#. Upload

1. Control 404 Error

• When can’t find object, Use error 404
• Implement

if (!video) {
  return res.render("404", { pageTitle: "Video not found." });
} else {
  return res.render("watch", { pageTitle: video.title, video });
}

2. GET

• Control get URL
• It is not different with GET Upload URL
• Implement

export const getEdit = async (req, res) => {
  const { id } = req.params;
  const video = await Video.findById(id);
  if (!video) {
    return res.render("404", { pageTitle: "Video not found." });
  }
  return res.render("edit", { pageTitle: `Editing ${video.title}`, video });
};

3. POST

• Get form data from req.body;
• Save data into object
• Implement

export const postEdit = async (req, res) => {
  const { id } = req.params;
  const { title, description, hastags } = req.body;
  const video = await Video.findById(id);
  if (!video) {
    return res.render("404", { pageTitle: "Video not found." });
  }
  video.title = title;
video.description = description;   
video.hashtags = hashtags
    .split(",")
    .map((word) => (word.startsWith("#") ? word : `#{word}`));
  await video.save();
  return res.redirect(`/videos/${id}`);
};

4. findOneAndUpdate()

• It is provided by mongoose with model.
• Need 2 props, the id of the video to update, the update info
• Implement

export const postEdit = async (req, res) => {
  const { id } = req.params;
  const { title, description, hastags } = req.body;
  const video = await Video.findById(id);
  if (!video) {
    return res.render("404", { pageTitle: "Video not found." });
  }
  await Video.findByIdAndUpdate(id, {
    title,
    description,
    hastags: hashtags
      .split(",")
      .map((word) => (word.startsWith("#") ? word : `#{word}`)),
  });
  return res.redirect(`/videos/${id}`);
};

5. Exists()

• Find object with condition (filter=which is mean any condition)
• Return true or false
• Implement

const video = await Video.exists({ _id: id });
  if (!video) {
    return res.render("404", { pageTitle: "Video not found." });
}

6. Check

• Middleware: Before update or save anything, gonna do something