Use a JavaScript SDK generated by API Gateway for a REST API

Note

These instructions assume you have already completed the instructions in Generate SDKs for an API using the API Gateway console.

Important

If your API only has ANY methods defined, the generated SDK package will not contain an apigClient.js file, and you will need to define the ANY methods yourself.

To install, initiate and call a JavaScript SDK generated by API Gateway for a REST API

1. Extract the contents of the API Gateway-generated .zip file you downloaded earlier.

2. Enable cross-origin resource sharing (CORS) for all of the methods the SDK generated by API Gateway will call. For instructions, see Enabling CORS for a REST API resource.

3. In your web page, include references to the following scripts.

   <script type="text/javascript" src="lib/axios/dist/axios.standalone.js"></script>
   <script type="text/javascript" src="lib/CryptoJS/rollups/hmac-sha256.js"></script>
   <script type="text/javascript" src="lib/CryptoJS/rollups/sha256.js"></script>
   <script type="text/javascript" src="lib/CryptoJS/components/hmac.js"></script>
   <script type="text/javascript" src="lib/CryptoJS/components/enc-base64.js"></script>
   <script type="text/javascript" src="lib/url-template/url-template.js"></script>
   <script type="text/javascript" src="lib/apiGatewayCore/sigV4Client.js"></script>
   <script type="text/javascript" src="lib/apiGatewayCore/apiGatewayClient.js"></script>
   <script type="text/javascript" src="lib/apiGatewayCore/simpleHttpClient.js"></script>
   <script type="text/javascript" src="lib/apiGatewayCore/utils.js"></script>
   <script type="text/javascript" src="apigClient.js"></script>

4. In your code, initialize the SDK generated by API Gateway by using code similar to the following.

   var apigClient = apigClientFactory.newClient();

   To initialize the SDK generated by API Gateway with AWS credentials, use code similar to the following. If you use AWS credentials, all requests to the API will be signed.

   var apigClient = apigClientFactory.newClient({
     accessKey: 'ACCESS_KEY',
     secretKey: 'SECRET_KEY',
   });

   To use an API key with the SDK generated by API Gateway, pass the API key as a parameter to the Factory object by using code similar to the following. If you use an API key, it is specified as part of the x-api-key header and all requests to the API will be signed. This means you must set the appropriate CORS Accept headers for each request.

   var apigClient = apigClientFactory.newClient({
     apiKey: 'API_KEY'
   });

5. Call the API methods in API Gateway by using code similar to the following. Each call returns a promise with a success and failure callbacks.

   var params = {
     // This is where any modeled request parameters should be added.
     // The key is the parameter name, as it is defined in the API in API Gateway.
     param0: '',
     param1: ''
   };
   
   var body = {
     // This is where you define the body of the request,
   };
   
   var additionalParams = {
     // If there are any unmodeled query parameters or headers that must be
     //   sent with the request, add them here.
     headers: {
       param0: '',
       param1: ''
     },
     queryParams: {
       param0: '',
       param1: ''
     }
   };
   
   apigClient.methodName(params, body, additionalParams)
       .then(function(result){
         // Add success callback code here.
       }).catch( function(result){
         // Add error callback code here.
       });

   Here, the methodName is constructed from the method request's resource path and the HTTP verb. For the SimpleCalc API, the SDK methods for the API methods of

   1. GET /?a=...&b=...&op=...
   2. POST /
   
      { "a": ..., "b": ..., "op": ...}
   3. GET /{a}/{b}/{op}

   the corresponding SDK methods are as follows:

   1. rootGet(params);      // where params={"a": ..., "b": ..., "op": ...} is resolved to the query parameters
   2. rootPost(null, body); // where body={"a": ..., "b": ..., "op": ...}
   3. aBOpGet(params);      // where params={"a": ..., "b": ..., "op": ...} is resolved to the path parameters