filtering data

For data filtering, we’ll use query parameters. This will allow clients to fetch all tasks, just the complete tasks, or just the incomplete tasks.

Filtering Data

The completed query parameter is on the task documents of MongoDB. This query parameter can be set to true or false. This will prevent clients from fetching unnecessary data tha they don’t plan on using.

First up, create an object to store the search criteria.

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const match = {}

From there, check if the query parameter was provided. The provided value should be parsed into a boolean and stored on match.completed.

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if (req.query.completed) {
  match.completed = req.query.completed === 'true'
}

Last up, match can be added onto populate to fetch just the users that match the search criteria.

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await req.user.populate({
  path: 'tasks',
  match
}).exexPopulate()

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// READ USER'S TASKS
// GET /tasks?completed=true
// GET /tasks?limit=10&skip=10
// GET /tasks?sortBy=createdAt:desc
router.get('/tasks', auth, async (req, res) => {
    const match = {}
    const sort = {}

    if (req.query.completed) {
        match.completed = req.query.completed === 'true'
    }

    if (req.query.sortBy) {
        const parts = req.query.sortBy.split(':')
        sort[parts[0]] = parts[1] === 'desc' ? -1 : 1
    }

    try {
        await req.user.populate({
            path: 'tasks',
            match,
            options: {
                limit: parseInt(req.query.limit),
                skip: parseInt(req.query.skip),
                sort
            }
        }).execPopulate();
        res.send(req.user.tasks);

    } catch (e) {
        res.status(500).send();
    }
})

출처 : NodeJS course on Udemy by Andrew Mead