OpenAPI (Swagger) Adapter

The OpenAPI Specification (formerly: Swagger specification) is a framework that is used to define interfaces, with which you can design, build, document, and consume REST APIs.

To configure an OpenAPI (Swagger) service in Quantum Fabric, you need a JSON or a YAML file (with any dependent files) that contains specifications for the required APIs. The service retrieves the metadata from the imported JSON or YAML files and displays the APIs.

From V9 ServicePack 2, Quantum Fabric supports OpenAPI 3.0. For more information about OpenAPI 3.0, you can refer to the following articles:

• A Guide to What’s New in OpenAPI 3.0
• A Visual Guide to What's New in Swagger 3.0

Configuring an OpenAPI (Swagger) End-point Adapter

To configure a OpenAPI (Swagger) adapter in Integration Service Definition tab, follow these steps:

1. On the Integration Service Definition page, from the Service Type list, select OpenAPI (Swagger).
2. Configure the service definition parameters. For more information, refer to the following sections.
   

   Parameter	Description
   Name	Specifies the name that Fabric uses to identify the service on the console.
   Version	Specifies the version number of the service. The version number ranges from 1.0 to 999.99. If you are creating a new service, the version number is 1.0 by default, and it cannot be changed.
   Description	Specifies the description of the service that is displayed on the console.

   Connection Parameters

   Parameter

   Description

   Swagger File

   Specifies the JSON or YAML file that contains the required API specifications. You can also upload a zip file that contains the JSON or YAML file. NOTE: Quantum Fabric V9SP5 GA supports uploading Swagger external reference files along with Swagger definition files, for Swagger 2.0 and OpenAPI 3.0 versions. To upload an OpenAPI specification file, click Upload, and then select a file from your local system. After you upload a file, Fabric displays additional parameters based on the OpenAPI spec version that is mentioned in the file.

   Connection Parameters for Swagger 2.0

   Parameter	Description
   Host URL	Specifies the domain name or the IP address of the server that hosts the APIs. For example: api.example.com or 93.184.216.34:8089
   Base Path	Specifies the path of the API relative to the host root. It must start with a forward slash (/). For example: /v2 or /api/v2
   Scheme	Specifies the scheme that must be used to form the connection URL at run time. Contains the following values: http https NOTE: If the Swagger file does not contain a scheme, https is selected by default. If the Swagger file contains both http and https, http is selected by default. If you import or open an existing Swagger 2.0 service in Fabric V9 SP3 or later, the scheme parameter is not parsed by default. To re-parse the file and read the scheme parameter, click Refresh next to the uploaded Swagger file. Reconfiguring the scheme is only available on Quantum Fabric versions V9 SP3 or later. If your runtime server version is V9 SP2 or earlier, the reconfigured scheme from the Fabric Console is not honored at run time. You can change the scheme before publishing the service by using the Configure and Publish option. For more information, refer to Reconfiguring a Service → Integration Service → OpenAPI (Swagger).

   Connection Parameters for OpenAPI 3.0

   Parameter	Description
   Server URL	Specifies the URL of the server that hosts the APIs. The default URL is the first Server URL in the specification file. For information about how Fabric parses the URLs, refer to the Miscellaneous section. For example: https://subdomain.site.com/version
   Server Description	Specifies the description for the server that is specified by the URL. For example: Development Server

   Authentication

   Parameter	Description
   Use Existing Identity Provider	Specifies the identity provider that you want to use to authenticate users for the service. You can select any Identity Service that is created on the Quantum Fabric cloud. For information about creating an Identity Service, refer to Configure Identity Service. NOTE: For more information on Externalizing Identity Services, refer to Replace the Identity Service references in a Fabric app.

   Advanced

   Field	Description
   Custom code	Specifies any custom JAR files that you want to associate with the service. To associate a JAR file with the service, follow either of the following steps. From the Select Existing JAR list, select a JAR file from the Quantum Fabric cloud Click Upload New, and then select a JAR file from the file explorer NOTE: For on-premises instances of Fabric, make sure that the JAR file that is built on the same JDK version that is used to install the Fabric Integration.
   API Throttling	Specifies whether Fabric must limit the number of request calls in a minute. To use API Throttling, follow these steps. In the Total Rate Limit box, type a required value. This limits the total number of requests that are processed by the service. In the Rate Limit Per IP box, type a required value. This limits the number of requests based on the IP Address of the request. You can also override throttling from the Quantum Fabric App Services Console. For more information, refer to Override API Throttling Configuration.

3. After you configure all the parameters, click SAVE.
   

   NOTE: If you want to add operations to the service, click SAVE AND ADD OPERATIONS.

Creating Operations for OpenAPI (Swagger)

After you create a service, you can view the existing operations and also create operations on the Operations List tab. For an OpenAPI endpoint, the operations are the paths that are defined in the Swagger file, for example: addPet or updatePet.

To create an operation, follow these steps:

1. From the Service Definition page, switch to the Operations List tab.
   Alternatively, click the plus (+) icon on the left pane, and then click Add New Operation.
2. On the Operations List tab, from the drop-down list, select the operations that you want to add to the service.
   When you select a path (operation), all the corresponding fields of the operation are populated.
   
   
3. After you select the operations, click ADD OPERATION. Fabric adds the selected operations to the Operations List tab.

   

4. Under Configured Operations, click an operation to view the details of the operation.

   

   Fabric displays the selected operation in the edit mode. You can configure the parameters to update the operation. For more information, refer to the following table.

   Field	Description
   Name	Specifies the name that Fabric uses to identify the operation on the console.
   Operation Security Level	Specifies the authentication that is required to invoke the operation. Contains the following options: Authenticated App User – It restricts the access to clients who have successfully authenticated using an Identity Service associated with the app. Anonymous App User – It allows the access from trusted clients that have the required App Key and App Secret. Authentication through an Identity Service is not required. Public – It allows any client to invoke this operation without any authentication. This setting does not provide any security to invoke this operation and you should avoid this authentication type if possible. Private - It blocks the access to this operation from any external client. It allows invocation either from an Orchestration/Object Service, or from the custom code in the same run-time environment.
   Description	Specifies the description of the service that is displayed on the console.

5. Configure the parameters in the Advanced section based on your requirement. For more information, refer to the following table.

   Advanced

   Custom Code Invocation	When you test, the services details of various stages in the service execution are presented to you for better debugging. All options in the Advanced section are optional. For more details, refer to Preprocessor and Postprocessor.   NOTE: The Pre and post-processing logic feature is not supported for a Swagger service.
   Additional Configuration Properties	Additional Configuration Properties allows you to configure service call time out cache response. For information on different types of configuration properties, refer Properties.
   Front-end API	Front-end API allows you map your endpoint (or) backend URL of an operation to a front-end URL. For detailed information, refer Custom Front-end URL.
   Server Events	Using Server Events you can configure this service to trigger or process server side events. For detailed information, refer Server Events.

6. After you configure the required parameters, click SAVE.

Configuring Request Parameters

The request input parameters are picked from the uploaded OpenAPI specification file. Any changes that are made to the parameters from the console are ignored.

IMPORTANT: Make sure that the input parameters are form-url-encoded.

To create a new parameter on the Request Input tab, follow these steps:

1. On the Body tab, click Add Parameter. A new row is added to the table of parameters.
2. Configure the fields (columns) for the input parameter. For more information, refer to the following table.

   Field	Description
   Name	Specifies a unique identifier for the parameter. The name is the key of the parameter in the request.
   VALUE	Specifies the source of the value of the parameter. Contains the following options. request The value is picked from the configuration of the request parameter. If you select request as the source, you need to configure the TEST VALUE and DEFAULT VALUE fields. session The value is picked from the session context. If you select session as the source, the TEST VALUE and DEFAULT VALUE fields are disabled. constant The value is a constant that is defined on the Fabric console. If you select constant as the source, you need to type a value for the parameter. identity The value is picked from the response that is sent by the specified identity provider. If you select identity as the source, you need to configure the provider, attribute, and value. For example: sampleAuth.profile.userID NOTE: For more information on Externalizing Identity Services, refer to Replace the Identity Service references in a Fabric app.
   TEST VALUE	Specifies the value of the parameter that is used while testing the service.
   DEFAULT VALUE	Specifies the value of the parameter that is used if the test value is empty.
   DATA TYPE	Specifies the data type of the parameter. Contains the following options: string A combination of alpha-numeric and special characters. Supports all formats (including UTF-8 and UTF-16) with no maximum size limit. boolean A value that can be true or false. number An integer or a floating point number. date A value that contains the day, month, year, and time. collection A set of multiple records. record A set of multiple objects. NOTE: The binary data type is not supported for operations in OpenAPI (Swagger).
   Record ID	Specifies the ID of the record that contains the parameter. This field is applicable for nested payloads.
   Collection ID	Specifies the ID of the collection that contains the parameter. This field is applicable for nested payloads.
   Description	Specifies the description for the request parameter.

3. After you configure all the parameters, you can validate the details by testing the service operation. For more information, refer to Test a Service Operation.

Configuring Response Parameters

You can view the details (such as name, scope, and data type) for the response parameters on the Response Output tab.

The Restrict Parameters to OpenAPI definition check box is selected by default. The check box specifies whether parameters are picked from the OpenAPI definition file or the Fabric console configuration.

To create a parameter based on the back-end response, follow these steps:

1. Clear the Restrict Parameters to OpenAPI definition check box.
2. From the Select Environment list, select a run-time environment, and then click Save and Fetch Response.
   The back-end response of the service appears in the Test window. The Backend Response pane displays the nodes of the response in a Tree view.
3. Point to the node that you want to add to the response output parameters, and then click Create response.
   
   A new row is created on the Response Output tab and the details of the selected node are added to it.

To create a parameter manually, follow these steps:

1. Clear the Restrict Parameters to OpenAPI definition check box.
2. Click Add Parameter. A new row is added to the parameters table.
3. Configure the fields for the parameters. For more information, refer to the following table.
   

   Field	Description
   Name	Specifies a unique identifier for the parameter. The name is the key of the parameter in the response.
   Scope	Specifies the scope at which the parameter is available. Contains the following options. response The parameter is available in the response. session The parameter is available throughout the user session. NOTE: If the parameters inside a record are defined as the session, the session scope is not reflected for the parameters.
   DATA TYPE	Specifies the data type of the parameter. Contains the following options: string A combination of alpha-numeric and special characters. Supports all formats (including UTF-8 and UTF-16) with no maximum size limit. boolean A value that can be true or false. number An integer or a floating point number. date A value that contains the day, month, year, and time. collection A set of multiple records. record A set of multiple objects. NOTE: The binary data type is not supported for operations in OpenAPI (Swagger).
   Record ID	Specifies the ID of the record that contains the parameter. This field is applicable for nested payloads.
   Collection ID	Specifies the ID of the collection that contains the parameter. This field is applicable for nested payloads.
   Description	Specifies the description for the request parameter.

4. After you configure all the parameters, click SAVE OPERATION.
   

   NOTE: If you want to test the operation, select a run-time environment from the drop-down list, and then click SAVE AND FETCH RESPONSE.

NOTE: You can view the service in the Data Panel feature of Quantum Visualizer. By using the Data Panel, you can link back-end data services to your application UI elements seamlessly with low-code to no code. For more information on Data Panel, click here.

Testing the Operation

After you create an operation and configure the request and response parameters, you can test the operation and validate the details that you configured.

To test an operation, select an environment from the Select Environment list, and then click SAVE AND FETCH RESPONSE. The result of the operation appears. For more details, refer Test a Service Operation.

NOTE: For Post or Put methods that contain nested payloads, you cannot test the service from the Quantum Fabric Console. You can only send a request from the App Services Console, or from Postman.

Miscellaneous

Swagger 2.0 in Quantum Fabric

• If the Swagger file does not specify a scheme, HTTPS is picked by default. If the file specifies both HTTP and HTTPS schemes, HTTP is picked.

OpenAPI 3.0 in Fabric V9 ServicePack 2

• With the OpenAPI 3.0 Specification, you can add multiple URLs to your definition and also include parameters in the URL. For more information, refer to A Visual Guide to What's New in Swagger 3.0.
  • While creating a service for OpenAPI 3.0 in Quantum Fabric V9 ServicePack 2, you can select only one URL as the Server URL. If your specification file contains multiple URLs, Fabric picks the first URL by default.
  • You can change the URL before you publish the service to the run time by reconfiguring the service before a publish. For more information, refer to Service Reconfiguration.
  • Parameters in the URL are not supported. Make sure that you add static server URLs to your specification file.
• The trace HTTP method is not supported and the APIs that use the trace method are ignored.
  APIs that use other HTTP methods are parsed by Fabric to create operations.
• If the HTTP response code is not 200, the console displays the response from the back-end server as is.
• OpenID Connect (OIDC) is not supported for authentication.
• Callbacks, which are used to define Webhooks, are not supported. Links, which are used to define the output one operation as input for another operation, are not supported. Make sure that you remove Callbacks and Links from your OpenAPI 3.0 spec before you upload it to Fabric.
• Serialization of parameters, which includes style (defines the delimiter for multiple parameters) and explode (specifies whether objects of an array are generated as separate parameters), is not supported.
• Fabric does not parse or validate examples from the specification file.