DataPower API Gateway

Validate - DataPower API Gateway

Use the Validate policy to validate the payload in an assembly flow against a schema.

Gateway support

Note: This page describes the Validate policy implementation in the DataPower® API Gateway. If you are using the DataPower Gateway (v5 compatible), see Validate - DataPower Gateway (v5 compatible).

For information on the different types of gateway, see API Connect gateway types.

Table 1. Table showing which gateways support this policy, and the corresponding policy version
Gateway Policy version
DataPower API Gateway 2.0.0

2.1.0 (DataPower API Gateway Version 10.0.1.0 or later)

2.2.0 (DataPower API Gateway Version 10.0.2.0 or later)

2.3.0 (DataPower API Gateway Version 10.0.2.0 or later)

2.4.0 (DataPower API Gateway Version 10.0.4.0 or later)

2.5.0 (DataPower API Gateway Version 10.5.0.0 or later)

2.6.0 (DataPower API Gateway Version 10.5.0.2 or later

2.7.0 (DataPower API Gateway Version 10.5.0.3 or later

This topic describes how to configure the policy in the assembly user interface; for details on how to configure the policy in your OpenAPI source, see validate - DataPower API Gateway.

About

Position this policy where required in the assembly flow as follows:
  • To validate the original input, position a Validate policy at the start of your flow.
  • To validate an intermediate response that is returned from other invoke actions or tasks, position a Validate policy after those actions or tasks.
  • To validate the response that is returned to the client application, position a Validate policy after the task that collates the response.
Note: With the DataPower API Gateway, the input to the Validate policy must be parsed data. One way to produce parsed data is to use a Parse policy before a Validate policy in your assembly flow, which provides explicit control of the parse action.

Properties

The following table lists the policy properties, indicates whether a property is required, specifies the valid and default values for input, and specifies the data type of the values.

Table 2. Validate policy properties
Property label Required Description Data type
Title Yes The title of the policy.

The default value is validate.

 string
Description No A description of the policy. string
Input No Specifies the name of a variable in the API context. The content of the body field of the variable, which is represented by variable_name.body, is the input data to validate. By default, the variable name is message. string
Output No Specifies the name of a variable in the API context.
  • If the validation passes, the body field of the output variable, which is represented by variable_name.body, stores the output of the assembly validate action.
  • If the schema to validate is a JSON schema, the validation also adds any default values that are missing from the payload.
  • If the validation fails, no output is stored.
  • If an output variable is not specified, the results of the assembly validate action are not saved.
 string
Validate against Yes Specifies the schema to be used for validating the payload.
Select one of the following values:
  • definition: Select this value if you want to use a previously defined schema to validate the payload that is returned from other invoke actions or tasks in the assembly flow.

    From the Definition Object list, select the required schema. For information on defining a schema for an OpenAPI 2.0 API definition, see Defining schema definitions for an API. For information on defining a schema for an OpenAPI 3.0 API definition, see Defining schema components.

  • URL: the schema is identified by a URL location.
    • In the JSON Schema URL field, enter the URL of the JSON schema to be used for validating a JSON payload.
    • From the XML Validation Mode list, select how XML validation is to be performed:
      • None: no XML payload validation is required.
      • xsd: an XML schema will be used to validate an XML payload. In the XML Schema URL field, enter the URL of the XML schema.
      • wsdl: a WSDL schema will be used to validate a SOAP payload. In the WSDL URL field, enter the URL of the WSDL schema.
      • soap-body: validate the body of a SOAP message against the XML schema only.
      Note: The following limitations apply to schemas used for JSON validation, which include JSON schemas and OpenAPI documents that are used as schemas for validation. Exceeding these limits can impact compilation performance and is not supported.
      • Maximum of 6,500 lines. Each key and each item in an array count as a line.
      • Maximum recursion depth of 250.
      • Maximum of 3,000 items in enum lists.
  • WSDL: (available with a SOAP service based API only) use the XML schema in the WSDL file associated with the API operation or the API path.
  • body-param: validate the request input against the schema definition that is specified in the TYPE field for the request parameter for this operation. For information about how to create a request parameter, see Defining parameters for an operation.
  • response-param: validate the response to be returned to the client application, against the schema definition that is specified in the SCHEMA field for the response parameter for this operation. For information about how to create a response parameter, see Defining responses for an operation.
  • GraphQL: (available for a GraphQL proxy API only) validate the payload against the GraphQL schema that has been imported into the GraphQL proxy API. In addition, either the GraphQL query or response, depending on the input, is analyzed against the GraphQL schema to calculate the cost, and the result is placed in the API context.

    For more information on GraphQL proxy APIs, see Creating a GraphQL proxy API and GraphQL context variables.

 string
XSLT version No The XSLT processor version. The default value is XSLT10. string
Strict No Whether to enable strict XSLT error checking. Non-strict operations attempt to recover from certain errors, such as use of undeclared variables, calling undeclared templates, and so forth. By default, strict XSLT error checking is enabled. boolean
Profile rule No Whether to enable stylesheet profiling. This option should not be used in production environments. By default, stylesheet profiling is disabled. boolean
Debug rule No Whether to run the stylesheet, XQuery script, and JSONiq script in debug mode. When a stylesheet, XQuery script, or JSONiq script is run in debug mode, it generates a custom web page instead of displaying its normal output. The web page details exactly what occurred during execution, including the values of variables and where particular pieces of the output came from. This option should not be used in production environments. By default, debug mode is disabled. boolean
Streaming rule No Whether the stylesheet must be run in streaming mode. Transformation of the document begins before the input is fully parsed. Not all stylesheets can be streamed. If the stylesheet cannot be streamed, an error is generated and the input is not processed. By default, streaming mode is disabled. boolean
Attempt streaming rule No Whether to attempt to run the stylesheet in streaming mode. Transformation of the document begins before the input is fully parsed. Not all stylesheets can be streamed. If the stylesheet cannot be streamed, a warning is generated during compilation and the stylesheet is read in the entire input as normal at execution time. By default, attempting to run the stylesheet in streaming mode is disabled. boolean
Minimum output escaping rule No Whether to escape output produced from the stylesheet during processing. Minimal escaping is particularly useful when handling non-English character sets. By default, minimum escaping is disabled. boolean
Maximum stack size No The maximum number of bytes that the stack is allowed to use while executing a stylesheet or other compiled content. This setting is used to block infinite recursion. The minimum value is 10 kilobytes, or 10,240 bytes. The maximum value is 100 megabytes, or 104,857,600 bytes. The default value is 1 megabyte, or 1,048,576 bytes. integer
WS-I Basic Profile validation No The validation behavior to apply to WSDL files that are checked for conformance to section 5 of WS-I Basic Profile (version 1.0, April 2004). The default setting is Warn.
Ignore
Disables conformance checking.
Warn
Logs warnings for violations.
Fail
Forces conformance. Fails if the file contains any violation.
 string
Validate message body No The validation behavior for the soap:Body. The default setting is Strict.
Strict
Validates this part of the message against the WSDL definition. Allows only messages that contain this part and that match the WSDL definition.
Lax
Validates this part of the message against the WSDL definition. If the message contains this part and the WSDL definition does not define this part, allow the message. If the message contains this part and the WSDL definition defines this part, allow the message only when there is a match.
Skip
Disables validation of this part of the message.
 string
Validate message headers No

The validation behavior for the soap:Header. The default setting is Lax.

Strict
Validates this part of the message against the WSDL definition. Allows only messages that contain this part and that match the WSDL definition.
Lax
Validates this part of the message against the WSDL definition. If the message contains this part and the WSDL definition does not define this part, allow the message. If the message contains this part and the WSDL definition defines this part, allow the message only when there is a match.
Skip
Disables validation of this part of the message.
 string
Validate message fault details No Specifies the validation behavior for the fault detail. The default setting is Strict.
Strict
Validates this part of the message against the WSDL definition. Allows only messages that contain this part and that match the WSDL definition.
Lax
Validates this part of the message against the WSDL definition. If the message contains this part and the WSDL definition does not define this part, allow the message. If the message contains this part and the WSDL definition defines this part, allow the message only when there is a match.
Skip
Disables validation of this part of the message.
 string
Require wrappers on fault details specified by type No Whether to require compatibility with RPC-style wrappers. By default, RPC-style wrappers are not required. boolean
Specifically allow xsi:type='SOAP-ENC:Array' rule No Whether to allow the schema to accept most uses of elements with xsi:type='SOAP-ENC:Array' consistent with SOAP 1.1 Section 5, even when these attributes violate the XML Schema specification. Normally, the xsi:type attribute must name a type equal to or derived from the actual type of the element. For schemas compiled with this option, xsi:type is accepted specifically for the SOAP 1.1 Encoding 'Array' complex type if the element type is derived from SOAP-ENC:Array. The opposite is the normal allowable case. By default, elements with xsi:type='SOAP-ENC:Array' are not accepted. boolean
Validate SOAP 1.1 encoding rule No Whether to perform extra schema validation following the encoding rules in SOAP 1.1 Section 5. When enabled, members of SOAP arrays are validated, attributes such as @id and @href are allowed even if they are not allowed by the schema, and @href values are checked to ensure that they have a corresponding @id element. By default, the extra validation is not performed. boolean
Wildcards ignore xsi:type rule No Whether xs:any elements in the schema validate only child elements by name. The XML Schema specification requires that, if a wildcard matches an element but that element does not have an element declaration, the element is instead validated according to an xsi:type attribute on it. This option ignores those xsi:type attributes. It should be used for cases such as SOAP envelope validation where a further validation step will validate the contents matching the wildcard, possibly using the SOAP 1.1 encoding rules. By default, xsi:type attributes are not ignored. boolean
Strict SOAP envelope version No Whether to strictly follow the SOAP binding in the WSDL. When enabled, only messages bound to SOAP 1.2 appear in SOAP 1.2 envelopes and only messages bound to SOAP 1.1 appear in SOAP 1.1 envelopes. By default, strict SOAP binding is disabled. boolean
Debug XACML policy No Whether to compile XACML policies with debug information. Note that the XACML debugging messages are also controlled by the log event in the XACML category. Use the debug log level to view the full XACML debugging messages. By default, XACML policies are not compiled with debug information. boolean
Accept MTOM/XOP optimized messages No Specifies whether the schema or WSDL document accepts messages where base64-encoded binary content was optimized according to the MTOM/XOP specifications. XOP binary-optimization replaces base64-encoded binary data with an xop:Include reference element that references the unencoded binary data located in an attachment. By default, MTOM/XOP optimized messages are disabled.
  • When disabled, such optimized messages are rejected by validation of the optimized form. Rejection occurs because the schema specifies a simple type that accepts base64-encoded data, such as xs:base64Binary or xs:string, but the message contains an xop:Include element instead.
  • When enabled, an xop:Include element can optionally appear in place of content for any XML Schema simple type that validates base64-encoded binary data. The xop:Include element itself will be validated according to the built-in schema in store:///schemas/xop.xsd.
 boolean
For examples, see validate - DataPower API Gateway.