JavaScript

Scenarios

To use JavaScript to call an API through App authentication, obtain the JavaScript SDK, create a new project, and then call the API by referring to the API calling example.

The JavaScript SDK can run in a Node.js or browser environment.

This section uses IntelliJ IDEA 2018.3.5 as an example to describe how to set up a Node.js development environment.

Preparing the Environment

• You have obtained the domain name, request URL, and request method of the API as well as the key and secret (or AppKey and AppSecret of the client) of the integration application. For details, see Preparations.
• The browser version is Chrome 89.0 or later.
• You have installed Node.js 15.10.0 or later. If not, download the Node.js installation package from the Node.js official website and install it.

  After Node.js is installed, run the npm command to install the moment and moment-timezone modules.

  npm install moment --save
  npm install moment-timezone --save
• You have installed IntelliJ IDEA 2018.3.5 or later. If not, download IntelliJ IDEA from the IntelliJ IDEA official website and install it.
• You have installed the Node.js plug-in on IntelliJ IDEA. If not, install the Python plug-in according to Figure 1.
  Figure 1 Installing the Node.js plug-in
  

Obtaining the SDK

Log in to the ROMA Connect console, choose API Connect > API Calling, and download the SDK. The directory structure after the decompression is as follows:

Creating a Project

1. Start IntelliJ IDEA and choose File > New > Project.

   In the New Project dialog box, choose Static Web and click Next.

   Figure 2 New Project
   

2. Click ..., select the directory where the SDK is decompressed, and click Finish.
   Figure 3 Selecting the SDK directory after decompression
   

3. View the directory structure shown in the following figure.
   Figure 4 Directory structure of the new project
   
   • node_demo.js: Sample code in Node.js. Modify the parameters in the sample code as required. For details about the sample code, see API Calling Example (Node.js).
   • demo.html: Browser sample code. Modify the parameters in the sample code as required. For details about the sample code, see API Calling Example (Browser).

4. Click Edit Configurations.
   Figure 5 Edit Configurations
   

5. Click + and select Node.js.
   Figure 6 Selecting Node.js
   

6. Set JavaScript file to node_demo.js and click OK.
   Figure 7 Selecting node_demo.js
   

API Calling Example (Node.js)

1. Import signer.js to your project.

   var signer = require('./signer')
   var http = require('http')

2. Generate a new signer and enter the AppKey and AppSecret.

   var sig = new signer.Signer()
   sig.Key = "4f5f626b-073f-402f-a1e0-e52171c6100c"
   sig.Secret = "******"

3. Generate a request, and specify the method, request URI, and request body.

   var r = new signer.HttpRequest("POST", "c967a237-cd6c-470e-906f-a8655461897e.apigw.exampleRegion.com/app1?a=1");
   r.body = '{"a":1}'

4. Add the x-stage header to the request to specify an environment name. Add other headers to be signed as necessary.

   r.headers = { "x-stage":"RELEASE" }

5. Execute the following function to generate HTTP(s) request parameters, and add the X-Sdk-Date and Authorization headers for signing the request:

   var opts = sig.Sign(r)

6. Access the API and view the access result. If you access the API using HTTPS, change http.request to https.request.

   var req=http.request(opts, function(res){
           console.log(res.statusCode)  
           res.on("data",	function(chunk){
   		console.log(chunk.toString())
   	})
   })
   req.on("error",function(err){
   	console.log(err.message)
   })
   req.write(r.body)
   req.end()

API Calling Example (Browser)

To use a browser to access APIs, you need to register an API that supports the OPTIONS method. For details, see Creating an API in OPTIONS Mode. The response header contains Access-Control-Allow-* headers. You can add these headers by enabling CORS when creating an API.

1. Import signer.js and dependencies to the HTML page.

   <script src="js/hmac-sha256.js"></script>
   <script src="js/moment.min.js"></script>
   <script src="js/moment-timezone-with-data.min.js"></script>
   <script src='signer.js'></script>

2. Sign the request and access the API.

   var sig = new signer.Signer()
   sig.Key = "4f5f626b-073f-402f-a1e0-e52171c6100c"
   sig.Secret = "******"
   var r= new signer.HttpRequest()
   r.host = "c967a237-cd6c-470e-906f-a8655461897e.apigw.exampleRegion.com"
   r.method = "POST"
   r.uri = "/app1"
   r.body = '{"a":1}'
   r.query = { "a":"1","b":"2" }
   r.headers = { "Content-Type":"application/json" }
   var opts = sig.Sign(r)
   var scheme = "https"
   $.ajax({
   	type: opts.method,
   	data: req.body,
   	processData: false,
   	url: scheme + "://" + opts.hostname + opts.path,
   	headers: opts.headers,
   	success: function (data) {
   		$('#status').html('200')
   		$('#recv').html(data)
   	},
   	error: function (resp) {
   		if (resp.readyState === 4) {
   			$('#status').html(resp.status)
   			$('#recv').html(resp.responseText)
   		} else {
   			$('#status').html(resp.state())
   		}
   	},
   	timeout: 1000
   });