In Flask Admin, I got a column of String values (I can't change the DB definition). When filtering this column in the index view, the user should be able to select the value from a dropdown.
The possible options for the filter should be computed when the user selects the filter. So I need a way to set the options based on a custom model query. Querying is rather fast as the column is indexed.
The SQLA custom filter example only shows how to apply a custom filter, but not how to make the options of a filter dynamic.
The options parameter can be a callable so do something like the following (using the example you've linked to):
def get_all_last_names():
unique_last_names = User.query.with_entities(User.last_name.distinct().label("last_name")).order_by(User.last_name.asc()).all()
return [(user.last_name, user.last_name) for user in unique_last_names]
class UserAdmin(sqla.ModelView):
column_filters = [
FilterEqual(column=User.last_name, name='Last Name', options=get_all_last_names),
]
# This is probably NOT the correct way to refresh the filters cache
@expose('/')
def index_view(self):
self._refresh_filters_cache()
return super(UserAdmin, self).index_view()
See single file demo below. Add new users and they will appear in the 'Last Name' filter. As pointed out by @sortas this version doesn't work when using the app factory method.
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_admin.contrib import sqla
from flask_admin import Admin, expose
# required for creating custom filters
from flask_admin.contrib.sqla.filters import BaseSQLAFilter, FilterEqual
app = Flask(__name__)
# Create dummy secrey key so we can use sessions
app.config['SECRET_KEY'] = '123456790'
# Create in-memory database
app.config['DATABASE_FILE'] = 'sample_db.sqlite'
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///' + app.config['DATABASE_FILE']
app.config['SQLALCHEMY_ECHO'] = True
db = SQLAlchemy(app)
# Flask views
@app.route('/')
def index():
return '<a href="/admin/">Click me to get to Admin!</a>'
# Create model
class User(db.Model):
id = db.Column(db.Integer, primary_key=True)
first_name = db.Column(db.String(100))
last_name = db.Column(db.String(100))
username = db.Column(db.String(80), unique=True)
email = db.Column(db.String(120), unique=True)
# Required for admin interface. For python 3 please use __str__ instead.
def __unicode__(self):
return self.username
# Create custom filter class
class FilterLastNameBrown(BaseSQLAFilter):
def apply(self, query, value, alias=None):
if value == '1':
return query.filter(self.column == "Brown")
else:
return query.filter(self.column != "Brown")
def operation(self):
return 'is Brown'
def get_options():
return [('1', 'Yes'), ('0', 'No')]
def get_all_last_names():
unique_last_names = User.query.with_entities(User.last_name.distinct().label("last_name")).order_by(
User.last_name.asc()).all()
return [(user.last_name, user.last_name) for user in unique_last_names]
# Add custom filter and standard FilterEqual to ModelView
class UserAdmin(sqla.ModelView):
column_filters = [
FilterEqual(column=User.last_name, name='Last Name', options=get_all_last_names),
FilterLastNameBrown(column=User.last_name, name='Last Name', options=(('1', 'Yes'), ('0', 'No')))
]
# This is probably NOT the correct way to refresh the filters cache
@expose('/')
def index_view(self):
self._refresh_filters_cache()
return super(UserAdmin, self).index_view()
admin = Admin(app, template_mode="bootstrap3")
admin.add_view(UserAdmin(User, db.session))
def build_sample_db():
db.drop_all()
db.create_all()
user_obj1 = User(first_name="Paul", last_name="Brown", username="pbrown", email="[email protected]")
user_obj2 = User(first_name="Luke", last_name="Brown", username="lbrown", email="[email protected]")
user_obj3 = User(first_name="Serge", last_name="Koval", username="skoval", email="[email protected]")
db.session.add_all([user_obj1, user_obj2, user_obj3])
db.session.commit()
if __name__ == '__main__':
build_sample_db()
app.run(port=5000, debug=True)
Single file example when using app factory.
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_admin.contrib import sqla
from flask_admin import Admin, expose
# required for creating custom filters
from flask_admin.contrib.sqla.filters import BaseSQLAFilter, FilterEqual
db = SQLAlchemy()
class User(db.Model):
id = db.Column(db.Integer, primary_key=True)
first_name = db.Column(db.String(100))
last_name = db.Column(db.String(100))
username = db.Column(db.String(80), unique=True)
email = db.Column(db.String(120), unique=True)
# Required for admin interface. For python 3 please use __str__ instead.
def __unicode__(self):
return self.username
# Create custom filter class
class FilterLastNameBrown(BaseSQLAFilter):
def apply(self, query, value, alias=None):
if value == '1':
return query.filter(self.column == "Brown")
else:
return query.filter(self.column != "Brown")
def operation(self):
return 'is Brown'
def get_options():
return [('1', 'Yes'), ('0', 'No')]
def get_all_last_names():
unique_last_names = User.query.with_entities(User.last_name.distinct().label("last_name")).order_by(
User.last_name.asc()).all()
return [(user.last_name, user.last_name) for user in unique_last_names]
# Add custom filter and dynamic FilterEqual to ModelView
class UserAdmin(sqla.ModelView):
column_filters = [
FilterLastNameBrown(column=User.last_name, name='Last Name', options=(('1', 'Yes'), ('0', 'No')))
]
def get_filters(self):
_dynamic_filters = getattr(self, 'dynamic_filters', None)
if _dynamic_filters:
return (super(UserAdmin, self).get_filters() or []) + _dynamic_filters
else:
return super(UserAdmin, self).get_filters()
@expose('/')
def index_view(self):
self.dynamic_filters = []
self.dynamic_filters.extend([
FilterEqual(column=User.last_name, name='Last Name', options=get_all_last_names),
# Add further dynamic filters here
])
self._refresh_filters_cache()
return super(UserAdmin, self).index_view()
def create_app():
app = Flask(__name__)
# Create dummy secrey key so we can use sessions
app.config['SECRET_KEY'] = '123456790'
# Create in-memory database
app.config['DATABASE_FILE'] = 'sample_db.sqlite'
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///' + app.config['DATABASE_FILE']
app.config['SQLALCHEMY_ECHO'] = True
db.init_app(app)
admin = Admin(app, template_mode="bootstrap3")
admin.add_view(UserAdmin(User, db.session))
# Flask views
@app.route('/')
def index():
return '<a href="/admin/">Click me to get to Admin!</a>'
@app.before_first_request
def build_sample_db():
db.drop_all()
db.create_all()
user_obj1 = User(first_name="Paul", last_name="Brown", username="pbrown", email="[email protected]")
user_obj2 = User(first_name="Luke", last_name="Brown", username="lbrown", email="[email protected]")
user_obj3 = User(first_name="Serge", last_name="Koval", username="skoval", email="[email protected]")
db.session.add_all([user_obj1, user_obj2, user_obj3])
db.session.commit()
return app
if __name__ == '__main__':
app = create_app()
app.run(port=5000, debug=True)
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