Flask: permission for cookies

flask-permission-for-cookies.md

1. Mandate a banner on any page base.html

{% if cookies_check() %}
        {# then user has already consented so no requirement for consent banner #}
{% else %}
        {# show a cookie consent banner #}
        <div id="cookie-consent-container">
            <button id="cookie-consent">I Consent</button>
        </div>
        <script>
            var fn = function () {
                document.cookie = "cookie_consent=true";
                document.getElementById('cookie-consent-container').hidden = true;
            };
            document.getElementById('cookie-consent').onclick = fn;
        </script>
{% endif %}

2. Inject the function into jijna2 to check the cookies

@app.app_context_processor
def inject_template_scope():
    injections = dict()

    def cookies_check():
        value = request.cookies.get('cookie_consent')
        return value == 'true'
    injections.update(cookies_check=cookies_check)

    return injections

It works.