Response Interceptor

A Response Interceptor is a function that receives the following parameters:

• body: the body of the response received from the destination API.
• headers the response headers to be sent by the gateway to the client.
• request: the request received by gateway from the client.
• callback: A callback function, like: callback(error, body, newHeaders). Where body will be the new response body and newHeaders inform a list of headers to be included into the response.

Each interceptor must be defined on its own .js file.

Example:

/**
 * Where request is the object created by [http](https://nodejs.org/api/http.html) module.
 * @param body the body of the response received from the destination API.
 * @param headers the response headers to be sent by the gateway to the client.
 * @param request the request received by gateway from the client.
 * @param callback A callback function, like: callback(error, body, newHeaders, removeHeaders). Where body will be the new response body,
 * newHeaders inform a list of headers to be included into the response and removeHeaders a list of headers to be suppressed.
 */
module.exports = function(body, headers, request, callback) {
   var data = JSON.parse(body.toString('utf8'));
   var newHeaders = {
      mySpecialHeader: 'header value',
      myOtherSpecialHeader: 'header value 2'
   };
   callback(null, data, newHeaders, ['excludedHeader']);
};

If the response already includes one of those headers, they will be overwritten.

Note that to be able to override a response body, you must set the parseResBody to true on the proxy config.

You can configure a request interceptor middleware through:

• Admin Rest API: POST /midleware/interceptors/response
• SDK: sdk.middleware.addResponseInterceptor(name, fileName);
• CLI: treeGatewayConfig middleware responseInterceptor -a <name> ./filename.js