codecombat/app/lib/LocalMongo.coffee
2014-07-04 19:27:37 +02:00

48 lines
2.2 KiB
CoffeeScript

LocalMongo = module.exports
# Checks whether func(l, r) is true for at least one value of left for at least one value of right
mapred = (left, right, func) ->
_.reduce(left, ((result, singleLeft) ->
result or (_.reduce (_.map right, (singleRight) -> func(singleLeft, singleRight)),
((intermediate, value) -> intermediate or value), false)), false)
doQuerySelector = (value, operatorObj) ->
value = [value] unless _.isArray value # left hand can be an array too
for operator, body of operatorObj
body = [body] unless _.isArray body # right hand can be an array too
switch operator
when '$gt' then return false unless mapred value, body, (l, r) -> l > r
when '$gte' then return false unless mapred value, body, (l, r) -> l >= r
when '$lt' then return false unless mapred value, body, (l, r) -> l < r
when '$lte' then return false unless mapred value, body, (l, r) -> l <= r
when '$ne' then return false if mapred value, body, (l, r) -> l == r
when '$in' then return false unless _.reduce value, ((result, val) -> result or val in body), false
when '$nin' then return false if _.reduce value, ((result, val) -> result or val in body), false
when '$exists' then return false if value[0]? isnt body[0]
else return false
true
matchesQuery = (target, queryObj) ->
return true unless queryObj
throw new Error 'Expected an object to match a query against, instead got null' unless target
for prop, query of queryObj
if prop[0] == '$'
switch prop
when '$or' then return false unless _.reduce query, ((res, obj) -> res or matchesQuery target, obj), false
when '$and' then return false unless _.reduce query, ((res, obj) -> res and matchesQuery target, obj), true
else return false
else
# Do nested properties
pieces = prop.split('.')
obj = target
for piece in pieces
unless piece of obj
obj = null
break
obj = obj[piece]
if typeof query != 'object' or _.isArray query
return false unless obj == query or (query in obj if _.isArray obj)
else return false unless doQuerySelector obj, query
true
LocalMongo.matchesQuery = matchesQuery