Parse

Use the Parse policy to control the parsing of an input document.

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

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 parse.

About

When the input document is a JSON string, the string is parsed instead of copied over. You can re-parse a JSON string as any of the allowed doc types (detect, xml, json, binary). For example, suppose that the JSON string "<a></b></a>" is parsed. You can re-parse it using doc type xml to extract the XML from that string.

With the parse policy, you can retrieve parse settings by using the following methods in increasing order of precedence:

Specify a valid parse settings configuration from which to retrieve its properties as the default parse settings.
Note: If you change the default name, you must separately configure a corresponding ParseSettings object on the DataPower API Gateway.
Specify a literal string as serialized XML or JSON properties as parse settings. These properties take precedence over any existing default properties. The literal string must be XML or JSON formatted.
- The XML format is "<ParseSettings><propertyName>propertyValue</propertyName></ParseSettings>".
- The JSON format is "{ \"ParseSettings\" : { \"propertyName\" : propertyValue } }".
A URL that represents a named context from which to retrieve the serialized XML or JSON properties as parse settings. These properties take precedence over any existing literal or default properties.

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. Parse policy properties
Property label	Required	Description	Data type
Title	No	The title of the policy. The default value is `parse`.	string
Description	No	A description of the policy.	string
Use Content Type	No	If this setting is enabled and the parse setting is configured to detect the document type, the parse action uses the `Content-Type` specified in the request headers. If this setting is enabled and the document type in the parse setting is configured for either JSON or XML, the parse action uses the `Content-Type` specified in the request headers and fails if the `Content-Type` in the request headers does not match the parse setting. Enabling this setting is applicable only when the expected `Content-Type` is either JSON or XML. If this setting is not enabled, the parse action uses either the document type that is specified in the parse setting, or the detected document type if the parse setting is configured to detect the document type. The check box is cleared by default.	boolean
Parse settings object reference	No	An existing valid object from which to retrieve default property values for the dynamic object.	string
Parse settings literal configuration	No	A literal string as serialized XML or JSON properties that are merged into the dynamic object. The literal property overrides any existing default properties.	string
Parse settings URL reference	No	A URL that represents a named context from which to retrieve the serialized XML or JSON properties that are merged into the dynamic object. These properties override any existing literal or default properties.	string
Message for parsing	No	The name of a variable in the API context. The content of the `body` field of the variable is the input to the policy. The default variable name is `message`.	string
Message for resulting parsed data	No	The name of a variable in the API context. The content of the body field of the variable is the output of the parse operation. The parse metrics of the parsed document can be stored in a different part of the message. The default variable name is the same as the input name, so by default the input message is overwritten by the output message.	string

For examples, see parse.