AirBnB clone v2

Objectives

What is Unit testing and how to implement it in a large project
What is *args and how to use it
What is **kwargs and how to use it
How to handle named arguments in a function
How to create a MySQL database
How to create a MySQL user and grant it privileges
What ORM means
How to map a Python Class to a MySQL table
How to handle 2 different storage engines with the same codebase
How to use environment variables

Project phase at last modification

Understanding and building a web framework with Flask
What is a route, how to define routes, and handle variables in routes
What is template, how to create dynamic templates and render them in Flask

Classes

AirBnB clone implements the following classes:

BaseModel
User
State
City
Amenity
Place
Review

Storage

The above classes are handled by one of either two abstracted storage engines, depending on the call - FileStorage or DBStorage.

FileStorage

The default mode.

In FileStorage mode, every time the backend is initialized, HolbertonBnB instantiates an instance of FileStorage called storage. The storage object is loaded/re-loaded from any class instances stored in the JSON file file.json. As class instances are created, updated, or deleted, the storage object is used to register corresponding changes in the file.json.

DBStorage

Run by setting the environmental variables HBNB_TYPE_STORAGE=db.

In DBStorage mode, every time the backend is initialized, HolbertonBnB instantiates an instance of DBStorage called storage. The storage object is loaded/re-loaded from the MySQL database specified in the environmental variable HBNB_MYSQL_DB, using the user HBNB_MYSQL_USER, password HBNB_MYSQL_PWD, and host HBNB_MYSQL_HOST. As class instances are created, updated, or deleted, the storage object is used to register changes in the corresponding MySQL database. Connection and querying is achieved using SQLAlchemy.

Note that the databases specified for DBStorage to connect to must already be defined on the MySQL server. This repository includes scripts setup_mysql_dev.sql and setup_mysql_test.sql to set up hbnb_dev_db and hbnb_test_db databases in a MySQL server, respectively.

Console

The console is a command line interpreter that permits management of the backend of HolbertonBnB. It can be used to handle and manipulate all classes utilized by the application (achieved by calls on the storage object defined above).

Using the Console

The HolbertonBnB console can be run both interactively and non-interactively. To run the console in non-interactive mode, pipe any command(s) into an execution of the file console.py at the command line.

$ echo "help" | ./console.py
(hbnb)
Documented commands (type help <topic>):
========================================
EOF  all  count  create  destroy  help  quit  show  update

(hbnb)
$

Alternatively, to use the HolbertonBnB console in interactive mode, run the file console.py by itself:

$ ./console.py

Remember, the console can be run with storage instantiated in either FileStorage or DBStorage mode. The above examples instantiate FileStorage by default, but DBStorage can be instantiated like so:

$ HBNB_MYSQL_USER=hbnb_dev HBNB_MYSQL_PWD=hbnb_dev_pwd HBNB_MYSQL_HOST=localhost HBNB_MYSQL_DB=hbnb_dev_db HBNB_TYPE_STORAGE=db ./console.py

The console functions identically regardless of the storage mode.

While running in interactive mode, the console displays a prompt for input:

$ ./console.py
(hbnb)

To quit the console, enter the command quit, or input an EOF signal (ctrl-D).

$ ./console.py
(hbnb) quit
$

$ ./console.py
(hbnb) EOF
$

Console Commands

The HolbertonBnB console supports the following commands:

create

Usage: create <class> <param 1 name>=<param 1 value> <param 2 name>=<param 2 value> ...

Creates a new instance of a given class. The class' ID is printed and the instance is saved to the file file.json. When passing parameter key/value pairs, any underscores contained in value strings are replaced by spaces.

$ ./console.py
(hbnb) create BaseModel
119be863-6fe5-437e-a180-b9892e8746b8
(hbnb)
(hbnb) create State name="California"
(hbnb) quit
$ cat file.json ; echo ""
{"BaseModel.119be863-6fe5-437e-a180-b9892e8746b8": {"updated_at": "2019-02-17T2
1:30:42.215277", "created_at": "2019-02-17T21:30:42.215277", "__class__": "Base
Model", "id": "119be863-6fe5-437e-a180-b9892e8746b8"}, {'id': 'd80e0344-63eb-43
4a-b1e0-07783522124e', 'created_at': datetime.datetime(2017, 11, 10, 4, 41, 7, 
842160), 'updated_at': datetime.datetime(2017, 11, 10, 4, 41, 7, 842235), 'name
': 'California'}}

show

Usage: show <class> <id> or <class>.show(<id>)

Prints the string representation of a class instance based on a given id.

$ ./console.py
(hbnb) create User
1e32232d-5a63-4d92-8092-ac3240b29f46
(hbnb)
(hbnb) show User 1e32232d-5a63-4d92-8092-ac3240b29f46
[User] (1e32232d-5a63-4d92-8092-ac3240b29f46) {'id': '1e32232d-5a63-4d92-8092-a
c3240b29f46', 'created_at': datetime.datetime(2019, 2, 17, 21, 34, 3, 635828), 
'updated_at': datetime.datetime(2019, 2, 17, 21, 34, 3, 635828)}
(hbnb)
(hbnb) User.show(1e32232d-5a63-4d92-8092-ac3240b29f46)
[User] (1e32232d-5a63-4d92-8092-ac3240b29f46) {'id': '1e32232d-5a63-4d92-8092-a
c3240b29f46', 'created_at': datetime.datetime(2019, 2, 17, 21, 34, 3, 635828), 
'updated_at': datetime.datetime(2019, 2, 17, 21, 34, 3, 635828)}
(hbnb)

destroy

Usage: destroy <class> <id> or <class>.destroy(<id>)

Deletes a class instance based on a given id.

$ ./console.py
(hbnb) create State
d2d789cd-7427-4920-aaae-88cbcf8bffe2
(hbnb) create Place
3e-8329-4f47-9947-dca80c03d3ed
(hbnb)
(hbnb) destroy State d2d789cd-7427-4920-aaae-88cbcf8bffe2
(hbnb) Place.destroy(03486a3e-8329-4f47-9947-dca80c03d3ed)
(hbnb) quit
$ cat file.json ; echo ""
{}

all

Usage: all or all <class> or <class>.all()

Prints the string representations of all instances of a given class. If no class name is provided, the command prints all instances of every class.

$ ./console.py
(hbnb) create BaseModel
fce2124c-8537-489b-956e-22da455cbee8
(hbnb) create BaseModel
450490fd-344e-47cf-8342-126244c2ba99
(hbnb) create User
b742dbc3-f4bf-425e-b1d4-165f52c6ff81
(hbnb) create User
8f2d75c8-fb82-48e1-8ae5-2544c909a9fe
(hbnb)
(hbnb) all BaseModel
["[BaseModel] (450490fd-344e-47cf-8342-126244c2ba99) {'updated_at': datetime.da
tetime(2019, 2, 17, 21, 45, 5, 963516), 'created_at': datetime.datetime(2019, 2
, 17, 21, 45, 5, 963516), 'id': '450490fd-344e-47cf-8342-126244c2ba99'}", "[Bas
eModel] (fce2124c-8537-489b-956e-22da455cbee8) {'updated_at': datetime.datetime
(2019, 2, 17, 21, 43, 56, 899348), 'created_at': datetime.datetime(2019, 2, 17,
21, 43, 56, 899348), 'id': 'fce2124c-8537-489b-956e-22da455cbee8'}"]
(hbnb)
(hbnb) User.all()
["[User] (8f2d75c8-fb82-48e1-8ae5-2544c909a9fe) {'updated_at': datetime.datetim
e(2019, 2, 17, 21, 44, 44, 428413), 'created_at': datetime.datetime(2019, 2, 17
, 21, 44, 44, 428413), 'id': '8f2d75c8-fb82-48e1-8ae5-2544c909a9fe'}", "[User] 
(b742dbc3-f4bf-425e-b1d4-165f52c6ff81) {'updated_at': datetime.datetime(2019, 2
, 17, 21, 44, 15, 974608), 'created_at': datetime.datetime(2019, 2, 17, 21, 44,
15, 974608), 'id': 'b742dbc3-f4bf-425e-b1d4-165f52c6ff81'}"]
(hbnb)
(hbnb) all
["[User] (8f2d75c8-fb82-48e1-8ae5-2544c909a9fe) {'updated_at': datetime.datetim
e(2019, 2, 17, 21, 44, 44, 428413), 'created_at': datetime.datetime(2019, 2, 17
, 21, 44, 44, 428413), 'id': '8f2d75c8-fb82-48e1-8ae5-2544c909a9fe'}", "[BaseMo
del] (450490fd-344e-47cf-8342-126244c2ba99) {'updated_at': datetime.datetime(20
19, 2, 17, 21, 45, 5, 963516), 'created_at': datetime.datetime(2019, 2, 17, 21,
45, 5, 963516), 'id': '450490fd-344e-47cf-8342-126244c2ba99'}", "[User] (b742db
c3-f4bf-425e-b1d4-165f52c6ff81) {'updated_at': datetime.datetime(2019, 2, 17, 2
1, 44, 15, 974608), 'created_at': datetime.datetime(2019, 2, 17, 21, 44, 15, 97
4608), 'id': 'b742dbc3-f4bf-425e-b1d4-165f52c6ff81'}", "[BaseModel] (fce2124c-8
537-489b-956e-22da455cbee8) {'updated_at': datetime.datetime(2019, 2, 17, 21, 4
3, 56, 899348), 'created_at': datetime.datetime(2019, 2, 17, 21, 43, 56, 899348
), 'id': 'fce2124c-8537-489b-956e-22da455cbee8'}"]
(hbnb)

count

Usage: count <class> or <class>.count()

Retrieves the number of instances of a given class.

$ ./console.py
(hbnb) create Place
12c73223-f3d3-4dec-9629-bd19c8fadd8a
(hbnb) create Place
aa229cbb-5b19-4c32-8562-f90a3437d301
(hbnb) create City
22a51611-17bd-4d8f-ba1b-3bf07d327208
(hbnb)
(hbnb) count Place
2
(hbnb) city.count()
1
(hbnb)

update

Usage: update <class> <id> <attribute name> "<attribute value>"

Updates a class instance based on a given id with a given key/value attribute pair or dictionary of attribute pairs. If update is called with a single key/value attribute pair, only "simple" attributes can be updated (ie. not id, created_at, and updated_at).

$ ./console.py
(hbnb) create User
6f348019-0499-420f-8eec-ef0fdc863c02
(hbnb)
(hbnb) update User 6f348019-0499-420f-8eec-ef0fdc863c02 first_name "Holberton" 
(hbnb) show User 6f348019-0499-420f-8eec-ef0fdc863c02
[User] (6f348019-0499-420f-8eec-ef0fdc863c02) {'created_at': datetime.datetime(
2019, 2, 17, 21, 54, 39, 234382), 'first_name': 'Holberton', 'updated_at': date
time.datetime(2019, 2, 17, 21, 54, 39, 234382), 'id': '6f348019-0499-420f-8eec-
ef0fdc863c02'}
(hbnb)

Testing

Unittests for the HolbertonBnB project are defined in the tests folder. To run the entire test suite simultaneously, execute the following command:

$ python3 unittest -m discover tests

Alternatively, you can specify a single test file to run at a time:

$ python3 unittest -m tests/test_console.py

Authors

Mendie Uwemedimo

SlamChillz/AirBnB_clone_v2