$ pip install flask-inertiaThe module needs to be initialized the usual Flask way and can be configured using
app.config keys:
from flask import Flask from flask_inertia import Inertia SECRET_KEY = "secret!" # mandatory key INERTIA_TEMPLATE = "base.html" app = Flask(__name__) app.config.from_object(__name__) inertia = Inertia() inertia.init_app(app) # or inertia = Inertia(app)
The config key INERTIA_TEMPLATE must be used to set globally the template used by
flask_inertia to render the server responses. This template must exists in the
Flask app templates folder.
For more information about InertiaJS, please read the docs provided by Inertia.
Whereas the Rails and Laravel adapters use a middleware to manage Inertia's
requests, this module doesn't. Once it has been initiliazed it will create
before_request and after_request hooks for your app to handle InertiaJS
frontend requests.
You will need to setup the root template that will be loaded on the first page
visit. It will be used to load your site assets (CSS and JavaScript), and will
also contain a root <div> to boot your JavaScript application in.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0" />
<title>My app</title>
<link href="{{ url_for('static', filename='/css/app.css') }}" rel="stylesheet" />
<script lang="javascript">
{{ inertia.include_router() }}
</script>
</head>
<body>
<div id="app" data-page='{{ page | tojson }}'></div>
<script src="{{ url_for('static', filename='/js/app.js') }}" defer></script>
</body>
</html>Warning
Be aware of the single quotes used for the data-page argument.
Jinja2 will not escape the double quotes of your JSON object
pallets/flask#1002
Your root div must set a HTML data-page attribute. It will be used by Flask,
using a Page JSON object
to communicate with Inertia.
To facilitate the route path resolving, the module provide a template context method
called inertia.include_router. It will expose the Flask views resolution (like
the url_for method) to your frontend Components.
This method has been extracted to django-js-routes
package and works the same way via a window.reverseUrl JavaScript method (
https://github.com/ellmetha/django-js-routes#usage).
This module provides a method render_inertia to render your frontend component
through Flask responses. It will wrap your Responses and act accordingly to Inertia
requests context responding a full html or a JSON reponse. It will be used instead
of Flask render_template method:
from flask.typing import ResponseReturnValue
from flask_inertia import render_inertia
@app.route("/test_inertia/")
def test_inertia() -> ResponseReturnValue:
"""An endpoint to test inertia integration."""
data = {
"username": "foo",
"login": "bar",
}
return render_inertia(
component_name="Index",
props=data,
view_data={},
)
This method take 3 arguments:
component_name: Your frontend component name (e.g. "Index" for an Index.vue Component for example)props: [OPTIONAL] Data used by your componentview_data: [OPTIONAL] Data used in your template but not sent to your JavaScript components
If you have a page that does not need a corresponding controller method (i.e. a frontend
component which does not need props nor view_data), like a "FAQ" or "about" page,
you can route directly to a component via the add_shorthand_route method:
from flask import Flask
from flask_inertia import Inertia
app = Flask(__name__)
app.config.from_object(__name__)
inertia = Inertia(app)
inertia.add_shorthand_route("/faq/", "FAQ")
inertia.add_shorthand_route("/about/", "About", "My About Page")
This method takes 3 arguments:
url: The URL rule as string as used inflask.add_url_rulecomponent_name: Your frontend component name (e.g. "Index" for an Index.vue Component for example)endpoint[OPTIONAL]: The endpoint for the registered URL rule. (by default thecomponent_namein lower case)
There are situations where you may want to access your prop data in your root Jinja2
template. These props are available via the page variable.
<meta name="author" content="{{ page['props']['username'] }}">You may want to provide data that will not be sent to your JavaScript components.
You can do this using the view_data dictionnary in the render_inertia method:
return render_inertia(
component_name="Index",
props=data,
view_data={
"description": "A test page"
}
)
You can then access this variable with the template variable view_data.
<meta name="content" content="{{ view_data['description'] }}">It is possible to redirect to an external website, or even another non-Inertia endpoint
in your app while handling an Inertia request. This can be accomplished using a
server-side initiated window.location visit via the inertia_location method:
from flask.typing import ResponseReturnValue
from flask_inertia import inertia_location
@app.route("/test_inertia/")
def external_url() -> ResponseReturnValue:
return inertia_location("http://foobar.com/")
It will generate a 409 Conflict response and include the destination URL in
the X-Inertia-Location header. When this response is received client-side,
Inertia will automatically perform a window.location = url visit.
Sometimes you need to access certain data on numerous pages within your application. For example, a common use-case for this is showing the current user in the site header. Passing this data manually in each response isn't practical. In these situations shared data can be useful.
This module provides a share method into the Inertia class to preassign
shared data for each request. Shared data will be automatically merged with the
page props provided in your controller. It takes as argument a key/value pair
to serialize it in JSON in the responses.
You can set the shared data statically or programmatically using the method as followed:
inertia = Inertia(app)
# set statically a shared data
inertia.share("foo", "bar")
# or a computed value
def shared_value() -> str:
return "buzz"
inertia.share("fizz", shared_value)
If the value is a callable, the module will resolve it during the response
resolution.
When making visits to the same page you are already on, it's not always necessary to re-fetch all of the page's data from the server. In fact, selecting only a subset of the data can be a helpful performance optimization if it's acceptable that some page data becomes stale.
For partial reloads to be most effective, be sure to also use lazy data evaluation
when returning props from your server-side routes or controllers. This can be
accomplished by wrapping all optional page data in a callable:
from flask.typing import ResponseReturnValue
from flask_inertia import render_inertia
def get_users() -> list[User]:
return User.query.all()
@app.route("/users/")
def users_view() -> ResponseReturnValue:
return render_inertia(
"Users",
props={
"users": get_users,
"companies": Company.query.all(),
}
)
When Inertia performs a request, it will determine which data is required and only then will it evaluate the callable. This can significantly increase the performance of pages that contain a lot of optional data.
Additionally, this module provides an lazy_include method to specify that a prop
should never be included unless explicitly requested using the only option. And
on the inverse, you can use the always_include method to specify that a prop
should always be included, even if it has not been explicitly required in a partial
reload:
from flask.typing import ResponseReturnValue
from flask_inertia import always_include, lazy_include, render_inertia
def get_users() -> list[User]:
return User.query.all()
@app.route("/users/")
def users_view() -> ResponseReturnValue:
return render_inertia(
"Users",
props={
# ALWAYS included on standard visits
# OPTIONALLY included on partial reloads
# ALWAYS evaluated
"users": User.query.all(), # or get_users()
# ALWAYS included on standard visits
# OPTIONALLY included on partial reloads
# ONLY evaluated when needed
"users": get_users,
# NEVER included on standard visits
# OPTIONALLY included on partial reloads
# ONLY evaluated when needed
"users": lazy_include(get_users),
# ALWAYS included on standard visits
# ALWAYS included on partial reloads
# ALWAYS evaluated
"users": always_include(User.query.all()), # or always_include(get_users())
}
)
To see a complete exemple on how to implement a project with this adapter, please read our Tutorial.
If you want to contribute to this project, please read the dedicated file : CONTRIBUTING.rst.