Assign content policy

Phase

onRequest	onResponse	onRequestContent	onResponseContent
-	-	X	X

Description

You can use the assign-content policy to change or transform the content of the request/response body or message.

This policy is compatible with the Freemarker template engine, which allows you to apply complex transformations, such as transforming from XML to JSON and vice versa.

By default, you can access multiple objects from the template context — request and response bodies, dictionaries, context attributes and more.

Compatibility with APIM

Plugin version	APIM version
Up to 1.6.x	Up to 3.9.x
1.7.x	3.10.x to 3.20.x
2.x	4.0 to latest

Configuration

Property	Required	Description	Type	Default
scope	X	The execution scope of the policy.	scope	REQUEST
body	X	The data to push as request or response body content.	string	-

Sample

"policy-assign-content": {
    "scope":"REQUEST",
    "body":"Put your content here"
}

Examples

Inject a dictionary value and the application into the request payload

{
  "example": "${context.dictionaries['my-dictionary']['my-value']}",
  "application": "${context.attributes['application']}"
}

Tip	You can find more information about default attributes in the Expression Language documentation in the API Publisher Guide.

Incoming request body content

{
  "symbol": "EUR"
}

Policy example to transform from JSON to XML

Input:

<#assign body = request.content?eval >
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:web="http://www.webserviceX.NET/">
   <soapenv:Header/>
   <soapenv:Body>
      <web:GetQuote>
         ${body.symbol}
      </web:GetQuote>
   </soapenv:Body>
</soapenv:Envelope>

Expected output:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:web="http://www.webserviceX.NET/">
 <soapenv:Header/>
 <soapenv:Body>
 <web:GetQuote>
 EUR
 </web:GetQuote>
 </soapenv:Body>
</soapenv:Envelope>

Errors

HTTP status code

Code	Message
500	The body content cannot be transformed.