Added support for Datatables

Added support for ajax-based server side validation (useful for validation of emails, duplicate usernames, etc.)
User form more or less ready in the basic version (i.e. without permission management)

models/users.js

@@ -0,0 +1,107 @@
+'use strict';
+
+const knex = require('../lib/knex');
+const hasher = require('node-object-hash')();
+const { enforce, filterObject } = require('../lib/helpers');
+const interoperableErrors = require('../shared/interoperable-errors');
+const passwordValidator = require('../shared/password-validator')();
+const dtHelpers = require('../lib/dt-helpers');
+const bcrypt = require('bcrypt-nodejs');
+const tools = require('../lib/tools');
+
+const allowedKeys = new Set(['username', 'name', 'email', 'password']);
+
+function hash(user) {
+    return hasher.hash(filterObject(user, allowedKeys));
+}
+
+async function getById(userId) {
+    const user = await knex('users').select(['id', 'username', 'name', 'email']).where('id', userId).first();
+    if (!user) {
+        throw new interoperableErrors.NotFoundError();
+    }
+
+    user.hash = hash(user);
+
+    return user;
+}
+
+async function getByUsername(username) {
+    const user = await knex('users').select(['id', 'username', 'name', 'email']).where('username', username).first();
+    if (!user) {
+        throw new interoperableErrors.NotFoundError();
+    }
+
+    user.hash = hash(user);
+
+    return user;
+}
+
+async function listDTAjax(params) {
+    return await dtHelpers.ajaxList(params, tx => tx('users'), ['users.id', 'users.username', 'users.name']);
+}
+
+async function create(user) {
+    const userId = await knex('users').insert(filterObject(user, allowedKeys));
+    return userId;
+}
+
+async function updateWithConsistencyCheck(user) {
+    await knex.transaction(async tx => {
+        const existingUser = await tx('users').where('id', user.id).first();
+        if (!user) {
+            throw new interoperableErrors.NotFoundError();
+        }
+
+        const existingUserHash = hash(existingUser);
+        if (existingUserHash != user.originalHash) {
+            throw new interoperableErrors.ChangedError();
+        }
+
+        const otherUserWithSameUsername = await tx('users').whereNot('id', user.id).andWhere('username', user.username).first();
+        if (otherUserWithSameUsername) {
+            throw new interoperableErrors.DuplicitNameError();
+        }
+
+        if (user.password) {
+            const passwordValidatorResults = passwordValidator.test(user.password);
+            if (passwordValidatorResults.errors.length > 0) {
+                // This is not an interoperable error because this is not supposed to happen unless the client is tampered with.
+                throw new Error('Invalid password');
+            }
+
+            bcrypt.hash(updates.password, null, null, (err, hash) => {
+                if (err) {
+                    return callback(err);
+                }
+
+                keys.push('password');
+                values.push(hash);
+
+                finalize();
+            });
+
+            tools.validateEmail(updates.email, false)
+
+        } else {
+            delete user.password;
+        }
+
+        await tx('users').where('id', user.id).update(filterObject(user, allowedKeys));
+    });
+}
+
+async function remove(userId) {
+    // FIXME: enforce that userId is not the current user
+    await knex('users').where('id', userId).del();
+}
+
+module.exports = {
+    listDTAjax,
+    remove,
+    updateWithConsistencyCheck,
+    create,
+    hash,
+    getById,
+    getByUsername
+};