JSON 总是返回“client_id 未指定”

Question

I'm trying to get a token from the ArcGIS Online service using a Javascript. However, it's always returning an error which indicates the client_id isn't specified.

Am I doing everything right here?

<script type="text/javascript">
    var MyJSONText = '{"client_id":"<<MY_CLIENT_ID>>","client_secret":"<<MY_CLIENT_SECRET>>","grant_type":"client_credentials","expiration":"1440","f":"json"}';
    var MyJSON = JSON.parse(MyJSONText);
    xhr = new XMLHttpRequest();
    xhr.open("POST", "https://www.arcgis.com/sharing/rest/oauth2/token/");
    xhr.send(MyJSON);
    xhr.onreadystatechange = function ()
    {
        if (xhr.readyState == 4 && xhr.status == 200)
        {
            alert(xhr.responseText);
        }
    }

</script>

Edit - full error is:

{"error":{"code":400,"error":"invalid_request","error_description":"client_id not specified","message":"client_id not specified","details":[]}}

Answer 1

I was able to retrieve an access token using application/x-www-form-urlencoded request:

POST https://www.arcgis.com/sharing/rest/oauth2/token HTTP/1.1
User-Agent: Fiddler
Content-Type: application/x-www-form-urlencoded
Host: www.arcgis.com
Content-Length: 126

client_id=<YOUR ID>&client_secret=<YOUR SECRET>&grant_type=client_credentials&expiration=1440&f=json

which means that you might need to specify the Content-Type request header when making the XHR request:

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

and of course properly formatting the body as application/x-www-form-urlencoded instead of JSON. In my tests this endpoint didn't work with JSON payload.

Unfortunately from what it looks, the token endpoint doesn't support setting the Content-Type request header in its CORS policy which means that you might be out of luck in calling it with javascript. Besides their documentation doesn't mention anything about javascript as a supported language.

So basically if you want to make this work you could get the access token on your server side and pass it along to the client.

Answer 2

Access Token Generation Url => https://www.arcgis.com/sharing/rest/oauth2/token

Headers enter image description here

For the Case of body in Post man select 'x-www-form-urlencoded'

enter image description here

After that you will get the respective expected result with token

{"access_token":"S-z3mxAqsZBeihx8NgFmNGsZAUGfzKZWCYVV2TiQO422u9XDLTCTZAkpoecyxx_LAc71I_tPkeeOlo2Pzkapv01bBOA03SzMRjRMOm-h3ljTl-pb3XdffoyYjCflE4F8LD377DbpjDWkupkdTaxJpg..","expires_in":7200}