Invoke a GET API

This procedure shows how to create a flow to invoke a GET API.

The sample code implements a procedure that uses connection properties to retrieve API host information.

Prerequisites:

The action is defined in the schema. The header and parameters (query/path) are input to the action.

1. Open the adapter definition document in Visual Studio Code.
2. In the flows code section of the document, define the flow with a single state of Operation type.

   Sample code:

   "flows": {  
      "postOrdersFlow" : {
         "id": "postOrdersFlow",
         "description": "postOrdersFlow",
         "version": "0.1",
         "start": "startState",
         "specVersion": "0.8",
         "functions": [
            
         ],
         "states": [
           {
             "actions": [
               
             ],
             "name": "startState",
             "type": "operation",
             "end": true
           }
         ]
       }
   }

3. Define a function with a unique name, of type custom, and operation connectivity::rest.

   Sample code:

   "functions": [
           {
             "name": "postOrdersFunction",
             "operation": "connectivity::rest",
             "type": "custom"
           }
         ]

4. Add an action to the state where:
   • The action refers to the function created in step 2.
   • Arguments to function define the HTTP method, URI, parameters (template and query), and body.
   • Response passes through, and the result is set to output.

   Sample code:

   {
                 "functionRef": {
                   "refName": "postOrdersFunction",
                   "arguments": {
                    "uri": "${.connectionProperties.baseURL + \"/customers/{customer_id}\"}",
                     "method": "GET",
                     "headers": "${ .input.headers }",
                     "parameters": "${ .input.parameters }"
                   }
                 },
                 "actionDataFilter": {
                   "results": "${ { body: .body, headers: .headers } }",
                   "toStateData": "${ .output }"
                 }
               }

Complete sample code:

"flows": {   
   "getCustomersCustomerIdFlow" : {
      "id": "getCustomersCustomerIdFlow",
      "description": "getCustomersCustomerIdFlow",
      "version": "0.1",
      "start": "startState",
      "specVersion": "0.8",
      "functions": [
        {
          "name": "getCustomersCustomerIdFunction",
          "operation": "connectivity::rest",
          "type": "custom"
        }
      ],
      "states": [
        {
          "actions": [
            {
              "functionRef": {
                "refName": "getCustomersCustomerIdFunction",
                "arguments": {
                  "uri": "${.connectionProperties.baseURL + \"/customers/{customer_id}\"}",
                  "method": "GET",
                  "headers": "${ .input.headers }",
                  "parameters": "${ .input.parameters }"
                }
              },
              "actionDataFilter": {
                "results": "${ { body: .body, headers: .headers } }",
                "toStateData": "${ .output }"
              }
            }
          ],
          "name": "startState",
          "type": "operation",
          "end": true
        }
      ]
    }
}