From c3eb8c157d079b91c1c92d1a899b5400e6fc63b6 Mon Sep 17 00:00:00 2001
From: Zaid Abdulla <zkam83@gmail.com>
Date: Fri, 22 Mar 2013 13:06:27 +0300
Subject: [PATCH] Added projection in query API

---
 api.coffee    | 14 +++++++++++++-
 common.coffee |  4 ++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/api.coffee b/api.coffee
index f77a885..a0e60a6 100644
--- a/api.coffee
+++ b/api.coffee
@@ -2,6 +2,7 @@ config = require './config'
 util = require 'util'
 http = require 'http'
 url = require 'url'
+common = require './common'
 db = require './db'
 mongodb = require 'mongodb'
 querystring = require 'querystring'
@@ -292,7 +293,18 @@ else
         else
           q = {}
         q = query.expand(q) if collectionName is 'devices'
-        cur = collection.find(q, {}, {batchSize : 50})
+
+        if urlParts.query.projection?
+          projection = {}
+          for p in urlParts.query.projection.split(',')
+            p = p.trim()
+            projection[p] = 1
+            if collectionName is 'devices'
+              for k,v of config.ALIASES
+                if k == p or common.startsWith(k, "#{p}.")
+                  projection[a] = 1 for a in v
+
+        cur = collection.find(q, projection, {batchSize : 50})
         
         cur.skip(parseInt(urlParts.query.skip)) if urlParts.query.skip?
         cur.limit(parseInt(urlParts.query.limit)) if urlParts.query.limit?
diff --git a/common.coffee b/common.coffee
index 3c257c9..860762a 100644
--- a/common.coffee
+++ b/common.coffee
@@ -15,6 +15,10 @@ exports.endsWith = (str, suffix) ->
   str.indexOf(suffix, str.length - suffix.length) isnt -1
 
 
+exports.startsWith = (str, prefix) ->
+  str.substring(0, prefix.length) == prefix
+
+
 exports.arrayToHash = (arr) ->
   hash = {}
   for i in arr