# Custom Globals

URL: /docs/extending/custom-globals/
Section: extending
Tags: extending, globals

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Custom Globals Globals are available in all templates without explicit passing. Add Variables from kida import Environment env = Environment() env.add_global("site_name", "My Site") env.add_global("current_year", 2024) env.add_global("debug_mode", False) Template usage: <title>{{ site_name }}</title> <footer>© {{ current_year }}</footer> Add Functions from datetime import datetime def now(): return datetime.now() def format_date(dt, pattern="%Y-%m-%d"): return dt.strftime(pattern) env.add_global("now", now) env.add_global("format_date", format_date) Template usage: <p>Generated: {{ format_date(now()) }}</p> <p>Today: {{ format_date(now(), "%B %d, %Y") }}</p> Add Classes from collections import namedtuple # Make types available env.add_global("Counter", Counter) env.add_global("namedtuple", namedtuple) Built-in Globals Kida includes common Python builtins: range, len, str, int, float, bool dict, list, set, tuple abs, min, max, sum sorted, reversed, enumerate, zip map, filter Common Patterns Site Configuration site_config = { "name": "My Site", "url": "https://example.com", "author": "Jane Doe", } env.add_global("site", site_config) <a href="{{ site.url }}">{{ site.name }}</a> <meta name="author" content="{{ site.author }}"> Utility Functions import json from urllib.parse import urlencode env.add_global("json_encode", json.dumps) env.add_global("urlencode", urlencode) <script>const data = {{ json_encode(config) }};</script> <a href="/search?{{ urlencode(params) }}">Search</a> Feature Flags features = { "dark_mode": True, "beta_features": False, "analytics": True, } env.add_global("features", features) {% if features.dark_mode %} <link rel="stylesheet" href="/css/dark.css"> {% end %} {% if features.analytics %} {% include "analytics.html" %} {% end %} Request Context (Web) def get_request_context(request): return { "user": request.user, "path": request.path, "is_authenticated": request.user.is_authenticated, } # Per-request globals env.add_global("request", get_request_context(request)) Translation Function import gettext def _(text): return translations.gettext(text) env.add_global("_", _) env.add_global("gettext", _) <h1>{{ _("Welcome") }}</h1> <p>{{ _("Hello, {}!").format(user.name) }}</p> Dynamic Globals For per-request values, update globals before rendering: def render_with_context(template_name, **context): # Add request-specific globals env.add_global("current_user", get_current_user()) env.add_global("csrf_token", generate_csrf()) return env.render(template_name, **context) Object as Namespace Group related globals: class Helpers: @staticmethod def format_date(dt, pattern="%Y-%m-%d"): return dt.strftime(pattern) @staticmethod def truncate(text, length=100): if len(text) <= length: return text return text[:length] + "..." env.add_global("helpers", Helpers) {{ helpers.format_date(post.date) }} {{ helpers.truncate(post.content, 200) }} Best Practices Immutable Configuration # ✅ Configuration object env.add_global("config", frozendict(settings)) # ❌ Mutable global env.add_global("settings", mutable_dict) Clear Naming # ✅ Descriptive names env.add_global("site_config", config) env.add_global("format_currency", format_money) # ❌ Vague names env.add_global("c", config) env.add_global("f", format_money) Avoid Side Effects # ✅ Pure function env.add_global("add", lambda a, b: a + b) # ❌ Function with side effects def log_and_add(a, b): print(f"Adding {a} + {b}") # Side effect return a + b See Also Rendering Contexts — Pass variables to templates Custom Filters — Transform values API Reference — Environment.add_global()

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