Access JSON data returned by SendGrid - php

Question

I am working with the SendGrid PHP Library (https://sendgrid.com/docs/Integrate/Code_Examples/php.html).
The response is sent ass JSON - e.g. should be something like:
{"message":"success"}
I can send a simple email via:
<?php
$root="../../";
require $root . 'vendor/autoload.php';
$sendgrid = new SendGrid($SendGrid);
$email = new SendGrid\Email();
$email
//->addTo('you#me.com')
->addTo('you#me.com')
->setFrom('me#bar.com')
->setSubject('Subject goes here')
->setText('Hello World!')
->setHtml('<strong>Hello World!</strong>')
;
$res = $sendgrid->send($email);
?>
When I display the output of $res e.g. using PHP-REF (https://github.com/digitalnature/php-ref) I can see that it looks like this:
It appears the response is an Object - presumably JSON?
However, I can't access the data as JSON because if I try this:
$newtxt = json_decode($res);
I get this error:
Warning: json_decode() expects parameter 1 to be string, object given in C:\xampp\htdocs\jim\001-jimpix\contact_old\test-send-grid.php on line 24
And if I try this:
$j_array = json_decode($res, true);
I get the same error.
I can hard code the "$res" value as:
$res = "{\"message\":\"success\"}";
And then that works.
However, I can't work out how to access the JSON returned by SendGrid.
I've tried various things like:
$res = json_decode(json_encode($res),TRUE);
Presumably there is a way to access the JSON returned by SendGrid so I can access the JSON data.
But I don't know how?

Answer 1

As you can see from the PHP-REF response, $res is not the raw JSON.
You can access the result simply by using $res->getBody(). This will give you the parsed JSON from SendGrid.
You do not need to json_decode this.