core.py

from werkzeug.contrib.cache import SimpleCache
from flask import request, Response, g, request, redirect, url_for, render_template, current_app, jsonify
from functools import wraps

CACHE_TIMEOUT = 300
cache = SimpleCache()

# Useful decorators refer to: http://flask.pocoo.org/docs/patterns/viewdecorators/

def cached(timeout=CACHE_TIMEOUT, key='view/%s'):
    def decorator(f):
        @wraps(f)
        def decorated_function(*args, **kwargs):
            cache_key = key % request.path
            rv = cache.get(cache_key)
            if rv is not None:
                return rv
            rv = f(*args, **kwargs)
            cache.set(cache_key, rv, timeout=timeout)
            return rv
        return decorated_function
    return decorator

def login_required(f):
    @wraps(f)
    def decorated_function(*args, **kwargs):
        if g.user is None:
            return redirect(url_for('login', next=request.url))
        return f(*args, **kwargs)
    return decorated_function

'''
Usage example:
@app.route('/')
@templated('index.html')
def index():
    return dict(value=42)
'''
def templated(template=None):
    def decorator(f):
        @wraps(f)
        def decorated_function(*args, **kwargs):
            template_name = template
            if template_name is None:
                template_name = request.endpoint \
                    .replace('.', '/') + '.html'
            ctx = f(*args, **kwargs)
            if ctx is None:
                ctx = {}
            elif not isinstance(ctx, dict):
                return ctx
            return render_template(template_name, **ctx)
        return decorated_function
    return decorator

def request_wants_json():
    best = request.accept_mimetypes \
        .best_match(['application/json', 'text/html'])
    return best == 'application/json' and \
        request.accept_mimetypes[best] > \
        request.accept_mimetypes['text/html']