http_client

This module defines the client_type derived type, which handles the process of making HTTP requests. The actual HTTP requests are executed using the Fortran-curl package as the underlying mechanism.

Uses

- iso_fortran_env
- iso_c_binding
- stdlib_optval
- http_pair
- http_request
- http_response
- curl
- http_version

Functions

new_request new_client client_get_response prepare_form_encoded_str set_method set_timeout set_body set_postfields set_auth client_response_callback client_header_callback

Interfaces

private interface client_type

Interface for new_client function.

private function new_client(request) result(client)

This is the constructor for the client_type derived type.

Arguments

Type	Intent	Optional	Attributes		Name
type(request_type),	intent(in)			::	request	Specifies the HTTP `request` to send.

Return Value type(client_type)

A client_type object containing the request field set to the input request object.

public interface request

Interface for new_request function.

private function new_request(url, method, header, data, form, file, timeout, auth) result(response)

This function create a request_type object and populates it. The function returns the response_type object containing the server's response.

Note :

If the header argument is not provided, default user-agent header is set to http-client/0.1.

Arguments

Type	Intent	Optional		Name
character(len=*),	intent(in)		::	url	Specifies the `URL` of the server.
integer,	intent(in),	optional	::	method	Specifies the HTTP `method` to use for the request. The default value is 1, which corresponds to the `HTTP_GET` method.
type(pair_type),	intent(in),	optional	::	header(:)	Specifies the request `headers` that need to be sent to the server.
character(len=*),	intent(in),	optional	::	data	Specifies the `data` that needs to be sent to the server.
type(pair_type),	intent(in),	optional	::	form(:)	Specifies the `form data` that needs to be sent to the server.
type(pair_type),	intent(in),	optional	::	file	Specifies the `file` that needs to be sent to the server.
integer,	intent(in),	optional	::	timeout	`Timeout` value for the request in seconds.
type(pair_type),	intent(in),	optional	::	auth	stores the `username` and `password` for `authentication` purposes.

Return Value type(response_type)

Stores the server's response.

Derived Types

type, private :: client_type

A derived type, responsible for making actual HTTP request using fortran-curl at backend.

Components

Type	Visibility	Attributes		Name		Initial
type(request_type),	public		::	request

Constructor

Interface for new_client function.

private function new_client (request)	This is the constructor for the `client_type` derived type. Read more…

Type-Bound Procedures

procedure , public , :: client_get_response Function

Functions

private function new_request(url, method, header, data, form, file, timeout, auth) result(response)

This function create a request_type object and populates it. The function returns the response_type object containing the server's response.

Arguments

Type	Intent	Optional		Name
character(len=*),	intent(in)		::	url	Specifies the `URL` of the server.
integer,	intent(in),	optional	::	method	Specifies the HTTP `method` to use for the request. The default value is 1, which corresponds to the `HTTP_GET` method.
type(pair_type),	intent(in),	optional	::	header(:)	Specifies the request `headers` that need to be sent to the server.
character(len=*),	intent(in),	optional	::	data	Specifies the `data` that needs to be sent to the server.
type(pair_type),	intent(in),	optional	::	form(:)	Specifies the `form data` that needs to be sent to the server.
type(pair_type),	intent(in),	optional	::	file	Specifies the `file` that needs to be sent to the server.
integer,	intent(in),	optional	::	timeout	`Timeout` value for the request in seconds.
type(pair_type),	intent(in),	optional	::	auth	stores the `username` and `password` for `authentication` purposes.

Return Value type(response_type)

Stores the server's response.

private function new_client(request) result(client)

This is the constructor for the client_type derived type.

Arguments

Type	Intent	Optional	Attributes		Name
type(request_type),	intent(in)			::	request	Specifies the HTTP `request` to send.

Return Value type(client_type)

A client_type object containing the request field set to the input request object.

private function client_get_response(this) result(response)

This function sends an HTTP request to a server using the fortran-curl package and stores the server's response in a response_type object.

Arguments

Type	Intent	Optional	Attributes		Name
class(client_type),	intent(inout)			::	this	Contains the HTTP `request` to send.

Return Value type(response_type), target

Contains the server's response.

private function prepare_form_encoded_str(curl_ptr, request) result(form_encoded_str)

This subroutine converts the request%form into a URL-encoded name-value string and returns it.

Arguments

Type	Intent	Optional	Attributes		Name
type(c_ptr),	intent(out)			::	curl_ptr	Pointer to the `curl` handler.
type(request_type),	intent(inout)			::	request	The HTTP `request` to send, which includes the `form` data to be encoded.

Return Value character(len=:), allocatable

Stores the URL Encoded string.

private function set_method(curl_ptr, method, response) result(status)

This function sets the HTTP method for the request.

Arguments

Type	Intent		Name
type(c_ptr),	intent(out)	::	curl_ptr	Pointer to the `curl` handler.
integer,	intent(in)	::	method	Specifies the HTTP `method` to use.
type(response_type),	intent(out)	::	response	The HTTP `response` from the server.

Return Value integer

The status of setting HTTP method.

private function set_timeout(curl_ptr, timeout) result(status)

This function sets the timeout value (in seconds).

Arguments

Type	Intent	Optional	Attributes		Name
type(c_ptr),	intent(out)			::	curl_ptr	Pointer to the `curl` handle.
integer(kind=int64),	intent(in)			::	timeout	`Timeout` seconds for request.

Return Value integer

Status code indicating whether the operation was successful.

private function set_body(curl_ptr, request) result(status)

The function sets the request body.

Arguments

Type	Intent	Optional	Attributes		Name
type(c_ptr),	intent(out)			::	curl_ptr	Pointer to the `curl` handle.
type(request_type),	intent(inout)			::	request	The HTTP request

Return Value integer

An integer value representing the status of the function call.

private function set_postfields(curl_ptr, data) result(status)

Set the data to be sent in the HTTP POST request body.

Arguments

Type	Intent	Optional	Attributes		Name
type(c_ptr),	intent(inout)			::	curl_ptr	Pointer to the CURL handle.
character(len=*),	intent(in),		target	::	data	The data to be sent in the request body.

Return Value integer

An integer indicating whether the operation was successful (0) or not (non-zero).

private function set_auth(curl_ptr, request) result(status)

Set the user name and password for Authentication.

Arguments

Type	Intent	Optional	Attributes		Name
type(c_ptr),	intent(out)			::	curl_ptr	Pointer to the CURL handle.
type(request_type),	intent(inout)			::	request	The HTTP request

Return Value integer

An integer indicating whether the operation was successful (0) or not (non-zero).

private function client_response_callback(ptr, size, nmemb, client_data) bind(c)

This function is a callback function used by the fortran-curl package to handle HTTP responses. It is called for each chunk of data received from the server and appends the data to a response_type object.

Arguments

Type	Intent	Attributes		Name
type(c_ptr),	intent(in),	value	::	ptr	Pointer to the CURL handle.
integer(kind=c_size_t),	intent(in),	value	::	size	Specifies the size of each data element.
integer(kind=c_size_t),	intent(in),	value	::	nmemb	Specifies the number of data elements received.
type(c_ptr),	intent(in),	value	::	client_data	Points to a response_type object.

Return Value integer(kind=c_size_t)

The number of bytes received.

private function client_header_callback(ptr, size, nmemb, client_data) bind(c)

This function is a callback function used by the fortran-curl package to handle HTTP headers.

Arguments

Type	Intent	Attributes		Name
type(c_ptr),	intent(in),	value	::	ptr	Pointer to the CURL handle. that points to the received header buffer.
integer(kind=c_size_t),	intent(in),	value	::	size	Specifies the size of each header element.
integer(kind=c_size_t),	intent(in),	value	::	nmemb	Specifies the number of header elements received.
type(c_ptr),	intent(in),	value	::	client_data	Pointer to a `response_type` object.

Return Value integer(kind=c_size_t)

The number of bytes received.

Subroutines

private subroutine prepare_request_header_ptr(header_list_ptr, req_headers)

This subroutine prepares headers in required format(Linked list) for an HTTP request.

Arguments

Type	Intent	Optional	Attributes		Name
type(c_ptr),	intent(out)			::	header_list_ptr	A `Pointer` that is allocated and points to a linked list of headers.
type(pair_type),	intent(in),		allocatable	::	req_headers(:)	The `headers` to be included in the request.

http_client Module

Contents

Uses

Contents

Interfaces

private interface client_type

private function new_client(request) result(client)

Arguments

Return Value type(client_type)

public interface request

private function new_request(url, method, header, data, form, file, timeout, auth) result(response)

Note :

Arguments

Return Value type(response_type)

Derived Types

type, private :: client_type

Components

Constructor

Type-Bound Procedures

Functions

private function new_request(url, method, header, data, form, file, timeout, auth) result(response)

Arguments

Return Value type(response_type)

private function new_client(request) result(client)

Arguments

Return Value type(client_type)

private function client_get_response(this) result(response)

Arguments

Return Value type(response_type), target

private function prepare_form_encoded_str(curl_ptr, request) result(form_encoded_str)

Arguments

Return Value character(len=:), allocatable

private function set_method(curl_ptr, method, response) result(status)

Arguments

Return Value integer

private function set_timeout(curl_ptr, timeout) result(status)

Arguments

Return Value integer

private function set_body(curl_ptr, request) result(status)

Arguments

Return Value integer

private function set_postfields(curl_ptr, data) result(status)

Arguments

Return Value integer

private function set_auth(curl_ptr, request) result(status)

Arguments

Return Value integer

private function client_response_callback(ptr, size, nmemb, client_data) bind(c)

Arguments

Return Value integer(kind=c_size_t)

private function client_header_callback(ptr, size, nmemb, client_data) bind(c)

Arguments

Return Value integer(kind=c_size_t)

Subroutines

private subroutine prepare_request_header_ptr(header_list_ptr, req_headers)

Arguments