To make an API call to the portal, the following steps need to be followed. 

1. Generate Access Token

• Register the Client App in the portal
  
• Click on settings -> Manage Clients. 
  
• Click on New to add a new client.
  
• Enter name, redirect url and check on verified.
  
• This will generate the Client Id & Client Secret which will be used to generate the access token
  
• Generate the token
  
• Pass the client id, secret, username and password to generate the access token. 
  
• A sample code is given below:  
  

function get_token(username,password){

var xhr = new XMLHttpRequest();

xhr.open("POST", "http://your_institution_domain.com/oauth/token", true);

xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');

xhr.onreadystatechange=function(e)

   {

    if (xhr.readyState==4 && xhr.status==200)

    {

     console.log(e.target.responseText);

    }

   }

 token=xhr.send("client_id=53a305cab608748as64eb6224831dab772105a989d8e454d4a8d8183afb560c414e2ef&client_secret=95318fad811212710db49aec17353c5983c10a1454cheadfthisis25sa25mp25le26a95e19c7c87dec332&grant_type=password&username="+username+"&password="+password+"&redirect_uri=http://localhost:3001/authorize");

return(token);

}

function callApi(token, path)

  {

   var httpRequest = new XMLHttpRequest();

   httpRequest.onreadystatechange = function(evt)

   {

    console.log("xhr.readyState :: "+httpRequest.readyState);

    console.log("xhr.status :: "+httpRequest.status);

    if (httpRequest.readyState==4 && httpRequest.status==200)

    {

     console.log(evt.target.responseText);

    }

   }

           

   httpRequest.open('GET', 'http://your_portal_domain.com/api/'+path);

   httpRequest.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');

   httpRequest.setRequestHeader('Authorization', 'Token token="'+token+'"');

   httpRequest.send();

  }