====== Flask MongoAlchemy ======
===== Install =====
<code>
pip install Flask-MongoAlchemy
</code>

===== Use =====
==== Initialization ====

<code python>
from flask import Flask
from flask.ext.mongoalchemy import MongoAlchemy
app = Flask(__name__)
app.config['MONGOALCHEMY_DATABASE'] = 'library'
db = MongoAlchemy(app)

class Author(db.Document):
    name = db.StringField()

class Book(db.Document):
    title = db.StringField()
    author = db.DocumentField(Author)
    year = db.IntField()
</code>

There are other ways to initialize it:
<code python>
app = Flask(__name__)
db = MongoAlchemy(app)
</code>
<code python>
db = MongoAlchemy()
def init_app():
    app = Flask(__name__)
    db.init_app(app)
    return app
</code>
==== Create, update, delete ====
Now you can create authors and books:
<code python>
>>> from application import Author, Book
>>> mark_pilgrim = Author(name='Mark Pilgrim')
>>> dive = Book(title='Dive Into Python', author=mark_pilgrim, year=2004)
>>> mark_pilgrim.save()
>>> dive.save()
</code>

If you make any changes on a document, you may call save() again:
<code python>
>>> mark_pilgrim.name = 'Mark Stalone'
>>> mark_pilgrim.save()
</code>
And you can remove a document from the database by calling its remove() method:
<code python>
>>> dive.remove()
</code>
==== Queries ====

Every document has a query class property. It’s very simple to use it:
<code python>
>>> mark = Author.query.get('76726')
>>> mark.name = 'Mark Pilgrim'
>>> mark.save()
</code>
You also can use the filter method instead of the get() method:
<code python>
>>> mark = Author.query.filter(Author.name == 'Mark Pilgrim').first()
>>> mark.name = 'Steve Jobs'
>>> mark.save()
</code>

=== Advanced ===
You can create your own queries:
<code python>
from flask.ext.mongoalchemy import BaseQuery
from application import db

class MyCustomizedQuery(BaseQuery):

    def get_johns(self):
        return self.filter(self.type.first_name == 'John')

class Person(db.Document):
    query_class = MyCustomizedQuery
    name = db.StringField()
</code>

There are other functions:
  * first_or_404()
  * get(mongo_id)
  * get_or_404(mongo_id)

=== Pagination ===
You can call a method for a query: ''paginate(page, per_page=20, error_out=True)''. This method returns a ''Pagination'' object in which you can call...
  * has_next()
  * has_prev()
  * items = None
  * next(error_out=False)
  * next_num
  * page = None
  * pages
  * per_page = None
  * prev(error_out=False)
  * prev_num
  * query = None
  * total = None

[[https://pythonhosted.org/Flask-MongoAlchemy/index.html#flask.ext.mongoalchemy.Pagination.has_next|Documentation for these methods]]
===== Configuration =====
<code python>
>>> app.config['MONGOALCHEMY_SERVER_AUTH'] = False
</code>
There are values to change in Mongo config:
  * MONGOALCHEMY_DATABASE
  * MONGOALCHEMY_SERVER	
  * MONGOALCHEMY_PORT	
  * MONGOALCHEMY_USER	
  * MONGOALCHEMY_PASSWORD	
  * MONGOALCHEMY_SAFE_SESSION	
  * MONGOALCHEMY_OPTIONS	
  * MONGOALCHEMY_SERVER_AUTH	
  * MONGOALCHEMY_REPLICA_SET	
  * MONGOALCHEMY_CONNECTION_STRING


When MongoAlchemy or init_app() are invoked with only one argument (the Flask instance), a configuration value prefix of MONGOALCHEMY is assumed; this can be overridden with the config_prefix argument, for example:
<code python>
app = Flask(__name__)
# defaulting to MONGOENGINE prefix
mongo1 = MongoAlchemy(app)
# using another database config
app.config['OTHER_DBNAME'] = 'other'
mongo2 = MongoAlchemy(app, config_prefix='OTHER')
</code>