Hoot Back-End Update Comment

Learning objective: By the end of this lesson, students will be able build a route that updates embedded subdocuments inside a single hoot.

Overview

In this section, we will create an update route to find and update a single comment within a hoot.

We will be following these specs when building the route:

CRUD Action: UPDATE
Method: PUT
Path: /hoots/:hootId/comments/:commentId
Response: JSON
Success Status Code: 200 Ok
Success Response Body: A JSON status message.
Error Status Code: 500 Internal Server Error
Error Response Body: A JSON object with an error key and a message describing the error

Define the route

Our route will listen for PUT requests on /hoots/:hootId/comments/:commentId:

PUT /hoots/:hootId/comments/:commentId

Add the following to controllers/hoots.js:

// controllers/hoots.js

router.put("/:hootId/comments/:commentId", verifyToken, async (req, res) => {
  // add route
});

🧠 This route might be seem intimidating at first. It requires both a hootId and a commentId, so that we can locate both the parent, and the child document within it.

❗ A user needs to be logged in to update a comment, so be sure to include the verifyToken middleware.

Code the controller function

Let’s breakdown what we’ll accomplish inside our controller function.

First we call upon the Hoot model’s findById() method. The retrieved hoot is the parent document that holds an array of comments. We’ll need to find the specific comment we wish to update within this array. To do so, we can use the MongooseDocumentArray.prototype.id() method. This method is called on the array of a document, and returns an embedded subdocument based on the provided ObjectId (req.params.commentId).
With the retrieved comment, we update its text property with req.body.text, before saving the parent document (hoot), and issuing a JSON response with a message of Ok.

Add the following to controllers/hoots.js:

// controllers/hoots.js

router.put("/:hootId/comments/:commentId", verifyToken, async (req, res) => {
  try {
    const hoot = await Hoot.findById(req.params.hootId);
    const comment = hoot.comments.id(req.params.commentId);

    // ensures the current user is the author of the comment
    if (comment.author.toString() !== req.user._id) {
      return res
        .status(403)
        .json({ message: "You are not authorized to edit this comment" });
    }

    comment.text = req.body.text;
    await hoot.save();
    res.status(200).json({ message: "Comment updated successfully" });
  } catch (err) {
    res.status(500).json({ err: err.message });
  }
});

Test the route in Postman

Now that we have finished the route let’s test it with Postman. We’ll do this by sending a PUT request to /hoots/:hootId/comments/:commentId.

Create a new request called Update Comment and set the request type to PUT.

Your Postman URL should look something like this:

http://localhost:3000/hoots/63390dddff7c27bc4b86a1aa/comments/633915e08845c5a891cd4bf2

Add the following to the Postman body section.

{
  "text": "my super cool update"
}

Your Postman request should look something like this.

Update comment request

The response should be an object containing a message: "Comment updated successfully" property:

Update comment response