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| var express = require('express')
var methodOverride = require('method-override')
var bodyParser = require('body-parser')
var _ = require('underscore')
var low = require('lowdb')
var utils = require('./utils')
low.mixin(require('underscore-db'))
low.mixin(require('underscore.inflections'))
low.mixin({
createId: utils.createId
})
module.exports = function (source) {
// Create router
var router = express.Router()
// Add middlewares
router.use(bodyParser.json({
limit: '10mb'
}))
router.use(bodyParser.urlencoded({
extended: false
}))
router.use(methodOverride())
// Create database
Eif (_.isObject(source)) {
var db = low()
db.object = source
} else {
var db = low(source)
}
// Expose database
router.db = db
// GET /db
function showDatabase(req, res, next) {
res.jsonp(db.object)
}
// GET /:resource
// GET /:resource?q=
// GET /:resource?attr=&attr=
// GET /:resource/:id
// GET /:parent/:parentId/:resource
// GET /:parent/:parentId/:resource/:resourceId etc. ad infinutum
// GET /:parent/:parentId/:resource?attr=&attr=
// GET /*?*&_end=
// GET /*?*&_start=&_end=
function parse(req, res, next) {
// Test if resource exists
if (!db.object.hasOwnProperty(req.params.resource)) {
return res.sendStatus(404)
}
// Set internals
req._internal = {}
// Filters list
req._internal.filters = {}
// Result array
var array
// Remove _start, _end and _limit from req.query to avoid filtering using those
// parameters. Attach to req._internal for use by future middleware
req._internal._start = req.query._start
req._internal._end = req.query._end
req._internal._sort = req.query._sort
req._internal._order = req.query._order
req._internal._limit = req.query._limit
delete req.query._start
delete req.query._end
delete req.query._sort
delete req.query._order
delete req.query._limit
// Handle sub resources if present, and assign id if it's not already there.
req._internal.subResources = []
if (req.params['0']) { // If anything beyond the first resource is provided
req._internal.subResources = req.params['0'].split('/')
req._internal.subResources.shift()
req._internal.subResourceMap = []
req._internal.originalId = req._internal.subResources.shift() // set the resource's original to the first variadic parameter
_.forEach(req._internal.subResources, function (value, index) { // build the subResource objects as provided
var obj = {}
if (index % 2 > 0) { // if this parameter is even, build an object with id, resource, and <parent>Id
obj.id = value
obj.resource = req._internal.subResources[index - 1]
if (index > 1) {
obj[req._internal.subResources[index - 3].slice(0, -1) + 'Id'] = req._internal.subResources[index - 2]
} else {
obj[req.params.resource.slice(0, -1) + 'Id'] = req._internal.originalId
}
req._internal.subResourceMap.push(obj)
} else if (index === (req._internal.subResources.length - 1)) { // if this parameter is odd AND the last one, build an object without an ID
obj.resource = value
if (index > 1) {
obj[req._internal.subResources[index - 2].slice(0, -1) + 'Id'] = req._internal.subResources[index - 1]
}
req._internal.subResourceMap.push(obj)
}
})
if (req._internal.subResourceMap.length > 0) { // if there are any subResources at all (e.g. /posts/12/comments, /posts/12/comments/247, /posts/12/comments/247/user, ...)
// Set up parents
if (req._internal.subResourceMap.length < 2) { // if there is only one subResource (e.g. /posts/12/comments, /posts/12/comments/247)
req._internal.parent = req.params.resource // Assign original resource and id to parent
req._internal.parentId = req._internal.originalId
} else { // if there is more than one subResource (e.g. /posts/12/comments/247/user, /posts/12/comments/247/user/25, ...)
req._internal.parent = req._internal.subResourceMap[req._internal.subResourceMap.length - 2].resource // Assign the second to last subResource as parent
req._internal.parentId = req._internal.subResourceMap[req._internal.subResourceMap.length - 2].id
}
req._internal.filters[req._internal.parent.slice(0, -1) + 'Id'] = +req._internal.parentId
// Set up resource
req.params.resource = req._internal.subResourceMap[req._internal.subResourceMap.length - 1].resource // assign the last subResource's data to resource and id
if (req._internal.subResourceMap[req._internal.subResourceMap.length - 1].id) {
req._internal.originalId = req._internal.subResourceMap[req._internal.subResourceMap.length - 1].id
} else {
delete req._internal.originalId // remove id if subResource doesn't have one
}
}
}
if (req._internal.originalId) {
req._internal.filters.id = +req._internal.originalId // convert original ID to number and set as filter
if (req._internal.filters.id.toString() === req._internal.originalId) {
delete req._internal.originalId
}
if (isNaN(req._internal.filters.id)) {
req._internal.filters.id = req._internal.originalId
}
}
// Add query parameters filters
// Convert query parameters to their native counterparts
for (var key in req.query) {
// don't take into account JSONP query parameters
// jQuery adds a '_' query parameter too
Eif (key !== 'callback' && key !== '_') {
req._internal.filters[key] = utils.toNative(req.query[key])
}
}
next()
}
// GET /:resource/:id
function find(req, res, next) {
if (req.query.q) {
// Full-text search
var q = req.query.q.toLowerCase()
req._internal.resource = db(req.params.resource).filter(function (obj) {
for (var key in obj) {
var value = obj[key]
if (_.isString(value) && value.toLowerCase().indexOf(q) !== -1) {
return true
}
}
})
return next() // don't worry about filters or 404ing, just move along.
}
if (_(req._internal.filters).isEmpty() || typeof req._internal.filters === 'undefined') { // No filters at all, including ID
req._internal.resource = db(req.params.resource).value()
} else { // filters present
req._internal.resource = db(req.params.resource).filter(req._internal.filters)
}
Eif (req._internal.resource) { // if there even is a resource found
if (req._internal.filters.id && req._internal.resource.length === 1) {
req._internal.resource = req._internal.resource[0]
}
if (req._internal.resource.length !== 0) {
return next()
}
}
res.status(404).jsonp({})
}
// Presentation layer: Apply sorting / pagination to response
function present(req, res, next) {
// Sort
if (req._internal._sort) {
req._internal._order = req._internal._order || 'ASC'
req._internal.resource = _.sortBy(req._internal.resource, function (element) {
return element[req._internal._sort];
})
if (req._internal._order === 'DESC') {
req._internal.resource.reverse();
}
}
// Slice result
if (req._internal._end || req._internal._limit) {
res.setHeader('X-Total-Count', req._internal.resource.length)
res.setHeader('Access-Control-Expose-Headers', 'X-Total-Count')
}
req._internal._start = parseInt(req._internal._start) || 0
if (req._internal._end) {
req._internal.resource = req._internal.resource.slice(req._internal._start, parseInt(req._internal._end))
} else if (req._internal._limit) {
// Convert strings to int and sum to get end value
req._internal.resource = req._internal.resource.slice(req._internal._start, parseInt(req._internal._start) + parseInt(req._internal._limit))
}
res.jsonp(req._internal.resource)
}
// POST /:resource
function create(req, res, next) {
for (var key in req.body) {
req.body[key] = utils.toNative(req.body[key])
}
var resource = db(req.params.resource)
.insert(req.body)
res.jsonp(resource)
}
// PUT /:resource/:id
// PATCH /:resource/:id
function update(req, res, next) {
for (var key in req.body) {
req.body[key] = utils.toNative(req.body[key])
}
var resource = db(req.params.resource)
.update(utils.toNative(req._internal.filters.id), req.body)
if (resource) {
res.jsonp(resource)
} else {
res.status(404).jsonp({})
}
}
// DELETE /:resource/:id
function destroy(req, res, next) {
db(req.params.resource).remove(utils.toNative(req._internal.filters.id))
// Remove dependents documents
var removable = utils.getRemovable(db.object)
_(removable).each(function (item) {
db(item.name).remove(item.id)
})
res.status(200).jsonp({})
}
router.get('/db', showDatabase)
router.route('/:resource*')
.get(parse, find, present)
.post(parse, create)
.put(parse, update)
.patch(parse, update)
.delete(parse, destroy)
return router
}
|