Users to whom the category is available

[Matvey]

Hey! I am just starting to deal with development and I have a task that I cannot cope with yet. I need to get a list of all users to whom the category is available. For now, I don't want to do this as a widget, but just use the filter: category.build hook in plugin.json and call the method in which I am experimenting. In general, I have not yet found a suitable ready-made method in the code of NodeBB.
In general, I see the task like this ... I need to write a function that will receive the user ID and category ID and the answer will return true or false, that is, whether the user can see this category or not

[baris]

If you have the userId and categoryId you can use the privilege methods to check if that user has a specific privilege on that category. The function looks like this

await privileges.categories.can('topics:read', cid, uid);

This will return true if the user can read topics in category cid

[Matvey]

@baris
Thank you! I'll check it out today.
But I still need help getting data about all users. I tried the method described in this post, but it doesn't work for me. Always gives an empty array.
https://community.nodebb.org/topic/8908/retrieve-select-info-of-all-users-in-database

[PitaJ]

@matvey what exactly have you tried? Show us the code

[Matvey]

@pitaj
Actually I just need a simple method to get all user IDs. I have now used the following code:

const nextUid = await db.getObjectField('global', 'nextUid');
const allUids = [];

for (let i = 1; i <= nextUid; i++) {
     allUids.push(i);
}

But I'm not sure if this is correct.

[Matvey]

could it be better this way?

user.getUidsFromSet ('users: joindate', 0, -1)

[Matvey]

As a result, I got such a script, maybe it will be useful to someone.

    const Theme = {}
    const user = require.main.require('./src/user')
    const privileges = require.main.require('./src/privileges')

    Theme.getUsersByCategory = async function(data) {
        const { templateData: { cid } } = data

        const allUserIds = await user.getUidsFromSet('users:joindate', 0, -1)

        const asyncFilter = async (arr, predicate) => {
            const results = await Promise.all(arr.map(predicate))

            return arr.filter((element, index) => results[index])
        }

        const availableUserIds = await asyncFilter(allUserIds, async (id) => {
            return await privileges.categories.can('read', cid, id)
        })

        data.templateData.availableUsers = await user.getUsersData(availableUserIds)

        return data
    }

    module.exports = Theme