Prepared statements do not work well with the partial indexes that
Nominatim uses because all Python constants are replaced with
parameters. A query like:
placex.select().where(placex.c.rank_address.between(4, 25)
gets translated into a prepared query with two parameters:
SELECT * FROM placex WHERE rank_address BETWEEN %s and %s
And this does not work with a partial index of:
CREATE INDEX on placex(geometry) WHERE rank_address between 4 and 25
The only allowable difference is precision of coordinates. Python uses
a precision of 7 digits where possible, which corresponds to the
precision of OSM data.
Also fixes some smaller bugs found by the BDD tests.
The implementation follows for most part the PHP code but introduces an
additional layer parameter with which the kind of places to be returned
can be restricted. This replaces the hard-coded exclusion lists.
Use adapted types for the different result types. This makes it
easier to have adapted output formatting and means there are only
result fields that are filled.
It is not possible to produce type annotations that work with both
versions 1.4 and 2.0. So keep to the principle of only supporting
newest versions when it comes to mypy. This means that some types
may have to be string quoted to not cause issues when running with
SQLAlchemy 1.4.
Also defines an extended connection object that includes access to
the table definitions. Makes it easier to access the tables from
code that has been split off into separate modules.
Most of the server implementation of V1 API now resides in
api.v1.server_glue. The webframeworks only supply some glue code
which is independent to changes in the API code.
Code is now organized by api version. So formatting has moved to
the api.v1 module. Instead of holding a separate ResultFormatter
object per result format, simply move the functions to the
formater collector and hand in the requested format as a parameter.
Thus reorganized, the api.v1 module can export three simple functions
for result formatting which in turn makes the code that uses
the formatters much simpler.
Use a directory for the submodule where the __init__ file contains
the public API. This makes it easier to separate public interface
from the internal implementation.