Modules

Modules

Module is useful to send custom response:

• Custom headers
• Custom dynamic page
• Custom URL
• Custom request (POST form, custom JSON content...)
• Custom authentication and permissions
• ...

Module is a python file or a package imported in WebScripts Server.

Custom functions

Signature:

from typing import TypeVar

Json = TypeVar("Json", dict, list, str, int, None)

def example(
        environ: _Environ,
        user: User,
        server_configuration: ServerConfiguration,
        filename: str,
        arguments: List[str],       # Arguments is a list of str, if you send a "WebScripts request" (a JSON object with "arguments" as attribute)
        inputs: List[str],          # Value of inputs
        csrf_token: str = None,
    ) -> Tuple[str, Dict[str, str], str]:

	return (
		"200 OK",
		{"Content-Security-Policy": "default-src 'self'"},
		"Response text."
	)

def example(
        environ: _Environ,
        user: User,
        server_configuration: ServerConfiguration,
        filename: str,
        arguments: Json,            # Arguments is a loaded JSON, if you send a JSON content without attribute named "arguments" 
        inputs: List[str],          # Inputs will be a empty list
        csrf_token: str = None,
    ) -> Tuple[str, Dict[str, str], str]:

        return (
                "200 OK",
                {"Content-Security-Policy": "default-src 'self'"},
                "Response text."
        )

def example(
        environ: _Environ,
        user: User,
        server_configuration: ServerConfiguration,
        filename: str,
        arguments: bytes,           # Arguments is bytes, if you send a non JSON request
        inputs: List[str],          # Inputs will be a empty list
        csrf_token: str = None,
    ) -> Tuple[str, Dict[str, str], str]:

        return (
                "200 OK",
                {"Content-Security-Policy": "default-src 'self'"},
                "Response text."
        )

Arguments

1. environ (no default value): WSGI environment variables for this request
2. user (no default value): User object (attributes: ["id", "name", "groups", "csrf", "ip", "check_csrf"] , optional: your custom user configurations)
3. server_configuration (no default value): Server configurations (attributes: ["interface", "port", "debug", "security", "active_auth", "auth_script", "accept_unknow_user", "accept_unauthenticated_user", "modules", "modules_path", "js_path", "statics_path", "documentations_path", "scripts_path", "json_scripts_config", "ini_scripts_config", "log_level", "log_filename", "log_level", "log_format", "log_date_format", "log_encoding", "auth_failures_to_blacklist", "blacklist_time"])
4. filename (no default value): element after the last /
5. arguments (no default value): list of command line arguments (to launch a script) or a loaded JSON (JSON content without "arguments" attribute) or bytes (non-JSON content)
6. inputs (no default value): list of inputs (for stdin of the script) or empty list (if the content is a non WebScripts request: non-JSON content or JSON without "arguments" attribute)
7. csrf_token (optional: default value is None)

The arguments and inputs lists are built from the JSON body with the WebScripts Server body parser, you must respect the default JSON syntax.

Return

1. Response code: the HTTP status of the response, the first three digits are required (example: 200 OK)
2. Headers: dictionary of HTTP headers (pairs of names and header values)
3. Response body: the HTTP body of the response

URLs

In the PATH_INFO the character / is like . (object attribute) in python code, the last / is a call (()).

Examples

URLs to call a function named hello in a hello module:

/hello/hello/                   # python code equivalent: hello.hello(), filename argument: ''
/hello/hello/abc                # python code equivalent: hello.hello(), filename argument: 'abc'

URLs to call a function named test in a class named Test in a module named Tests in a package named Example:

/Example/Tests/Test/test/       # python code equivalent: Example.Tests.Test.test(), filename argument: ''
/Example/Tests/Test/test/abc    # python code equivalent: Example.Tests.Test.test(), filename argument: 'abc'

Headers

Some default security headers are sended for all response, you can change the value but you can't delete these headers.

Custom error pages

To build your custom error pages (HTTP errors: 500, 403, 404...) create a module (the name does not matter) with functions named: page_<error>, for example on error 500 the function used will be page_500.

Look at /path/of/WebScripts/scripts/py/hello.py this is a demonstration.

Try

To try a module you can comment/uncomment lines (16-19) in server.ini, to get the following configuration:

# modules                                                                                        # Add custom modules (names) to the server
# modules_path                                                                                   # Add directory to import custom modules
modules=hello
modules_path=./scripts/py

Start the WebScripts Server and open these URL in your web broswer:

1. Hello function.
2. Custom error 500 page (only if the debug configuration is false).
3. Custom error 404 page (only if the debug configuration is false).
4. Custom error 403 page

Get the code in /path/of/WebScripts/project/scripts/py/hello.py.