http_server.pl -- HTTP server library

This library combines the core server functionality provided by several libraries that are needed by almost any web server. It exports the commonly used predicates from library(http/thread_httpd), library(http/http_dispatch), library(http/http_wrapper), library(http/http_parameters), library(http/html_write), library(http/http_json), and library(http/http_dyn_workers).

http_server(+Options) is det: Create an HTTP server using http_dispatch/1 for handling requests. See http_server/2 and http_dispatch/1 for details.

Re-exported predicates

The following predicates are exported from this file while their implementation is defined in imported modules or non-module files loaded by this module.

reply_html_page(:Head, :Body) is det

reply_html_page(+Style, :Head, :Body) is det

Provide the complete reply as required by http_wrapper.pl for a page constructed from Head and Body. The HTTP Content-type is provided by html_current_option/1.

See also: - reply_html_partial/1 to avoid adding a DOCTYPE, and required outer HTML elements such as <html>.

html_meta(+Heads) is det

This directive can be used to declare that an HTML rendering rule takes HTML content as argument. It has two effects. It emits the appropriate meta_predicate/1 and instructs the built-in editor (PceEmacs) to provide proper colouring for the arguments. The arguments in Head are the same as for meta_predicate or can be constant html. For example:

:- html_meta
      page(html,html,?,?).

is_json_content_type(+ContentType) is semidet

True if ContentType is a header value (either parsed or as atom/string) that denotes a JSON value.

http_read_json_dict(+Request, -Dict) is det

http_read_json_dict(+Request, -Dict, +Options) is det

Similar to http_read_json/2,3, but by default uses the version 7 extended datatypes.

http_read_json_dict(+Request, -Dict) is det

http_read_json_dict(+Request, -Dict, +Options) is det

Similar to http_read_json/2,3, but by default uses the version 7 extended datatypes.

reply_json_dict(+JSONTerm) is det

reply_json_dict(+JSONTerm, +Options) is det

As reply_json/1 and reply_json/2, but assumes the new dict based data representation. Note that this is the default if the outer object is a dict. This predicate is needed to serialize a list of objects correctly and provides consistency with http_read_json_dict/2 and friends.

reply_json_dict(+JSONTerm) is det

reply_json_dict(+JSONTerm, +Options) is det

http_parameters(+Request, ?Parms) is det

http_parameters(+Request, ?Parms, :Options) is det

Get HTTP GET or POST form-data, applying type validation, default values, etc. Provided options are:

attribute_declarations(:Goal): Causes the declarations for an attributed named A to be fetched using call(Goal, A, Declarations).
form_data(-Data): Return the data read from the GET por POST request as a list Name = Value. All data, including name/value pairs used for Parms, is unified with Data.

The attribute_declarations hook allows sharing the declaration of attribute-properties between many http_parameters/3 calls. In this form, the requested attribute takes only one argument and the options are acquired by calling the hook. For example:

    ...,
    http_parameters(Request,
                    [ sex(Sex)
                    ],
                    [ attribute_declarations(http_param)
                    ]),
    ...

http_param(sex, [ oneof(male, female),
                  description('Sex of the person')
                ]).

bug: - If both request parameters (?name=value&...) and a POST are present the parameters are extracted from the request parameters. Still, as it is valid to have request parameters in a POST request this predicate should not process POST requests. We will keep the current behaviour as the it is not common for a request to have both request parameters and a POST data of the type application/x-www-form-urlencoded.
In the unlikely event this poses a problem the request may be specified as [method(get)|Request].

http_parameters(+Request, ?Parms) is det

http_parameters(+Request, ?Parms, :Options) is det

Get HTTP GET or POST form-data, applying type validation, default values, etc. Provided options are:

attribute_declarations(:Goal): Causes the declarations for an attributed named A to be fetched using call(Goal, A, Declarations).
form_data(-Data): Return the data read from the GET por POST request as a list Name = Value. All data, including name/value pairs used for Parms, is unified with Data.

    ...,
    http_parameters(Request,
                    [ sex(Sex)
                    ],
                    [ attribute_declarations(http_param)
                    ]),
    ...

http_param(sex, [ oneof(male, female),
                  description('Sex of the person')
                ]).

bug: - If both request parameters (?name=value&...) and a POST are present the parameters are extracted from the request parameters. Still, as it is valid to have request parameters in a POST request this predicate should not process POST requests. We will keep the current behaviour as the it is not common for a request to have both request parameters and a POST data of the type application/x-www-form-urlencoded.
In the unlikely event this poses a problem the request may be specified as [method(get)|Request].

Undocumented predicates

The following predicates are exported, but not or incorrectly documented.