Otera (お寺, "temple") renders Jinja templates in pure Elixir, with the semantics of Python Jinja2.
iex> Otera.render("Hello {{ name }}!", %{name: "World"})
{:ok, "Hello World!"}Variables are Elixir values, which templates see as Python values: maps are dicts, lists are lists, nil is None, and atom keys become strings. See Otera.Value for the full mapping, and Otera.Dict for the key order of dicts.
To render the chat template of a Hugging Face model like transformers, see Otera.ChatTemplate.
Options
:trim_blocks- removes the first newline after a block tag. The default isfalse.:lstrip_blocks- removes the spaces and tabs before a block tag at the start of a line. The default isfalse.:keep_trailing_newline- keeps the final newline of the template. The default isfalse.:globals- a map of names to values or Elixir functions that the template can use.:filters- a map of names to Elixir functions, called with the value and the filter arguments.:tests- a map of names to Elixir functions, called with the value and the test arguments.:autoescape- escapes the HTML characters in the output of each{{ ... }}, except anOtera.Markup. A boolean, or a function that gets the name of the template and gives a boolean, likeselect_autoescapeof Jinja2. A template from a string has the namenil. The default isfalse.:loader- the templates that{% extends %},{% include %},{% import %}andload/2can load by name. SeeOtera.Loader.:name- the name of the template forparse/2, which errors and autoescape use.load/2gives each template its name.:cache- the name of anOtera.Cache, which keeps the templates of the loader for the next renders.
A plain Elixir function gets the positional arguments of the call. For keyword arguments and defaults, give an Otera.Function, which has a Python signature. Values that a function returns become template values, like variables.
The break and continue statements of the loopcontrols extension and the {% generation %} block of transformers are always available.
Summary
Functions
Loads the template name with the :loader option, like get_template of Jinja2.
Parses source into a template that renders many times.
Renders a template, given as source or as a parsed Otera.Template, with variables.
Like render/3, but raises the error.
Types
Functions
@spec load(String.t(), keyword()) :: {:ok, Otera.Template.t()} | {:error, error()}
Loads the template name with the :loader option, like get_template of Jinja2.
Returns {:ok, template}, {:error, %Otera.Error{kind: :template_not_found}} when the loader has no template with that name, or {:error, %Otera.SyntaxError{}}. The other options are the options of parse/2.
iex> {:ok, template} = Otera.load("hello.txt", loader: %{"hello.txt" => "Hello {{ name }}!"})
iex> Otera.render(template, %{name: "World"})
{:ok, "Hello World!"}@spec parse(String.t(), keyword()) :: {:ok, Otera.Template.t()} | {:error, Otera.SyntaxError.t()}
Parses source into a template that renders many times.
The options are the options of the module documentation. They apply to every render of the template.
@spec render(String.t() | Otera.Template.t(), map() | keyword(), keyword()) :: {:ok, String.t()} | {:error, error()}
Renders a template, given as source or as a parsed Otera.Template, with variables.
variables is a map or a keyword list. Returns {:ok, string}, or {:error, exception} with an Otera.SyntaxError or an Otera.Error.
Like render/3, but raises the error.