chameleon_flask 0.0.5

Adds integration of the Chameleon template language to Flask and Quart.

chameleon-flask

Adds integration of the Chameleon template language to Flask and Quart.

Installation

Simply pip install chameleon_flask.

Usage

This is easy to use. Just create a folder within your web app to hold the templates such as:

├── app.py
├── views.py
│
├── templates
│   ├── home
│   │   └── index.pt
│   └── shared
│       └── layout.pt

In the app startup, tell the library about the folder you wish to use:

import os
from pathlib import Path
import chameleon_flask

dev_mode = True

BASE_DIR = Path(__file__).resolve().parent
template_folder = str(BASE_DIR / 'templates')
chameleon_flask.global_init(template_folder, auto_reload=dev_mode)

Then just decorate the Flask or Quart view methods (works on sync and async methods):

@app.get('/async')
@chameleon_flask.template('async.pt')
async def async_world():
    await asyncio.sleep(.01)
    return {'message': "Let's go async Chameleon!"}

The view method should return a dict to be passed as variables/values to the template.

If a flask.Response is returned, the template is skipped and the response along with status_code and other values is directly passed through. This is common for redirects and error responses not meant for this page template. Otherwise the dictionary is used to render async.pt in this example.

Friendly 404s and errors

A common technique for user-friendly sites is to use a custom HTML page for 404 responses. This library has support for friendly 404 pages using the chameleon_flask.not_found() function.

Here's an example:

@app.get('/catalog/item/{item_id}')
@chameleon_flask.template('catalog/item.pt')
async def item(item_id: int):
    item = service.get_item_by_id(item_id)
    if not item:
        chameleon_flask.not_found()
    
    return item.dict()

This will render a 404 response with using the template file templates/errors/404.pt. You can specify another template to use for the response, but it's not required.

An example

See the example/example_app.py file for a working example to play with.