dm_dwd_api Module

HTTP abstraction layer for Deutsche Wetterdienst (DWD) API. This module must be linked against libcurl (-lcurl).

To fetch weather data, create an URL of the DWD weather report directory and make an HTTP GET request. The data will be cached in a scratch file. The file may be opened as formatted or unformatted (byte stream):

character(len=:), allocatable :: url
integer                       :: rc
type(rpc_request_type)        :: request
type(rpc_response_type)       :: response

type(dwd_weather_report_type), allocatable :: reports(:)

rc = dm_rpc_init()

open (action='readwrite', form='formatted', newunit=response%unit, status='scratch')
url = dm_dwd_api_weather_report_url(id='10281', tls=.false.)
rc  = dm_rpc_get(request, response, url, callback=dm_dwd_api_callback)

rewind (response%unit)
rc = dm_dwd_weather_report_read(reports, response%unit)
close (response%unit)

call dm_rpc_shutdown()

Uses

  • module~~dm_dwd_api~~UsesGraph module~dm_dwd_api dm_dwd_api curl curl module~dm_dwd_api->curl iso_c_binding iso_c_binding module~dm_dwd_api->iso_c_binding module~dm_dwd dm_dwd module~dm_dwd_api->module~dm_dwd module~dm_error dm_error module~dm_dwd_api->module~dm_error module~dm_kind dm_kind module~dm_dwd_api->module~dm_kind module~dm_dwd->module~dm_error module~dm_dwd->module~dm_kind module~dm_file dm_file module~dm_dwd->module~dm_file module~dm_time dm_time module~dm_dwd->module~dm_time module~dm_util dm_util module~dm_dwd->module~dm_util module~dm_error->module~dm_kind module~dm_ascii dm_ascii module~dm_error->module~dm_ascii iso_fortran_env iso_fortran_env module~dm_kind->iso_fortran_env module~dm_file->module~dm_error module~dm_file->module~dm_kind module~dm_time->module~dm_error module~dm_time->module~dm_kind module~dm_time->module~dm_util unix unix module~dm_time->unix module~dm_util->module~dm_error module~dm_util->module~dm_kind

Used by

  • module~~dm_dwd_api~~UsedByGraph module~dm_dwd_api dm_dwd_api module~dmpack dmpack module~dmpack->module~dm_dwd_api

Functions

public function dm_dwd_api_callback(ptr, sz, nmemb, data) result(n) bind(c))

C-interoperable write callback function for libcurl. Writes response chunks to file unit in passed client data of type response_type.

Arguments

Type IntentOptional Attributes Name
type(c_ptr), intent(in), value :: ptr

C pointer to a chunk of the response.
integer(kind=c_size_t), intent(in), value :: sz

Always 1.
integer(kind=c_size_t), intent(in), value :: nmemb

Size of the response chunk.
type(c_ptr), intent(in), value :: data

C pointer to argument passed by caller.

Return Value integer(kind=c_size_t)

Number of bytes consumed.

public function dm_dwd_api_weather_report_url(id, tls) result(url)

Returns allocatable string of URL to DWD weather report endpoint of given station id id. Uses the URL API of libcurl to create the URL. The function returns an empty string on error. TLS is disabled by default.

Arguments

Type IntentOptional Attributes Name
character(len=DWD_MOSMIX_STATION_ID_LEN), intent(in) :: id

MOSMIX station id.
logical, intent(in), optional :: tls

Use HTTPS.

Return Value character(len=:), allocatable

DWD weather report URL.