add pagination support

Author: adierebel

README.md

@@ -32,4 +32,4 @@ Install requirements and package:
 
 Test:
 
-	nosetests -v --with-coverage --cover-package=microngo test.py
+	nosetests -v --with-coverage --cover-erase --cover-package=microngo test.py

examples/basic.py

@@ -1,6 +1,7 @@
 from microngo import Microngo
 from datetime import datetime
 from random import randrange
+from time import time
 
 #
 # Client
@@ -75,4 +76,11 @@
 calls_data = db.query("Calls").find().limit(5).sort('No', 1).all()
 for call in calls_data:
 	print("Call No", call.No)
-	call.remove()
+	call.remove()
+
+#
+# Paginate
+#
+s = time()
+paginated_data = db.query("Calls").find().paginate(1, per_page=5)
+print("Time:", time()-s)

microngo/__init__.py

@@ -1 +1,2 @@
-from .microngo import Microngo, Document, Query
+from microngo.microngo import Microngo, Document, Query
+from microngo.pagination import Pagination

microngo/microngo.py

@@ -1,8 +1,9 @@
 from pymongo import MongoClient
 from pymongo.cursor import Cursor
 from pymongo.command_cursor import CommandCursor
+from microngo.pagination import Pagination
 
-class Microngo():
+class Microngo(object):
 	def __init__(self, *args, **kwargs):
 		'''
 		:param str db: Database name. This param is optional, you can use :func:`~microngo.Microngo.database` to set current database.
@@ -61,7 +62,7 @@ def insert(self, collection):
 
 		return Document(self._collection(collection))
 
-class Document():
+class Document(object):
 	def __init__(self, collection, data=None):
 		'''
 		:param obj collection: PyMongo collection object
@@ -70,16 +71,16 @@ def __init__(self, collection, data=None):
 		'''
 
 		# Variables
-		self.microngo_collection	= collection
-		self.microngo_payloads		= []
-		self.microngo_document_id	= None
+		self._microngo_collection	= collection
+		self._microngo_payloads		= []
+		self._microngo_document_id	= None
 
 		# Dict data
 		if data:
 			if isinstance(data, dict):
 				# Set documen id if exist
 				if data.get("_id"):
-					self.microngo_document_id = data.get("_id")
+					self._microngo_document_id = data.get("_id")
 				# Update data
 				self.__dict__.update(data)
 
@@ -91,38 +92,38 @@ def _get_payloads(self):
 		payloads = dict(self.__dict__)
 
 		# Remove internal variables and return data
-		del payloads['microngo_collection']
-		del payloads['microngo_payloads']
-		del payloads['microngo_document_id']
+		del payloads['_microngo_collection']
+		del payloads['_microngo_payloads']
+		del payloads['_microngo_document_id']
 		return payloads
 
 	def _clear_payloads(self):
 		# Cache variable
-		cache_collection	= self.microngo_collection
-		cache_payloads		= self.microngo_payloads
-		cache_document_id	= self.microngo_document_id
+		cache_collection	= self._microngo_collection
+		cache_payloads		= self._microngo_payloads
+		cache_document_id	= self._microngo_document_id
 
 		# Clear self variables
 		payloads = self.__dict__
 		payloads.clear()
 
 		# Reasign internal variables from cache
-		payloads['microngo_collection']		= cache_collection
-		payloads['microngo_payloads']		= cache_payloads
-		payloads['microngo_document_id']	= cache_document_id
+		payloads['_microngo_collection']	= cache_collection
+		payloads['_microngo_payloads']		= cache_payloads
+		payloads['_microngo_document_id']	= cache_document_id
 		return self
 
 	def add(self):
 		'''
 		Add document to list, then insert to collection with insert_many function.
 		'''
 
-		if not self.microngo_document_id:
+		if not self._microngo_document_id:
 			# Get payloads
 			payloads = self._get_payloads()
 
 			# Append to cache
-			self.microngo_payloads.append(payloads)
+			self._microngo_payloads.append(payloads)
 
 			# Clear previous payload and return
 			self._clear_payloads()
@@ -141,38 +142,38 @@ def save(self):
 		'''
 		Save document to collection.
 
-		:return: str or ObjectID
+		:return: list of OjectId or single ObjectId
 		'''
 
-		if self.microngo_document_id:
+		if self._microngo_document_id:
 			# Update
-			self.microngo_collection.update_one(
-				{'_id': self.microngo_document_id},
+			self._microngo_collection.update_one(
+				{'_id': self._microngo_document_id},
 				{'$set': self._get_payloads()},
 				upsert=False
 			)
-			return self.microngo_document_id
+			return self._microngo_document_id
 		else:
 			# Insert
-			if len(self.microngo_payloads) > 0:
-				data = self.microngo_payloads
-				return self.microngo_collection.insert_many(data).inserted_ids
+			if len(self._microngo_payloads) > 0:
+				data = self._microngo_payloads
+				return self._microngo_collection.insert_many(data).inserted_ids
 			else:
 				data	= self._get_payloads()
-				doc_id	= self.microngo_collection.insert_one(data).inserted_id
-				self.microngo_document_id = doc_id
+				doc_id	= self._microngo_collection.insert_one(data).inserted_id
+				self._microngo_document_id = doc_id
 				return doc_id
 
 	def remove(self):
 		'''
 		Remove document from collection.
 		'''
 
-		if self.microngo_document_id:
+		if self._microngo_document_id:
 			# Delete
-			self.microngo_collection.delete_one({'_id': self.microngo_document_id})
+			self._microngo_collection.delete_one({'_id': self._microngo_document_id})
 
-class Query():
+class Query(object):
 	def __init__(self, collection, cursor=None):
 		'''
 		:param obj collection: PyMongo collection object
@@ -281,4 +282,21 @@ def all(self):
 		else:
 			raise Exception("cursor type is '%s'" % (type(self.cursor)))
 
-		return documents
+		return documents
+
+	def paginate(self, page, per_page=20):
+		'''
+		Crate pagination query
+		
+		:return: :class:`~pagination.Pagination` or None
+		'''
+		if page < 1:
+			return None
+
+		total = self.cursor.count()
+		items = self.skip((page - 1) * per_page).limit(per_page).all()
+
+		if len(items) < 1 and page != 1:
+			return None
+
+		return Pagination(self, page, per_page, total, items)

microngo/pagination.py

@@ -0,0 +1,32 @@
+from math import ceil
+
+class Pagination(object):
+	def __init__(self, query, page, per_page, total, items):
+		self.query		= query
+		self.page		= page
+		self.per_page	= per_page
+		self.total		= total
+		self.items		= items
+
+	@property
+	def pages(self):
+		'''The total number of pages'''
+		return int(ceil(self.total / float(self.per_page)))
+
+	@property
+	def next_num(self):
+		'''The next page number.'''
+		return self.page + 1
+
+	def has_next(self):
+		'''Returns ``True`` if a next page exists.'''
+		return self.page < self.pages
+
+	@property
+	def prev_num(self):
+		'''The previous page number.'''
+		return self.page - 1
+
+	def has_prev(self):
+		'''Returns ``True`` if a previous page exists.'''
+		return self.page > 1

test.py

@@ -1,4 +1,4 @@
-from microngo import Microngo, Query, Document
+from microngo import Microngo, Query, Document, Pagination
 from datetime import datetime
 from bson.objectid import ObjectId
 from random import randrange
@@ -88,7 +88,24 @@ def test_05_find_all(self):
 		for i in documents:
 			self.assertEqual(type(i.No), int)
 
-	def test_06_raw(self):
+	def test_06_pagination(self):
+		# Normal state
+		documents = self.db.query("collection_two").find().paginate(1)
+		self.assertEqual(type(documents), Pagination)
+		# If page below 1
+		documents_2 = self.db.query("collection_two").find().paginate(0, per_page=20)
+		self.assertEqual(documents_2, None)
+		# If result empty and page higher than 1
+		documents_3 = self.db.query("collection_two").find({"No": 100}).paginate(2)
+		self.assertEqual(documents_3, None)
+		# Get info from pagination
+		self.assertEqual(type(documents.pages), int)
+		self.assertEqual(type(documents.next_num), int)
+		self.assertEqual(type(documents.has_next()), bool)
+		self.assertEqual(type(documents.prev_num), int)
+		self.assertEqual(type(documents.has_prev()), bool)
+
+	def test_07_raw(self):
 		document	= self.db.query("collection_two").find_by()
 		raw_query	= document.raw()
 		docs		= document.first()
@@ -97,7 +114,7 @@ def test_06_raw(self):
 		self.assertEqual(type(docs), Document)
 		self.assertEqual(type(raw_docs), dict)
 
-	def test_07_update(self):
+	def test_08_update(self):
 		documents = self.db.query("collection_two").find().all()
 		self.assertEqual(type(documents), list)
 		# Check per item
@@ -107,7 +124,7 @@ def test_07_update(self):
 			result = i.save()
 			self.assertEqual(type(result), ObjectId)
 
-	def test_08_error_test(self):
+	def test_09_error_test(self):
 		# Test db error
 		with self.assertRaises(Exception) as ctx:
 			self.db2.query("collection_two").find().all()
@@ -138,7 +155,7 @@ def test_08_error_test(self):
 		with self.assertRaises(Exception) as ctx:
 			doc_all_b = self.db.query("collection_one").find_one().all()
 
-	def test_09_delete(self):
+	def test_10_delete(self):
 		# Delete one
 		document = self.db.query("collection_one").find_one().one()
 		self.assertEqual(type(document), Document)