jsonify(response='error', reason='api_invalid_method', response_type="str", data="wrong method %s" % method)

    try:
        response = getattr(API,method)(request.form if request.method == 'POST' else request.args)
        response_type = str(type(response).__name__)
        return jsonify(response="success", reason="api_call_%i_%s" % (api_version, method), response_type=response_type, data=response)
    except Exception as e:
        return jsonify(response="error", reason="api_call_%i_%s" % (api_version, method), response_type="str", data=str(e))

@app.errorhandler(404)
def page_not_found(e):
    return jsonify(response="error", reason="api_call_unknown", response_type="str", data="API request is invalid")

if __name__ == "__main__":
    app.run(debug=CONF_DEBUG)

api1.py

# -*- coding: utf-8 *-*
"""
    API, version 0
    ~~~~~~~~~~~~~~

    Basic API object, implements core functions that should not be replaced in any child classes
"""
from config import *
import psycopg2

class API(object):
    """API, version 0 (core)"""
    version = 0
    PgDB = None

    def __init__(self):
        super(API, self).__init__()

    def get_version (self, request):
        """ Get current API version 
        
            :Returns:
                api version number, integer
        """
        return self.version

    def get_server_time (self, request):
        """ Get current time on API server 

            :Returns:
                date and time in format 2012-08-26 16:20:07, string
        """
        import datetime
        return datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")

    def get_random_uuid (self, request):
        """ Generate random UUID 

            :Returns:
                random UUID, string
        """
        from uuid import uuid4
        return str(uuid4())

    def __initDB(self):
        """ Initialize PostgreSQL connection """
        self.PgDB = psycopg2.connect(host=CONF_DB_HOST, database=CONF_DB_NAME, user=CONF_DB_USER, password=CONF_DB_PASSWORD)

    def __del__(self):
        if not self.PgDB == None and self.PgDB.closed == 0:
            self.PgDB.close()