tvf.py

"""

 SAFRS example calling a postgres TVF.
 
 Suppose the database has this function defined:
 
---
CREATE FUNCTION public.f_2(v1 integer, OUT v2 integer, OUT v3 integer) RETURNS record
    LANGUAGE plpgsql
    AS $$
BEGIN
    v2 := v1;
    v3 := v1 + 1;
END
$$;
---

In psql this returns:

test=# SELECT * FROM f_2(1) AS t1;
 v2 | v3
----+----
  1 |  2
(1 row)


We expose this function through /MyService/f2_rpc 
Then call invoke the function with

$ curl -X POST "http://localhost:5000/MyService/f2_rpc" -H  "accept: application/vnd.api+json" -H  "Content-Type: application/json" -d "{  \"arg\": 0}"
{
  "result": [
    0,
    1
  ]
}


"""

import sys
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from safrs import SAFRSAPI, jsonapi_rpc
from safrs import JABase, DB

db = SQLAlchemy()


class MyService(JABase):
    """
        description: Example class without SQLa Model
    """

    @staticmethod
    @jsonapi_rpc(http_methods=["POST"], valid_jsonapi=False)
    def f2_rpc(arg):
        """
        description: rpc example
        args:
            arg : 0
        """
        sql_query = db.text("SELECT * FROM f_2(:arg)")
        query_result = db.engine.execute(sql_query, arg=arg)
        result = query_result.fetchall()

        return {"result" : list(result[0])}


HOST = sys.argv[1] if len(sys.argv) > 1 else "0.0.0.0"
PORT = 5000
app = Flask("SAFRS Demo Application")
app.config.update(SQLALCHEMY_DATABASE_URI="postgresql://test:test@localhost/test", DEBUG=True)


if __name__ == "__main__":
    db.init_app(app)
    db.app = app
    API_PREFIX = ""

    with app.app_context():
        api = SAFRSAPI(app, host="{}".format(HOST), port=PORT, prefix=API_PREFIX)
        # Expose the database objects as REST API endpoints
        api.expose_object(MyService)
        # Register the API at /api/docs
        print("Starting API: http://{}:{}{}".format(HOST, PORT, API_PREFIX))
        app.run(host=HOST, port=PORT)