[Python][FastAPI] Added support for library mode

docs/generators/python-fastapi.md

@@ -24,6 +24,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |enumUnknownDefaultCase|If the server adds new enum cases, that are unknown by an old spec/client, the client will fail to parse the network response.With this option enabled, each enum will have a new case, 'unknown_default_open_api', so that when the server sends an enum case that is not known by the client/spec, they can safely fallback to this case.|<dl><dt>**false**</dt><dd>No changes to the enum's are made, this is the default option.</dd><dt>**true**</dt><dd>With this option enabled, each enum will have a new case, 'unknown_default_open_api', so that when the enum case sent by the server is not known by the client/spec, can safely be decoded to this case.</dd></dl>|false|
 |fastapiImplementationPackage|python package name for the implementation code (convention: snake_case).| |impl|
+|isLibrary|whether to generate minimal python code to be published as a separate library or not| |false|
 |legacyDiscriminatorBehavior|Set to false for generators with better support for discriminators. (Python, Java, Go, PowerShell, C# have this enabled by default).|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |packageName|python package name (convention: snake_case).| |openapi_server|
 |packageVersion|python package version.| |1.0.0|

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonFastAPIServerCodegen.java

@@ -63,7 +63,9 @@ public void serialize(Boolean value, JsonGenerator gen, SerializerProvider seria
 
     final Logger LOGGER = LoggerFactory.getLogger(PythonFastAPIServerCodegen.class);
 
+    private String implPackage;
     protected String sourceFolder;
+    protected boolean isLibrary = false;
 
     private static final String BASE_CLASS_SUFFIX = "base";
     private static final String SERVER_PORT = "serverPort";
@@ -73,8 +75,7 @@ public void serialize(Boolean value, JsonGenerator gen, SerializerProvider seria
     private static final String DEFAULT_SOURCE_FOLDER = "src";
     private static final String DEFAULT_IMPL_FOLDER = "impl";
     private static final String DEFAULT_PACKAGE_VERSION = "1.0.0";
-
-    private String implPackage;
+    private static final String IS_LIBRARY = "isLibrary";
 
     @Override
     public CodegenType getTag() {
@@ -86,6 +87,18 @@ public String getHelp() {
         return "Generates a Python FastAPI server (beta). Models are defined with the pydantic library";
     }
 
+    public void setIsLibrary(final boolean isLibrary) {
+        this.isLibrary = isLibrary;
+    }
+
+    public void setImplPackage(final String implPackage) {
+        this.implPackage = implPackage;
+    }
+
+    public void setSourceFolder(final String sourceFolder) {
+        this.sourceFolder = sourceFolder;
+    }
+
     public PythonFastAPIServerCodegen() {
         super();
 
@@ -128,36 +141,41 @@ public PythonFastAPIServerCodegen() {
         implPackage = DEFAULT_IMPL_FOLDER;
         apiTestTemplateFiles().put("api_test.mustache", ".py");
 
-        cliOptions.add(new CliOption(CodegenConstants.PACKAGE_NAME, "python package name (convention: snake_case).")
-                .defaultValue(DEFAULT_PACKAGE_NAME));
-        cliOptions.add(new CliOption(CodegenConstants.PACKAGE_VERSION, "python package version.")
-                .defaultValue(DEFAULT_PACKAGE_VERSION));
-        cliOptions.add(new CliOption(SERVER_PORT, "TCP port to listen to in app.run")
-                .defaultValue(String.valueOf(DEFAULT_SERVER_PORT)));
-        cliOptions.add(new CliOption(CodegenConstants.SOURCE_FOLDER, "directory for generated python source code")
-                .defaultValue(DEFAULT_SOURCE_FOLDER));
-        cliOptions.add(new CliOption(CodegenConstants.FASTAPI_IMPLEMENTATION_PACKAGE, "python package name for the implementation code (convention: snake_case).")
-                .defaultValue(implPackage));
+        // Adds the following options in the codegen CLI
+        addOption(CodegenConstants.PACKAGE_NAME,
+                "python package name (convention: snake_case).",
+                DEFAULT_PACKAGE_NAME);
+
+        addOption(CodegenConstants.PACKAGE_VERSION,
+                "python package version.", 
+                DEFAULT_PACKAGE_VERSION);
+
+        addOption(SERVER_PORT,
+                "TCP port to listen to in app.run",
+                String.valueOf(DEFAULT_SERVER_PORT));
+
+        addOption(CodegenConstants.SOURCE_FOLDER,
+                "directory for generated python source code",
+                DEFAULT_SOURCE_FOLDER);
+
+        addOption(CodegenConstants.FASTAPI_IMPLEMENTATION_PACKAGE,
+                "python package name for the implementation code (convention: snake_case).",
+                implPackage);
+
+        addSwitch(IS_LIBRARY,
+                "whether to generate minimal python code to be published as a separate library or not",
+                isLibrary);       
     }
 
     @Override
     public void processOpts() {
         super.processOpts();
 
-        if (additionalProperties.containsKey(CodegenConstants.PACKAGE_NAME)) {
-            setPackageName((String) additionalProperties.get(CodegenConstants.PACKAGE_NAME));
-        }
-
-        if (additionalProperties.containsKey(CodegenConstants.SOURCE_FOLDER)) {
-            this.sourceFolder = ((String) additionalProperties.get(CodegenConstants.SOURCE_FOLDER));
-        }
-
-        if (additionalProperties.containsKey(CodegenConstants.FASTAPI_IMPLEMENTATION_PACKAGE)) {
-            this.implPackage = ((String) additionalProperties.get(CodegenConstants.FASTAPI_IMPLEMENTATION_PACKAGE));
-            // Prefix templating value with the package name
-            additionalProperties.put(CodegenConstants.FASTAPI_IMPLEMENTATION_PACKAGE,
-                    this.packageName + "." + this.implPackage);
-        }
+        // converts additional property values into corresponding type and passes them to setter
+        convertPropertyToStringAndWriteBack(CodegenConstants.PACKAGE_NAME, this::setPackageName);
+        convertPropertyToStringAndWriteBack(CodegenConstants.SOURCE_FOLDER, this::setSourceFolder);
+        convertPropertyToStringAndWriteBack(CodegenConstants.FASTAPI_IMPLEMENTATION_PACKAGE, this::setImplPackage);
+        convertPropertyToBooleanAndWriteBack(IS_LIBRARY, this::setIsLibrary);
 
         modelPackage = packageName + "." + modelPackage;
         apiPackage = packageName + "." + apiPackage;
@@ -166,8 +184,12 @@ public void processOpts() {
         supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));
         supportingFiles.add(new SupportingFile("openapi.mustache", "", "openapi.yaml"));
         supportingFiles.add(new SupportingFile("main.mustache", String.join(File.separator, new String[]{sourceFolder, packageName.replace('.', File.separatorChar)}), "main.py"));
-        supportingFiles.add(new SupportingFile("docker-compose.mustache", "", "docker-compose.yaml"));
-        supportingFiles.add(new SupportingFile("Dockerfile.mustache", "", "Dockerfile"));
+
+        if (!this.isLibrary) {
+            supportingFiles.add(new SupportingFile("docker-compose.mustache", "", "docker-compose.yaml"));
+            supportingFiles.add(new SupportingFile("Dockerfile.mustache", "", "Dockerfile"));
+        }
+
         supportingFiles.add(new SupportingFile("requirements.mustache", "", "requirements.txt"));
         supportingFiles.add(new SupportingFile("security_api.mustache", String.join(File.separator, new String[]{sourceFolder, packageName.replace('.', File.separatorChar)}), "security_api.py"));
         supportingFiles.add(new SupportingFile("extra_models.mustache", StringUtils.substringAfter(modelFileFolder(), outputFolder), "extra_models.py"));
@@ -178,12 +200,15 @@ public void processOpts() {
             namespacePackagePath.append(File.separator).append(tmp);
             supportingFiles.add(new SupportingFile("__init__.mustache", namespacePackagePath.toString(), "__init__.py"));
         }
+
         supportingFiles.add(new SupportingFile("__init__.mustache", StringUtils.substringAfter(modelFileFolder(), outputFolder), "__init__.py"));
         supportingFiles.add(new SupportingFile("__init__.mustache", StringUtils.substringAfter(apiFileFolder(), outputFolder), "__init__.py"));
-        supportingFiles.add(new SupportingFile("__init__.mustache", StringUtils.substringAfter(apiImplFileFolder(), outputFolder), "__init__.py"));
 
+        if (!this.isLibrary) {
+            supportingFiles.add(new SupportingFile("__init__.mustache", StringUtils.substringAfter(apiImplFileFolder(), outputFolder), "__init__.py"));
+        }
+
         supportingFiles.add(new SupportingFile("conftest.mustache", testPackage.replace('.', File.separatorChar), "conftest.py"));
-
         supportingFiles.add(new SupportingFile("gitignore.mustache", "", ".gitignore"));
         supportingFiles.add(new SupportingFile("pyproject_toml.mustache", "", "pyproject.toml"));
         supportingFiles.add(new SupportingFile("setup_cfg.mustache", "", "setup.cfg"));

modules/openapi-generator/src/main/resources/python-fastapi/api.mustache

@@ -5,7 +5,10 @@ import importlib
 import pkgutil
 
 from {{apiPackage}}.{{classFilename}}_{{baseSuffix}} import Base{{classname}}
+{{^isLibrary}}{{#fastapiImplementationPackage}}
 import {{fastapiImplementationPackage}}
+{{/fastapiImplementationPackage}}{{/isLibrary}}
+
 
 from fastapi import (  # noqa: F401
     APIRouter,
@@ -30,10 +33,13 @@ from {{modelPackage}}.extra_models import TokenModel  # noqa: F401
 
 router = APIRouter()
 
+{{^isLibrary}}
+{{#fastapiImplementationPackage}}
 ns_pkg = {{fastapiImplementationPackage}}
 for _, name, _ in pkgutil.iter_modules(ns_pkg.__path__, ns_pkg.__name__ + "."):
     importlib.import_module(name)
-
+{{/fastapiImplementationPackage}}
+{{/isLibrary}}
 
 {{#operations}}
 {{#operation}}

modules/openapi-generator/src/main/resources/python-fastapi/base_api.mustache

@@ -1,20 +1,25 @@
 # coding: utf-8
 
 from typing import ClassVar, Dict, List, Tuple  # noqa: F401
+{{#isLibrary}}
+from abc import ABC, abstractmethod
+{{/isLibrary}}
 
 {{#imports}}
 {{import}}
 {{/imports}}
 {{#securityImports.0}}from {{packageName}}.security_api import {{#securityImports}}get_token_{{.}}{{^-last}}, {{/-last}}{{/securityImports}}{{/securityImports.0}}
 
-class Base{{classname}}:
+class Base{{classname}}{{#isLibrary}}(ABC){{/isLibrary}}:
     subclasses: ClassVar[Tuple] = ()
 
     def __init_subclass__(cls, **kwargs):
         super().__init_subclass__(**kwargs)
         Base{{classname}}.subclasses = Base{{classname}}.subclasses + (cls,)
+
 {{#operations}}
-{{#operation}}
+{{#operation}}{{#isLibrary}}
+    @abstractmethod{{/isLibrary}}
     async def {{operationId}}(
         self,
         {{#allParams}}
@@ -25,7 +30,7 @@ class Base{{classname}}:
         ...{{/notes}}{{^notes}}...{{/notes}}
 {{^-last}}
 
-
 {{/-last}}
 {{/operation}}
 {{/operations}}
+

modules/openapi-generator/src/main/resources/python-fastapi/security_api.mustache

@@ -1,6 +1,7 @@
 # coding: utf-8
 
 from typing import List
+{{#isLibrary}}from abc import ABC, abstractmethod{{/isLibrary}}
 
 from fastapi import Depends, Security  # noqa: F401
 from fastapi.openapi.models import OAuthFlowImplicit, OAuthFlows  # noqa: F401
@@ -56,10 +57,22 @@ oauth2_implicit = OAuth2(
     )
 )
 {{/isImplicit}}
+{{#isLibrary}}
 
+{{>security_base_cls_init}}
 
+    @abstractmethod
+    def get_token(self, security_scopes: SecurityScopes, token: str) -> TokenModel:
+        ...
+
+    @abstractmethod
+    def validate_scope(self, required_scopes: SecurityScopes, token_scopes: List[str]) -> bool:
+        ...
+
+{{/isLibrary}}
 def get_token_{{name}}(
-    security_scopes: SecurityScopes, token: str = Depends(oauth2_{{#isPassword}}password{{/isPassword}}{{#isCode}}code{{/isCode}}{{#isImplicit}}implicit{{/isImplicit}})
+    security_scopes: SecurityScopes, 
+    token: str = Depends(oauth2_{{#isPassword}}password{{/isPassword}}{{#isCode}}code{{/isCode}}{{#isImplicit}}implicit{{/isImplicit}})
 ) -> TokenModel:
     """
     Validate and decode token.
@@ -69,9 +82,8 @@ def get_token_{{name}}(
     :return: Decoded token information or None if token is invalid
     :rtype: TokenModel | None
     """
-
-    ...
-
+    {{^isLibrary}}...{{/isLibrary}}
+    {{#isLibrary}}return Base{{name}}.subclasses[0]().get_token(security_scopes, token){{/isLibrary}}
 
 def validate_scope_{{name}}(
     required_scopes: SecurityScopes, token_scopes: List[str]
@@ -86,12 +98,24 @@ def validate_scope_{{name}}(
     :return: True if access to called API is allowed
     :rtype: bool
     """
-
-    return False
-
+    {{^isLibrary}}return False{{/isLibrary}}
+    {{#isLibrary}}return Base{{name}}.subclasses[0]().validate_scope(required_scopes, token_scopes){{/isLibrary}}
 {{/isOAuth}}
 {{#isApiKey}}
+{{#isLibrary}}
+
+{{>security_base_cls_init}}
+
+    @abstractmethod
+    def get_token(
+        self,{{#isKeyInHeader}}
+        token_api_key_header: str,{{/isKeyInHeader}}{{#isKeyInCookie}}
+        token_api_key_cookie: str,{{/isKeyInCookie}}{{#isKeyInQuery}}
+        token_api_key_query: str,{{/isKeyInQuery}}
+    ) -> TokenModel:
+        ...
 
+{{/isLibrary}}
 def get_token_{{name}}(
     {{#isKeyInHeader}}token_api_key_header: str = Security(
         APIKeyHeader(name="{{keyParamName}}", auto_error=False)
@@ -113,34 +137,46 @@ def get_token_{{name}}(
     :return: Information attached to provided api_key or None if api_key is invalid or does not allow access to called API
     :rtype: TokenModel | None
     """
-
-    ...
-
+    {{^isLibrary}}...{{/isLibrary}}
+    {{#isLibrary}}return Base{{name}}.subclasses[0]().get_token(
+        {{#isKeyInHeader}}token_api_key_header,{{/isKeyInHeader}}{{#isKeyInCookie}}
+        token_api_key_cookie,{{/isKeyInCookie}}{{#isKeyInQuery}}
+        token_api_key_query,{{/isKeyInQuery}}
+    ){{/isLibrary}}
 {{/isApiKey}}
 {{#isBasicBasic}}
-
 basic_auth = HTTPBasic()
+{{#isLibrary}}
 
+{{>security_base_cls_init}}
 
-def get_token_{{name}}(
-    credentials: HTTPBasicCredentials = Depends(basic_auth)
-) -> TokenModel:
+    @abstractmethod
+    def get_token(self, credentials: HTTPBasicCredentials) -> TokenModel:
+        ...
+
+{{/isLibrary}}
+def get_token_{{name}}(credentials: HTTPBasicCredentials = Depends(basic_auth)) -> TokenModel:
     """
     Check and retrieve authentication information from basic auth.
 
     :param credentials Credentials provided by Authorization header
     :type credentials: HTTPBasicCredentials
     :rtype: TokenModel | None
     """
-
-    ...
-
+    {{^isLibrary}}...{{/isLibrary}}
+    {{#isLibrary}}return Base{{name}}.subclasses[0]().get_token(credentials){{/isLibrary}}
 {{/isBasicBasic}}
 {{#isBasicBearer}}
-
 bearer_auth = HTTPBearer()
+{{#isLibrary}}
+
+{{>security_base_cls_init}}
 
+    @abstractmethod
+    def get_token(self, credentials: HTTPAuthorizationCredentials) -> TokenModel:
+        ...
 
+{{/isLibrary}}
 def get_token_{{name}}(credentials: HTTPAuthorizationCredentials = Depends(bearer_auth)) -> TokenModel:
     """
     Check and retrieve authentication information from custom bearer token.
@@ -150,8 +186,7 @@ def get_token_{{name}}(credentials: HTTPAuthorizationCredentials = Depends(beare
     :return: Decoded token information or None if token is invalid
     :rtype: TokenModel | None
     """
-
-    ...
-
+    {{^isLibrary}}...{{/isLibrary}}
+    {{#isLibrary}}return Base{{name}}.subclasses[0]().get_token(credentials){{/isLibrary}}
 {{/isBasicBearer}}
 {{/authMethods}}

modules/openapi-generator/src/main/resources/python-fastapi/security_base_cls_init.mustache

@@ -0,0 +1,6 @@
+class Base{{name}}(ABC):
+    subclasses: ClassVar[Tuple] = ()
+
+    def __init_subclass__(cls, **kwargs):
+        super().__init_subclass__(**kwargs)
+        Base{{name}}.subclasses = Base{{name}}.subclasses + (cls,)

samples/server/petstore/python-fastapi/src/openapi_server/apis/fake_api.py

@@ -5,8 +5,11 @@
 import pkgutil
 
 from openapi_server.apis.fake_api_base import BaseFakeApi
+
 import openapi_server.impl
 
+
+
 from fastapi import (  # noqa: F401
     APIRouter,
     Body,
@@ -34,7 +37,6 @@
 for _, name, _ in pkgutil.iter_modules(ns_pkg.__path__, ns_pkg.__name__ + "."):
     importlib.import_module(name)
 
-
 @router.get(
     "/fake/query_param_default",
     responses={

samples/server/petstore/python-fastapi/src/openapi_server/apis/fake_api_base.py

@@ -13,10 +13,13 @@ class BaseFakeApi:
     def __init_subclass__(cls, **kwargs):
         super().__init_subclass__(**kwargs)
         BaseFakeApi.subclasses = BaseFakeApi.subclasses + (cls,)
+
+
     async def fake_query_param_default(
         self,
         has_default: Annotated[Optional[StrictStr], Field(description="has default value")],
         no_default: Annotated[Optional[StrictStr], Field(description="no default value")],
     ) -> None:
         """"""
         ...
+