Starting the implementation of the Document data type

To PUT (or POST) a document, we need to send something when doing
a request, so the _do_request() function was changed to receive a new
param, the content.

This new param receives *LUA objects*. They will be converted to json
and then sent to couchdb.

When content is available, a custom header (Content-Type) is also set.

couchdb.lua

@@ -21,9 +21,11 @@ local socket = require("socket")
 local http = require("socket.http")
 local ltn12 = require("ltn12")
 
+Session = {uri="http:https://localhost:5984"}
+
 Database = {session=nil, name=nil}
 
-Session = {uri="http:https://localhost:5984"}
+Document = {id=nil, rev=nil, schema=nil}
 
 function Session:new(uri)
  local o = {}
@@ -44,12 +46,36 @@ function Database:new(session, name)
  return o
 end
 
-local function _do_request(url, method)
+function Document:new(schema)
+ local o = {}
+ setmetatable(o, self)
+ self.__index = self
+ self.schema = schema
+ if schema.id ~= nil then
+ self.id = schema.id
+ end
+ return o
+end
+
+local function _do_request(url, method, content)
  local t = {}
+ local source = nil
+ local headers = nil
+
+ -- Converting lua object in content to json. If content is set, we should
+ -- also set the Content-Type header
+ if content ~= nil then
+ source = ltn12.source.string(json.encode(content))
+ headers = {}
+ headers['Content-Type'] = 'application/json'
+ end
+
  local _, code, headers, human_readable_error = http.request{
  url=url,
  method=method,
- sink=ltn12.sink.table(t)
+ headers=headers,
+ sink=ltn12.sink.table(t),
+ source=source
  }
 
  -- Getting the body content from the ltn12 sink
@@ -79,4 +105,19 @@ function Database:delete()
  return _do_request(self.session.uri .. "/" .. self.name, "DELETE")
 end
 
+function Database:put(doc)
+ local result = nil
+ if doc.id ~= nil then
+ result = _do_request(
+ string.format("%s/%s/%s", self.session.uri, self.name, doc.id),
+ "PUT", doc.schema)
+ else
+ result = _do_request(
+ string.format("%s/%s", self.session.uri, self.name), "POST",
+ doc.schema)
+ end
+ doc.id = result.id
+ doc.rev = result.rev
+end
+
 return _M