Welcome to Flask-Inertia’s documentation¶

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Contents:

Installation¶

$ pip install flask-inertia

Configuration¶

The 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.

Use¶

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.

Your templates¶

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 https://github.com/pallets/flask/issues/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).

Create responses¶

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_inertia import render_inertia

@app.route("/test_inertia/")
def test_inertia():
    """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 component

view_data: [OPTIONAL] Data used in your template but not sent to your JavaScript components

Shorthand routes¶

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 in flask.add_url_rule

component_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 the component_name in lower case)

Root template data¶

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'] }}">

External redirects¶

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_inertia import inertia_location

@app.route("/test_inertia/")
def external_url():
    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.