Python (Flask) serving Angular project's index.html file

Question

Does anyone know how to serve an Angular single page application using Flask?

I\'m having trouble serving the default route, \'/\', which should load index.html and

Answer 1

This is an old question but accepted answer did not work for me. So here is my solution that works with angular routing:

---

My folder structure:

/angular
    /src
    angular.json
    ... angular project files
/public
    index.html
    ... angular build files
/venv
server.py

---

In my angular.json I changed outputPath to achive above structure:

"outputPath": "../public"

---

And in server.py:

import os.path

@app.route("/custom-endpoint")
def custom_endpoint_handler():
    return jsonify(myKey="myValue")


# Serving static files
@app.route('/', defaults={'path': ''})
@app.route('/<string:path>')
@app.route('/<path:path>')
def static_proxy(path):
    if os.path.isfile('public/' + path):
        # If request is made for a file by angular for example main.js
        # condition will be true, file will be served from the public directory
        return send_from_directory('public', path)
    else:
        # Otherwise index.html will be served,
        # angular router will handle the rest
        return app.send_static_file("index.html")

Footnote: I am new to flask. So any improvements or fixes if there are any errors are welcomed.

Answer 2

As mentioned in Flask docs:

Just create a folder called static in your package or next to your module and it will be available at /static on the application.

So, if you use the template in:

templates/dist/templates/index.html
static/ # set static folder there

Or, depending how you have your application sorted:

templates/dist/static/ # set static folder there

Have a look at how they sort the application in the docs:

/application.py
/templates
    /hello.html

or if you use module folders:

/application
    /__init__.py
    /templates
        /hello.html

Answer 3

To simplify the setup, consider using Angular CLI to place all of the files in a distribution directory during the build process, i.e., by specifying the outputPath in angular.json. You can use the angular.json assets section to move your Python files during the build.

angular.json

"your-project": {
  "root": "your-project-directory",
  "sourceRoot": "your-project-directory/src",
  "projectType": "application",
  "architect": {
    "build": {
    "builder": "@angular-devkit/build-angular:browser",
    "options": {
      "outputPath": "dist",
      "index": "your-project-directory/src/index.html",
      "main": "your-project-directory/src/main.ts",
      ...

      "assets": [
        {
          "glob": "**/*",
          "input": "your-project-directory/src/assets/",
          "output": "assets"
        },
        {
          "glob": "**/*",
          "input": "your-project-directory/src/python/",
          "output": "."
        }

---

In the top level of the dist directory, place your main.py with the basic Flask setup along with index.html. Note the static_proxy to ensure that supporting files are served.

main.py

from flask import Flask, send_from_directory

app = Flask(__name__)


@app.route('/<path:path>', methods=['GET'])
def static_proxy(path):
  return send_from_directory('./', path)


@app.route('/')
def root():
  return send_from_directory('./', 'index.html')


if __name__ == '__main__':
  # This is used when running locally only. When deploying use a webserver process 
  # such as Gunicorn to serve the app.
  app.run(host='127.0.0.1', port=8080, debug=True)


@app.errorhandler(500)
def server_error(e):
  return 'An internal error occurred [main.py] %s' % e, 500