Template Functions¶

This page lists all template functions available in Burrow templates. Functions come from two sources:

Static (HasFuncMap) — registered at parse time, available in all templates
Request-scoped (HasRequestFuncMap) — cloned per request, can access the current request context

Core Functions¶

Provided by the framework itself. Always available.

Static:

Function	Example	Description
`safeHTML`	`{{ safeHTML .RawHTML }}`	Mark a string as safe HTML (no escaping)
`safeURL`	`{{ safeURL .Link }}`	Mark a string as safe URL
`safeAttr`	`{{ safeAttr .Attr }}`	Mark a string as safe HTML attribute
`add`	`{{ add .Page 1 }}`	Integer addition
`sub`	`{{ sub .Total 1 }}`	Integer subtraction
`pageURL`	`{{ pageURL .BasePath .RawQuery 3 }}`	Builds a pagination URL preserving existing query parameters
`pageNumbers`	`{{ range pageNumbers .Current .Total }}`	Generates a slice of page numbers with ellipsis gaps (`-1`)
`mediaURL`	`{{ mediaURL .Hero }}`	Returns the public URL for a `document.Attachment`. Auto-registered when Den is opened with `den.WithStorage(...)`; unregistered (and a parse-time error) when no Storage is configured.
`icon`	`{{ icon "auth/icon_people" }}`	Looks up the named template define and returns its rendered HTML. Returns empty when the name is empty or unknown. Used by layouts to render `NavItem.Icon` / `NavLink.Icon` / `admin.DashboardItem.Icon` (all hold template-define names). See Navigation › Icon convention.
`dict`	`{{ template "x" (dict "Page" .Page "BasePath" "/x") }}`	Builds a `map[string]any` from alternating key/value pairs. Useful for passing multiple values to a sub-template. Keys must be strings.
`appName`	`<title>{{ appName }}</title>`	The configured application name (from `--app-name`, env `APP_NAME`, toml `server.app_name`; defaults to the binary basename). Same source feeds WebAuthn passkey dialogs and SMTP `From`-name decoration.

Navigation (request-scoped, provided by the framework):

Function	Example	Description
`navItems`	`{{ range navItems }}`	Raw `[]NavItem` from all `HasNavItems` apps. No filtering or active state.
`navLinks`	`{{ range navLinks }}`	Filtered `[]NavLink` with `IsActive` computed from the request path. Hides `AuthOnly`/`AdminOnly` items based on the `AuthChecker` in context.

i18n (request-scoped, always available — the framework's i18n bundle is pre-registered by Server.boot and the locale middleware runs on every request):

Function	Example	Description
`lang`	`<html lang="{{ lang }}">`	Current locale (e.g., `"en"`, `"de"`). Resolved from the `Accept-Language` header by the bundle's locale middleware.
`t`	`{{ t "welcome-title" }}`	Simple translation lookup by message ID. Returns the message ID itself when no translation is loaded.
`tData`	`{{ tData "greeting" .Data }}`	Translation with interpolation data (`map[string]any`).
`tPlural`	`{{ tPlural "items-count" .Count }}`	Pluralised translation.

Apps contribute translation files via HasTranslations; the framework auto-discovers them at boot. No separate contrib/i18n app is needed.

Contrib App Functions¶

staticfiles¶

Function	Type	Example	Description
`staticURL`	Static	`{{ staticURL "app/app.min.css" }}`	Returns content-hashed URL for a static file. Paths are prefixed by the contributing app's prefix (e.g., `app/filename`).

csrf¶

These funcs only exist when contrib/csrf is registered. Templates that use them fail to parse at server boot if csrf is missing — there are no silent fallbacks. Apps that ship templates calling csrfToken / csrfField / csrfHxHeaders must declare csrf in their Dependencies().

Function	Type	Example	Description
`csrfToken`	Request	`{{ csrfToken }}`	Returns the raw CSRF token string.
`csrfField`	Request	`{{ csrfField }}`	Renders a complete `<input type="hidden">` element with the CSRF token.
`csrfHxHeaders`	Request	`<body {{ csrfHxHeaders }}>`	Renders the `hx-headers='{"X-CSRF-Token": "…"}'` attribute so all htmx requests carry the CSRF token.

messages¶

Function	Type	Example	Description
`messages`	Request	`{{ range messages }}{{ .Text }}{{ end }}`	Returns the flash messages collected during this request (`[]messages.Message`). Registered by `contrib/messages` via `HasRequestFuncMap`.

auth¶

Static (HasFuncMap):

Function	Type	Example	Description
`credName`	Static	`{{ credName .Credential }}`	Returns the credential's `Name`, falling back to `"Passkey"` when empty.
`deref`	Static	`{{ deref .StringPtr }}`	Dereferences a `*string`, returns empty string if nil.

Request-scoped (HasRequestFuncMap):

Function	Type	Example	Description
`currentUser`	Request	`{{ if $u := currentUser }}{{ $u.Email }}{{ end }}`	Returns the authenticated `*auth.User[auth.EmptyProfile]` or `nil`.
`isAuthenticated`	Request	`{{ if isAuthenticated }}...{{ end }}`	Returns `true` if a user is logged in.
`authLogo`	Request	`{{ authLogo }}`	Returns the auth logo HTML.

How It Works¶

At startup, the framework:

Creates a base template.FuncMap with the core functions
Merges static FuncMap entries from all HasFuncMap apps
Parses all .html template files from HasTemplates apps into one *template.Template

Per request:

Clones the parsed template set
Collects request-scoped functions from all HasRequestFuncMap apps
Injects them into the clone via template.Funcs()

This means static functions are resolved at parse time (fast), while request-scoped functions are resolved per request (slightly slower but can access *http.Request).

Name collisions

The framework panics at startup if two apps register the same function name. See the HasFuncMap reference for the full list of reserved names.