Testing the connection with method Echo

Info

Each service implemented in the Mercury DB (HgDB) 3.0 system contains the echo method (a request sent using the POST method). It allows for verifying the correctness of the defined communication between the client and the server. An example of using the method is the implementation of the data source for the Grafana system: datasource.ts where the testDatasource() method uses the echo method call of the CaseSearchRest service.

echo

A method for testing the connection.

Method request

The table below describes the individual components of the request sent to the echo method via the REST protocol:

Parameter	Description	Sample value
context	Request context, control data, see SOAP/REST Services Request Context.	{"userName": "anonymous", "userFullName": null, "locale": null, "timeZone": null, "maxResults": 1, "currentRole": 'anonymous', "userRoles": null, "sourceOfRequest": null,"maxDepthResult": 1, "decodeResult": "DECODE_DATE_AND_LOB", "ignoreCaseHeaderInResponse": false, "requestProperties": {}}
someText	Text value that should be returned in the response.	Hello World!

JSON request example

{ 
  "context": {
    "appName": "mercury-ws-app",
    "appVersion": "1.0",
    "userName": "anonymous",
    "comment": null,
    "maxResults": 10000,
    "queryTimeout": 2147483647,
    "locale": "pl_PL",
    "timeZone": "Europe/Warsaw",
    "userFullName": null,
    "eager4omdBuilder": "true",
    "trustedData": false,
    "ignoredCustomFields": null,
    "currentRole": null,
    "userRoles": null,
    "sourceOfRequest": "USER_DEV.localhost",
    "rootVersionContextID": null,
    "rootTagName": null,
    "directRequest": false,
    "formats": {
      "date.format.long": "dd-MM-yyyy HH:mm:ss XXX"
    },
    "ignoreAlternateFields": true,
    "decodeResult": "DATE_AND_LOB",
    "maxDepthResult": 3,
    "decodeRequest": "DATE_AND_LOB",
    "ignoreCaseHeaderInResponse": true,
    "cacheUsage": "REFRESH",
    "httpResponseCacheUsage": "NONE",
    "defaultLuceneSortClause": null,
    "viewDefinition": null
  }, 
  "someText": "Hello World!"
}

Method response

The table below describes the individual components of the response returned by the echo method:

Parameter	Description	Example value
errorCode	Error code. When the operation is successful, it takes the value null.	null
errorMessage	The content of the error message. When the operation is successful, it takes the value null.	null
value	The value of the response. When the operation is successful, it takes the value of the input parameter someText	Hello World!

Example of the service response in JSON

{
   "errorCode": null,
   "errorMessage": null,
   "value": "Hello World!"
}